Incidental findings in a series of 2500 gene panel tests for a genetic predisposition to cancer: Results and impact on patients

With next generation sequencing, physicians are faced with more complex and uncertain data, particularly incidental findings (IF). Guidelines for the return of IF have been published by learned societies. However, little is known about how patients are affected by these results in a context of oncogenetic testing. Over 4 years, 2500 patients with an indication for genetic testing underwent a gene cancer panel. If an IF was detected, patients were contacted by a physician/genetic counsellor and invited to take part in a semi-structured interview to assess their understanding of the result, the change in medical care, the psychological impact, and the transmission of results to the family. Fourteen patients (0.56%) were delivered an IF in a cancer predisposition gene (RAD51C, PMS2, SDHC, RET, BRCA2, CHEK2, CDKN2A, CDH1, SUFU). Two patients did not collect the results and another two died before the return of results. Within the 10 patients recontacted, most of them reported surprise at the delivery of IF, but not anxiety. The majority felt they had chosen to obtain the result and enough information to understand it. They all initiated the recommended follow-up and did not regret the procedure. Information regarding the IF was transmitted to their offspring but siblings or second-degree relatives were not consistently informed. No major adverse psychological events were found in our experience. IF will be inherent to the development of sequencing, even for restricted gene panels, so it is important to increase our knowledge on the impact of such results in different contexts.