Prognostic value of chromosome 1p allelic loss in colon cancer

Background & Aims: Current evidence suggests that there may be a tumor-suppressor gene on chromosome 1p associated with colorectal cancer. The aim of the present study was to determine whether allelic loss on chromosome 1p is of prognostic value in colorectal cancer. Methods: Polymerase chain reaction was used to assess allelic loss of five chromosome 1p microsatellite markers in tumor specimens. Genomic DNA was prepared from archival tumor and corresponding normal tissue specimens from 116 patients who had undergone curative treatment for adenocarcinoma of the colon. Allelic loss was correlated with disease-free interval and survival. Results: Deletion of 1p sequence was detected in 22 of 82 tumors. Deletions of the microsatellite markers D1S228 (1p36) and HY-TM1 (1p32) were significantly associated with poor survival (P < 0.05): relative risk, 4.1; 95% confidence interval, 1.25-9.23 for D1S228; and relative risk, 6.6; 95% confidence interval, 1.4-19 for HY-TM1. Loss of heterozygosity at D1S228 was also associated with shorter disease-free interval: relative risk, 4.5; 95% confidence interval, 1.3-11. Conclusions: Allelic loss in the 1p36 and 1p32 regions of chromosome 1 appears to be an independent predictor of poor prognosis in patients with adenocarcinoma of the colon.