Cancer incidence and mortality trends in Asia based on regions and human development index levels: an analyses from GLOBOCAN 2020

Abstract

Objective

As Asian countries transition socially and economically to higher Human Development Index (HDI) levels, cancer trends are expected to shift to those seen in the Western World. A strong correlation also exists between HDI levels and age-standardized rates (ASR) for the incidence and mortality of cancer. However, there are very few reports on the trends in Asian countries, particularly in Low and Middle-Income Countries (LMICs). In this study, we have investigated the relationship between socioeconomic developments in Asia (determined using HDI levels of countries) and cancer incidence and mortality in these nations.

Methods

The GLOBOCAN 2020 database was used to study the cancer incidence and mortality data for all cancers combined and those most commonly diagnosed in Asia. The difference in data was analyzed based on region and HDI level. Further, the predictions for cancer incidence and mortality in 2040 according to the GLOBOCAN 2020 were analyzed using the updated HDI stratification described in the UNDP 2020 report.

Results

Asia has the highest cancer burden compared to the other regions worldwide. Lung cancer carries the highest cancer incidence and mortality rates in the region. Inequitable distribution of cancer incidence and mortality is seen across regions and HDI levels in Asia.

Conclusions

Inequalities in cancer incidence and mortality can only be expected to increase unless innovative and cost-effective interventions are urgently implemented. An effective cancer management plan is needed in Asia, particularly in LMICs, prioritizing effective cancer prevention and control measures for health systems.

Keywords:

• Age-standardized rates
• Asia
• cancer
• HDI
• incidence
• LMICs
• mortality

Introduction

Cancer reduces lifespans and exacts morbidity in every country, and age group in the world. Once only given significant importance in developed nations and among the wealthy, cancer is now understood to account for an increasing share of the overall disease burden among the poor and those in LMICs in Asia and worldwide. In parallel with a shift to higher cancer rates, many LMICs in Asia have undergone economic advances as measured by higher scores on the Human Development Index (HDI). Social changes that are associated with increases in HDI, such as decline in fertility, increase in longevity, and an increasingly older population, may even contribute to increased cancer rates relative to other causes of mortality¹. Today, two-thirds of all cancer deaths occur in these countries undergoing the societal, economic, and lifestyle changes associated with globalization and a higher disposable income. If trends towards higher HDI continue in Asian LMICs, cancer can be expected to become an increasingly important medical and public health concern. Hence addressing cancer is critical to improving the health, and wellbeing of over 4.5 billion people living in Asia and in LMICs globally^1,2.

However, LMICs face several problems in controlling the growing burden of cancer. While cancer incidence is rising, the resources for prevention and control have not increased proportionately. Most populations lack access to effective cancer prevention, treatment and palliation³.

Changing dynamics of cancer-related burden in Asia

Incidence of new cancer cases in Asia is estimated to grow from 6.1 million in 2008 to 10.6 million in 2030 with the increase in ageing populations and lifestyle changes associated with economic development in the region^4,5. While the cancer incidence rate is lower in Asia compared to the West, the reverse is the case for mortality⁶. It is alarming to note that in some Asian countries, the incidence rates for certain cancers such as lung and colorectal have surpassed that of Western countries. This change has been attributed to the adoption of unhealthy lifestyles, increasing levels of environmental pollutants and occupational hazards, including HIV, Hepatitis B and C and use of contaminated syringes in healthcare settings⁶. Additionally, genetics, ethnic backgrounds and lifestyles of Asians also predispose them to specific cancers⁷.

Relationship between income and development status of a country and cancer incidence and mortality

There is a strong disparity in cancer incidence and mortality rates in high-income countries (HICs) and LMICs³. According to WHO’s International Agency for Research on Cancer, the incidence of cancer in the very high, high, medium and low HDI countries was 571, 253, 100 and 65 per 100,000 population, respectively in 2020⁸. In HICs, cancer survival is high, though strongly dependent on the type of cancer. In LMICs, less than one-third survive; in some, the proportion is even smaller³. The difference in survival is largely because of limited preventive measures, early diagnosis and treatment of cancer in LMICs compared to HICs³. In LMICs, the financial burden of cancer treatment is borne by the patients, which sets limits to healthcare access and treatment and frequently pushes many families into poverty³.

A strong association has been observed between a nation’s cancer incidence and HDI levels⁹. It is observed that as countries transit to higher levels of human development, the general population adapts to lifestyles associated with high-income and Westernized societies, which has a bearing on incidence rates and types of cancers. In LMICs, there has been a decrease in infection-based cancers and an increase in cancers common in HICs. The changing cancer burden needs to be considered while planning public healthcare and clinical services. Hence, a detailed analysis of types of cancers across regions and countries is warranted⁷.

As observed in global epidemiological studies, a strong correlation also exists between HDI levels and age-standardized rates (ASR) for incidence and mortality of cancer. The age-standardized rate is a weighted average of the age-specific rates per 100,000 persons, where the weights are the proportions of persons in the corresponding age groups of the WHO standard population¹⁰. However, the validity and recent trends for this observation in Asian countries remain largely unexplored. In this study, we have reviewed the relationship between updated levels of socioeconomic development in Asia (determined using HDI levels of countries) and cancer-specific incidence and mortality. The HDI is evaluated by the United Nations Development Programme (UNDP) and indicates human capabilities within a country⁹. It is defined as the average achievement of the following three dimensions of human development: a long and healthy life (which is based on life expectancy at birth); being knowledgeable (based on expected mean years of schooling); and having a decent standard of living (based on gross national income per capita)¹¹. By comparing the incidence and mortality data in countries with differing HDI levels, we provide an overview of the association of specific cancers with the socioeconomic milieu of the country. However, as several countries have transitioned across HDI categories in the HDR 2020 report, we have utilized the latest classification of HDI to present the trends in incidence and mortality in these countries over the next 20 years¹².

Methods

The burden of cancer in Asia was studied based on estimates from the GLOBOCAN database created by the International Agency for Research on Cancer (IARC). The resources and methods used in compiling the GLOBOCAN estimates for 2020 are described online at the Global Cancer Observatory (GCO) website (https://gco.iarc.fr)¹³. The GCO website allows tabulation and graphic visualization of the GLOBOCAN database for 185 countries and 36 cancers, as well as all the cancers combined by age and sex. We analyzed the incidence and mortality data for all cancers combined and the most common cancers in Asia. The difference in data was analyzed based on the countries’ geographical location and economic development. The GLOBOCAN 2020 database uses the 4-tier Human Development Index stratification described in the UNDP 2019 report¹⁴.

Further, we analyzed the predictions for cancer incidence and mortality in 2040 according to the GLOBOCAN 2020. We used the updated 4-tier HDI stratification described in the UNDP 2020 report¹². We also analyzed the trends for the future of each Asian country according to the geographical regions. We used age-standardized rates (ASR) and cumulative risk (CR) to compare the different populations. The total number of incident cancer cases estimated in the GLOBOCAN 2020 database is reported alongside the ASR to give an idea of the actual disease burden.

GLOBOCAN database includes the age-standardized incidence or mortality rates per 100,000 person-years populated based on the 1966 Segi-Doll World standard population. This is the world standard population used to calculate the GLOBOCAN data. It was developed by the cancer epidemiologist Segi in 1960 as an intermediate world standard based on the experience of 46 countries. WHO uses European and world standards to calculate ASRs¹⁵.

The cumulative risk refers to the probability of developing or dying from cancer before age 75 (assuming absence of competing causes of death), and is expressed as a percentage. ASR and cumulative risk allow comparisons between populations that are not influenced by differences in their age structures.

In our analyses, colon, rectum, and anal cancers have been grouped as colorectal cancers.

Non-melanoma skin cancers were included in the study as “other cancers”.

Regarding regions within Asia, Western Asia includes Armenia, Azerbaijan, Bahrain, Gaza Strip (and West Bank), Israel, Iraq, Georgia, Jordan, Kuwait, Lebanon, Qatar, Oman, Syrian Arab Republic, Saudi Arabia, Turkey, United Arab Emirates, and Yemen, with a total population of 278,429,416. South-Central Asia includes Afghanistan, Bangladesh, Bhutan, India, Iran, the Islamic Republic of Kazakhstan, Kyrgyzstan, Maldives, Nepal, Pakistan, Sri Lanka, Tajikistan, Turkmenistan, and Uzbekistan, with a total population of 2,014,708,545. South-Eastern Asia includes Brunei Darussalam, Cambodia, Indonesia, Lao People’s Democratic Republic, Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste, and Viet Nam with a total population of 668,619,857. Eastern Asia includes China, Japan, Korea, the Democratic Republic of Korea, and the Republic of Mongolia, with a population of 1,678,089,640.

We did not seek ethics approval for conducting this study because we used the population-based secondary data and its analysis from the GLOBOCAN database, which is openly accessible to the public. In addition, the study did not involve any individual human subject or identifiable data.

Results

The detailed analyses of the cancer burden in Asia compared to other regions of the World are populated in the supplementary appendix (Figures S1–S7). The analyses also compare the incidence, mortality, cumulative risk and most prevalent cancers across the geographical regions and the 4-tier HDI countries in Asia.

Distribution of cases and deaths in Asia compared to global

With an estimated 9,503,710 new cases and 5,809,431 deaths occurring yearly, Asia has the highest disease burden compared to the other regions in the World (Figures S1(A)). Lung cancer carries the highest incidence and mortality rates in the region, contributing to 1,315,136 new cases and 1,112,517 deaths yearly. It is followed by cancers of the breast, colorectum, stomach, liver, oesophagus, prostate, cervix uteri, thyroid, lip and oral cavity as the top 10 cancers in Asia (Figure S1(B)). The percentage incidence and mortality of the top 10 most common cancers is marginally higher in Asia at 70% compared to the global percentages (Figure S1(C)).

Most common cancers in Asia

The three most common cancers in Asia are lung (13.8%), breast (10.8%), and colorectal (10.6%) cancers (Figure S3(A)). The most common causes of cancer mortality are cancers of the lung (19.2%), liver (10.5%), and stomach (9.9%) (Figure S3(A)). Lung cancer is the most common cancer in Asian men (891,989/year; 17.8%) and causes the highest mortality (757,218/year; 22.8%) (Figure S3(B)). It is comparatively less frequent in Asian females (423,238/year; 9.4%) (Figure S3(C)). The most common cancers in Asian women are breast (22.9%), colorectum (9.7%), and lung (9.4%). Lung cancer carries the highest cancer mortality in females (355,299/year; 14.4%), followed closely by breast cancer (346,009/year; 14.1%) (Figure S3(C)).

The distribution of most prevalent cancer varies across countries, attributed to variations in local demographics, cultures and socioeconomic levels. However, lung cancer is the most common cancer in men across most countries in Asia. Colorectal cancer is more frequent in Arab nations, while lip and oral cavity cancers are most common in India and Pakistan (Figure S4(A)). Breast cancer is the most common cancer in Asian women across most countries, and cervical cancer is the most common in women from Nepal, Myanmar, and Kyrgyzstan (Figure S4(B)). However, liver cancer is the most common cancer in men and women in Mongolia.

Mortality due to cancer type generally correlates with the most common cancer in the particular country except in Japan and China (Figure S5(A,B)). Though prostate and breast cancers are the most common among Japanese men and women, respectively, the highest deaths are caused by cancers of the lung in men and colorectum in women. Similarly in China. breast cancer is the most common cancer in women, but the highest mortality in women is due to lung cancer (Figure S5(B)).

Regional variations in incidence of cancer

The distribution of cancer in the various regions within Asia also varies and may be attributed to the genetic and cultural variations in the populations. Eastern Asia has the highest number of incident cases (6,008,355/year) and deaths (3,617,104/year) compared to the other regions. South-Central Asia has the highest population, however, as several countries have transitioned across HDI categories in the HDR 2020 report, the incidence of new cases in South-Central Asia (1,951,843/year) is less than one-third that of Eastern Asia (6,008,355/year) (Figure S2(A,B)). Lung and breast cancers are the most prevalent in all regions (Figure S2(C)).

Stomach cancer is the second most common cancer in Eastern Asia and is much more prevalent in this region than in others (Figure S2(C)). In South-Central Asia, lip and oral cavity and cervical cancer are more common than in other regions (Figure S2(C)). Eastern Asia carries the highest ASR and cumulative risk for cancer. Though the incident cases in Western Asia are the least, which can be attributed to the lower population in this region, the ASR incidence and mortality rates are second highest in Asia (Figure S6(A)).

Variations in cancer distribution based on HDI level

The distribution trends of cancer also varied depending on the socio-economic development of the countries. Lung cancer has the highest incidence and mortality rate irrespective of the HDI of the country (Figure S7(A)). Prostate cancer is more common and has a higher incidence in very high HDI countries like Japan and China, than in lower HDI countries like Vietnam and Philippines (Figure S7(A)). Breast cancer has the highest incidence in women across all economies (Figure S7(B)). Cervical cancer is seen across all economies, but its ASR is higher in medium and low HDI countries such as Indonesia, India and Syria (Figure S7(B)).

Predicted trends for cancer in Asia in 2040

We analyzed the predicted cancer incidence and mortality trends in 2040 based on the GLOBOCAN database. Here, the latest HDR 2020 report⁹ was used to archetype the countries according to the 4-tier HDI categories.

The lowest percentage increase in incidence (absolute numbers) is expected in the very high HDI countries in both males (37.9%) and females (24.9%). The highest percentage increase in incidence (absolute numbers) is expected in the low HDI countries in both males (102%) and females (101.3%) (Figure 1).

Figure 1. Projected number of new cases for all cancers in men and women in 2040 according to the 4-tier HDI in Asia. The trends in cancer incidence were populated according to the latest HDI ranks (2019) as available in the HDR 2020 report. Increasing trends for cancer incidence were noted across all economies in males and females. Abbreviation. HDI, Human Development Index. Note: Very High HDI: Bahrain, Brunei Darussalam, Georgia, Israel, Japan, Kazakhstan, Jordan, Republic of Korea, Kuwait, Malaysia, Oman, Qatar, Saudi Arabia, Singapore, United Arab Emirates, Turkey. High HDI: Azerbaijan, Armenia, Sri Lanka, China, Palestine, Indonesia, Iran, Jordan, Lebanon, Maldives, Mongolia, Philippines, Vietnam, Thailand, Turkmenistan, Uzbekistan. Medium HDI: Bangladesh, Bhutan, Myanmar, Cambodia, India, Iraq, Kyrgyzstan, Laos, Nepal, Pakistan, Timor-Leste, Syria, Tajikistan. Low HDI: Afghanistan and Yemen.

The highest percentage increase in mortality is expected in low HDI countries in males (106.1%) and females (105.3%). The least percentage rise in cases is expected to occur in the Very High HDI countries in men (60%) and women (49.2%) (Figure 2).

Figure 2. Projected number of mortalities for all cancers in men and women in 2040 according to the 4-tier HDI in Asia. The cancer mortality trends were populated according to the latest HDI ranks (2019) as available in the HDR 2020 report. Increasing trends for cancer mortalities were noted across all economies in males and females. Abbreviation. HDI, Human Development Index. Note: Very High HDI: Bahrain, Brunei Darussalam, Georgia, Israel, Japan, Kazakhstan, Jordan, Republic of Korea, Kuwait, Malaysia, Oman, Qatar, Saudi Arabia, Singapore, United Arab Emirates, Turkey. High HDI: Azerbaijan, Armenia, Sri Lanka, China, Palestine, Indonesia, Iran, Jordan, Lebanon, Maldives, Mongolia, Philippines, Vietnam, Thailand, Turkmenistan, Uzbekistan. Medium HDI: Bangladesh, Bhutan, Myanmar, Cambodia, India, Iraq, Kyrgyzstan, Laos, Nepal, Pakistan, Timor-Leste, Syria, Tajikistan. Low HDI: Afghanistan and Yemen.

We also analyzed the projections for 2040 according to geographical regions and country-wise in Asia. It is estimated that the number of new cases of cancer in Asia will increase from 9.39 million in 2020 to 14.2 million in 2040. Consequently, cancer mortality in Asia will increase from 5.75 million in 2020 to 9.67 million in 2040. The trends between the different geographical regions appear to be similar in men and women with an increase in the number of cancer cases expected in all countries. (Tables 1, 2). Currently, Japan has the highest cancer incidence risk, while Mongolia has the highest cancer mortality risk in Asia. However, in the coming decades, the highest percentage rise in incidence and mortality of cancer is expected in the Arab nations in both men and women. While the percentage rise of cancer in Georgia (+7.5%) and Japan (+7.5%) is expected to be the lowest, Qatar (+272.9%), UAE (+231.7%) and Kuwait (+179.4%) will see the highest percentage rise in cancer in the population by 2040.

Table 1. Projected change in cancer incidence and mortality in men in 2040.

	Incidence					Mortality
	2020	2040	% change	ASR	CR	2020	2040	% change	ASR	CR
Eastern Asia	3,295,730			243.5	48.66	2,174,803			157.5	38.93
China	2,475,945	3,856,856	+55.8%	225.4	43.79	1,820,002	3,051,232	+67.6%	163.9	38.84
Japan	599,243	674,881	+12.6%	328.1	62.39	239,505	298,363	+24.6%	105.6	35.82
Republic of Korea	121,263	206,770	+70.5%	259.4	50.82	53,685	112,186	+109.0%	106	35.37
Democratic People’s Republic of Korea	27,121	40,964	+51.0%	181.4	36.95	20,943	32,083	+53.2%	140.6	30.97
Mongolia	3018	5757	+90.8%	257.6	47.79	2526	4978	+97.1%	224.4	47.22
South Central Asia	966,677			103.2	21.07	660,359			71.2	15.83
Afghanistan	10,528	21,627	+105.4%	107.7	22.18	8003	16,768	+109.5%	85.6	18.44
Bangladesh	88,075	155,110	+76.1%	119.3	22.1	63,541	114,372	+80.0%	87.1	17.34
Bhutan	311	578	+85.9%	82.9	16.79	265	497	+87.5%	71.6	14.65
India	646,030	1,035,543	+60.3%	95.7	19.02	438,297	714,683	+63.1%	65.4	13.93
Islamic Republic of Iran	70,704	141,065	+99.5%	165	40.93	46,436	94,194	+102.8%	107.9	32.98
Kazakhstan	16,690	27,217	+63.1%	192.7	36.5	11,258	18,587	+65.1%	130.7	27.45
Kyrgyzstan	3241	5909	+82.3%	145.3	29.58	2453	4521	+84.3%	110.6	23.65
Maldives	257	661	+157.2%	121.5	23.97	163	462	+183.4%	84.5	20.11
Nepal	8943	15,464	+72.9%	78.6	17.54	6244	11,117	+78.0%	56.1	13.76
Pakistan	88,015	155,190	+76.3%	107	20.48	60,783	108,770	+78.9%	75.6	15.85
Sri Lanka	14,136	19,301	+36.5%	107.9	20.38	8746	12,226	+39.8%	65.6	13.72
Tajikistan	2555	5170	+102.3%	90.6	23.88	1932	4031	+108.6%	71.4	20.06
Turkmenistan	3049	5158	+69.2%	131.7	22.75	2147	3731	+73.8%	95.1	17.8
Uzbekistan	14,143	25,837	+82.7%	108.4	22.09	10,091	18,741	+85.7%	78.4	17.12
South-Eastern Asia	526,190			159.2	33.45	373,795			114.1	28.4
Brunei Darussalam	448	1064	+137.5%	217	50.93	236	644	+172.9%	122.4	39.06
Cambodia	8418	15,829	+88.0%	149.3	30.86	6481	12,619	+94.7%	119.1	27.4
Indonesia	183,368	311,862	+70.1%	138.9	27.25	124,698	221,781	+77.9%	96.3	22.39
Lao People Democratic Republic	4532	8431	+86.0%	177.5	34.47	3520	6731	+91.2%	142.2	30.87
Malaysia	23,052	42,252	+83.3%	137.8	29.33	15,601	30,489	+95.4%	92.9	25
Myanmar	34,197	53,905	+57.6%	146.3	29.5	26,370	42,525	+61.3%	114.9	25.81
Philippines	67267	124,048	+84.4%	164.6	40.09	47,046	90,367	+92.1%	119.5	35.43
Singapore	12,196	26,347	+116.0%	238.4	51.14	7003	17,693	+152.6%	134	39.64
Thailand	93,425	148,896	+59.4%	173.1	39.04	68,087	114,720	+68.5%	122	33.11
Timor-Leste	371	626	+68.7%	86.4	21.93	272	474	+74.3%	66.2	19.4
Viet Nam	98,916	164,463	+66.3%	191.5	33.59	74,481	128,602	+72.7%	144.5	29.14
Western Asia	232,598			198.3	42.77	141,031			123.5	33.68
Armenia	4902	6309	+28.7%	257.5	48.67	3441	4532	+31.7%	175.7	40.69
Azerbaijan	8232	14,149	+71.9%	161.5	34.55	5730	10,224	+78.4%	113.7	28.72
Bahrain	572	1864	+225.9%	108.5	31.8	312	1162	+272.4%	68.1	25.67
Georgia	6654	7334	+10.2%	229.5	41.43	4523	5094	+12.6%	150.9	33.39
Iraq	14,070	30,087	+113.8%	127	28.45	9418	20,719	+120.0%	90.5	23.74
Israel	14,197	22,931	+61.5%	247.2	47.29	6789	12,057	+77.6%	104.6	31.97
Jordan	5311	10,530	+98.3%	154.6	34.31	3337	6906	+107.0%	102.2	27.23
Kuwait	1840	5878	+219.5%	101.3	27.74	948	3458	+264.8%	59.8	21.32
Lebanon	5787	10,101	+74.5%	159.1	36.6	3457	6446	+86.5%	94.4	28.12
Oman	2232	5518	+147.2%	108.4	21.26	1351	3741	+176.9%	73	16.95
Qatar	901	3799	+321.6%	101.4	29.55	465	2310	+396.8%	61.2	21.94
Saudi Arabia	14,253	32,689	+129.3%	89	21.32	7693	20,168	+162.2%	53.5	16.15
Syrian Arab Republic	9243	25,654	+177.6%	145.5	32.93	6398	18,378	+187.2%	103.7	27.65
Turkey	132,816	237,284	+78.7%	291.5	53.6	78,949	149,976	+90.0%	171.6	41.87
United Arab Emirates	2155	9202	+327.0%	82.5	25.93	1012	5174	+411.3%	46.9	19.7
Yemen	7159	14,106	+97.0%	92.7	23.2	5667	11,407	+101.3%	77.9	21.29

Analyses of projected percentage change in the incidence and mortalities for cancer in 2040 in men according to the geographical regions and countries showed increasing trends. Country-wise variations in age-standardized rates and cumulative risk for incidence and mortality were noted. Abbreviations. ASR, age-standardized rate; CR, cumulative risk.

Table 2. Projected change in cancer incidence and mortality in women in 2040.

	Incidence					Mortality
	2020	2040	% change	ASR	CR	2020	2040	% change	ASR	CR
Eastern Asia	2,712,625			196.7	34.18	1,442,301			92.9	24.19
China	209,2809	2,988,931	+42.8%	188.2	32.17	1,182,897	2,019,298	+70.7%	98.1	24.77
Democratic People Republic of Korea	30,535	41,208	+35.0%	152.2	27.52	19,020	27,103	+42.5%	90.5	20.35
Japan	429,415	453,176	5.50%	253.8	41.57	180,619	218,990	+21.2%	62.6	20.6
Mongolia	2696	5441	+101.8%	183.6	37.15	1943	4308	+121.7%	138.8	34.77
Republic of Korea	109,054	143,827	+31.9%	238.5	34.95	34,912	64,424	+84.5%	52.9	17.69
South Central Asia	985,166			102.5	17.69	598,324			63.1	12.93
Afghanistan	12,289	25,121	+104.4%	111.9	18.64	8015	16,626	+107.4%	78.1	14.47
Bangladesh	68,700	123,388	+79.6%	92.4	15.99	45,449	85,936	+89.1%	62.9	12.29
Bhutan	261	461	+76.6%	80.6	13.33	191	348	+82.2%	60.5	10.71
India	678,383	1,050,551	+54.9%	99.3	16.92	413,381	666,684	+61.3%	61	12.28
Islamic Republic of Iran	60,487	113,804	+88.1%	139	29.1	32,700	72,057	+120.4%	78.9	23.5
Kazakhstan	18,676	26,910	+44.1%	154.6	25.46	9701	14,641	+50.9%	78.3	15.69
Kyrgyzstan	3834	6562	+71.2%	123.5	23.22	2227	4016	+80.3%	73	15.86
Maldives	239	488	+104.2%	131.5	20.26	101	242	+139.6%	60.5	12.27
Nepal	11,565	20,900	+80.7%	82.6	16.54	7385	13,868	+87.8%	53.9	12.77
Pakistan	90,373	164,205	+81.7%	113.7	19.31	56,366	104,351	+85.1%	72.8	14.16
Sri Lanka	15,468	19,585	+26.6%	105.1	15.24	7945	10,787	+35.8%	50.8	9.07
Tajikistan	3167	6104	+92.7%	90.3	18.02	1911	3981	+108.3%	58.5	14
Turkmenistan	3848	5972	+55.2%	129.9	18.54	2188	3596	+64.4%	76.1	12.59
Uzbekistan	17,876	29,600	+65.6%	110.1	17.66	10,764	18,953	+76.1%	68.4	12.99
South Eastern Asia	573,847			149.3	25.64	315,298			80.8	18.82
Brunei Darussalam	539	992	+84.0%	235	40.7	198	480	+142.4%	94.4	27.26
Cambodia	9957	16,629	+67.0%	128	22.8	6157	10,958	+78.0%	81.9	18.3
Indonesia	213,546	333,574	+56.2%	145.4	22.8	109,813	189,456	+72.5%	75.9	15.78
Lao People Democratic Republic	4601	8190	+78.0%	157.4	26.54	2688	5068	+88.5%	96.6	20.81
Malaysia	25,587	44,414	+73.6%	151.4	26.46	13,929	26,780	+92.3%	82.2	20.32
Myanmar	40,396	60,536	+49.9%	131.7	24.24	26,571	42,566	+60.2%	87.6	19.99
Philippines	86,484	151,287	+74.9%	167.3	30.16	45,560	87,895	+92.9%	88.2	22.77
Singapore	11,436	19,686	+72.1%	234	40.85	5127	11,340	+121.2%	91.9	26.93
Thailand	97,211	141,292	+45.3%	159	29.43	56,779	95,300	+67.8%	83.6	21.84
Timor-Leste	443	763	+72.2%	94.6	18.35	267	469	+75.7%	58.9	14.47
Viet Nam	83,647	126,631	+51.4%	135.5	22.11	48,209	80,295	+66.6%	74.8	16.12
Western Asia	210,877			162.3	28.61	103,520			79.1	19.81
Armenia	4359	5807	+33.2%	166.6	31.73	2655	3779	+42.3%	93.4	23.49
Azerbaijan	8084	12,579	+55.6%	128.6	23.7	4736	8062	+70.2%	74.7	17.73
Bahrain	643	1403	+118.2%	130.7	23.3	281	734	+161.2%	65.6	16.71
Georgia	6527	6838	+4.8%	177.8	28.27	3692	4081	+10.5%	88.1	18.89
Iraq	19,803	39,633	+100.1%	144.6	24.6	10,368	21,780	+110.1%	81.2	18.08
Israel	14,507	21,234	+46.4%	238.3	39.27	6261	10,153	+62.2%	79.4	23.97
Jordan	6248	10,979	+75.7%	159.3	26.21	2853	5436	+90.5%	77.2	17.14
Kuwait	2002	4858	+142.7%	144.6	29.47	771	2510	+225.6%	71	21.77
Lebanon	5802	8594	+48.1%	159.8	26.48	2981	4823	+61.8%	80.2	17.82
Oman	1481	2969	+100.5%	108.7	15.23	678	1575	+132.3%	56.8	10.37
Qatar	581	1728	+197.4%	139.3	29.72	239	944	+295.0%	76.9	23.25
Saudi Arabia	13,632	27,740	+103.5%	111.9	20.15	5376	12,798	+138.1%	50	12.83
Syrian Arab Republic	11,716	29,957	+155.7%	155.3	25.75	6569	17,866	+172.0%	90	19.07
Turkey	101,018	155,504	+53.9%	188	31.13	47,386	83,430	+76.1%	81.4	20.6
United Arab Emirates	2652	6740	+154.1%	170.9	34.98	884	3077		79	24.59
Yemen	9317	18,364	+97.1%	102.2	21.3	6436	13,046	+102.7%	76.1	18.52

Analyses of projected percentage change in the incidence and mortalities for cancer in 2040 in women according to the geographical regions and countries showed increasing trends. Country-wise variations in age-standardized rates and cumulative risk for incidence and mortality were noted. Abbreviations. ASR, age-standardized rate; CR, cumulative risk.

Discussion

Our analyses confirm that Asia has the highest global burden of cancer in terms of numbers of incident cancer and mortality. However, the ASR for incidence and mortality is lower than the other regions of the World. The low ASR in Asia could be attributed to an ageing population versus the aged population in the other regions. Eastern Asia carries the highest burden of cancer and has the highest ASR and cumulative risk for incidence and mortality.

Most common cancers in Asia

Lung cancer is the most common in Asia and across all economies and carries a high mortality. This highlights the importance of implementing prevention strategies, particularly tobacco control, which is a challenge in LMICs. While the LMICs are equipped with the knowledge gained from HICs on averting the epidemic, they sometimes lack resources, infrastructure, implementation and political will³. For example, preventive strategies against lung cancer, which contributes the highest cancer burden, are often unsuccessful in LMIC owing to the tactics of multinational tobacco companies³. There are cases of national treasuries profiting from state-owned tobacco companies, thus eliminating political determination to combat the disease³.

Breast cancer is the second most common cancer in Asia and most common in women in most countries irrespective of the socio-economic status10. However, there remains a gradient, with the ASR being higher in very high HDI countries compared to low HDI countries. Increasing life expectancy, nulliparity, no breast feeding, and screening likely contribute to the increased detected incidence of breast cancer in higher HDI countries, in addition to increased prevalence of other risk factors associated with westernization, such as obesity and alcohol consumption¹¹.

Liver cancer carries the second-largest mortality burden. Though it is largely preventable cancer with HBV vaccination, it contributes to 608,898 deaths yearly. This highlights the importance of HBV vaccination to prevent liver cancer in the coming decades. The global vaccine coverage for HBV is now high, estimated to be 81% in 2013³.

Regional variations in cancer distribution

Culture and local customs also contribute greatly to the incidence of cancer. These are often difficult to tackle being strongly ingrained in the lifestyle of populations. The high incidence of lip and oral cavity cancer in India and Pakistan could be attributed to tobacco chewing practices in the local community¹⁶. A strong association of oral cancers with tobacco smoking and chewing betel quid is known.¹⁶ Betel quid chewing is an emerging health issue being the fourth most common psychoactive habit practiced worldwide. Betel quid contains areca, a recognized carcinogen, combined with the leaf of a betel vine, slaked lime, and often tobacco^17,18. Approximately 10% of the world population use a certain variety of betel quid mainly in South East and South Asia, the Indo-Pakistan subcontinent, mainland China, Taiwan and South Pacific region (Palau, Papua New Guinea and Solomon Islands)¹⁸.

A significantly high number of cancers can be attributed to infections: The associations of liver cancer with hepatitis B and C viruses (HBV and HCV), colorectal and stomach cancers with H. pylori, and cervical cancer with Human Papillomavirus (HPV) are well documented. The high incidence rates of liver cancer in Mongolia have been attributed to high Hepatitis C and B infection rates and widespread alcohol use¹⁹. Due to the recent trend in adopting Western lifestyles, including, increased consumption of red meat and animal fat and decreased physical activity by the Arab population, there has been an exponential rise in the incidence of CRC²⁰. It has been shown to affect the younger population as well²⁰. In addition, new risk factors have been reported, such as low serum levels of selenium and vitamin D, high use of food preservatives, and microsatellite instability²⁰.

Stomach cancer is more prevalent in Eastern Asia. In Japan and Korea, the incidence of stomach cancer is one of the highest among Asian countries. Unsurprisingly, the prevalence of H. Pylori infection among asymptomatic adults is as high as 80–90%⁶.

A higher cancer incidence was seen in Eastern and Western Asia. Lifestyle variations between these sub-regions likely contribute to the variation in cancer incidence⁶. The prevalence of smoking in men was found to be much higher in China (57.4%) compared to India (32.7%) or Pakistan (27.3%)⁶. This can probably explain the relatively higher incidence of lung and oesophagal cancer in Eastern Asia.

Influence of economic development on cancer incidence and mortality trends in Asia

Lung cancer and breast cancer have a high incidence across all economies, and prostate cancer is more common in more developed economies. It has been well established that Asians, particularly Chinese men have a lower risk of prostate cancer than black and white men²¹. Recently, there has been a rise in prostate cancer incidence in countries such as the Philippines, Japan, China, and Singapore. This is most likely due to the increased prostate-specific antigen (PSA) screening uptake in these countries²².

All the countries in Asia are adopting a more Westernized lifestyle, including a high-fat, low-fibre diet. East Asian countries, such as Japan and South Korea, have seen a rise in the incidence of colorectal cancer, which is associated with a low-fibre diet⁶. A high-fat, high-calorie diet and sedentary lifestyle in some Asian countries have also contributed to the rising incidence of obesity and is associated with breast cancer⁶. In some Asian populations, such as the Chinese, weight gain is related to an increased risk of breast cancer in postmenopausal women, even in non-obese women. This may explain the high incidence of breast cancer in Western Asia, which has the highest prevalence of female obesity in Asia⁶.

Environmental factors such as air pollution may also play an important role as the developing countries become more industrialized⁶.

A greater increase in cases is expected in the LMICs compared to the developed nations in the coming decades. Such forecasted projections highlight the need for resource-driven prevention strategies, particularly in the developing World¹¹.

Certain countries show trends toward higher mortality risk. In contrast, countries with resources and priorities to combat the disease can curtail the rise with appropriate preventive strategies²³. Japan has the highest risk of incidence. However, it is expected that Japan will have one of the lowest percentage rises in cancer (12.6% in men; 5.5% in women) in Asia (Tables 1 and 2). In the last two decades, the relatively high-income countries, Japan, Korea, and Singapore, have developed and implemented national cancer control programs²³. The highest rise in incidence and mortality of cancer is expected in the highly developed countries in Western Asia, particularly in UAE and Qatar. Long-term projections have shown that by 2030 there will be a 1.8-fold increase in cancer incidence in the Gulf States and Eastern Mediterranean Region²⁴. While national cancer control policies are in place in 80% of these countries, only 45% of them are operational. Further, the effectiveness of these programs remains to be seen²⁴. Factors like unhealthy lifestyles, smoking, and alcohol consumption have contributed to about 70–90% of cancer cases. This is further accentuated by the environmental and air pollution in the Arab World²⁴. The Eastern Mediterranean Region has a high prevalence of obesity and diabetes. The associated increase in body mass indexes (BMI) is expected to contribute to the rising incidence of liver, colorectal and gastric cancers²⁴. Social taboos and psychological barriers also contribute to the rising cancers in the region. An earlier survey showed poor acceptance of breast cancer screening programs among women in Saudi Arabia, where health services are free of cost²⁴.

Cancer is already a major cause of mortality in low- and middle-income countries (LMICs). With ageing populations and declining mortality due to other causes, cancer is slated to contribute to a major percentage of deaths in the future^3,23. Many cancers share modifiable risk factors, such as tobacco use, unhealthy diet, lack of physical activity and alcohol abuse, overweight and obesity²³. Addressing these factors needs to find a place in cancer prevention strategies to curb the rising cancer incidence.

Potential health interventions to reduce the incidence of cancer

Tobacco cessation

Tobacco is the most widely used carcinogen and the leading avoidable cause of cancer. One-third of male cancers and 70% of lung cancer can be attributed to tobacco smoking²³. As such, stopping tobacco use and dissuading new users plays a significant role in cancer prevention. A tried and tested strategy includes higher tobacco taxes which, in addition to discouraging tobacco use, also add to government revenues³. Experience with such initiatives has resulted in an immediate reduction in tobacco users and a significant reduction in mortality 5–10 years after the measures are implemented. Unfortunately, dedicated robust smoking cessation programs and resources are rare in LMICs³. The WHO has set a framework for reducing tobacco consumption, including evidence-based and cost-effective interventions such as an increase in tobacco tax and prices of tobacco products, smoke-free environments, health warnings and advertising bans²³. Compared to 2007, more than four times as many people are now covered by at least one WHO-recommended tobacco control measure²⁵.

Alcohol control

The other preventable cause of cancer and a major risk factor for non-communicable diseases (NCDs) is alcohol consumption. Alcohol consumption is implicated in the oral cavity, pharynx, larynx, oesophagus, liver, colorectum and female breast cancers. In 2010, WHO recommended ten target areas for countries to reduce alcohol abuse. These include awareness and commitment by the leadership, counselling and treatment through the health services, identification of needs and solutions through community involvement, limiting the availability of alcohol, policies against drunk driving, regulations of marketing and pricing of alcoholic products, and monitoring and surveillance²³.

Infection control

Infections are an important risk factor for cancer in LMICs and some HICs in Eastern Asia. A study from the Republic of Korea attributed up to one-quarter of all the cancer cases and deaths to infection with Helicobacter pylori, human papillomavirus, hepatitis B and C viruses²³. Cancer prevention strategies should also include initiatives to avoid or control cancer-associated infections²³. Vaccination against HBV will play an essential role in reducing the future incidence of associated cancers. HPV vaccination is also gaining momentum in several LICs in Sub-Saharan Africa mainly through support from GAVI, the vaccine alliance. A similar initiative needs to be taken in Asia, even though the effects of these vaccinations will be seen only decades later when the vaccines reach middle age³.

Besides the cancers caused by tobacco, alcohol and infections, most other cancers are not preventable. However, mortality can be reduced by early diagnosis and treatment. Early breast and cervical cancer are common and often treatable; precancerous cervical lesions are even more curable³. Though screening effectively limits cancer morbidity and mortality, it is expensive and requires considerable infrastructure³.

As risk factors for NCDs like tobacco and alcohol consumption, lack of physical activity and unhealthy diet al.so increase the risk of cancer, an integrated approach to controlling them can help prevent cancer. Early diagnosis and treatment can be improved by strengthening the primary healthcare systems. Well-equipped and functioning primary care systems are needed to ensure appropriate care for cancer patients. Good surveillance systems are also required to capture the prevalence of risk factors, incidence and mortality and performance of the health system and prevention programs.

A variety of factors influence the chances of survival in patients with cancer. These factors can be highly variable between LMICs versus HIC leading to significant differences in the mortality rates between the countries (Figure 3)¹⁹. For example, the 5-year survival for patients diagnosed with lung cancer during 2010–2014 was 33% in Japan and only 4% in India¹⁹. Though survival has increased in recent decades due to advances in treatment options and oncology drugs, in particular, access to these life-saving drugs is often limited in the LMICs due to budget restrictions of health systems¹⁹. LMICs should invest more in NCD surveillance systems and disease registries, such as cancer registries, as a priority to tackle the emerging problem of cancer and other NCDs²³.

Figure 3. Disparities in healthcare spending and access between HICs and LMICs. A significant disparity exists in the healthcare spending on cancer and access to cancer treatment among the HICs and LMICs. Abbreviations. HIC, high-income countries; LMIC, low- and middle-income countries.

Study limitations

The limitations of this study are related to the data sources utilized. For country-specific incidence estimates from GLOBOCAN 2020, the accuracy of the data depends on the quality and availability of information at the given time. The accuracy will be higher in countries with high-quality population-based cancer registries. Estimates, especially projections, do not reflect the impact of the COVID-19 pandemic as the projections are based on the extrapolations of cancer data collected in earlier years before the pandemic. Delays in diagnosis and treatment, suspension of the screening programs, and reduced availability and access to care are expected to cause a real-world short-term decline in cancer incidence followed by increases in advanced-stage diagnoses and cancer mortality.

Using four levels of HDI to describe socioeconomic transitions has limitations as it deemphasizes the diversity of cancer occurrence worldwide and how it varies across countries. Also, HDI does not take into account inequalities within countries. Using the Inequality-adjusted HDI could provide a better insight. The HDR 2020 report has not reported the Inequality-adjusted HDI of many Asian countries like Kuwait, Malaysia, Brunei, Saudi Arabia, Bahrain, UAE, Afghanistan, Syria, Myanmar, Turkmenistan, etc²⁶. Hence, it could not be used in this study.

Further research is still warranted on the association between cancer and HDI, especially using the specific components of HDI or other UNDP human development measures. Investigations into the cancer variations within HDI levels regionally and nationally can elucidate the relative importance of social, economic, cultural, and environmental factors contributing to the disease’s scale and profile.

Conclusion

The national cancer burden depends on local risk factors and the availability of medical care and interventions. As a result, wide variations exist in cancer incidence within countries with different HDI levels. The HDI level provides a valuable framework to map the continuing transitions in cancer and highlight the current and projected cancer burden in low-HDI countries compared to the high-HDI ones. Although the cancer incidence rates are higher in countries with very high HDI, those living in countries with low HDI experience disproportionately higher mortality and are projected to be most affected by the disease in the near future. These inequalities can only be expected to increase unless established effective and cost-effective interventions are urgently implemented.

Cancer is projected to become the leading cause of mortality worldwide in the coming decades due to decline in mortality rates due to cardiovascular diseases, relative to cancer¹. According to global mortality data (2019), for every ten premature deaths due to non-communicable diseases, four occur due to cardiovascular diseases and three due to cancer. Recent trends indicate that cancer may surpass CVD as the leading cause of premature mortality in the years to come²⁷. It is increasingly evident that cancer control initiatives will also play an essential role in decreasing inequalities in all-cause mortality. The development and implementation of effective, practical, affordable, and sustainable cancer control measures in transitioning countries can therefore be seen as an effort to decrease differential burden of cancer. Effective cancer management plan in Asia, especially in LMICs, requires political leadership in prioritizing effective cancer control measures for health systems.

Transparency

Declaration of financial/other relationships

Authors Manmohan Singh, Roberto Uehara and Stephen E. Schachterle are Pfizer employees and own Pfizer stocks. The authors report no other conflicts of interest in this work. The results and discussions in this article do not represent or reflect in any way the official policy or position of the current or previous employers of the authors. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

All authors made substantial contributions to the conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Acknowledgements

The authors sincerely appreciate the medical writing support provided by Dr. Veena Angle, Singapore, on behalf of Transform Medical Communications, New Zealand.

Additional information

Funding

Data analytics and medical writing support were provided by Transform Medical Communications, which was funded by Pfizer.