Clinicopathologic features of colorectal cancer combined with synchronous and metachronous gastric cancer

BACKGROUND/AIMS: The purpose of this study was to investigate the clinicopathologic features of double primary cancers of the stomach and colorectum, compared to colorectal cancer alone.

METHODS: A retrospective analysis was made of 5,288 patients who underwent colorectal cancer surgery between January 2000 and December 2009 at Severance Hospital of Yonsei University. The clinicopathologic features were analyzed between 63 patients of double primary cancers and case-matched 126 patients of colorectal cancer alone. We classified double primary cancers into subgroups as premetachronous, synchronous and postmetachronous gastric cancer to identify differences between the three subgroups also.

RESULTS: Double primary cancers group showed 4.3 year-older age, lower BMI, and higher percentage of peritoneal metastasis, compared to colorectal cancer alone group. Overall and colorectal cancer specific survival did not have any significant difference between two groups. In histologic type of gastric cancer, a high percentage of undifferentiated adenocarcinoma (55.6%) and signet ring cell carcinoma (30.2%) were noted.

CONCLUSIONS: Double primary cancers of the stomach and colorectum had older-age onset, lower BMI and higher metastasis to peritoneum than colorectal cancer alone. Combined gastric cancer consisted of high percentage of undifferentiated and signet ring cell carcinomas.