Dr. Manji on Treatment for Right-Sided Tumors in CRC

Gulam A. Manji, MD, PhD, director, Medical Oncology and Translational Research for The Pancreas Center, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, discusses the difference between right- and left-sided tumors in colorectal cancer (CRC) and the appropriate treatment for right-sided tumors based on a subgroup analysis.

Patients with right-sided tumors tend to have an increased amount of BRAF, PIK3CA, and KRAS mutations while patients with left-sided tumors have a higher incidence of HER2-positive disease, explains Manji. Results of a subgroup analysis of patients who were previously treated with chemotherapy and combinations of EGFR-directed therapy show that patients with right-sided tumors do not benefit from EGFR-directed regimens, says Manji.

Therefore, patients with right-sided tumors, regardless of whether they have KRAS mutations or not, should not be treated with first-line EGFR-directed therapy. Instead, according to Manji, they should be treated with a combination of chemotherapy and VEGF-directed therapy, such as bevacizumab (Avastin).