A new phase II study finds that if chemotherapy is offered before radiation and surgery, more patients will be able to tolerate it and receive a full regimen of treatment. Reordering the regimen to administer chemotherapy before chemoradiation and therapy enabled all but 6 of 39 patients to undergo a full course of standard treatment for rectal cancer. This study was presented at the American Society for Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.
Studies have shown that only approximately 60% of patients with rectal cancer comply with postoperative chemotherapy, said lead researcher Kimberly Perez, MD, assistant professor of medicine in the Warren Alpert Medical School of Brown University and a cancer physician at Rhode Island Hospital. In the phase II trial, Complete Neoadjuvant Therapy in Rectal Cancer (CONTRE), more than 90% of the patients were able to complete a regimen of mFOLFOX6 when it was moved to the front of the line.
“The thought was, what can we do to make it more tolerable and get the benefit that we wanted,” said Perez. “It’s encouraging because we were able to get the numbers up of patients who were able to get all the chemotherapy indicated.”
All but one patient in the study underwent surgery, and 85% underwent the middle step of chemoradiation after completing chemotherapy. The vast majority therefore received all three courses of standard treatment, albeit in a new order.
Almost all of the patients came into the study with rectal bleeding, but that symptom abated for all of them during treatment, Perez said.
Regarding the cancer itself, a majority of patients, 32 of whom entered the trial at stage III and seven of whom were less advanced at stage II, responded at least to some degree to the induction chemotherapy and chemoradiation treatments. By the time they got to surgery, 13 patients had no tumor left (deemed a pathologic complete response), 10 regressed back to stage I, seven were at stage II, and eight remained at stage III.
The study occurred too recently, however, to provide a measure of overall survival, Perez acknowledged. The last patient finished surgery in January 2014.
The rate of side effects such as neutropenia, an adverse impact on the immune system, was not unusual.
The results of the CONTRE trial are now feeding into the development of a new national rectal cancer trial spearheaded by NRG Oncology, Perez said. The protocol will involve chemotherapy first, then chemoradiation with biologic anticancer agents, and finally surgery. Brown University Oncology Group and the Cancer Center of Rhode Island Hospital and associated satellites will be one of the study sites, Perez said.