(HealthDay News) – Neither induction chemotherapy (ICT) nor high-dose radiation boost is associated with an improvement in five-year colostomy-free survival (CFS) in patients with locally advanced anal canal carcinoma (LAACC).
To investigate whether dose escalation of the radiation boost or two cycles of ICT before radiotherapy would improve CFS, Didier Peiffert, MD, PhD, of the Centre Alexis Vautrin in Vandoeuvre-le`s-Nancy, France, and colleagues conducted a randomized controlled trial involving 307 patients with LAACC tumors. Patients were randomly allocated to four treatment arms: two ICT cycles, radiochemotherapy, and standard-dose boost (A); two ICT cycles, radiochemotherapy, and high-dose boost (B); radiochemotherapy and standard-dose boost (C); and radiochemotherapy with high-dose boost (D).
The researchers found that 283 patients completed the full treatment. After a median follow-up period of 50 months, the five-year CFS rates in the four treatment arms were 69.6, 82.4, 77.1, and 72.7% for arms A, B, C, and D, respectively. There was no significant ICT effect (comparing groups A and B with C and D) or boost-dose effect (A and C vs. B and D).
“Using CFS as our main end point, we did not find an advantage for either ICT or high-dose radiation boost in LAACC,” the authors write. “Nevertheless, the results of the most treatment-intense arm B should prompt the design of further intensification studies.”
Several authors disclosed financial ties to the pharmaceutical industry.