(ChemotherapyAdvisor)–A “sizeable minority” of patients with stage II/III rectal cancer treated with curative-intent neoadjuvant chemoradiotherapy at eight US specialty cancer centers do not complete the postoperative chemotherapy recommended by practice guidelines, results of a study using the National Comprehensive Cancer Network (NCCN) Colorectal Cancer Database reported in the Journal of Clinical Oncology online November 19.
“Strategies to facilitate the ability to complete this third and final component of curative intent treatment are necessary,” reported Al B. Benson III, MD, Division of Hematology/Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, and colleagues.
A total of 2,073 patients with stage II/III rectal cancer were enrolled in the NCCN Colorectal Cancer Database, which tracks longitudinal care, between September 2005 and December 2012. For this analysis, 1,193 patients receiving neoadjuvant chemoradiotherapy were included, as were 203 patients who received no adjuvant chemotherapy.
Factors significantly associated with not receiving adjuvant chemotherapy—after controlling for center and clinical TNM stage—were age, ECOG performance status ≥1, on Medicaid/indigent vs private insurance, complete pathologic response, presence of re-operation/wound infection, and no closure of ileostomy/colostomy.
“Our analysis found that the most common reasons adjuvant chemotherapy was not recommended by a medical oncologist was secondary to comorbid illness (25 of 50, 50%) and recommended but not received was patient refusal (54 of 74, 73%),” they wrote, noting similar findings have been observed in other studies of colorectal cancer.
For example, “a population-based cohort of patients with both stage II/III rectal cancer and stage III colon cancer from the California Cancer Registry demonstrated that the principal reasons for not receiving adjuvant chemotherapy differed by patient age. Among patients ≥85 years of age, comorbidities and advanced age were cited as primary reasons. For those offered postoperative therapy, age remained the strongest predictor of patient refusal, with lower rates for younger patients and reaching almost 50% in the group ≥85 years of age.”
They concluded that prospective clinical trials are needed to provide the evidence that will define systemic treatment strategies, enhance patient selection, and improve survival for patients with stage II/III rectal cancer.