Preoperative Radiotherapy in Elderly Patients With Locally Advanced Rectal Cancer: A Retrospective Cohort Study

Purpose To explore the outcomes of elderly patients (≥75 years) with locally advanced rectal cancer (LARC) treated with either short-course radiotherapy (SCRT) or chemoradiotherapy (CRT) at a regional cancer center. Methods A retrospective chart review was conducted for patients aged ≥75 with biopsy-confirmed rectal adenocarcinoma treated with either SCRT or CRT between January 2017 and June 2020. Patients were excluded if they had metastatic disease, recurrent cancer, or received palliative radiotherapy without surgical intent. SCRT consisted of 25 Gy in five fractions, with surgery performed either immediately or after a delay of six to eight weeks. CRT consisted of 50.4 Gy in 28 fractions with concurrent capecitabine, followed by delayed surgery. Outcomes assessed included surgical margin status, pathological complete response (pCR), local recurrence, distant metastasis (DM), overall survival (OS), and cancer-specific survival (CSS). Results A total of 46 patients met the inclusion criteria (SCRT: 34; CRT: 12). Radiotherapy was completed in 34 patients (100%) in the SCRT group and 11 patients (92%) in the CRT group. Surgery was performed in 28 (82%) of the SCRT patients and 11 (92%) of CRT patients. R0 resection was achieved in 86% (n=24) of SCRT and 100% (n=12) of CRT patients. No pathologic complete responses were observed. Local recurrence was observed in 2 SCRT patients (5.9%), and no recurrences occurred in the CRT group. Distant metastases developed in 3 SCRT (8.8%) and 2 CRT (16.7%) patients. With a median follow-up of 24 months, OS was 73.5% (SCRT) vs. 75% (CRT), and CSS was 73.5% (SCRT) vs. 91.7% (CRT), with no statistically significant differences. Conclusion Both SCRT and CRT were well tolerated and achieved high R0 resection rates with low recurrence in elderly patients with LARC. CRT showed slight trends toward greater nodal downstaging, while SCRT offered comparable survival with fewer treatment-related complications and greater flexibility in surgical timing.