Genetics Remains Paramount for Moving Rare Cancers Forward

In recent years,clinicians, particularly pathologists, have improved at identifying and treating salivary gland cancers, even when they pop up in unsuspecting places such as the breast, skin, cervix (in women) and prostate (in men).

For patients with this type of salivary gland cancer, called adenoid cystic carcinoma, genetic and

genomic testing is paramount, with the results determining the most effective treatment plan. For example, patients with HER2-positive disease may respond best to the monoclonal antibody Herceptin (trastuzumab), whereas others may do better with the targeted drug Vitrakvi (larotrectinib), approved in 2018 for patients with solid tumors that harbor fusions of the NTRK gene.

Thanks to the constantly evolving understanding of cancer genetics, as well as increased use of next-generation sequencing, more drugs are being investigated for use in cancers with certain molecular makeups, regardless of location. This is a landmark change for rare cancers that traditionally are understudied because of the small number of people with the disease.

A feature story in this issue of CURE® discusses My Pathway, a phase 2 clinical trial that matched patients with a diversity of cancers to one of six targeted therapies based on the genetics of their tumor. Although just 19 patients with salivary cancers were involved, most (63%) responded to their individualized treatment, eliminating the need for a larger, salivary gland cancer-specific trial, for which it likely would be difficult to find enough enrollees.

Advances in genetics continue to fuel breakthroughs for nearly all cancer types but perhaps hold special value for rare cancers, in which there are limited patients to join studies and few professionals who specialize in their treatment. Now, more than ever, it is crucial that patients with these diseases ask their treatment teams about the role of tumor genetics for their situation and clinical trials for which they might be eligible.