Comparison of non-schistosomal colorectal cancer and schistosomal colorectal cancer
Abstract Aim The purpose of this study was to compare clinicopathological features of patients with non-schistosomal and schistosomal colorectal cancer to explore the prognostic role of schistosoma infection in colorectal cancer(CRC). Methods 354 cases of CRC were retrospectively analyzed in a tissue microarray format. Survival curves were constructed by using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazard regression models were performed to identify associations with outcome variables. Results Patients with schistosomiasis (CRC-S) were significantly older ( P <0.001) and were mostly in stage III and IV tumors ( P <0.001) than patients without schistosomiasis (CRC-NS). However, there were no significant difference between CRC-S and CRC-NS patients in other clinicopathological features. Overall, CRC-S patients were associated with adverse overall survival upon K-M analysis ( P =0.0239). By univariate and multivariate analysis, CRC-S patients were significantly correlated with OS ( P =0.041), but it was not an independent prognostic factor. In addition, age( P =0.013), gender ( P =0.008), tumor differentiation ( P =0.018) and invasive depth ( P =0.013) were all independent predictors. When patients were stratified according to clinical stage and lymph node metastasis state, the prognostic role was not consistent. In patients with stage III-IV tumors and with lymph node metastasis, schistosomiasis, gender and invasive depth were independent predictors, but not in patients with stage I-II tumors and in patients without lymph node metastasis. Conclusion Schistosomiasis is an unfavorable factor for OS and could be considered to refine risk stratification and provide better risk-oriented treatment for CRC patients with different clinical stage or lymph node metastasis state.