Sustained Organ Preservation in Patients With Rectal Cancer After Sequential Short-Course Radiation Therapy and Chemotherapy.

BackgroundNonoperative management in patients with rectal cancer with complete response to radiation therapy and chemotherapy is of increasing interest. Most of the data on nonoperative management have centered around patients treated with long-course chemoradiotherapy. The ability of short-course radiation-based treatment courses to achieve durable complete responses with sustained organ preservation is less defined. This study updates our institution's long-term experience with nonoperative management following upfront short-course radiation therapy and sequential/consolidation chemotherapy.MethodsWe retrospectively reviewed patients with nonmetastatic rectal cancer treated with sequential short-course radiation therapy and chemotherapy who reached complete response and were subsequently followed with nonoperative management. We report on disease control outcomes, including rates of regrowth and results of salvage surgery. We investigated characteristics associated with local tumor regrowth.ResultsOur study included 52 patients. The 2-year freedom from local regrowth for the entire cohort was 75%. Notably, patients with high-risk disease characteristics at diagnosis exhibited a trend toward a higher rate of local tumor regrowth. No patient with sustained clinical complete response developed metastatic disease. Of the twelve patients undergoing surgical salvage for regrowth of disease, ten were resected with complete/near-complete total mesorectal surgical specimens with negative margins.ConclusionsThe optimal approach to achieving sustained organ preservation through the use of radiation therapy and chemotherapy is not well defined. Our findings show the viability of neoadjuvant therapy incorporating short-course radiation therapy to achieve durable complete responses.