Germline Genetic Testing Among Women ≤ 45 Years of Age with Ductal Carcinoma In Situ Versus Invasive Breast Cancer in a Large Integrated Health Care System.

BACKGROUND: We compared the results of hereditary cancer multigene panel testing among patients ≤ 45 years of age diagnosed with ductal carcinoma in situ (DCIS) versus invasive breast cancer (IBC) in a large integrated health care system. METHODS: A retrospective cohort study of hereditary cancer gene testing among women ≤ 45 years of age diagnosed with DCIS or IBC at Kaiser Permanente Northern California between September 2019 and August 2020 was performed. During the study period, institutional guidelines recommended the above population be referred to genetic counselors for pretesting counseling and testing. RESULTS: A total of 61 DCIS and 485 IBC patients were identified. Genetic counselors met with 95% of both groups, and 86.4% of DCIS patients and 93.9% of IBC patients (p = 0.0339) underwent gene testing. Testing differed by race/ethnicity (p = 0.0372). Among those tested, 11.76% (n = 6) of DCIS patients and 16.71% (n = 72) of IBC patients had a pathogenic variant (PV) or likely pathogenic variant (LPV) based on the 36-gene panel (p = 0.3650). Similar trends were seen in 13 breast cancer (BC)-related genes (p = 0.0553). Family history of cancer was significantly associated with both BC-related and non-BC-related PVs in IBC, but not DCIS. CONCLUSION: In our study, 95% of patients were seen by a genetic counselor when age was used as an eligibility criterion for referral. While larger studies are needed to further compare the prevalence of PVs/LPVs among DCIS and IBC patients, our data suggest that even in younger patients, the prevalence of PVs/LPVs in BC-related genes is lower in DCIS patients.

Factors influencing genetic counseling and testing for hereditary breast and ovarian cancer syndrome in a large US health care system.

Investigate whether disparities and other factors influence referral to genetic counseling and testing for hereditary breast and ovarian cancer syndrome (HBOC) in a large health care system. Examination of clinical, demographic, and socioeconomic factors from electronic health records associated with genetic referral and testing within 12 months after a new cancer diagnosed between August 1, 2013 and December 31, 2018. For patients meeting institutional criteria for HBOC testing, 60.6% were referred for genetic counseling, 88% of whom underwent germline testing; at least one pathogenic variant was found in 15.3%. Referral rates for patients with breast (69%) or ovarian cancer (65.7%) were much higher than for metastatic prostate (11.1%, p < 0.0001) or pancreatic cancer (22.3%, p < 0.0001); referral criteria were implemented more recently for the latter two cancers. Younger age, family history, and chemotherapy were associated with referral. Higher Elixhauser comorbidity score and prior cancer were associated with non-referral. No other factors were associated with genetic referral for all eligible cancers combined, although differences were seen in specific cancers. Race was a significant factor only for breast cancer, with fewer Asians than Whites referred. Health disparities in referral to genetics for HBOC cancers are mitigated in a comprehensive integrated health care system.

Streamlining genetic testing for women with ovarian cancer in a Northern California health care system.

OBJECTIVE: Referral to Genetics for pre-testing counseling may be inefficient for women with ovarian cancer. This study assesses feasibility of gynecologic oncologists directly offering genetic testing. METHODS: A prospective pilot study was conducted at two gynecologic oncology hubs in an integrated healthcare system from May 1 to November 6, 2019. Gynecologic oncologists offered multigene panel testing to women with newly diagnosed ovarian cancer, followed by selective genetic counseling. Outcomes were compared between study participants and women from other hubs in the health system. RESULTS: Of ovarian cancer patients at study sites, 40 participated and all underwent genetic testing. Of 101 patients diagnosed at other sites, 85% were referred to genetics (p = .0061 compared to pilot participants) and 67% completed testing (p < .0001). The time from diagnosis to blood draw and notification of result was 18.5 and 34 days for the pilot group compared to 25.5 and 53 days at other sites. Panel testing detected 9 (22.5%) and 7 (10.3%, p = .08) pathogenic mutations in each group, respectively. Patients and providers were highly satisfied with the streamlined process. CONCLUSION: Genetic testing performed at the gynecologic oncology point of care for patients with ovarian cancer is feasible, increases uptake of testing, and improves time to results.