The prognostic role of c-MYC amplification in schistosomiasis-associated colorectal cancer.

OBJECTIVE

The purpose of this study was to explore the prognostic role of c-MYC amplification in colorectal cancer, particularly in schistosomiasis-associated colorectal cancer.

METHODS

Three hundred and fifty four cases of colorectal cancer, which were from Qingpu Branch of Zhongshan Hospital affiliated to Fudan University, were retrospectively analyzed in a tissue microarray (TMA) format, with fluorescence in situ hybridization (FISH) assay and immunohistochemistry (IHC).

RESULTS

c-MYC gene amplification was found in 14.1% (50 out of 354) of patients with colorectal cancer and was correlated with old age (P = 0.028), positive lymph node metastasis (P = 0.004) and advanced stage tumors (P = 0.002). The overexpression of c-MYC was closely associated with the amplification status (P = 0.023). Kaplan-Meier survival curves for overall survival (OS) showed a statistically significant difference for patients with c-MYC amplification in full cohort of colorectal cancer, stage III-IV set and patients with lymph node metastasis (P = 0.002, 0.034, 0.012, respectively). Further analysis found c-MYC amplification associated with poorer survival in the subgroup of colorectal cancer with schistosomiasis (CRC-S, P < 0.001), but not in colorectal cancer without schistosomiasis (CRC-NS, P = 0.155). By multivariate analysis, c-MYC amplification was an independent poor-prognostic factor in CRC-S set (P = 0.046).

CONCLUSIONS

Our study firstly found c-MYC amplification could predict poor prognosis in schistosomiasis-associated colorectal cancer, but not in colorectal cancer without schistosomiasis.