Abstract P2-09-01: Patient reported outcomes of multiplex breast cancer susceptibility testing utilizing a tiered-binned counseling and informed consent model in BRCA1/2 negative patients

Abstract

Abstract Background:The risks, benefits and utilities of multiplex panels for breast cancer susceptibility are unknown and new counseling and informed consent models are needed. We sought to obtain patient reported outcomes of multiplex testing in BRCA1/2 negative patients utilizing a novel, previously piloted tiered-binned counseling model for multiplex testing. Methods:BRCA1/2 negative participants completed pre(V1) and post-test counseling(V2) and surveys evaluating cognitive, affective and behavioral responses to a 25-gene multiplex testing panel. We used linear regressions with estimation by GEE where appropriate. Results:376 patients have been approached. To date, 124 participants(33%) have consented to the study, 21(6%) declined and 231(61%) are considering. Of 95 who have completed pre-test counseling(V1), 88(93%) elected to proceed with 25-gene panel testing and (81%) were classified as making an informed choice after tiered-binned counseling. 6/53(11%) participants received a positive result, including 1 mutation in MSH2 and 5 in moderate penetrance genes (2 ATM, 1 BARD1, 1 CHEK2, 1 PALB2). 22/53(42%) participants received a variant of unknown significance(VUS). General anxiety and perceived utility decreased significantly with pre-test counseling and after results (Table 1). Knowledge increased with pre-test counseling; cancer worry increased after receipt of multiplex results. Higher cancer worry was associated only with lower income (2.6 points/income category, p<0.01). Those with a VUS had greater decreases in perceived utility compared to negative (p=0.01) or positive (p=0.003) results. To date, there are no other significant differences in knowledge, distress or uncertainty by test result. Medical management recommendations for the proband changed in 3/6 with a positive result. Cascade testing in the family was discussed as an option in 3/6 with a positive result. Conclusions:Many BRCA1/2-negative patients proceed with 25-gene cancer susceptibility testing if offered and most make informed choices utilizing a tiered-binned genetic counseling model. The tiered-binned counseling model is associated with increased knowledge, decreases in general anxiety and uncertainty after pre-test counseling and disclosure of results, but an increase in cancer worry after result disclosure. The clinical utility, long-term outcomes and differences in patient reported outcomes by test result remain unknown. Table 1 Baseline, Mean(SD)After V1, Mean(SD)After V2, Mean(SD) N=75ˆ;N=49ˆˆN=75ˆ;N=49ˆˆN=49ˆˆGeneral Anxiety (range 0-21)6.4(3.9)*;6.9(3.9)**6.0(4.3)*;6.6(4.2)**5.8(4.5)**General Depression (range 0-212.8(2.9);3.1(3.2)3.0(3.5);3.1(3.6)3.0(3.7)State Anxiety (range 20-80)35.5(11.2);36.6(11.9)35.5(11.8);36.8(11.9)36.1(12.2)Cancer Worry (range 0-75)18.2(13.5);20.1(13.8)**16.7(12.5);17.2(11.9)**21.0(13.9)**Knowledge (range 17-82)65.7(5.0)**;66.5(5.0)**68.0(5.7)**;68.4(5.6)**67.3(4.9)**Uncertainty (range 0-15)5.8(3.9);6.2(4.3)5.6(3.7);5.4(3.2)5.6(3.5)Perceived Utility (range 24-120)75.2(14.0)*;75.9(14.0)**73.0(14.1)*;74.1(13.4)**68.4(16.9)***p≤0.05 **p≤0.01. ˆcompleted V1. ˆˆcompleted V1 & V2. To date, 53 have received results and 49 have completed post-disclosure surveys. Citation Format: Bradbury AR, Patrick-Miller L, Egleston BE, Maxwell KN, Brandt A, Brower J, DiGiovanni L, Long JM, Powers J, Stopfer J, Nathanson KL, Domchek SM. Patient reported outcomes of multiplex breast cancer susceptibility testing utilizing a tiered-binned counseling and informed consent model in BRCA1/2 negative patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-01.