The impact of implementing current treatment modalities and female sex on gastric cancer outcomes, 2000–2016: a longitudinal nationwide cohort study

Figures & data

Table 1. Baseline characteristics of gastric cancer patients diagnosed in 2000–2008 and 2009–2016 in Finland (n = 9223).

	2000–2008		2009–2016
	n (%)		n (%)		p
Total cases	5174		4049
Median age	72	IQR 61–79	71	IQR 63–80	0.001
Female	2280	(44)	1652	(41)	0.004
Catchment area					0.005
Helsinki	1306	(25)	1132	(28)
Tampere	1154	(22)	883	(22)
Turku	1021	(20)	737	(18)
Kuopio	955	(19)	692	(17)
Oulu	707	(14)	581	(14)
Charlson comorbidity index					<0.001
0	2899	(56)	1786	(44)
1	1181	(23)	904	(22)
2	643	(12)	647	(16)
3+	451	(9)	712	(18)
Tumor localization					<0.001
Cardia	940	(18)	845	(21)
Non-cardia	525	(10)	1609	(40)
Unknown	3709	(72)	1595	(39)
Histology^1					<0.001
Adenocarcinoma, diffuse	1468	(28)	1360	(34)
Adenocarcinoma, intestinal	664	(13)	1006	(25)
Adenocarcinoma, unspecified	3042	(59)	1683	(42)
Stage					<0.001
Local	869	(17)	342	(8)
Locally advanced	728	(14)	410	(10)
Metastatic	2243	(43)	1387	(34)
Unknown	1334	(26)	1910	(47)
Surgery
Gastric surgery	2282	(44)	1368	(34)	<0.001
Elective^2	1957	(86)	1159	(85)
Emergency^2	316	(14)	201	(15)	0.464
Diagnostic surgery/nonresectable	453	(9)	202	(5)	<0.001
No surgery	2439	(47)	2480	(61)	<0.001

IQR: interquartile range.

¹According to Lauren et al. [47]. ²The frequency within the gastric surgery group.

Table 2. Surgical and other oncological treatments for gastric cancer among patients diagnosed in 2000–2008 and 2009–2016 (n = 9223).

	Total		2000–2008		2009–2016
Surgery and other oncological treatments^1	n	(%)	n	(%)	n	(%)	p^2
Gastric surgery	3650	(40)	2282	(44)	1368	(34)	<0.001
Perioperative	177	(5)	7	(0)	170	(12)	<0.001
Preoperative only	57	(2)	5	(0)	52	(4)	<0.001
Postoperative only	575	(16)	275	(12)	300	(22)	<0.001
None	2841	(78)	1995	(87)	846	(62)	<0.001
Diagnostic surgery / nonresectable	655	(7)	453	(9)	202	(5)	<0.001
Preoperative	11	(2)	1	(0)	10	(5)	<0.001
Postoperative	98	(15)	45	(10)	53	(26)	<0.001
None	545	(83)	407	(90)	138	(68)	<0.001
No surgery	4918	(53)	2439	(47)	2479	(61)	<0.001
Palliative	824	(17)	165	(7)	659	(27)	<0.001
None	4095	(83)	2274	(93)	1821	(74)	<0.001

¹Chemotherapy and/or radiotherapy. ²Bonferroni-adjusted p values.

Figure 1. Kaplan–Meier for overall survival of gastric cancer patients in Finland among the following treatment groups: (A) gastric surgery, (B) diagnostic surgery/nonresectable, and (C) no surgery, comparing the time periods 2000–2008 and 2009–2016. The Bonferroni correction was used to adjust the log-rank test p values.

Table 3. Overall survival among gastric cancer patients diagnosed in 2000–2008 and 2009–2016 stratified by (A) surgery and other oncological treatment and (B) stage (n = 9223).

	2000–2008					2009–2016
Surgery and other oncological treatment^1	1 y	3 y	5 y	Mdn	(95% CI)	1 y	3 y	5 y	Mdn	(95% CI)	P^2
A
Gastric surgery	0.74	0.46	0.36	30	(28–33)	0.81	0.51	0.40	38	(33–42)	0.006
Perioperative	0.86	0.43	0.29	29	(0–69)	0.94	0.64	0.49	56	(36–75)	0.486
Preoperative only	0.80	0.40	0.20	28	(0–61)	0.71	0.50	0.42	31	(3–59)	1.000
Postoperative only	0.87	0.47	0.32	33	(28–37)	0.84	0.42	0.29	30	(26–33)	1.000
None	0.73	0.46	0.36	30	(27–33)	0.77	0.51	0.39	39	(33–45)	0.180
Diagnostic surgery/nonresectable	0.23	0.01	0.00	6	(6–7)	0.27	0.05	0.03	7	(6–7)	0.098
Preoperative	0.00	0.00	0.00	11	NC	0.60	0.00	0.00	12	(11–13)	1.000
Postoperative	0.33	0.04	0.00	10	(9–12)	0.42	0.13	0.07	9	(6–13)	1.000
None	0.22	0.01	0.00	6	(5–6)	0.20	0.01	0.01	6	(4–7)	1.000
No surgery	0.24	0.09	0.06	4	(4–5)	0.29	0.11	0.08	6	(5–6)	<0.001
Palliative	0.49	0.10	0.06	12	(9–14)	0.47	0.14	0.09	12	(11–13)	1.000
None	0.23	0.09	0.06	4	(4–4)	0.23	0.10	0.08	4	(3–4)	1.000

Table

	2000–2008					2009–2016
Stage	1 y	3 y	5 y	Mdn	(95% CI)	1 y	3 y	5 y	Mdn	(95% CI)	P^2
B
Local	0.82	0.61	0.52	68	(57–79)	0.80	0.63	0.55	77	(56–99)	0.904
Locally advanced	0.77	0.42	0.30	29	(25–32)	0.74	0.40	0.27	25	(21–29)	1.000
Metastatic	0.26	0.07	0.04	6	(5–6)	0.27	0.09	0.07	5	(5–6)	1.000
Unknown	0.40	0.21	0.16	8	(7–9)	0.49	0.25	0.19	12	(11–12)	<0.001

1 y: 1 year; 3 y: 3 years; 5 y: 5 years; Mdn: median in months; CI: confidence interval; NC: not calculated. ¹Chemotherapy and/or radiotherapy. ²Bonferroni-adjusted p values.

Table 4. Cox regression analysis of the risk of death among patients who underwent gastric surgery. A hazard Ratio (HR) > 1 indicates a higher risk of death (n = 2482)^a.

	Univariate				Multivariable
			95% CI				95% CI
	p	HR	Lower	Upper	p	HR	Lower	Upper
Age at diagnosis^2
		1.00				1.00
≥72 years	<0.001	1.34	1.20	1.50	<0.001	1.40	1.25	1.59
Sex
Male		1.00				1.00
Female	0.004	0.91	0.84	1.00	0.007	0.88	0.81	0.97
Year of diagnosis
2000–2008		1.00				1.00
2009–2016	0.051	0.90	0.82	1.00	<0.001	0.78	0.70	0.87
Catchment area
Helsinki		1.00				1.00
Turku	0.084	0.89	0.78	1.02	0.316	0.93	0.82	1.07
Tampere	0.555	0.96	0.85	1.09	0.554	0.96	0.84	1.10
Kuopio	0.578	0.96	0.84	1.11	0.690	0.97	0.84	1.12
Oulu	0.131	0.90	0.77	1.03	0.324	0.93	0.80	1.08
Stage^1
Localized		1.00				1.00
Regional	<0.001	2.90	2.44	3.44	<0.001	3.02	2.53	3.59
Distant	<0.001	7.33	6.14	8.74	<0.001	7.35	6.13	8.80
Charlson comorbidity index^2
0	<0.001	1.59	1.39	1.83	<0.001	1.44	1.25	1.65
1		1.00				1.00
2	<0.001	1.33	1.15	1.53	0.001	1.27	1.10	1.47
≥3	<0.001	1.38	1.17	1.62	<0.001	1.37	1.16	1.62
Surgery
Open subtotal gastrectomy		1.00				1.00
Laparoscopic subtotal gastrectomy	0.108	0.66	0.39	1.10	0.343	0.77	0.45	1.32
Total gastrectomy	<0.001	0.85	0.78	0.93	0.986	1.00	0.91	1.10
Elective surgery		1.00				1.00
Emergency surgery	<0.001	2.23	1.99	2.51	<0.001	1.89	1.67	2.13
Other oncological treatment^3
None		1.00				1.00
Perioperative	0.007	0.63	0.45	0.88	0.369	0.85	0.59	1.22
Preoperative only	0.806	1.07	0.62	1.85	0.005	2.23	1.28	3.89
Postoperative only	0.814	1.02	0.88	1.17	0.012	0.82	0.71	0.96

HR: hazard ratio; CI: confidence interval. ¹In 151 cases, the preoperative treatment began more than 12 months before gastric surgery or the delay in initiating postoperative treatment following gastric surgery exceeded six months. These patients as well as patients with an unknown stage were excluded from the model. ²Age at diagnosis, stage, and Charlson comorbidity index exhibited minor deviations from the Cox regression assumption of a constant hazard over time. A time-dependent correction term (HR 1.08/year for age, 0.92/year for regional stage, 0.81/year for distant stage, and 0.92/year for CCI = 0) was used to account for this deviation. Possible interactions between age and stage as well as sex and stage, respectively, were detected in the multivariable model, but these were ignored.

^aChemotherapy and/or radiotherapy.

van der Kaaij RT, Koemans WJ, van Putten M, et al. A population-based study on intestinal and diffuse type adenocarcinoma of the oesophagus and stomach in The Netherlands between 1989 and 2015. Eur J Cancer. 2020;130:23–31. doi: 10.1016/j.ejca.2020.02.017.

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Data availability statement

Due to legal restrictions, the data underlying this study cannot be shared.