A comparative study between screen-detected and clinically diagnosed colorectal cancer with stratification by gender and age

• Published in: Journal of Gastroenterological Mass Survey Vol. 42; no. 4; pp. 418 - 432
• Main Authors: KUMAGAI, Yuji, KONNO, Yutaka, TAKAGI, Sho, MORIMOTO, Tomizo, AIDA, Shigemitu, KINOUCHI, Yoshitaka, SHIMADA, Takenobu, YAMASHITA, Kazuyoshi, TSUBONO, Yoshitaka, SHIBUYA, Daisuke, KIKUCHI, Tatsuya, HIWATASHI, Nobuo
• Format: Journal Article
• Language: Japanese
• Published: The Japanese Society of Gastroenterological Cancer Screening 2004; 一般社団法人 日本消化器がん検診学会
• Subjects: 大腸がん検診; 対象年齢; 生存率
• ISSN: 1345-4110; 2186-7321
• DOI: 10.11404/jsgcs2000.42.4_418

As an attempt to define the appropriate age group for colorectal cancer screening, we compared survival rates between screen-detected and clinically diagnosed colorectal cancer. During 1993-1999, 12114 cases of malignant neoplasm of colorectum were registered to the Miyagi Prefectural Cancer Registry. We excluded 4600 cases in which information was derived only from death certificates, histological types of lesions were not carcinoma (e. g. malignant lymphoma, sarcoma and carcinoid tumor), depth of lesions were limited into the mucosa, dates of diagnosis were unknown, or reasons of diagnosis were not distinguished whether screening or not. After these exclusions, 7514 cases of colorectal cancer remained for the analyses (1522 screen-detected and 5992 clinically diagnosed cases). After stratification by gender and 5-year age class, screen-detected group and clinically diagnosed group were compared for the state of performing operation, the stage of disease and the survival rate (observed, cause-specific and relative survival rates). For men and women 40-79 years of age, survival rates were significantly better in screen-detected groups than in clinically diagnosed groups. In contrast, we did not observe significant survival benefit in screendetected groups for men and women 80-89 years of age. These results suggest that screening for colorectal cancer is effective for people 40-79 years of age but not for those aged 80 years and older. Because the number of cases aged 80 years and older was relatively small in this study, our results require confirmation in further studies.