Prevalence of Synchronous Colorectal Neoplasms Detected by Colonoscopy in Patients with Gastric Cancer

Purpose Our purpose was to study the characteristics of colorectal neoplasms in patients with gastric cancer (GC). Methods The study group comprised GC patients who underwent colonoscopy before resection of their GC. We examined the prevalence, site, and histology of colorectal neoplasms, as well as the clinicopathological features and treatment of the patients who had synchronous colorectal cancers (CRC). The logistic regression model was applied to investigate the features of the GC patients with concurrent CRC. Results We studied 466 GC patients (mean age 64.5 years; 147 women, 319 men), 143 (31%) of whom had a family history of gastrointestinal cancer. Synchronous colorectal adenoma and cancer were detected in 182 (39%) and 18 (4%) patients, respectively. Among the 18 synchronous CRCs, 11 were in the early stages and 10 of these were resected endoscopically. The other eight required simultaneous open radical surgery. All the GC patients with synchronous CRC were older than 50 years. Statistical analysis did not show a significant difference between the features of the patients with and those without concurrent CRC. Conclusions The possibility of synchronous colorectal neoplasms in GC patients cannot be disregarded in clinical practice; however, screening of the large bowel may not be necessary in GC patients younger than 50 years.