Dr. Overman on Implications of Tumor Location Data for Patients With mCRC

Michael J. Overman, MD, associate professor, Department of Gastrointestinal Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses how the results of the phase III FIRE-3 and CALGB/SWOG 80405 studies will impact treatment of patients with metastatic colorectal cancer (mCRC).

In a retrospective analysis of the phase III 80405 trial, survival outcomes in patients with KRAS wild-type mCRC were found to be significantly longer among those with tumors originating on the left versus the right side of the colon. In the FIRE-3 trial, patients recieved FOLFIRI plus either bevacizumab or cetuximab in the frontline setting for KRAS wild-type mCRC. In a subgroup of 167 patients from FIRE-3, the median OS was 38.7 months in patients with left-sided tumors versus 16.1 months in patients with right-sided tumors.

Data suggest that there is differential benefit from anti-EGFR therapy that could be related to left- and right-sided tumors, Overman explains. Additionally, there are interesting data examining the molecular context of this. Overman says this is interesting because the molecular context is likely driving some of these differences.