Breadth of Genetic Testing Selected by Patients at Risk of Hereditary Breast and Ovarian Cancer.

Szender JB1, Kaur J, Clayback K, Hutton ML, Mikkelson J, Odunsi K, Dresbold C.

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Abstract

OBJECTIVE:

The aim of this study was to evaluate the ability of patients at risk of hereditary breast and ovarian cancer (HBOC) syndrome to select the extent of genetic testing personally preferred and the impact of demographic factors on the breadth of testing pursued.

METHODS:

A single-institution cohort was enumerated consisting of patients referred for clinical genetic counseling secondary to risk of HBOC syndrome. This was a retrospective study of consecutive patients seen for genetic counseling; all patients completed an epidemiologic questionnaire and provided personal and family medical histories. Patients meeting guidelines for testing were offered testing at 3 levels: single gene/condition (Single), small panels with highly penetrant genes (Plus), and large panels with high and moderately penetrant genes (Next). Associations between personal or family-related factors and breadth of testing selected were investigated. Continuous and categorical variables were compared using Student t and χ tests, as appropriate. Joint classification tables were used to test for effect modification, and a log-binomial model was used to compute rate ratios (RR) with a threshold of P < 0.05 considered significant.

RESULTS:

We identified 253 patients who underwent genetic counseling for HBOC syndrome. Most patients were personally affected by cancer (63.6%), reported at least some college (79.2%), met the National Comprehensive Cancer Network guidelines for BRCA testing (94.5%), and opted to undergo genetic testing (94.1%). Most (84.9%) patients opted for panel testing. An increased likelihood of choosing Next-level testing was found to be associated with patients having any college experience (RR, 1.53; 95% confidence interval, 1.02-2.30), as well as being unaffected by cancer (RR, 1.30; 95% confidence interval, 1.03-1.64).

CONCLUSIONS:

Clinical genetic counseling is a highly specialized service, which should be provided to patients at risk of hereditary cancer syndromes. Although some epidemiologic factors can predict a patient's preference for testing breadth, patients were sufficiently able to self-identify the level of testing they were comfortable with after receiving genetic counseling. Most practitioners do not have the time or expertise to provide the degree of counseling needed to enable and empower patients to choose the level of testing they are comfortable with. When available, referral to genetic counselors remains an important component of comprehensive care for women with a personal or family history of cancer suggestive of hereditary risk.