Objective: A prospective study in 82 consecutive patients with mid- and distal rectal adenocarcinomas having specific histology and tumor stage was conducted to asses impact of curative surgery.
Methods: Patients with moderately differentiated adenocarcinoma (MDAC) with or without mucinous differentiation underwent curative resection. Forty patients were in Stage B1-B2 and 42 patients were in Stage C1-C2. Surgery options were: (1) Abdominoperineal resection (APR) for tumors located within 6cm of the anal verge and (2) Tumor specific mesorectal excision (TSME) and low anterior anastomosis (LAA) for those located between 6 to 12cm from the anal verge. The primary endpoints were overall (OS) and disease-free survival (DFS).
Results: Patients in Stage B1-B2 had a local failure rate of 15% compared with 31% of patients in stage C1-C2 (p=0.18). Satellite tumor nodule formation (STN) was observed in one patient in B group and in 13/42 (31%) of Stage C tumors. LR did not vary with mucinous differentiation. Only lymph node involvement (N1-3) (p=0.028) had an impact on locoregional recurrence and both lymph node involvement and STN formation influenced disease-free survival (p=0.008).
Conclusion: Preoperative precise detection of Stage C rectal adenocarcinomas is of utmost importance to facilitate the implementation of therapies for downstaging and for better local and distant control following surgery.