Study finds inherited link to appendix cancer

One of every 10 patients with appendiceal cancer carries a germline genetic variant associated with cancer predisposition, according to a study in JAMA Oncology that is the first to show inherited risk factors for this rare cancer.

Appendiceal cancer affects about one or two people per million annually. Historically it has been thought that appendiceal cancer is not hereditary, but its rarity has presented challenges to understanding the characteristics of the disease 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 panel testing data from a nationwide clinical testing laboratory in the U.S. for a total of 131 patients with appendiceal cancer. They found that 11.5% of patients had at least one germline genetic variant in a cancer susceptibility gene. In addition, among the subset of patients with appendix cancer as the first and only primary tumour they observed a similar prevalence (10.8%), further linking a familial component to this disease.

The findings suggest all patients with appendix cancer should consider genetic evaluation as well as cascade testing and genetic counselling of at-risk family members for cancer prevention and surveillance. However, further studies are warranted to identify novel genetic factors and use this evidence to tailor which genes are selected in genetic testing for appendiceal cancer, Holowatyj said.

"Based on these data, we are able to recommend genetic counselling and multigene panel testing of cancer susceptibility genes for all appendix cancer patients, regardless of age or family history of cancer," Holowatyjsaid. "While there is still much to learn from our discovery, we have found the tip of an iceberg — potentially a really big iceberg."