Age-50 cutoff for genetic testing would miss most inherited cancer variants, MSK study suggests

A study in Cancer Discovery, a journal of the American Association for Cancer Research, reports results of offering germline (inherited) genetic testing to nearly 39,000 patients with solid tumours at Memorial Sloan Kettering Cancer Center, regardless of age.

Findings

• 16.3% of all patients carried at least one pathogenic germline variant in the genes studied.
• If testing had been limited to patients under 50 — a common cutoff — 4,601 carriers, or 72% of all patients with such variants, would have been missed.
• High- and moderate-penetrance variants were common among older patients, which the authors say shows a uniform age-50 cutoff is insufficient.

Study co-author Luis Diaz of MSK said hereditary cancer “can occur at any age” and argued for considering testing for every patient diagnosed with cancer.

Limitations

The data come from a single large cancer centre whose patients may differ from those in community hospitals. Finding a variant does not always mean it caused the cancer or changes treatment, and universal testing raises questions of cost, genetic counselling capacity and access that the study does not settle.