Short-Course vs. Long-Course Chemoradiation Therapy for Rectal Cancer
Posted: Wednesday, March 6, 2019
In patients with stage II or III rectal cancer, short-course radiation therapy with multiagent chemotherapy prior to surgery seems to be at least as effective as long-course chemoradiation therapy, according to study findings presented at the 2019 Gastrointestinal Cancers Symposium (Abstract 486) in San Francisco. Short-course total neoadjuvant therapy yielded a numerically higher pathologic complete response rate and similar overall recurrence rate as long-course chemoradiation therapy, concluded William Chapman, MD, of the Washington University School of Medicine, and colleagues.
For the retrospective cohort study, the researchers analyzed 388 patients who underwent neoadjuvant therapy followed by total mesorectal excision for stage II or III rectal cancer. Of the patients, 236 were treated with chemoradiation therapy, and 152 underwent short-course total neoadjuvant therapy.
After a univariate analysis, patients treated with the short-course therapy had more advanced disease (77% stage III disease) and longer elapsed time between radiation completion and surgery (131 days) than their chemoradiation counterpart (67% and 63 days, respectively). The short-course group also achieved a pathologic complete response rate of 25%, compared with 19% for the chemoradiation therapy group.
Furthermore, the researchers also found that the odds of achieving a “low” neoadjuvant rectal (NAR) score was higher among the short-course patients (overall response 1.49) and that recurrence rates between short-course total neoadjuvant therapy and chemoradiation therapy were similar (14.9% vs. 14.3%, respectively). NAR scores were categorized as low (< 8), intermediate (8–16), and high (> 16).
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.