High-resolution analysis of DNA copy number alterations in rectal cancer: correlation with metastasis, survival, and mRNA expression.

BACKGROUND AND PURPOSE

This study aimed to determine the candidate genes and chromosomal imbalances capable of predicting occurrences of metastasis in patients with rectal cancer.

PATIENTS AND METHODS

Fresh frozen tumor tissues from 80 patients with rectal cancer were prospectively collected and analyzed using Affymetrix HG-U133 Plus 2.0 gene expression arrays and high-resolution Illumina single-nucleotide polymorphism (SNP) arrays. Endpoints of the study were metastasis-free survival (MFS) and cancer-specific survival (CSS).

RESULTS

The median follow-up was 102 months (1-146). Deletions of 8p and 1p36-35 correlated with worse MFS (p = 0.005 and p = 0.01, respectively) and CSS (p = 0.001 and p = 0.01, respectively). Multivariate analysis identified 8p deletion as an independent prognostic factor for MFS (p = 0.04) and CSS (p = 0.003); 97 genes located on the 8p chromosome were significantly underexpressed in tumors with 8p deletion.

CONCLUSION

This study shows for the first time in rectal cancer an independent correlation of 8p deletion with MFS and CSS and highlights potential new tumor suppressor genes.