The clinical utility and costs of whole-genome sequencing to detect cancer susceptibility variants-a multi-site prospective cohort study.

BACKGROUND: Many families and individuals do not meet criteria for a known hereditary cancer syndrome but display unusual clusters of cancers. These families may carry pathogenic variants in cancer predisposition genes and be at higher risk for developing cancer. METHODS: This multi-centre prospective study recruited 195 cancer-affected participants suspected to have a hereditary cancer syndrome for whom previous clinical targeted genetic testing was either not informative or not available. To identify pathogenic disease-causing variants explaining participant presentation, germline whole-genome sequencing (WGS) and a comprehensive cancer virtual gene panel analysis were undertaken. RESULTS: Pathogenic variants consistent with the presenting cancer(s) were identified in 5.1% (10/195) of participants and pathogenic variants considered secondary findings with potential risk management implications were identified in another 9.7% (19/195) of participants. Health economic analysis estimated the marginal cost per case with an actionable variant was significantly lower for upfront WGS with virtual panel ($8744AUD) compared to standard testing followed by WGS ($24,894AUD). Financial analysis suggests that national adoption of diagnostic WGS testing would require a ninefold increase in government annual expenditure compared to conventional testing. CONCLUSIONS: These findings make a case for replacing conventional testing with WGS to deliver clinically important benefits for cancer patients and families. The uptake of such an approach will depend on the perspectives of different payers on affordability.

TRACEBACK: Testing of Historical Tubo-Ovarian Cancer Patients for Hereditary Risk Genes as a Cancer Prevention Strategy in Family Members.

PURPOSE: Tubo-ovarian cancer (TOC) is a sentinel cancer for BRCA1 and BRCA2 pathogenic variants (PVs). Identification of a PV in the first member of a family at increased genetic risk (the proband) provides opportunities for cancer prevention in other at-risk family members. Although Australian testing rates are now high, PVs in patients with TOC whose diagnosis predated revised testing guidelines might have been missed. We assessed the feasibility of detecting PVs in this population to enable genetic risk reduction in relatives. PATIENTS AND METHODS: In this pilot study, deceased probands were ascertained from research cohort studies, identification by a relative, and gynecologic oncology clinics. DNA was extracted from archival tissue or stored blood for panel sequencing of 10 risk-associated genes. Testing of deceased probands ascertained through clinic records was performed with a consent waiver. RESULTS: We identified 85 PVs in 84 of 787 (11%) probands. Familial contacts of 39 of 60 (65%) deceased probands with an identified recipient (60 of 84; 71%) have received a written notification of results, with follow-up verbal contact made in 85% (33 of 39). A minority of families (n = 4) were already aware of the PV. For many (29 of 33; 88%), the genetic result provided new information and referral to a genetic service was accepted in most cases (66%; 19 of 29). Those who declined referral (4 of 29) were all male next of kin whose family member had died more than 10 years before. CONCLUSION: We overcame ethical and logistic challenges to demonstrate that retrospective genetic testing to identify PVs in previously untested deceased probands with TOC is feasible. Understanding reasons for a family member's decision to accept or decline a referral will be important for guiding future TRACEBACK projects.

Lynch syndrome associated endometrial carcinomas in Western Australia: an analysis of universal screening by mismatch repair protein immunohistochemistry.

BACKGROUND: In 2016 universal screening with mismatch repair protein immunohistochemistry in all newly diagnosed endometrial carcinomas was introduced in Western Australia. OBJECTIVE: To compare the prevalence of Lynch syndrome associated endometrial carcinomas between 2016 and 2019 with a historical control (2015). Additionally, to compare the number of cases appropriately referred for genetic assessment. METHODS: A cross-sectional study of cases presented at the Western Australia gynecologic oncology tumor board was carried out. The primary outcome was the prevalence of Lynch syndrome associated endometrial carcinomas. A secondary outcome was the number of cases appropriately referred for genetic assessment. The following variables were extracted: date of birth; age at diagnosis; vital status; tumor mismatch repair protein expression status (retained or lost) and if lost, the specific mismatch repair protein deficiency; patients who were referred to a genetic clinic; and family history, if recorded. Data were collected from the clinical databases of the Familial Cancer Program at Genetic Services of Western Australia and WOMEN Center, to determine whether patients were appropriately referred for genetic evaluation and to ascertain the results of genetic testing. RESULTS: Between 2016 and 2019, there were 1040 new endometrial carcinomas. Tumors of 883 (85%) patients underwent mismatch repair protein immunohistochemistry compared with 117 of 199 patients (59%) in 2015 (χ2 73.14, p<0.001). Of 883 tumors tested, 242 (27%) showed loss of mismatch repair protein expression. In 2015, 30 (26%) tumors of 117 tested showed loss of mismatch repair protein expression. During the 4 years of universal screening, 13 (1.5%) of 883 patients screened were diagnosed with Lynch syndrome compared with 2 (1.7%) of 117 in 2015 (Fisher's exact test 0.04, p=0.69). In 2015, 11 (37%) of 30 patients with loss of mismatch repair protein expression were not referred for genetic assessment compared with 36 (17%) of 209 patients in the universal screening group (χ2 6.28, p=0.02). No cases of Lynch syndrome were diagnosed in patients aged over 70 years. CONCLUSIONS: Universal immunohistochemical screening did not increase the proportion of Lynch syndrome associated endometrial carcinomas identified, although the study was underpowered to detect small differences. There was an improvement in appropriate referrals for genetic assessment.

Uptake of testing for germline BRCA mutations in patients with non-mucinous epithelial ovarian cancers in Western Australia: a comparison of different genetic counseling methods.

INTRODUCTION: Patients with non-mucinous epithelial tubo-ovarian cancers should be referred for genetic testing because approximately 15% will carry an inherited mutation in the BRCA1 or BRCA2 cancer susceptibility genes. However, referral rates for genetic testing remain low. For patients who carry a BRCA mutation, failure to refer for genetic testing results in missed opportunities for therapy and prevention of future cancers in the patient and at-risk relatives. In Western Australia between July 2013 and June 2015, 40.6% of patients with non-mucinous epithelial tubo-ovarian cancers discussed at a statewide gynecologic oncology tumor board were referred for genetic testing. Our objective was to investigate the proportion of patients with non-mucinous epithelial tubo-ovarian cancers in Western Australia referred for BRCA1/2 testing from July 2015 to December 2017, following the introduction of mainstreaming and tele-counseling. A secondary aim was to compare the uptake of genetic testing between different genetic counseling modalities. METHODS: Retrospective case series. All patients with high-grade non-mucinous epithelial tubo-ovarian cancers discussed at the weekly Western Australian gynecologic oncology tumor board meeting, between July 1, 2015 and December 31, 2017, and those referred for BRCA mutation testing, were ascertained. RESULTS: A total of 343 women were eligible for referral; 63 patients were excluded, leaving 280 patients for analysis. 220/280 patients were referred for genetic testing (78.6%). There were no differences in uptake of genetic testing by mode of genetic counseling. DISCUSSION: A significant increase in referrals of eligible patients for genetic testing was observed in 2015-2017 compared with 2013-2014. Although there were no differences in uptake of genetic testing by mode of counseling, mainstreaming and tele-counseling provide alternative options for patients that may lead to higher uptake of genetic testing.

Investigating barriers to genetic counseling and germline mutation testing in women with suspected hereditary breast and ovarian cancer syndrome and Lynch syndrome.

OBJECTIVE: The aim of the current study was to explore barriers to genetic counseling and testing in women with gynecological cancers deemed at significant risk of carrying a germline mutation. METHODS: A qualitative study using semi-structured interviews and inductively analysed thematically. Eight patients with ovarian or endometrial cancer participated in individual semi-structured telephone interviews that assessed motivation for genetic counseling and testing, perceived benefits and barriers, timing of the approach, perceptions of the referral process to genetic services and locus of control in relation to cancer and health. RESULTS: Analysis of the interview transcripts revealed five themes relating to perceptions of genetic counseling and testing: Lack of importance; Level of information received; Timing of referral processes; Fear and anxiety; Resistance to and perceptions of counseling. CONCLUSIONS: Participants had a limited understanding of hereditary cancer syndromes and did not appreciate the benefits of genetic testing. A consistent approach at the time of referral to genetic services is needed to ensure that the level and format of information is appropriate for patients. PRACTICE IMPLICATIONS: The rationale for genetic testing needs to be better explained to patients and the timing of referral should be based both on treatment priorities and patient preferences.

Prognostic Role of Histological Tumor Regression in Patients Receiving Neoadjuvant Chemotherapy for High-Grade Serous Tubo-ovarian Carcinoma.

OBJECTIVE: Our objective was to validate the prognostic role of the chemotherapy response score (CRS), which has been proposed for measuring tumor response to neoadjuvant chemotherapy in patients with high-grade serous tubo-ovarian carcinoma, in predicting progression-free survival (PFS) and overall survival (OS). METHODS: A retrospective cohort study was conducted of patients with advanced high-grade serous tubo-ovarian carcinoma diagnosed between January 1, 2010, and December 31, 2014, and treated with neoadjuvant chemotherapy. Treatment-related tumor regression was determined according to the 3-tier CRS, and results were compared with standard clinicopathological variables. Survival analysis was performed using Cox proportional hazards models and the log-rank test. RESULTS: Seventy-one patients were eligible for analysis. Median OS was 25.5 months. Fifty-eight patients (82%) had disease recurrence and 32 (45%) had died at study census. Of the 71 patients, 19, 29, and 23 patients had a CRS of 1, 2, and 3, respectively. On univariate analysis, the CRS significantly predicted PFS (hazard ratio [HR], 3.77; 95% confidence interval [CI], 1.83-7.78; P = 0.000) and OS (HR, 2.81; 95% CI, 1.16-6.79; P = 0.022). In a multivariate model, the CRS was significantly associated with PFS (HR, 2.81; 95% CI, 1.16-6.79; P = 0.022) but not with OS (HR, 2.39; 95% CI, 0.47-3.08; P = 0.079). Patients with CRS of 1 and 2 combined were twice as likely to progress during the study period compared with patients with a CRS of 3 (HR, 2.0; 95% CI, 1.06-3.78; P = 0.032; median PFS, 16 vs 26 months). No significant association was observed for OS (CRS 1/2 vs 3; HR, 1.57; 95% CI, 0.68-3.65; P = 0.291). CONCLUSIONS: In this study, the CRS showed independent prognostic significance for PFS but not for OS.

Impact of Clinical Genetics Attendance at a Gynecologic Oncology Tumor Board on Referrals for Genetic Counseling and BRCA Mutation Testing.

OBJECTIVES: The objectives of this work were to determine the proportion of eligible patients with ovarian cancer discussed at a gynecologic oncology tumor board who were referred for counseling and BRCA mutation testing; to compare referral rates before genetics attendance at the tumor board to referral rates after genetics attendance; and to ascertain the proportions of women with germline BRCA mutations. MATERIALS AND METHODS: Eligible cases were identified from the minutes of the weekly Western Australian gynecologic oncology tumor board from July 1, 2013 to June 30, 2015.Patients with ovarian cancer who met eligibility criteria for genetics referral were identified and checked against the records of the genetic services database to ascertain whether a referral was received. Outcomes including attendance for counseling and results of mutation testing were analyzed. RESULTS: Two hundred sixty-one patients were eligible for referral during the 24-month study period. One hundred six patients (40.6%) were referred for counseling and germline mutation testing. Of the eligible patients, 26.7% were referred in the 12 months before genetics attendance at the tumor board compared to 51.7% of the eligible patients in the 12 months after genetics attendance (P ≤ 0.0001). Ninety-seven patients were offered BRCA mutation testing, and 73 underwent testing with 65 results reported to date. Twenty-two patients (33.8 %) tested positive for a germline BRCA mutation. CONCLUSIONS: Patients with ovarian cancer had a high rate of BRCA mutations. Attendance of a genetics service at a tumor board was associated with an improved rate of referral of patients for genetic counseling and BRCA mutation testing.