Long-term outcomes after high-dose chemoradiotherapy for non-surgical management of distal rectal cancer.

Abstract

3611 Background: Surgery is standard treatment for rectal cancer, but neoadjuvant chemoradiotherapy (CRT) may result in clinical complete response (cCR) in selected patients, allowing for non-surgical management (NSM). Prospective studies of NSM strategies are sparse however, and long-term data on quality of life (QoL) are limited. We conducted a single-arm phase II trial of high-dose CRT for NSM of distal rectal cancer; we report secondary long-term patient-reported outcomes (PROs), local regrowth and overall survival (OS) in patients managed non-surgically. Methods: Fifty-one patients with resectable, T2 or T3, N0–N1, low adenocarcinoma received 65Gy (IMRT, brachytherapy boost) and oral tegafur-uracil. Patients with cCR 6 weeks after treatment (clinical examination, MRI, biopsy) were referred for observation, and followed closely with clinical examinations, endoscopies, PET-CTs, and PROs for 5 years. Overall colorectal cancer specific QoL and specific symptom scores were compared between timepoints using paired Wilcoxon tests. Local regrowth was estimated using cumulative incidence; overall survival using Kaplan-Meier estimates. Results: Forty patients achieved cCR after treatment; 28 were in follow-up at 24m, 21 at 36m, 18 at 60m. Patients left the trial due to local tumor regrowth (n=12), distant metastases (n=3), new primary cancers (n=6) and loss to follow-up (n=1). Average QoL score did not differ between baseline (median 11.1) and 24m (13.7), 48m (11.1,) or 60m (6.9). See Table for individual scores; only rectal bleeding deteriorated from baseline (significantly worse at 24m). At median follow-up of 5.0 years, local regrowth rate and OS were 31% (95 CI 15%-47%) and 85% (95 CI 75%-97%), respectively. Conclusions: Long term follow-up after NSM of early rectal cancer showed excellent general colorectal cancer QoL and local symptom scores. (NCT00952926). EORTC QLQ – CR 29. Proportion reporting ‘quite a bit’ or ‘very much’ on symptom scales. Clinical trial information: NCT00952926. [Table: see text]