Presence of schistosome eggs in lymph nodes predict unfavorable prognosis in colorectal cancer patients

Aim: The purpose of this study was to investigate the prognostic significance of schistosome eggs location in schistosomal colorectal cancer (SCRC). Methods: : Two hundred and one cases of SCRC were retrospectively analyzed. Patient demographics, clinicopathological parameters and survival rates were analyzed. Results: : There were 120 males and 81 females, the median age was 71 years (range, 44-91). All patients were followed, and the median time was 3.85 years (range, 0.08-6.30). The 5-year disease free survival (DFS) and overall survival (OS) were 60.3% and 70.7% respectively. There were 104 patients with PS1 (presence site 1, eggs deposited in the mucosa) and 97 patients with PS2 (presence site 2, eggs deposited in the muscularis propria or throughout the full thickness of the intestinal wall), 184 patients presented with eggs in cutting edges and 98 patients in lymph nodes (LNs). Hepatic schistosomiasis was found in 28.9% of patients by imaging modalities and correlated to patients with PS2 ( P < 0.001) and LNs’ eggs ( P < 0.001). Survival analysis showed that eggs in LNs associated with worse DFS ( P = 0.001) or marginal worse OS ( P = 0.067) in stage III-IV SCRC, not in stage I-II SCRC. Multivariate analysis revealed perineural invasion was an independent prognostic factor for DFS and OS ( P < 0.001, 0.027, respectively), histology grade was an independent prognostic factor for OS ( P = 0.001). Conclusion: Schistosome eggs’ presence in LNs could predict poor prognosis in advanced SCRC. Deeper egg deposition, and LNs’ eggs, are associated with hepatic schistosomiasis.