Distal intramural spread is an independent prognostic factor for distant metastasis and poor outcome in patients with rectal cancer: A multivariate analysis

Background: The aim of this study was to clarify the prognostic value of distal intramural spread of tumor for survival and recurrence in patients with rectal cancer. Methods: Microscopic distal intramural spread was examined in 134 consecutive specimens of resected rectal cancer. Correlations among distal intramural spread, established clinicopathologic factors, and patients' prognoses were examined by univariate and multivariate analyses. American Joint Committee on Cancer classification and stage groupings were used for tumor assessment. Results: Thirty-three patients (24.6%) had distal intramural spread. Multivariate logistical regression analysis revealed that T3/T4 and M1 were independent predictive variables for the presence of distal intramural spread. Patients with distal intramural spread had a shorter disease-specific or disease-free survival time after curative surgery than those without distal intramural spread (P = .0003 and P = .0006, respectively). Most patients with distal intramural spread developed distant recurrence. Cox's regression with multiple covariates showed that distal intramural spread is an independent factor in predicting distant recurrence and worse outcomes after curative surgery in patients with rectal cancer. Conclusions: Distal intramural spread is an independent risk factor for distant metastasis and poor prognosis in patients with rectal cancer.