Short course radiation therapy for rectal cancer in the elderly: can radical surgery be avoided?

Rectal cancer in elderly patients can be difficult to manage. Short course radiation therapy (SCRT) has shown to be effective when given immediately prior to surgery. Here we report outcomes of elderly patients who underwent SCRT either alone or prior to resection. Between 2010 and 2015, elderly patients with rectal cancer and no distant metastatic disease were identified. Symptoms at diagnosis, therapies, toxicities, and pathologic and clinical response were recorded from patient charts. The SCRT prescription dose was 5 Gy ×5 to the rectal tumor and 4 Gy ×5 to the mesorectum, omitting the iliac nodes. Twenty patients were identified with median age of 85 years (range, 71-93 years). No patient received systemic therapy. Sixty percent of patients were cT3 at diagnosis. Half underwent resection post SCRT and half received SCRT as definitive therapy. The 1- and 2-year overall survival was 75% and 54%. Overall survival did not differ between patients treated with SCRT and surgery compared to SCRT alone (P=0.8). Of the 10 surgical patients, 3 had a complete pathologic response at time of resection and 3 patients died within 2 weeks due to perioperative complications. Of patients treated with SCRT alone, 8 were symptomatic at presentation and 5 had a clinician defined symptomatic response. No patient treated with SCRT monotherapy required additional palliative measures for outflow obstruction, but 2 progressed locally and died. SCRT is well tolerated, results in pathologic complete responses in a small percentage of patients, and achieves 63% symptom improvement rate as monotherapy. A high peri-operative complication rate was observed in this small series. In elderly patients, SCRT as initial treatment with a watch and wait approach for surgery is feasible and should be evaluated prospectively.