Neoadjuvant Treatment Response Surrogate for Outcome in Rectal Cancer
(ChemotherapyAdvisor) – Patients who achieve complete response after preoperative chemoradiotherapy for locally advanced rectal cancer and undergo radical resection have excellent prognosis with low risk for local or distant recurrence, a study in Journal of Clinical Oncology online April 9 has found.
“Final pathologic stage is an early response indicator for long-term outcomes that provides better prognostication than does the clinical stage,” the investigators wrote.
The retrospective record review identified 725 patients with locally advanced rectal carcinoma diagnosed from 1993 to 2008 treated with preoperative chemoradiotherapy and radical resection. Median radiation dose was 50.4Gy with concurrent chemotherapy. Recurrence-free survival, distant metastasis, and local recurrence rates were compared among patients with complete, intermediate, or poor response.
A total of 131 patients (18.1%) had complete response, 210 (29%) intermediate, and 384 (53%) poor response. Age, sex, cN stage, and tumor location were not related to tumor response. Tumor response (complete vs. intermediate vs. poor) was associated with five-year recurrence-free survival (90.5% vs. 78.7% vs. 58.5%; P<0.001); five-year distant metastasis rates (7% vs. 10.1% vs. 26.5%; P<0.001); and five-year local recurrence only rates (0% vs. 1.4% vs. 4.4%; P<0.002).
“These data provide guidance with response-stratified oncologic benchmarks for comparisons of novel treatment strategies,” they concluded.