Randomized Noninferiority Trial of Telephone vs In-Person Disclosure of Germline Cancer Genetic Test Results

Abstract

Background: Germline genetic testing is standard practice in oncology. Outcomes of telephone disclosure of a wide range of cancer genetic test results, including multigene panel testing (MGPT) are unknown.

Methods: Patients undergoing cancer genetic testing were recruited to a multicenter, randomized, noninferiority trial (NCT01736345) comparing telephone disclosure (TD) of genetic test results with usual care, in-person disclosure (IPD) after tiered-binned in-person pretest counseling. Primary noninferiority outcomes included change in knowledge, state anxiety, and general anxiety. Secondary outcomes included cancer-specific distress, depression, uncertainty, satisfaction, and screening and risk-reducing surgery intentions. To declare noninferiority, we calculated the 98.3% one-sided confidence interval of the standardized effect; t tests were used for secondary subgroup analyses. Only noninferiority tests were one-sided, others were two-sided.

Results: A total of 1178 patients enrolled in the study. Two hundred eight (17.7%) participants declined random assignment due to a preference for in-person disclosure; 473 participants were randomly assigned to TD and 497 to IPD; 291 (30.0%) had MGPT. TD was noninferior to IPD for general and state anxiety and all secondary outcomes immediately postdisclosure. TD did not meet the noninferiority threshold for knowledge in the primary analysis, but it did meet the threshold in the multiple imputation analysis. In secondary analyses, there were no statistically significant differences between arms in screening and risk-reducing surgery intentions, and no statistically significant differences in outcomes by arm among those who had MGPT. In subgroup analyses, patients with a positive result had statistically significantly greater decreases in general anxiety with telephone disclosure (TD -0.37 vs IPD +0.87, P = .02).

Conclusions: Even in the era of multigene panel testing, these data suggest that telephone disclosure of cancer genetic test results is as an alternative to in-person disclosure for interested patients after in-person pretest counseling with a genetic counselor.

Figure 1.

Consort diagram. *Individuals approached prior to non-BRCA1/2 and multigene testing adaptation. †Multiple reasons for decline were reported per participant. ‡Participants who expressed a preference for in-person communication were enrolled into a third, nonrandomized arm, where outcomes were collected, but they received results in-person. §Survey not completed within seven days. ‖Canceled because of lack of insurance coverage. ¶Individuals who were disclosed by telephone at the participant’s behest (n = 31), disclosed by telephone due to illness/financial burden (n = 3), and received results in-person with a non-COGENT provider (n = 3). #This includes 37 who declined intervention as assigned and did not complete the postdisclosure survey within seven days.

Figure 2.

Noninferiority analyses comparing telephone to usual care in-person disclosure of genetic test results. *Primary postdisclosure outcomes. Black arrows depict the 98.3% confidence interval (one-sided) for primary outcomes/95% confidence interval (one-sided) for all other outcomes. The blocked area indicates the noninferiority range. If the confidence intervals completely fall within the noninferiority range, then noninferiority can be concluded. The arrows indicate the direction in which the effect would show that telephone disclosure is more favorable than in-person disclosure. For example, more negative average change scores (ie, less than 0) in state anxiety between arms would indicate that telephone disclosure decreased state anxiety more than in-person disclosure. Similarly, more positive average change scores (ie, greater than 0) in knowledge would indicate that telephone disclosure increased knowledge more than in-person disclosure. With imputed data, the estimated effects (one-sided CI) were state anxiety –0.04 (0.09), general anxiety –0.08 (0.05), and genetic knowledge –0.07 (–0.24), which were all within the noninferiority range.