Preoperative Chemoradiation Followed by Extensive Pelvic Surgery Improved the Outcome of Posterior Invasive Locally Recurrent Rectal Cancer without Deteriorating Surgical Morbidities: A Retrospective, Single-Institution Analysis.

Purpose: The main feature of locally recurrent rectal cancer (LRRC) is infiltrating growth; thus, preoperative chemoradiation therapy (preCRT) is recommended to improve patient outcomes. However, no studies have reported the potential impact of preCRT on oncological and surgical outcomes in posterior invasive LRRC (piLRRC) that requires sacrectomy.
Methods: Forty-one patients with piLRRC were treated with (n = 25) or without (n = 16) preCRT. Oncological outcomes regarding local re-recurrence-free survival, distant metastasis-free survival, and overall survival (OS) were analyzed. Surgical complications were assessed using the Clavien-Dindo scale.
Results: The preCRT group had higher 5-year local re-recurrence-free survival (24.4 vs. 0 %) and OS (46.6 vs. 29.3 %) than the non-preCRT group. Univariate analysis demonstrated that preCRT (p = 0.03) and microlymphatic involvement (p = 0.01) were significantly related to local re-recurrence. Microlymphatic involvement occurred less frequently in the preCRT group than in the non-preCRT group (23.8 vs. 71.4 %; p = 0.01) despite the similarity in primary cancers between groups. Major infectious complications occurred with similar frequency in the preCRT and non-preCRT groups (24 vs. 18.8 %, p = 1).
Conclusions: PreCRT significantly benefited oncological outcome without compromising surgical results for piLRRC.