A Study for The Changing Subsite Distribution of Colorectal Cancer with Age and Sex

Cho, Yong Kyun; Pyun, Yu Jang; Sung, Ki Chul; Lee, Hee Moo; Choi, Yoon Sang; Park, Chang Young; Jeon, Woo Kyu; Kim, Byung Ik; Lee, Man Ho; Lee, Sang Jong; Kim, Myung Sook

Abstract

BACKGROUND/AIMS: Changes in subsite distribution of colorectal cancer have been shown in recent years. The carcinoma tend to shift to more proximal colon and this proximal shift is influenced by age and sex. This study was designed to delineate the relationship of age to subsite incidence of colorectal cancer and to define the role of gender in this difference. METHOD: We have analyzed the data by patients with colorectal cancer from 1985 to 1995 for elucidate the relationships between age, sex and prinmry location of colorectal cancer. 749 patients(male 454, female 295) were diagnosed of colorectal cancer performed by colonoscopy and/or sigmoidoeopy were divided into three groups by their location of cancer (Right colon: appendix, ascending colon, hepatic flexure, T-colon proximal 2/3 Left colon: T-colon distal 1/3, splenic flexure, descending colon, sigmoid colon Rectum: rectum).
RESULTS
1) The mean age of all patients was 53.84 +/- 13.11(yr). Mean ages of Right colon, Left colon, and Rectal cancer group were 55.54 +/- 14.12, 55.32 +/- 12.51, 52.22 +/- 13.09(yr), respectively. The mean age of Right colon and Left colon cancer group is significantly older than that of Rectal cancer group (p=0.0040, p=0.0042). 2) Infemale age group over 56, mean age of Right colon cancer group is shown to be 3.35 and 4.82 years older than Left colon cancer group and Rectal cancer group, respectively (p=0.0062, p=0.0053) and Colon cancer tend to develop on more right side according to increase in age. 3) Above correlation was not observed below 55 of both sexes and male age group over 56. 4) No significant differences in histological differentiation and tumor stage were observed among the three groups. 5) The study was conducted to evaluate the difference in the location of colorectal cancer between two following groups; The first group diagnosed from 1985 to 1990 and the second group from 1991 to 1995, yet significant statistical difference was not observed.
CONCLUSION
Age increase seems to show correlation with right shifting of colon cancer, and this correlation was most significant in old women age group. This finding suggests unknown factor strongly linked to age and sex might play important role in carcinogenesis of colorectal cancer.