Loss of heterozygosity at 3p23 is correlated with poor survival in patients with colorectal carcinoma

BACKGROUND. Loss of heterozygosity (LOH) of chromosome 3p has been observed commonly in carcinomas of various tumor tissues, including colorectal carc inoma (CRC). Because there is no report analyzing 3p deletions in relation to patient prognosis in CRC, the authors investigated the prognostic value of LOH on 3p in 87 patients with sporadic CRC. METHODS, DNA samples from tumor and nontumor tissues were amplified by usin g polymerase chain reaction (PCR) and were analyzed for LOH on 3p using fou r different polymorphic human dinucleotide repeat DNA markers that map on t his chromosome arm. The correlations with prognosis were established by the Kaplan-Meier method, and the Cox proportional hazards model was used to id entify which independent factors jointly had a significant influence on pat ient survival. RESULTS, Overall, allelic losses were detected in 19.5% of the patients eva luated. Only considering informative tumors, the data indicated that LOH wa s observed in 17 of 71 (29.4%) informative cases. Results from survival ana lysis showed a significant correlation between this molecular abnormality a nd both overall survival and disease free survival (P = 0.02 and P = 0.0005 , respectively). The worst prognosis was found for the group of patients wi th LOW at 3p233 This alteration was an independent prognostic factor accord ing to Cox multivariate analysis. CONCLUSIONS. This study is the first to demonstrate the prognostic signific ance of LOH at chromosome arm 3p for patients CRC and may help to identify patients who need an intensive postoperative follow-up protocol. (C) 2000 A merican Cancer Society.