Background and aim: In patients with gastric adenocarcinoma (GA), the most common double primary cancer is colorectal cancer. The aim of the present study was to evaluate the necessity of preoperative colonoscopy in patients with GA who have no symptoms of colorectal disease or any past/family history of colorectal cancer.
Materials: Colonoscopy was carried out in 205 patients before gastric surgery for treatment of GA. The prevalence of colorectal neoplasms (CRN, adenoma and adenocarcinoma) was evaluated according to age, sex, body mass index (BMI) and stage, location and differentiation of GA.
Results: The median age and BMI were 59 years (range 32-81) and 22.9 (range 17.0-42.3), respectively. There were 135 male patients (65.9%). Synchronous adenoma and adenocarcinoma were detected in 68 (33.2%) and four (2.0%) patients, respectively. Univariate analysis showed that patients 50 years and older, male or with multiple GA had a significantly higher incidence of CRN (P = 0.005, 0.019, and 0.023, respectively). All of the GA patients with synchronous colorectal adenocarcinoma were older than 50 years. The stage, location and differentiation of GA and BMI did not show a significant difference in the incidence of CRN. Multivariate analysis showed that age (50 years and older) was the only risk factor of CRN in GA patients (odds ratio 2.470; 95% confidence interval 1.058-5.767).
Conclusion: Preoperative colonoscopy for screening of CRN should be considered in GA patients > or = 50 years because of a relatively high prevalence of CRN and the possibility of synchronous CRC.