BACKGROUND: Local re-recurrence after R0 resection of local recurrence of rectal cancer (LRRC) is not rare. The purpose of this study was to examine the pathological features of LRRC and determine the prognostic factors. METHODS: Twenty-one patients underwent R0 resection of LRRC without preoperative therapy from 2000 to 2008. Tumor progression patterns were classified into three types: A, expanding type; B, infiltrating type; and C, intermediate type. Distant isolated cancer cells (DICCs) were defined as cancer cells present in isolation and at a distance (>1 mm) from the tumor edge. RESULTS: Venous invasion was identified in all but one patient (95%). DICCs were observed in 11 of 21 cases. Type A patients had a significantly lower local re-recurrence rate (0/5) compared with type B and/or C patients (11/16, P = 0.012) and a significantly lower incidence of distant metastasis compared with type B and C patients (0/5 vs. 13/16, respectively; P = 0.0028). Multivariate regression analysis identified venous invasion of the primary lesion (P = 0.027) and tumor progression patterns (P = 0.039) as independent predictors of local re-recurrence. CONCLUSIONS: The main features of LRRC were infiltrating growth, venous invasion, and DICCs. Tumor progression patterns correlated with local re-recurrence and distant metastasis. Preoperative adjuvant therapy to terminate peri-tumor cancer cells may be required for better tumor control.
BACKGROUND: Local re-recurrence after R0 resection of local recurrence of rectal cancer (LRRC) is not rare. The purpose of this study was to examine the pathological features of LRRC and determine the prognostic factors. METHODS: Twenty-one patients underwent R0 resection of LRRC without preoperative therapy from 2000 to 2008. Tumor progression patterns were classified into three types: A, expanding type; B, infiltrating type; and C, intermediate type. Distant isolated cancer cells (DICCs) were defined as cancer cells present in isolation and at a distance (>1 mm) from the tumor edge. RESULTS: Venous invasion was identified in all but one patient (95%). DICCs were observed in 11 of 21 cases. Type A patients had a significantly lower local re-recurrence rate (0/5) compared with type B and/or C patients (11/16, P = 0.012) and a significantly lower incidence of distant metastasis compared with type B and C patients (0/5 vs. 13/16, respectively; P = 0.0028). Multivariate regression analysis identified venous invasion of the primary lesion (P = 0.027) and tumor progression patterns (P = 0.039) as independent predictors of local re-recurrence. CONCLUSIONS: The main features of LRRC were infiltrating growth, venous invasion, and DICCs. Tumor progression patterns correlated with local re-recurrence and distant metastasis. Preoperative adjuvant therapy to terminate peri-tumor cancer cells may be required for better tumor control.