Bryan F. Curtin, MD, on Surveillance in Hereditary Gastric Cancer Syndrome
Individuals with the CDH1 mutation are recommended to undergo total gastrectomy—a life-altering surgery—early in adulthood to prevent the development of gastric cancer. More options are needed to predict when individuals should undergo total gastrectomy, as well as more sensitive gastric surveillance protocols.
Results from a prospective study showed the systematic screening protocol (SSP) was significantly more sensitive for detecting stage T1a gastric adenocarcinomas compared with standard esophagogastroduodenoscopy.
Gastroenterology Consultant caught up with Bryan F. Curtin, MD, Gastroenterology and Hepatology Attending Physician, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases/National Institutes of Health, about the research.
Gastroenterology Consultant: What prompted you to conduct the study?
Bryan Curtin: Hereditary diffuse gastric cancer is a terrible disease which affects families worldwide. Patients afflicted have as much as a 70% lifetime risk of cancer and are faced with the choice of proceeding with a major surgery—prophylactic total gastrectomy—or undergoing multiple surveillance endoscopies. At our institution, we noted that endoscopic surveillance rarely detected early cancer, even using the Cambridge protocol assessment tool that is currently recommended by international guidelines. We noticed that it is very difficult to visually detect these malignancies on endoscopy, and when they were discovered, it was typically at random. We adapted the SSP for the stomach, which is a rigorous, reproducible method to ensure maximum sampling.
GASTRO CON: What do you think is the most important finding?
BC: In many ways, the most important finding is that we still have a long way to go to optimize our screening for early hereditary diffuse gastric cancer. However, I am happy with the progress we have made with SSP. When judged against the gold standard of surgical explant, standard endoscopy only detected 18% of early cancers, whereas SSP detected 59% in their group. Furthermore, we identified that most tumors occur in the fundus, and not a single tumor appeared in the antrum.
GASTRO CON: How can a gastroenterologist or specialist apply these findings to clinical practice?
BC: One of our biggest goals with this work is to spread knowledge about hereditary diffuse gastric cancer. Many patients with the disease have told me stories of doctors and specialists looking up the diagnosis during their visit. We as gastroenterologists must improve from an educational perspective. Secondly, there are evolving standardized methods to surveying cancer in this patient population. We haven’t progressed to the point that endoscopy should be performed in lieu of surgery, but we are closer than before.
GASTRO CON: What are the next steps of your research?
BC: We will continue to work on optimizing our endoscopic surveillance techniques for this patient population. We are currently in the middle of a phase 2 trial investigating the use of confocal endoscopy. After our initial findings are published, SSP could be further modified in order to increase sensitivity even more. We are also performing genetic research to deepen our understanding of CDH1, the main gene implicated in hereditary diffuse gastric cancer.
Reference:
Curtin BF, Hernandez JM, Quezado M, Heller T, Koh C, Davis JL. Systematic screening protocol for the stomach (SSP) is superior to standard endoscopy for the detection of early malignancy in hereditary gastric cancer syndrome patients. Presented at: Digestive Disease Week; May 18-21; San Diego, CA. https://www.gastrojournal.org/article/S0016-5085(19)36828-3/pdf. Accessed May 23, 2019.