Through DNA sequencing, scientists can identify targetable somatic driver mutations in cancer. During this process, doctors have the potential to also detect germline variants revealing predispositions to other diseases, such as a familial cancer syndrome, or variants of unknown significance.
Some doctors are hesitant to reveal incidental information out of concern for the best interests of patients since, in contrast with planned germline testing where there is counseling available both before and after testing, patients who have tumor profiling don’t typically receive any counseling. The new information can also bring patients new worries and stresses, both emotionally and financially, as these concerns are further investigated. As such, doctors’ responses to incidental findings include a wide range of disclosure, from full disclosure to limited disclosure or no disclosure at all.
In 2013, the American College of Medical Genetics and Genomics (ACMG) published a set of guidelines recommending mandatory reporting. This guideline was recommended regardless of patient preference, for a well-defined set of variants in 57 genes, each with an unequivocal disease association. Some practitioners disagreed with this policy and called for revisions. As a result, the ACMG reissued the guidelines in 2014, adding an opt-out policy for patients who did not want to learn of incidental findings. More recently, the ACMG recommended a new policy allowing patients to dictate how much information they receive.
Considering individual patients each have a unique perspective regarding incidental findings, Yushak et al. surveyed patients to get their opinions regarding unexpected discoveries resulting from tumor profiling.1 The team queried 413 oncology patients using a 45-item questionnaire designed to mimic a variety of hypothetical situations.
The authors found that 77% of patients surveyed would like doctors to inform them of variants that could increase their risk of a serious but preventable illness. Just over half (56%) wanted to know about variants that cause serious but unpreventable illnesses, and just under half (49%) wanted to know about variants of uncertain significance.
The majority of patients (75%) indicated they would share hereditary information regarding predisposition to preventable diseases with family, and more than half (62%) would share information concerning unpreventable diseases. The most frequent concerns about incidental findings were the ability to obtain health insurance (48%) or life insurance (41%). Only 21% of patients were concerned about privacy of information.
Yushak et al. determined that there is a high variability of opinions when it comes to incidental information from germline variants. Rather than a blanket approach, the authors recommend that doctors discuss the patient’s personal preferences for incidental findings before ordering a tumor profiling test.
1. Yushak, M.L., et al. (2016) “Patient preferences regarding incidental genomic findings discovered during tumor profiling.” Cancer, 122(10) (pp. 1588–1597), doi: 10.1002/cncr.29951.