The results of tumor profile testing may be useful in making individualized treatment decisions for patients with metastatic colorectal cancer (mCRC). It is important to expand upfront testing, as the results are useful for drug development and treatment planning, according to Heinz-Josef Lenz, MD. Colon cancer is highly heterogeneous—there are many possible combinations of mutations, and combination therapy is necessary to address multiple mutations, Lenz says. However, identifying actionable mutations is a challenge, notes Marwan Fakih, MD.

Alan Venook, MD, believes that a BRAF and a KRAS analysis should be ascertained for all patients. However, a key pathway that will change the treatment landscape for CRC has not yet been identified, he says. In metastatic disease, the molecular profile may vary depending on the location of the metastatic lesion that is biopsied. What could be interpreted as treatment resistance may actually be a case of targeting the wrong mutation, Venook believes.

Regarding rebiopsy, Johanna Bendell, MD, remarks that she prefers incoming patients have a new biopsy performed, to ensure that a core biopsy is gained from the central area of the tumor.