Incidence and survival of stomach cancer in a high-risk population of Chile

Table 1 SIR of stomach cancer by selected characteristics, Valdivia, Chile, 1998-2002

Characteristic	Cases	Males: 365			Females: 164			Male vs female
		%	SIR	95% CI	%	SIR	95% CI	RR	P-value
All	529	69	40.8	36.7-45.2	31	14.8	12.1-16.7	2.8	< 0.001
Age (yr)
< 35	8	0.8	0.5	0.0-1.2	3.0	0.9	0.1-1.8	0.6	0.45
35-44	22	4.4	11.7	5.9-17.4	3.6	4.6	0.9-8.2	2.6	0.04
45-54	55	11.2	44.6	30.9-58.2	8.4	15.4	7.3-23.4	2.9	< 0.001
55-64	94	21.4	125.7	97.8-153.6	9.6	23.9	12.2-35.6	5.3	< 0.001
65-74	164	32.1	291.3	238.6-344.0	28.7	100.5	72.1-128.9	2.9	< 0.001
75-84	86	14.8	448.7	329.3-568.1	19.8	214.3	141.3-287.4	2.1	0.001
≥ 85	100	15.3	501.4	370.4-632.4	26.9	292.2	206.9-377.4	1.7	0.006
Ethnicity Mapuche	89	15	47.2	34.5-59.9	21.0	28.1a	18.5-37.7	1.7	0.016
Hispanic/European	440	85	40.0	35.5-44.5	79.0	12.7a	10.5-15.0	3.1	< 0.001
School years
≤ 8	420	81	43.3a	38.1-48.5	92.0	16.2a	13.3-19.1	2.7	< 0.001
> 8	77	19	27.6a	20.5-34.7	8.0	3.7a	1.5-5.9	7.5	< 0.001
Residence rural	220	48	48.0a	40.7-55.3	30.0	14.5	10.4-18.7	3.3	< 0.001
Urban	297	52	34.5a	29.5-39.6	70.0	13.9	11.2-16.6	2.5	< 0.001

^aSignificant risk factors between characteristics groups; RR: Relative risk.

Table 2 Clinical characteristics of the stomach cancer cases entered in the population-based cancer registry of Valdivia 1998-2002 (n = 529)

Characteristic	Cases	Total (%)	Males (%)	Females (%)	P-value sex diff.
Sign and symptoms at diagnosis
Weight loss	294	55.6	61.1	43.3	< 0.001
Epigastric pain	285	53.9	57.0	47.0	0.03
Gastrointestinal bleeding	108	20.4	21.4	18.3	0.42
Vomiting	106	20.0	20.8	18.3	0.50
Abdominal distension	83	15.7	14.8	17.7	0.40
Palpable epigastric mass	56	14.7	12.9	19.2	0.016
Ascites	51	13.4	13.3	13.5	0.97
Supraclavicular adenopathy	31	8.5	9.7	5.1	0.16
Main detection source
Histological studies1	404	76.4	81.3	65.2	< 0.001
Radiological diagnosis	25	4.7	4.9	4.3	0.74
Clinical or autopsy	39	7.3	7.2	7.9	0.75
Only death certificate	61	11.5	6.6	22.6	< 0.001
Duration of symptoms2
< 3 mo	126	32.9	35.9	24.2	0.033
3 to 6 mo	98	25.6	25.4	26.3	0.86
> 6 mo	159	41.5	38.7	49.5	0.06
Main diagnostic workout
Gastric endoscopy	412	79.4	84.6	67.7	< 0.001
Gastric biopsy	401	75.8	80.8	64.6	< 0.001
Ecography	191	36.1	37.8	32.3	0.22
Computed tomography	114	21.6	22.7	18.9	< 0.001
Staging TNM
Stage I	9	1.7	2.2	0.6	0.19
Stage II	20	3.8	2.5	6.7	0.02
Stage III	53	10.0	10.4	9.1	0.65
Stage IV	297	56.1	58.6	50.6	0.09
Not determined	150	28.4	26.3	32.9	0.12
Histological type
Tubular adenocarcinoma	148	36.0	35.2	38.3	0.56
Tubulopapillary adenocarcinoma	35	8.5	7.6	11.2	0.25
Papillary adenocarcinoma	11	2.7	2.0	4.7	0.14
Mucinous adenocarcinoma	11	2.7	2.3	3.7	0.43
Undefined adenocarcinoma	83	20.2	22.4	14.0	0.06
Signet ring cell carcinoma	77	18.7	18.1	20.6	0.57
Non Hodgkin lymphoma	6	1.5	1.6	0.9	0.60
Neuroendocrine carcinoma	4	1.0	0.7	1.9	0.27
Other carcinoma	36	8.8	9.5	6.5	0.35
Tumor location
Body	57	10.8	11.5	9.1	0.42
Fundus	158	29.9	33.7	21.3	0.004
Antrum	122	23.1	21.9	25.6	0.35
All stomach	33	6.2	6.8	4.9	0.39
Unknown	159	30.1	26.0	39.0	0.003
Habits
Tobacco use	346	44.8	51.4	29.1	< 0.001
Alcohol use	338	61.2	73.6	31.3	< 0.001

¹Includes 3 cases diagnosed based on a biopsy of metastasis;

²Time between first symptoms and diagnosis.

Table 3 Factors associated with SC survival. Valdivia 1998-2002. Kaplan-Meier (n = 445 cases). Univariate analyses

Variable	n(%)	3-yr survival		5-yr survival		P-value 5-yr survival
		%	95% CI	%	95% CI
Sex
Female	120 (27.0)	20.3	13.0-27.6	12.9	6.7-19.1	-
Male	325 (73.0)	13.4	9.7-17.1	9.8	6.5-13.1	0.56
Age (yr)
< 55	81 (18.2)	21.0	12.1-29.9	17.3	9.1-25.5	0.037
55-79	300 (67.4)	15.5	11.3-19.7	9.9	6.4-13.4	0.006
> 80	64 (14.4)	6.3	0-12.8	4.2	0-9.7	-
Ethnic group
Mapuche1	76 (17.1)	7.3	1.2-13.4	4.4	0-9.2	-
Hispanic	369 (82.9)	16.9	13.0-20.8	11.9	8.5-15.3	0.02
School years
0 to 8	348 (83.6)	9.1	6.0-12.2	6.4	3.7-9.1	-
> 8	68 (16.4)	19.7	10.2-29.3	8.9	2.0-15.8	0.08
Home
Urban	248 (57.1)	18.7	13.8-23.6	12.9	8.6-17.2	0.006
Rural	186 (42.9)	10.6	6.1-15.1	8.2	4.1-12.3	-
Sign and symptoms at diagnosis
Supraclavicular adenopathy
Yes	28 (8.0)	0	-	0	-	-
No	321 (92.0)	18.6	14.3-22.9	13.8	9.9-17.7	0.00018
Palpable mass
Yes	52 (14.4)	8.7	1.0-16.4	6.2	0-13.1	-
No	310 (85.6)	17.8	13.5-22.1	13.0	9.2-16.8	0.00001
Ascitis
Yes	47 (13.0)	0	-	0	-	-
No	315 (87.0)	18.9	14.5-23.3	13.8	9.9-17.0	0.000002
GI bleeding
Yes	101 (22.7)	20.1	12.2-28.0	13.7	6.9-20.5	0.87
No	344 (77.3)	13.8	10.1-17.5	9.7	6.5-12.9	-
Vomiting
Yes	100 (22.5)	10.3	4.3-16.3	6.2	1.4-11.0	-
No	345 (77.5)	16.8	12.8-20.8	11.9	8.4-15.4	0.046
Weight loss
Yes	277 (62.2)	13.6	9.5-17.7	10.0	6.4-13.6	0.45
No	168 (37.8)	18.1	12.2-24.0	11.5	6.5-16.5	-
Abdominal distension
Yes	78 (17.5)	11.5	4.4-18.6	7.7	1.8-13.6	0.13
No	367 (82.5)	16.1	12.3-19.9	11.2	7.9-14.5
Pain
Yes	271 (60.9)	19.0	14.2-23.8	14.5	10.2-18.8	0.14
No	174 (39.1)	9.6	5.2-14.0	4.6	1.4-7.8
Months with symptoms
< 3	117 (32.3)	14.9	8.3-21.5	9.3	3.9-14.7
3 to 6	95 (26.2)	17.6	9.9-25.3	14.2	7.1-21.3	0.32
> 6	150 (41.4)	16.6	10.5-22.7	13.7	8.1-19.4	0.30
Gastrectomy
Yes	128 (28.8)	44.8	36.0-53.6	33.6	25.1-42.1	0.0000001
No	317 (71.2)	3.5	1.4-5.6	1.3	0-2.6	-
Surgical intention
Curative	89 (42.4)	50.4	39.9-60.9	38.6	28.3-48.9	0. 0000001
Palliative	121 (57.6)	14.4	5.8-23.0	10.4	2.6-18.2	-
Lauren class
Intestinal	220 (59.1)	21.0	15.5-26.5	14.6	9.8-19.4	0.0000003
Diffuse	152 (40.9)	11.2	6.1-16.3	7.0	2.9-11.1	-
Tumor
Localized	325 (91.0)	20.0	15.6-24.4	14.6	10.6-18.6	0.004
All stomach	32 (9.0)	0	-	0	-	-
Size
< 4 cm	16 (12.8)	67.0	43.3-90.7	60.0	35.1-84.9	-
4 to 9.9 cm	71 (56.8)	48.3	36.3-60.3	35.5	23.9-47.1	0.161
> 10 cm	38 (30.4)	29.0	15.6-43.4	21.1	8.1-34.1	0.006
Depth
Mucosa	9 (7.1)	100	-	100	-	-
Muscle/subserosa	7 (5.6)	85.7	59.8-100	71.4	37.9-100	0.14
Serosa	110 (87.3)	38.2	29.0-47.5	27.2	18.6-35.8	0.003
Lymphatic invasion stage
0	21 (17.8)	94.9	85.1-100	77.1	57.3-96.9	-
I	36 (30.5)	55.4	39.1-71.7	40.2	23.8-56.6	0.008
II	33 (28.0)	38.3	21.5-55.1	25.3	10.1-40.5	0.0005
III	28 (23.7)	10.7	0-22.2	10.7	0-22.2	0.00001
Metastasis
0	185 (47.0)	30.6	23.5-37.4	22.2	16.0-28.4	-
1	209 (53.0)	2.5	0.3-4.7	1.5	0-3.2	0.0000001
TNM
I	9 (2.1)	100	-	85.7	59.8-100	-
II	18 (4.1)	77.3	57.7-96.9	65.4	42.9-87.9	0.24
III	53 (12.1)	49.2	35.5-62.9	32.2	19.1-45.3	0.011
IV	281 (64.0)	3.0	1.0-5.0	2.2	0.4-4.0	0.00003
Unknown	78 (17.8)	12.3	4.9-19.7	3.8	0-8.3	0.00007

¹Native American Indian residents of southern Chile.

Table 4 Multivariate analysis of prognostic factors of stomach cancer survival population-based registry of Valdivia (Kaplan-Meier)

	OR	95% CI	P-value
Staging TNM
Stage I	1.0
Stage II	2.77	0.3-23.8	0.35
Stage III	6.87	0.9-50.6	0.06
Stage IV	22.53	3.1-165.2	0.002
Unknown	23.35	3.1-173.6	0.002
Lauren classification
Intestinal	1.0
Diffuse	1.68	1.3-2.2	< 0.001
Metastasis
No	1.0
Yes	1.58	1.1-2.3	0.019
Supraclavicular adenopathy
No	1.0
Yes	1.69	1.0-2.8	0.037
Palpable tumor
No	1.0
Yes	2.04	1.4-3.1	0.001
Hepatitis or ascites
No
Yes	2.51	1.6-3.9	< 0.001