Medical Program: Characteristic Clinical Presentations of Tumor Sidedness: Diagnostic & Prognostic Impacts

Announcer:
Welcome to Conversations on Colorectal Cancer on ReachMD, sponsored by Lilly.

On today’s program, we’ll hear from Dr. Putao Cen, Associate Professor of Medical Oncology at the University of Texas Health Science Center McGovern Medical School. Here’s Dr. Cen now, discussing clinical presentations of tumor sidedness in colorectal cancer patients.

Dr. Cin:
So the most common topic is on the sidedness; left side versus right side, is the clinical presentation and the prognosis and the difference in treatment. So colorectal cancer on the right side is derived from the embryonic midgut, so including appendix, cecum, ascending colon, hepatic flexure, and proximal two-third of the transverse colon. On the right side tumor, they are more frequently characterized by the adverse prognostic factor on a molecular testing study for somebody with higher BRAF mutations, and then RAS mutation positive, and also MSI, relatively higher than the left side colon. And also on the clinical presentation on the right side colon, they have a greater proportion of patients are female, older age at diagnosis. And also at initial presentation, the patient often diagnoses with more advanced tumor stage, more iron deficiency anemia instead of hematochezia, and also like the, uh, cecum is the thinnest wall of the entire colon and they easy to perforate it if, uh, tumor causing obstructions and the cecum easy to perforate it. And so the tumor also often metastasizes to the peritoneum compared to left side colon. And on the other hand, on the left side colon, it derive from the embryonic highgut, including the rectum, sigmoid colon, descending colon, splenic flexure, and distal – distal one-third of the transverse colon. Left side colon more frequent possess gene expression profile that characterize – with the characteristic with EGFR inhibitor sensitive phenotype, EGFR indications. On the clinical presentations, the left side colon frequently present with infiltrating constricted lesions. The patient easily present with constipations because the distal colon, hematochezia, and more likely metastasis to the liver and the lung. And there’s increase incidence in the young populations in the world in the left side colon. And for the prognosis, with backbone with chemo, FOLFOX or FOLFIRI or 5-FU backbone chemotherapy, on metastatic colorectal cancer, overall survival in the left side colon is better than the right side colon, around five to six months in overall survival.

Announcer:
That was Dr. Putao Cen talking about the diagnostic and prognostic impacts of tumor sidedness in colorectal cancer. To revisit any part of this discussion and to access other episodes in this series, visit ReachMD.com/mCRC, where you can Be Part of the Knowledge.