Non-Operative Management is Feasible and Safe in Patients with Rectal Cancer Who Achieve Clinical Complete Response to Short-Course Radiation Therapy and Consolidation Chemotherapy

Abstract

<h3>Purpose/Objective(s)</h3> The purpose of this study was to report on patients with localized rectal adenocarcinoma followed with non-operative management (NOM) with a watch-and-wait (W&W) strategy after achieving clinical complete response (cCR) to short-course radiation therapy (SCRT) and consolidation chemotherapy. <h3>Materials/Methods</h3> Patients with rectal adenocarcinoma who achieved cCR to SCRT and consolidation chemotherapy and were subsequently managed with NOM were included in this study. Endpoints included overall survival (OS), freedom from local failure (FFLF), freedom from distant metastasis (FFDM), and disease-free survival (DFS). cCR was defined by absence of residual tumor, nodularity, and ulceration on endoscopic evaluation. FFLF was defined as time from achieving cCR to development of intraluminal recurrence on endoscopic evaluation. DFS was defined as time from completion of SCRT to death, local-regional failure, or distant failure. Local failures that were successfully salvaged were not considered disease progression. Patients with sustained cCR were given surveys to assess general and bowel quality of life: 1. EORTC Quality of Life Questionnaire Core 30, 2. EORTC Quality of Life Questionnaire-Colorectal Cancer 29, and 3. Low anterior resection syndrome (LARS) score. <h3>Results</h3> A total of 87 patients were treated with SCRT and chemotherapy, of which 33 had cCR. Of the 33 with cCR, 26 patients were managed with NOM. Median age was 63 years (range, 44-79 years). Median follow-up was 20.4 months (range, 7.2-46.2 months). All patients were treated with SCRT to 25 Gy in 5 fractions. Chemotherapy regimens included mFOLFOX (n=20), CAPOX (n=3), mFOLFOX and CAPOX (n=1), mFOLFOX and FLOX (n=1), CAPOX and capecitabine (n=1), for a median of 4.5 months (range, 2.0-9.0 months). Median FFLF was not reached, with 6-month, 1-year, and 2-year FFLF rates of 85.7%, 68.0%, and 68.0%, respectively. Seven (26.9%) patients developed local failure at a median of 6.8 months (range, 3.4-30.2 months) after achieving cCR, of which 5 (71.4%) were successfully salvaged. Median OS was not reached with 6-month, 1-year, and 2-year OS rates of 100%. Median FFDM was not reached, with 6-month, 1-year, and 2-year FFDM rates of 100%, 94.7%, and 89.2%, respectively. Median DFS was not reached, with 6-month, 1-year, and 2-year DFS rates of 100%, 95.0%, and 89.4%, respectively. Survey response rate was 83.3%. Median LARS score was 27 (range, 0-37) and mean LARS score was 20.9. Major LARS, minor LARS, and no LARS occurred in 3 patients (20%), 6 patients (40%), and 6 patients (40%), respectively. There were no differences in EORTC and LARS survey scores between patients who had > 50% of their anal sphincter region included in the prescription-dose radiation volume and those who did not. <h3>Conclusion</h3> Non-operative management with W&W strategy may be an appropriate option for patients with rectal adenocarcinoma who achieve cCR to SCRT and consolidation chemotherapy. Furthermore, anorectal function appears to be adequate with this approach.