Study shows hereditary risk factors for appendix cancer

One in 10 appendix cancer patients carry germline genetic variant associated with predisposition to cancer, study finds JAMA Oncology it is the first to show hereditary risk factors for this rare cancer.

Appendix cancer affects about one or two people per million each year. Historically, appendicular cancer was thought not to be inherited, but its rarity has presented challenges in understanding disease characteristics and developing therapies. A research team led by Andreana Holowatyj, PhD, MSCI, assistant professor of medicine and cancer biology at Vanderbilt University Medical Center, analyzed multigene test data from a national clinical trials laboratory in the United States for a total of 131 patients with appendicular cancer. They found that 11.5% of patients had at least one germline genetic variant in a cancer susceptibility gene. Additionally, among the subset of patients with appendix cancer as their first and only primary tumour, they observed a similar prevalence (10.8%), further linking a familial component to this disease.

The results suggest that all patients with appendix cancer should consider genetic evaluation as well as cascade testing and genetic counseling of at-risk family members for cancer prevention and monitoring. However, further studies are warranted to identify new genetic factors and use this evidence to fit selected genes in genetic testing for appendix cancer, Holowatyj said.

Based on this data, we are able to recommend genetic counseling and a multi-gene cancer susceptibility gene testing panel for all patients with appendix cancer, regardless of age or background. families of cancer. Although there is still much to learn from our discovery, we have found the tip of an iceberg -; potentially a very large iceberg.”

Andreana Holowatyj, PhD, MSCI, Assistant Professor of Medicine and Cancer Biology, Vanderbilt University Medical Center

The study was published simultaneously as Holowatyj presented its findings at the 2022 annual meeting of the Collaborative Group on Hereditary Gastrointestinal Cancer of the Americas (CGA-IGC) in Nashville.

Although appendix cancer is rare, it is becoming more common for unknown reasons. Last year, Holowatyj and his colleagues conducted the first study of appendicular cancer patterns and survival in patients under age 50 (early disease) in the United States. They found worse disease outcomes in non-Hispanic blacks than in non-Hispanic whites, and in men. compared to women.

This study, published in Gastroenterology, was followed by another investigation by Holowatyj that compared the molecular landscapes of early and late onset appendicular cancer. The second study, published in Open JAMA Networkrevealed distinct non-silent mutations in tumors from younger patients, paving the way for the development of potential therapeutic advances.

A third study, published in Cancer epidemiology, biomarkers and prevention by Holowatyj’s groupfound that one in three cases of appendix cancer occurs in people younger than 50, and that these early cases have distinct clinical features from those that occur in people 50 and older.

Holowatyj and the research team received support from the Dalton Family Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health.

The other Vanderbilt researchers who co-authored the study are Mary K. Washington, MD, PhD, and Cathy Eng, MD.

People who have been diagnosed with appendix cancer and want to participate in a clinical research study -; the Genetics of Cancer of the Appendix (GAP) study; are invited to visit www.gapcancerstudy.org.