"The thought was, what can we do to make it more tolerable and get the benefit that we wanted," said Perez, who will speak at 4 p.m. CDT on Saturday, May 31, 2014 at ASCO. "It's encouraging because we were able to get the numbers up of patients who were able to get all the chemotherapy indicated."
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 ("pathologic complete response"), 10 got all they way 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. That protocol will involve chemo first, then chemoradiation with biological anti-cancer agents, and finally surgery. Brown Univeristy Oncology Group and the Cancer Center of Rhode Island Hospital and associated satellites will be one of the study sites, Perez said.
Presented at the American Society for Clinical Oncology annual meeting 2014 in Chicago.