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.

Management of ovarian and breast cancer risk in non-BRCA HBOC pathogenic variant carriers in a large California health care system.

PURPOSE: To describe breast and ovarian cancer risk reduction strategies in the clinical management of women who test positive for non-BRCA hereditary breast and ovarian cancer (HBOC) pathogenic variants compared to those who test positive for pathogenic BRCA variants or have negative germline panel testing. METHODS: Examination of imaging and preventive surgeries in women undergoing HBOC genetic testing from 1/1/2015 to 12/31/2018, with follow up to 03/31/2020 in Kaiser Permanente Northern California. RESULTS: A total of 13,271 tests which included HBOC genes were identified. Rate of bilateral salpingo-oophorectomy after genetic testing were similar for BRCA and the non-BRCA moderate risk ovarian pathogenic variants (PVs) (47.4% vs 54%, p = 0.25). Rates were lower for low risk or unknownrisk non-BRCA PVs (12.8%, p < 0.001, 5.3% (p < 0.001). Rates of surveillance for ovarian cancer with ultrasound and CA 125 in the first year was 63.3% and 64.7% for BRCA PV, 37.5% and 27.1%, for non-BRCA moderate risk PVs and 13.7% and 4.6%, for low-risk PVs. Bilateral mastectomy rates were 19.7% for BRCA PV, 10.1% (p = 0.028) for non-BRCA breast high risk PVs, for moderate risk PVs 7.7% (p < 0.001) and for unknown risk 0.4% (p < 0.001). MRI surveillance rates in the first year similarly were 47.4% for non-BRCA BRCA PV, 43% for breast high risk PV, 39.4% for moderate risk and 4.9% for unknown risk PV. CONCLUSION: Surgical and surveillance strategies are underutilized for HBOC PV, however there is concordance of uptake of preventive strategies with specific risk associated with non-BRCA PVs.

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.

Electronic Family History Screening Tool for Detection of Inherited Cancer Risk: A Prospective Pilot Study.

Family history screening to identify individuals at increased risk for hereditary cancers could be a powerful strategy to prevent cancer but is used inconsistently in primary care. The objective was to improve identification of women with at-risk family histories using a point-of-care family history screening tool administered on an electronic tablet device during well-woman appointments. A total of 288 women were invited to participate and 136 women (47.2%) completed the electronic family history screening tool. Significantly more women were identified and referred to the genetics department with the electronic family history screening tool than the standard-of-care paper questionnaire (11.8% versus 0.8%, P < 0.001). There were no statistically significant differences in the proportion of referred women who were evaluated by the genetic counselors, and no pathogenic variants were found with either family history screening method. Implementing innovative self-reporting tools may improve inherited cancer risk detection.

Efficacy of paired tumor and germline testing in evaluation of patients with Lynch-like syndrome in a large integrated healthcare setting.

Patients with mismatch repair (MMR) deficient colorectal cancer (CRC) without detectable germline pathogenic variants (PVs) or likely pathogenic variants (LPVs) in MMR genes are often labeled as Lynch-like syndrome (LLS). We sought to evaluate the efficacy of paired tumor and germline testing in risk stratification of patients with LLS in a large, community-based, integrated healthcare setting. Through the universal screening program for Lynch syndrome at Kaiser Permanente Northern California, we identified all patients with MMR deficient colorectal tumors without detectable germline PVs or LPVs between April 2011 and October 2018. These patients were categorized as LLS and were offered paired tumor and germline testing. Risk stratification and patient management were assessed upon completion of all testing. Of the 50 patients with LLS who underwent paired tumor and germline testing, 62% (n = 31) were categorized as sporadic, 6% (n = 3) had Lynch syndrome, and 32% (n = 16) remained inconclusive. Among the sporadic cases, 65% (n = 20) had a PV (n = 18) or LPV (n = 2) in combination with loss of heterozygosity while 35% (n = 11) had two somatic PVs/LPVs involving the same MMR gene. Our findings showed paired tumor and germline testing resolved the etiology in the majority of patients and is a valuable strategy in risk stratification and management of patients with LLS. Further studies are needed to assess the optimal application of paired testing in different practice settings, particularly with evolving technology and decreasing cost of molecular sequencing.

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.

Variation in physician-directed immunohistochemistry screening among women with endometrial cancer.

OBJECTIVE: Immunohistochemistry screening is a reliable method for identifying women with endometrial cancer who are at risk for Lynch syndrome, but clinical workflows used to implement immunohistochemistry screening protocols can vary by institution. The goal of this study was to investigate variation in performance of immunohistochemistry screening when a physician order is required. METHODS: Retrospective study from an integrated healthcare system with a risk-based immunohistochemistry screening policy for Lynch syndrome from January 2015 to December 2016. Immunohistochemistry screening was indicated for all women with endometrial cancer aged <60 years and women with endometrial cancer aged ≥60 years who had a personal/family history suggestive of Lynch syndrome. However, a physician order was needed to have immunohistochemistry screening performed on the tumor specimen as our health system did not have reflex screening in the clinical workflow. Demographics and tumor characteristics were reviewed, and patients were stratified by immunohistochemistry screening status. Multivariable regression was performed to identify factors associated with immunohistochemistry performance and reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: There were 1399 eligible patients in the study. With a required physician order, immunohistochemistry screening rates (20% overall, 34% aged <60 years) were significantly lower than previous reports (36% overall, 90% aged <60 years, p≤0.0001 for both comparisons). Significant factors associated with immunohistochemistry screening performance identified by multivariable analysis included age, race, body mass index, personal/family cancer history, diabetes, endometrioid histology, and tumor grade. Asian women were most likely to have immunohistochemistry screening (OR 1.58, 95% CI 1.07 to 2.34) whereas black women were least likely (OR 0.43, 95% CI 0.22 to 0.91). CONCLUSIONS: Immunohistochemistry screening rates in women with endometrial cancer were lower in our health system compared with prior reports in the literature, and there were variations in screening performance according to patient age, race, and body mass index. Requiring a physician order for immunohistochemistry screening likely creates a barrier in screening uptake, therefore automated immunohistochemistry screening is recommended.

Comparison of two Lynch screening strategies in endometrial cancer in a California health system.

OBJECTIVE: Compare detection of Lynch syndrome in endometrial cancer between regions of a health care system with different screening strategies. METHODS: A retrospective study of endometrial cancer (EC) cases from 2 regions of an integrated health care system (Kaiser Permanente Northern (KPNC) and Southern (KPSC) California). Within KPNC, immunohistochemistry tumor screening (IHC) was physician ordered and risk-based; within KPSC, IHC was universal and automated. Clinical risk factors associated with abnormal IHC and Lynch Syndrome (LS) were identified. RESULTS: During the study, there were 2045 endometrial cancers: 1399 in the physician-order group and 646 in the universal testing group. In the physician-order group: among women < age 60, 34% underwent IHC; 9.6% were abnormal, and 3% were possible LS after methylation testing; among women ≥60, 11% underwent IHC, 3% were abnormal and <1% were possible LS. In the universal group, 87% of women age <60 had IHC, 19.4% were abnormal, and 6% were possible LS; Among women age ≥60, 82% underwent IHC, 26% were abnormal, and 2% were possible LS. There were no differences in LS cases between the physician-order group and the universal group in either age strata (<60: 3% vs. 3.6%, p=0.62; ≥60: <1% vs. 1%, p=0.63) Factors associated with LS were younger age (odds ratio (OR) 0.11, 95% confidence interval (CI) 0.04-0.29) and lower body mass index (BMI), (OR 0.38 95% CI 0.18-0.80). CONCLUSIONS: Universal IHC screening did not result in increased LS detection in EC.

Splicing profile by capture RNA-seq identifies pathogenic germline variants in tumor suppressor genes.

Germline variants in tumor suppressor genes (TSGs) can result in RNA mis-splicing and predisposition to cancer. However, identification of variants that impact splicing remains a challenge, contributing to a substantial proportion of patients with suspected hereditary cancer syndromes remaining without a molecular diagnosis. To address this, we used capture RNA-sequencing (RNA-seq) to generate a splicing profile of 18 TSGs (APC, ATM, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, MLH1, MSH2, MSH6, MUTYH, NF1, PALB2, PMS2, PTEN, RAD51C, RAD51D, and TP53) in 345 whole-blood samples from healthy donors. We subsequently demonstrated that this approach can detect mis-splicing by comparing splicing profiles from the control dataset to profiles generated from whole blood of individuals previously identified with pathogenic germline splicing variants in these genes. To assess the utility of our TSG splicing profile to prospectively identify pathogenic splicing variants, we performed concurrent capture DNA and RNA-seq in a cohort of 1000 patients with suspected hereditary cancer syndromes. This approach improved the diagnostic yield in this cohort, resulting in a 9.1% relative increase in the detection of pathogenic variants, demonstrating the utility of performing simultaneous DNA and RNA genetic testing in a clinical context.

Comparison of Universal Versus Age-Restricted Screening of Colorectal Tumors for Lynch Syndrome Using Mismatch Repair Immunohistochemistry: A Cohort Study.

Background: Guidelines recommend screening all patients with newly diagnosed colorectal cancer (CRC) for Lynch syndrome (LS). However, the efficiency of universal LS screening in elderly populations has not been well studied. Objective: To compare the performance of age-restricted and universal LS screening using reflex mismatch repair (MMR) immunohistochemistry (IHC) of CRC tumors. Design: Retrospective cohort study. Setting: A large, diverse, community-based health care system. Participants: 3891 persons with newly diagnosed CRC who had LS screening between 2011 and 2016. Measurements: Diagnostic yield of different LS screening strategies. Results: Sixty-three LS cases (diagnostic yield, 1.62%) were identified by universal screening, with only 5 (7.9%) detected after age 70 years and 1 (1.6%) detected after age 80 years. When all patients with CRC who had universal screening were used as the denominator, 58 LS cases (diagnostic yield, 1.49% [95% CI, 1.13% to 1.92%]) were identified in patients with CRC diagnosed at or before age 70 years, 60 LS cases (diagnostic yield, 1.54% [CI, 1.18% to 1.98%]) were identified in those with CRC diagnosed at or before age 75 years, and 62 LS cases (diagnostic yield, 1.59% [CI, 1.22% to 2.04%]) were identified in those with CRC diagnosed at or before age 80 years. Using 75 years as the upper age limit for screening missed 3 of 63 (4.8%) LS cases but resulted in 1053 (27.1%) fewer cases requiring tumor MMR IHC. Using 80 years as the upper age limit missed 1 of 63 (1.6%) LS cases and resulted in 668 (17.2%) fewer cases requiring tumor MMR IHC. Limitation: Persons who were eligible for but did not complete germline analysis were excluded from calculations of performance characteristics. Conclusion: The incremental diagnostic yield decreased substantially after age 70 to 75 years. Stopping reflex CRC screening for LS after age 80 years may be reasonable because of very low efficiency, particularly in resource-limited settings, but this merits further investigation. Studies evaluating the effect of diagnosing LS in elderly persons on their family members are needed. Primary Funding Source: Kaiser Permanente Northern California Division of Research.

Does the diagnosis of breast or ovarian cancer trigger referral to genetic counseling?

OBJECTIVE: Kaiser Permanente Northern California is a large integrated health care delivery system in the United States that has guidelines for referring women with newly diagnosed BRCA1-and BRCA2-associated cancers for genetic counseling. This study assesses adherence to genetic counseling referral guidelines within this health system. METHODS: Chart review was performed to identify patients with cancer who met the following pathology-based Kaiser Permanente Northern California guidelines for referral for genetic counseling: invasive breast cancer, younger than age 40; nonmucinous epithelial ovarian, fallopian tube, or peritoneal cancer, younger than age 60; women with synchronous or metachronous primary cancers of the breast and ovaries; and male breast cancer. We assessed compliance with referral guidelines. An electronic notice was sent to the managing physician of patients with newly diagnosed cancer to assess the feasibility of this intervention. RESULTS: A total of 340 patients were identified with breast cancer at younger than age 40 or with ovarian, peritoneal, or tubal cancer between January and June, 2008. Upon chart review, 105 of these patients met pathology-based criteria for referral to genetic counseling, of whom 47 (45%) were referred within the 2-year study period. Of the 67 subjects with breast cancer, 40 subjects (60%) were referred. In contrast, only 7 (21%) of 33 patients with ovarian cancer were referred (P < 0.001). A pilot study was performed to test the feasibility of notifying managing oncologists with an electronic letter alerting them of eligibility for genetic referral of patients with new diagnosis (n = 21). In the 3 to 6 months after this notification, 12 of these 21 patients were referred for counseling including 5 of 7 patients with a diagnosis of ovarian cancer. CONCLUSION: There is a missed opportunity for referring patients to genetic counseling, especially among patients with ovarian cancer. A pilot study suggests that alerting treating physicians is a feasible strategy to increase appropriate referral.