Abstract
BACKGROUND: At present no objective parameters to identify the risk of liver metastasis after surgery have been established in rectal cancer. OBJECTIVE: To identify the chromosomal aberrations that are correlated with liver metastasis of rectal cancer. METHODS: Primary tumor tissues of rectal carcinoma were analyzed by array-based comparative genomic hybridization (array-CGH). Genomic aberrations were identified by Genomic Workbench and MD-SeeGH. RESULTS: The most frequent gains in rectal cancer were at 20q11.21-q13.33, 8q11.21-q24.3, 13q12.11-q14.2 and losses in 5q13.2, 8p23.3-p22, 17p13.3-p13.2 and 18q11.2-q23. Seven amplifications at 6p21.1, 8q24.21, 8q24.3, 13q13.2 and 20q13.2-q13.32 and nine homozygous deletions at 1q31.3, 4q12-q13.1, 4q32.3-q33, 5q13.2, 8p23.2, 8q11.23, 16p13.2, 19p13.11 and 19q13.41 were identified. Both frequency plot comparison and SAM (Significance analysis of microarray) methods indicated that losses at 1p35.3, 4p14, 14q23.1-q32.11 and 18p11.32-p11.21 were more frequent in patients without liver metastasis. CONCLUSIONS: These liver metastasis associated genomic changes may be useful to reveal the mechanism of metastasis and identify candidate biomarkers.