ASCO20: Preoperative Short-Course Radiotherapy Before Chemotherapy in Locally Advanced Rectal Cancer
Posted: Thursday, June 18, 2020
Preoperative short-course radiotherapy, followed by chemotherapy and total mesorectal excision may produce lower rates of disease-related treatment failure than conventional chemoradiotherapy in patients with high-risk locally advanced rectal cancer, according to Geke Hospers, MD, PhD, of the University of Groningen, the Netherlands, and colleagues. The results of the phase III RAPIDO trial were presented during the ASCO20 Virtual Scientific Program (Abstract 4006).
“The combination of short-course radiotherapy followed by neoadjuvant chemotherapy for patients with locally advanced rectal cancer resulted in more patients with complete response at the time of surgery and less tumor recurrence with comparable tolerability to standard care,” commented Muhammad Shaalan Beg, MD, MS, of the Harold C. Simmons Comprehensive Cancer Center, Dallas, in an ASCO press release. “This study supports total neoadjuvant therapy as a standard approach for patients with advanced rectal cancer.”
A total of 920 patients with locally advanced rectal cancer were randomly assigned to a treatment arm. The experimental arm underwent short-course radiation therapy, followed by treatment with either CAPOX (capecitabine, oxaliplatin) or FOLFOX4 (leucovorin, fluorouracil, oxaliplatin). Subsequently, total mesorectal excision was performed. The standard arm received capecitabine-based chemoradiotherapy before undergoing total mesorectal excision.
The experimental treatment seemed to produce a higher pathologic complete response rate than the standard treatment (27.7% vs. 13.8%). After 3 years, the cumulative probability of disease-related treatment failure was 23.7% versus 30.4% in the experimental and standard arms, respectively. The probability of distant metastasis was significantly lower in the experimental arm than the standard arm (19.8% vs. 26.6%; P = .004). There was no significant difference in the probability of locoregional failure (P = .10), overall health (P = .192), quality of life (P = .125), and low anterior resection syndrome score (P = .136) between the arms. Hospital policy for postoperative chemotherapy did not significantly impact disease-related treatment failure (P = .37).
Disclosure: For full disclosures of the study authors, visit coi.asco.org.