Dr. Cohen on the Importance of Obtaining an Adequate Tissue Sample in GI Malignancies

Steven J. Cohen, MD, medical director, Asplundh Cancer Pavilion, chief, Medical Oncology and Hematology Division, vice chair, Department of Medical Oncology, Sidney Kimmel Cancer Center, Jefferson Health – Abington, professor of medical oncology, Thomas Jefferson University, discusses the importance of obtaining an adequate tissue sample for molecular testing in gastrointestinal (GI) cancers.

The role of molecular testing is evolving in GI cancers; however, it is critical to ensure that adequate tissue is available for testing, Cohen explains. Oftentimes, patients with GI malignancies, such as esophagogastric cancer or colorectal cancer (CRC), are diagnosed in the community setting by an endoscopy or colonoscopy. In many cases, the tissue samples obtained from these tests are limited. As such, it is critical to have a discussion with the patient about the importance of biopsying metastatic lesions to obtain larger tissue samples for testing, Cohen says.

In addition, the role of circulating tumor DNA (ctDNA) is evolving in GI malignancies, but is perhaps furthest along in CRC, Cohen says. Studies are ongoing to determine the prognostic and predictive roles of ctDNA as a potential means to guide therapeutic decisions in patients with stage II or III CRC, Cohen concludes.