Incidence rate of ovarian cancer cases in Saudi Arabia: an observational descriptive epidemiological analysis of data from Saudi Cancer Registry 2001–2008

Figures & data

Figure 1 Number and percentage of ovarian cancer cases (A and B) in Saudi Arabia from 2001–2008. Overall number and percentage of ovarian cancer cases’ distribution by age group (C) in Saudi Arabia from 2001–2008.

Table 1 Ovarian cancer cases distribution by age group in Saudi Arabia from 2001–2008

Year	Age group of ovarian cancer
	0–14		15–29		30–44		45–59		60–74		≥75		Total
	#	%	#	%	#	%	#	%	#	%	#	%	Total	% of total
2001	4	4	15	14.8	17	16.8	31	30.7	21	20.8	13	12.9	101	3.7
2002	6	6	15	16	13	14	29	30	24	25	9	9	96	3.3
2003	4	4	14	12.8	18	16.5	33	30	26	23.9	14	12.8	109	3.4
2004	6	6	11	10	22	20	32	30	27	25	10	9	108	3.1
2005	8	6	17	12.5	18	13	39	29	40	29.5	14	10	136	3.5
2006	2	2	15	11	22	17	44	33	38	29	11	8	132	3.2
2007	10	6.7	19	12.8	25	17	47	31.5	36	24	12	8	149	3.1
2008	6	3.7	17	10.6	22	13.7	51	32	50	31	14	9	160	3.5
Average	6	5	15	13	20	16	38	31	33	26	12	9.8	123.9	3.4

Figure 2 CIR and ASIR of ovarian cancer cases (A) in Saudi Arabia from 2001–2008. Overall CIR and ASIR of ovarian cancer cases’ distribution by region (B) in Saudi Arabia from 2001–2008.

Abbreviations: CIR, crude incidence rate; ASIR, age standardized incidence rate.

Table 2 CI for %, CIR, and ASIR of ovarian cancer cases in Saudi Arabia from 2001–2008

Year	Percentage		CIR per 100,000		ASIR per 100,000
	%	95% CI	CIR	95% CI	ASIR	95% CI
2001	3.7	1.7–5.7	1.3	0.6–2.0	2.3	1.3–3.3
2002	3.3	1.5–4.8	1.2	0.5–1.9	2.0	1.0–3.0
2003	3.4	1.6–5.0	1.4	0.7–2.2	2.0	0.9–3.1
2004	3.1	0.6–3.7	1.3	0.4–1.7	2.2	1.4–3.0
2005	3.5	0.8–4.3	1.6	0.7–2.5	2.8	2.0–3.6
2006	3.2	0.7–3.9	1.5	0.5–2.5	2.8	1.9–3.7
2007	3.1	0.8–3.9	1.7	1.0–2.4	2.6	1.8–3.4
2008	3.5	1.3–4.8	1.8	0.9–2.7	3.0	2.3–3.7
Overall	3.4	1.1–4.5	1.5	0.6–2.2	2.5	1.5–3.3

Note: Values in bold denote there are no significant differences between years of diagnosis, P-value >0.05.

Abbreviations: CIR, crude incidence rate; ASIR, age-standardized incidence rate; CI, confidence interval.

Table 3 CI for overall percentage, CIR, and ASIR of ovarian cancer cases in the regions of Saudi Arabia from 2001–2008

Regions	Overall percentage		Overall CIR		Overall ASIR
	%	95% CI	CIR	95% CI	ASIR	95% CI
Asir	3.8	2.6–5.0	1.3	0.8–1.8	2.96	1.25–2.66
Baha	5.0	3.4–6.6	1.8	1.0–2.6	2.28	1.32–3.25
Jazan	1.6	0.5–2.7	0.3	0.1–0.5	0.57	0.17–0.97
Madinah	3.7	2.5–4.9	1.3	1.0–1.6	2.27	1.67–2.87
Hail	3.4	1.8–5.0	1.0	0.5–1.5	1.35	0.70–1.99
Qassim	2.3	1.2–3.4	0.9	0.3–1.5	1.46	0.69–2.23
Riyadh	3.4	3.1–3.7	1.9	1.6–2.2	3.30	2.68–3.91
Makkah	3.6	3.1–4.1	1.7	1.4–2.0	2.81	2.20–3.42
Najran	3.1	1.0–5.2	0.8	0.3–1.3	1.92	0.52–3.32
Jouf	4.8	1.4–8.2	1.4	0.7–2.1	3.13	1.50–4.76
Tabuk	3.0	2.5–3.5	1.1	0.8–1.4	2.35	1.51–3.18
Eastern region	3.2	2.6–3.8	1.6	1.3–1.9	2.92	2.39–3.45
Northern region	2.6	0.7–4.5	0.8	0.3–1.3	1.55	0.24–2.85

Note: Values in bold denote for CIR, Riyadh, Baha and Makkah were significantly higher than other regions of Saudi Arabia, P-value <0.05; for ASIR, Riyadh, Jouf and Asir were significantly higher than other regions of Saudi Arabia, P-value <0.05.

Abbreviations: CI, confidence interval; CIR, crude incidence rate; ASIR, age-standardized incidence rate.

Table 4 Segi (world) standard for making comparisons with intermediate-age population (Segi, 1960)

Age group	Segi (world) standard
0–4	12,000
5–9	10,000
10–14	9,000
15–19	9,000
20–24	8,000
25–29	8,000
30–34	6,000
35–39	6,000
40–44	6,000
45–49	6,000
50–54	5,000
55–59	4,000
60–64	4,000
65–69	3,000
70–74	2,000
75+	2,000
Total	100,000

Note: The Segi (world) standard can be used in direct method of standardization to calculate the ASIR and ASMR. ASIR is a technique used to compare the incidence rates among different populations when the confounding variable is age. ASMR is a technique used to compare mortality rates among different populations when the confounding variable is age.

Abbreviations: ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate.

Table 5 Poisson regression model to calculate the IRR and check if there is an effect due to geographical area

# casesa	IRR	P-value	95% CI
Regions
1. Asir	0.55	0.06	0.34–0.87
2. Baha	2.56	0.05*	1.56–3.98
3. Jazan	1 referenceb
4. Madinah	2.21	0.08	1.39–3.50
5. Hail	0.76	0.23	0.49–1.18
6. Qassim	1.21	0.40	0.77–1.91
7. Riyadh	6.3	0.001*	4.10–9.82
8. Makkah	6.4	0.001*	4.12–9.83
9. Najran	0.50	0.09	0.32–0.81
10. Jouf	0.48	0.12	0.30–0.76
11. Tabuk	0.98	0.60	0.64–1.51
12. Eastern region	4.52	0.001*	2.93–6.98
13. Northern region	0.44	0.10	0.26–0.62

Notes:

a Number of cases occurring in regions numbered from 1 to 13.

b Reference is the comparison region, and can be used for comparison with other regions and to calculate IRR. There are no significant differences between regions, P-value >0.05

* P-value <0.05.

Abbreviations: IRR, incidence rate ratio; CI, confidence interval.

Table 6 Differences in the percentage, CIR, and ASIR of ovarian cancer cases in the regions of Saudi Arabia from 2001–2008

Regions	Percentage %			CIR per 100,000			ASIR per 100,000
	2008	2001	Difference	2008	2001	Difference	2008	2001	Difference
Asir	4.7	4.0	0.7	1.9	0.9	0.9	3.0	1.7	1.3
Baha	8.8	2.5	6.4	3.3	0.4	2.9a	4.2	0.6	3.6a
Jazan	2.0	2.5	−0.5	0.5	0.3	0.2	1.1	0.4	0.7
Madinah	3.6	6.5	−2.9	1.6	1.7	−0.1	2.6	3.7	−1.1
Hail	2.2	5.1	−2.9	0.8	1.3	−0.5	1.2	2.3	−1.1
Qassim	2.6	1.4	1.2	1.1	0.5	0.6	2.0	0.9	1.1
Riyadh	4.0	3.6	0.4	2.5	1.8	0.7	4.5	3.8	0.7
Makkah	3.8	3.1	0.7	2.1	1.0	1.1	3.5	1.5	1.5
Najran	1.5	6.8	−5.8	0.5	1.8	−1.3	1.1	5.2	−4.1
Jouf	3.2	3.6	−0.4	1.2	0.5	0.7	2.8	3.3	−0.5
Tabuk	2.4	2.5	−0.1	0.9	0.8	0.1	1.9	1.1	0.8
Eastern region	2.2	3.8	−1.6	1.3	1.6	−0.3	2.1	3.2	−1.1
Northern region	1.9	0.0	1.9	0.8	0.0	0.8	1.3	0.0	1.3

Note: Values in bold denote the differences in the percentages, CIRs and ASIRs of ovarian cancer cases between 2001 and 2008 in different regions of Saudi Arabia.

a For CIR and ASIR, the region of Baha showed the greatest changes compared to other provinces of Saudi Arabia, P-value <0.05.

Abbreviations: CIR, crude incidence rate; ASIR, age-standardized incidence rate.