Comparison of non-schistosomal colorectal cancer and schistosomal colorectal cancer

Aim: The purpose of this study was to compare clinicopathological features of patients with non-schistosomal and schistosomal colorectal cancer to explore the effect of schistosomasis on colorectal cancer (CRC) patients` clinical outcomes. Methods: : 351 cases of CRC were retrospectively analyzed in this study. Survival curves were constructed by using the Kaplan-Meier (K-M) method. Univariate and multivariate Cox proportional hazard regression models were performed to identify associations with outcome variables. Results: : Colorectal cancer patients with schistosomiasis (CRC-S) were significantly older ( P ＜0.001) than the patients without schistosomiasis (CRC-NS). However, there were no significant differences between CRC-S and CRC-NS patients in other clinicopathological features. Schistosomiasis were associated with adverse overall survival (OS) upon K-M analysis ( P =0.0277). By univariate and multivariate analysis, gender ( P =0.003), TNM stage ( P ＜0.001), schistosomiasis ( P =0.025), lymphovascular invasion ( P =0.030) and lymph nodes positive for CRC ( P ＜0.001) were all independent predictors in the whole cohort. When patients were stratified according to clinical stage and lymph node metastasis state. Schistosomiasis was also an independent predictors in patients with stage Ⅲ-Ⅳ tumors and in patients with lymph node metastasis, but not in patients with stage Ⅰ-Ⅱ tumors and in patients without lymph node metastasis. Conclusion: Schistosomiasis was significantly correlated with OS and it was an independent prognostic factor for OS in the whole cohort. When patients were stratified according to clinical stage and lymph node metastasis state, schistosomiasis was still an independent unfavorably prognosis factor for OS in patients with stage Ⅲ-Ⅳ tumors or patients with lymph node metastasis.