Clinical analysis of multiple primary gastrointestinal malignant tumors: A 10-year case review of a single-center

Table 1 Clinicopathological features of multiple primary malignant tumors, % (n/N)

Variable	First primary tumor	Second primary tumor	Third primary tumor
No. of patients, n	85	85	2
Median age, yr (range)	58 (26-89)	61 (35-89)
Sex, n
Male	57	57	0
Female	28	28	2
P value		> 0.1
Age, n
≤ 50 yr	26	18	0
> 50 yr	59	67	2
P value		> 0.1
Tumor distribution
Stomach	41.46 (34/85)	12.94 (11/85)	0
Small bowel	1.18 (1/85)	3.53 (3/85)	0
Colon	32.94 (28/85)	43.53 (37/85)	50 (1/2)
Rectum	25.88 (22/85)	40.00 (34/85)	50 (1/2)
P value		< 0.05
Pathological type
Adenocarcinoma	100 (85/85)	97.65 (83/85)	100 (2/2)
Neuroendocrine carcinoma	0	1.18 (1/85)	0
GIST	0	1.18 (1/85)	0
P value		> 0.1
Clinical stage
Tis	11.32 (6/53)	8.22 (6/73)
I	13.20 (7/53)	12.33 (9/73)	50 (1/2)
II	30.19 (16/53)	28.76 (21/73)	50 (1/2)
III	37.74 (20/53)	27.40 (20/73)
IV	7.55 (4/53)	23.29 (17/73)
P value		> 0.1
Treatment
Surgery	17.65 (15/85)	14.12 (12/85)	50 (1/2)
Surgery + chemotherapy	76.47 (65/85)	48.23 (41/85)	50 (1/2)
Chemotherapy ± radiotherapy	3.53 (3/85)	21.18 (18/85)
Best supportive care	2.35 (2/85)	16.47 (14/85)
P value		< 0.001

All statistical comparisons were between the first primary tumor and the second primary tumor by independent χ²-test. Due to the small number of samples of the third primary tumor, statistical comparisons were not performed. MPMTs: Multiple primary malignant tumors; GIST: Gastrointestinal stromal tumors.

Table 2 Cases and ratios of multiple primary malignant tumors in the gastrointestinal tract

Sites	Number of MPMTs	Total number	Incidence (%)	Incidence (%) in gastrointestinal MPMTs
Stomach	45	3618	1.24	26.16
Small bowel	4	126	3.17	2.33
Colon	66	1450	4.55	38.37
Left colon	41			23.84
Right colon	25			14.53
Rectum	57	2865	1.99	33.14

MPMTs: Multiple primary malignant tumors.