Organ Preservation in cT2N0 Rectal Cancer After Neoadjuvant Chemoradiation Therapy: The Impact of Radiation Therapy Dose-escalation and Consolidation Chemotherapy.

Abstract

To demonstrate the difference in organ-preservation rates and avoidance of definitive surgery among cT2N0 rectal cancer patients undergoing 2 different chemoradiation (CRT) regimens. Patients with cT2N0 rectal cancer are more likely to develop complete response to neoadjuvant CRT. Organ preservation has been considered an alternative treatment strategy for selected patients. Radiation dose-escalation and consolidation chemotherapy have been associated with increased rates of response and may improve chances of organ preservation among these patients. Patients with distal and nonmetastatic cT2N0 rectal cancer managed by neoadjuvant CRT were retrospectively reviewed. Patients undergoing standard CRT (50.4 Gy and 2 cycles of 5-FU-based chemotherapy) were compared with those undergoing extended CRT (54 Gy and 6 cycles of 5-FU-based chemotherapy). Patients were assessed for tumor response at 8 to 10 weeks. Patients with complete clinical response (cCR) underwent organ-preservation strategy ("Watch and Wait"). Patients were referred to salvage surgery in the event of local recurrence during follow-up. Thirty-five patients underwent standard and 46 patients extended CRT. Patients undergoing extended CRT were more likely to undergo organ preservation and avoid definitive surgical resection at 5years (67% vs 30%; P = 0.001). After development of a cCR, surgery-free survival is similar between extended and standard CRT groups at 5 years (78% vs 56%; P = 0.12). Dose-escalation and consolidation chemotherapy leads to increased long-term organ-preservation rates among cT2N0 rectal cancer. After achievement of a cCR, the risk for local recurrence and need for salvage surgery is similar, irrespective of the CRT regimen.