A prospective prostate cancer screening programme for men with pathogenic variants in mismatch repair genes (IMPACT): initial results from an international prospective study.

BACKGROUND: Lynch syndrome is a rare familial cancer syndrome caused by pathogenic variants in the mismatch repair genes MLH1, MSH2, MSH6, or PMS2, that cause predisposition to various cancers, predominantly colorectal and endometrial cancer. Data are emerging that pathogenic variants in mismatch repair genes increase the risk of early-onset aggressive prostate cancer. The IMPACT study is prospectively assessing prostate-specific antigen (PSA) screening in men with germline mismatch repair pathogenic variants. Here, we report the usefulness of PSA screening, prostate cancer incidence, and tumour characteristics after the first screening round in men with and without these germline pathogenic variants. METHODS: The IMPACT study is an international, prospective study. Men aged 40-69 years without a previous prostate cancer diagnosis and with a known germline pathogenic variant in the MLH1, MSH2, or MSH6 gene, and age-matched male controls who tested negative for a familial pathogenic variant in these genes were recruited from 34 genetic and urology clinics in eight countries, and underwent a baseline PSA screening. Men who had a PSA level higher than 3·0 ng/mL were offered a transrectal, ultrasound-guided, prostate biopsy and a histopathological analysis was done. All participants are undergoing a minimum of 5 years' annual screening. The primary endpoint was to determine the incidence, stage, and pathology of screening-detected prostate cancer in carriers of pathogenic variants compared with non-carrier controls. We used Fisher's exact test to compare the number of cases, cancer incidence, and positive predictive values of the PSA cutoff and biopsy between carriers and non-carriers and the differences between disease types (ie, cancer vs no cancer, clinically significant cancer vs no cancer). We assessed screening outcomes and tumour characteristics by pathogenic variant status. Here we present results from the first round of PSA screening in the IMPACT study. This study is registered with ClinicalTrials.gov, NCT00261456, and is now closed to accrual. FINDINGS: Between Sept 28, 2012, and March 1, 2020, 828 men were recruited (644 carriers of mismatch repair pathogenic variants [204 carriers of MLH1, 305 carriers of MSH2, and 135 carriers of MSH6] and 184 non-carrier controls [65 non-carriers of MLH1, 76 non-carriers of MSH2, and 43 non-carriers of MSH6]), and in order to boost the sample size for the non-carrier control groups, we randomly selected 134 non-carriers from the BRCA1 and BRCA2 cohort of the IMPACT study, who were included in all three non-carrier cohorts. Men were predominantly of European ancestry (899 [93%] of 953 with available data), with a mean age of 52·8 years (SD 8·3). Within the first screening round, 56 (6%) men had a PSA concentration of more than 3·0 ng/mL and 35 (4%) biopsies were done. The overall incidence of prostate cancer was 1·9% (18 of 962; 95% CI 1·1-2·9). The incidence among MSH2 carriers was 4·3% (13 of 305; 95% CI 2·3-7·2), MSH2 non-carrier controls was 0·5% (one of 210; 0·0-2·6), MSH6 carriers was 3·0% (four of 135; 0·8-7·4), and none were detected among the MLH1 carriers, MLH1 non-carrier controls, and MSH6 non-carrier controls. Prostate cancer incidence, using a PSA threshold of higher than 3·0 ng/mL, was higher in MSH2 carriers than in MSH2 non-carrier controls (4·3% vs 0·5%; p=0·011) and MSH6 carriers than MSH6 non-carrier controls (3·0% vs 0%; p=0·034). The overall positive predictive value of biopsy using a PSA threshold of 3·0 ng/mL was 51·4% (95% CI 34·0-68·6), and the overall positive predictive value of a PSA threshold of 3·0 ng/mL was 32·1% (20·3-46·0). INTERPRETATION: After the first screening round, carriers of MSH2 and MSH6 pathogenic variants had a higher incidence of prostate cancer compared with age-matched non-carrier controls. These findings support the use of targeted PSA screening in these men to identify those with clinically significant prostate cancer. Further annual screening rounds will need to confirm these findings. FUNDING: Cancer Research UK, The Ronald and Rita McAulay Foundation, the National Institute for Health Research support to Biomedical Research Centres (The Institute of Cancer Research and Royal Marsden NHS Foundation Trust; Oxford; Manchester and the Cambridge Clinical Research Centre), Mr and Mrs Jack Baker, the Cancer Council of Tasmania, Cancer Australia, Prostate Cancer Foundation of Australia, Cancer Council of Victoria, Cancer Council of South Australia, the Victorian Cancer Agency, Cancer Australia, Prostate Cancer Foundation of Australia, Asociación Española Contra el Cáncer (AECC), the Instituto de Salud Carlos III, Fondo Europeo de Desarrollo Regional (FEDER), the Institut Català de la Salut, Autonomous Government of Catalonia, Fundação para a Ciência e a Tecnologia, National Institutes of Health National Cancer Institute, Swedish Cancer Society, General Hospital in Malmö Foundation for Combating Cancer.

Oncologists' perspectives of telephone genetic counseling to facilitate germline BRCA1/2 testing for their patients with high-grade serous ovarian cancer.

Poly ADP ribose polymerase (PARP) inhibitors offer a survival advantage to women with high-grade serous ovarian cancer who have a germline BRCA1/2 pathogenic variant (PV). Yet, rates of genetic testing among this population have remained persistently low. A national, centralized telephone genetic counseling service was established in January 2016 in Australia to improve access to genetic services and facilitate BRCA1/2 testing for this population to inform treatment. Medical oncologists can refer their patients with high-grade serous ovarian cancer to this service for genetic testing. This study aimed to explore oncologists' experiences of using this telephone genetic counseling service for their patients with high-grade serous ovarian cancer. A qualitative approach using semi-structured telephone interviews was undertaken with Australian oncologists who had referred patients to the telephone genetic counseling service. Sixteen oncologists participated and described referring patients to the telephone genetic counseling service due to the timeliness of obtaining a genetic counseling appointment and BRCA1/2 test results. They also reported this service offered convenience for patients living in regional or rural areas who then did not have to travel for an appointment with a clinical genetics service. Many oncologists noted the importance of in-person genetic counseling for patients who received positive BRCA1/2 results. Areas for improvement identified by the oncologists related to communication issues between the service and the patient. Overall, findings suggest that oncologists perceived telephone genetic counseling as an acceptable and useful healthcare service for patients with high-grade serous ovarian cancer. Moreover, they perceived telephone genetic counseling to be efficient, delivering convenient genetic counseling to patients.

Interim Results from the IMPACT Study: Evidence for Prostate-specific Antigen Screening in BRCA2 Mutation Carriers.

BACKGROUND: Mutations in BRCA2 cause a higher risk of early-onset aggressive prostate cancer (PrCa). The IMPACT study is evaluating targeted PrCa screening using prostate-specific-antigen (PSA) in men with germline BRCA1/2 mutations. OBJECTIVE: To report the utility of PSA screening, PrCa incidence, positive predictive value of PSA, biopsy, and tumour characteristics after 3 yr of screening, by BRCA status. DESIGN, SETTING, AND PARTICIPANTS: Men aged 40-69 yr with a germline pathogenic BRCA1/2 mutation and male controls testing negative for a familial BRCA1/2 mutation were recruited. Participants underwent PSA screening for 3 yr, and if PSA > 3.0 ng/ml, men were offered prostate biopsy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PSA levels, PrCa incidence, and tumour characteristics were evaluated. Statistical analyses included Poisson regression offset by person-year follow-up, chi-square tests for proportion t tests for means, and Kruskal-Wallis for medians. RESULTS AND LIMITATIONS: A total of 3027 patients (2932 unique individuals) were recruited (919 BRCA1 carriers, 709 BRCA1 noncarriers, 902 BRCA2 carriers, and 497 BRCA2 noncarriers). After 3 yr of screening, 527 men had PSA > 3.0 ng/ml, 357 biopsies were performed, and 112 PrCa cases were diagnosed (31 BRCA1 carriers, 19 BRCA1 noncarriers, 47 BRCA2 carriers, and 15 BRCA2 noncarriers). Higher compliance with biopsy was observed in BRCA2 carriers compared with noncarriers (73% vs 60%). Cancer incidence rate per 1000 person years was higher in BRCA2 carriers than in noncarriers (19.4 vs 12.0; p = 0.03); BRCA2 carriers were diagnosed at a younger age (61 vs 64 yr; p = 0.04) and were more likely to have clinically significant disease than BRCA2 noncarriers (77% vs 40%; p = 0.01). No differences in age or tumour characteristics were detected between BRCA1 carriers and BRCA1 noncarriers. The 4 kallikrein marker model discriminated better (area under the curve [AUC] = 0.73) for clinically significant cancer at biopsy than PSA alone (AUC = 0.65). CONCLUSIONS: After 3 yr of screening, compared with noncarriers, BRCA2 mutation carriers were associated with a higher incidence of PrCa, younger age of diagnosis, and clinically significant tumours. Therefore, systematic PSA screening is indicated for men with a BRCA2 mutation. Further follow-up is required to assess the role of screening in BRCA1 mutation carriers. PATIENT SUMMARY: We demonstrate that after 3 yr of prostate-specific antigen (PSA) testing, we detect more serious prostate cancers in men with BRCA2 mutations than in those without these mutations. We recommend that male BRCA2 carriers are offered systematic PSA screening.

Evaluation of telephone genetic counselling to facilitate germline BRCA1/2 testing in women with high-grade serous ovarian cancer.

Systemic healthcare issues and geographical challenges restrict women's access to BRCA1/2 testing to inform the use of tailored treatments for high-grade serous ovarian cancer. Consequently, BRCA1/2 testing in this population is low and improved testing pathways are urgently needed. This study aimed to determine the acceptability and feasibility of telephone genetic counselling (TGC) to facilitate treatment-focused BRCA1/2 testing in Australia for women with high-grade serous ovarian cancer. Women who received TGC were invited to complete a survey examining their experiences of the service. A cost analysis was conducted to compare the service to standard, in-person genetic counselling. One hundred and seven women responded (48% response rate); 8 had a BRCA1/2 variant affecting function. Geographical barriers prevented women from accessing genetic services in the past. All participants had a positive attitude towards testing, and regret following testing was minimal. While the impact of testing was greater for those with a positive test result, overall, genetic testing did not put the additional psychosocial burden on the participants. Participant's evaluations of the telephone interactions with the genetic counsellors were highly satisfactory. The service was also found to be cost-effective. This model of telephone genetic counselling was an acceptable and effective way to reduce barriers to BRCA1/2 testing for women with ovarian cancer.

Breast Tissue Composition and Immunophenotype and Its Relationship with Mammographic Density in Women at High Risk of Breast Cancer.

AIM: To investigate the cellular and immunophenotypic basis of mammographic density in women at high risk of breast cancer. METHODS: Mammograms and targeted breast biopsies were accrued from 24 women at high risk of breast cancer. Mammographic density was classified into Wolfe categories and ranked by increasing density. The histological composition and immunophenotypic profile were quantified from digitized haematoxylin and eosin-stained and immunohistochemically-stained (ERα, ERß, PgR, HER2, Ki-67, and CD31) slides and correlated to mammographic density. RESULTS: Increasing mammographic density was significantly correlated with increased fibrous stroma proportion (rs (22) = 0.5226, p = 0.0088) and significantly inversely associated with adipose tissue proportion (rs (22) = -0.5409, p = 0.0064). Contrary to previous reports, stromal expression of ERα was common (19/20 cases, 95%). There was significantly higher stromal PgR expression in mammographically-dense breasts (p=0.026). CONCLUSIONS: The proportion of stroma and fat underlies mammographic density in women at high risk of breast cancer. Increased expression of PgR in the stroma of mammographically dense breasts and frequent and unexpected presence of stromal ERα expression raises the possibility that hormone receptor expression in breast stroma may have a role in mediating the effects of exogenous hormonal therapy on mammographic density.

Large genomic rearrangements in the familial breast and ovarian cancer gene BRCA1 are associated with an increased frequency of high risk features.

Large genomic rearrangements (LGRs) account for at least 10% of the mutations in BRCA1 and 5% of BRCA2 mutations in outbred hereditary breast and ovarian cancer (HBOC) families. Data from some series suggest LGRs represent particularly penetrant mutations. 1,034 index cases from HBOC families underwent comprehensive BRCA1 and BRCA2 mutation testing, including screening for LGRs. The personal and family history of 254 identified mutation carriers were compared based on mutation type. Thirty-six LGRs were detected; 32/122 (26%) BRCA1 and 4/132 (3%) BRCA2 mutations. High risk features (bilateral breast cancer, diagnosis <40 years, ovarian cancer, male breast cancer) were more commonly associated with an LGR than a non-LGR mutation (p = 0.008), In families with a BRCA1 LGR the mean age of breast cancer diagnosis was younger than in families with a non-LGR BRCA1 mutation (42.5 vs. 46.1 years, p = 0.007). Across the entire group of mutation positive families the number of relatives affected by breast or ovarian cancer was increased [LGR 3.7 vs. non- LGR 2.8 per family, p value (adjusted for genotype) = 0.047]. Excluding index cases, the odds ratio for breast cancer in BRCA1 families with an LGR was 1.42 (95% CI 1.24-1.63) and for ovarian cancer 1.66 (95% CI 1.10-2.49). The increased cancer risk was reflected in significantly higher risk assessments by mutation prediction tools. LGRs are associated with higher cancer risks. If validated, LGRs could be included in cancer risk prediction tools to improve personalised cancer risk prediction estimates and may guide cost-minimising mutation screening strategies in some healthcare settings.

A role for common genomic variants in the assessment of familial breast cancer.

PURPOSE: Genome-wide association studies have identified common genomic variants associated with increased susceptibility to breast cancer. In the general population, the risk associated with these known variants seems insufficient to inform clinical management. Their contribution to the development of familial breast cancer is less clear. PATIENTS AND METHODS: We studied 1,143 women with breast cancer who had completed BRCA1 and BRCA2 mutation screening as a result of a high risk for hereditary breast cancer. Genotyping of 22 breast cancer-associated genomic variants was performed. A polygenic risk score (PRS), calculated as the sum of the log odds ratios for each allele, was compared with the same metric in 892 controls from the Australian Ovarian Cancer Study. The clinical features associated with the high and low ends of the polygenic risk distribution were compared. RESULTS: Women affected by familial breast cancer had a highly significant excess of risk alleles compared with controls (P = 1.0 × 10(-16)). Polygenic risk (measured by the PRS) was greater in women who tested negative for a BRCA1 or BRCA2 mutation compared with mutation carriers (P = 2.3 × 10(-6)). Non-BRCA1/2 women in the top quartile of the polygenic risk distribution were more likely to have had early-onset breast cancer (< 30 years of age, odds ratio [OR]= 3.37, P = .03) and had a higher rate of second breast cancer (OR 1.96, P = .02) compared with women with low polygenic risk. CONCLUSION: Genetic testing for common risk variants in women undergoing assessment for familial breast cancer may identify a distinct group of high-risk women in whom the role of risk-reducing interventions should be explored.

The consequences of risk reducing salpingo-oophorectomy: the case for a coordinated approach to long-term follow up post surgical menopause.

Women with germline mutations in BRCA1 and BRCA2 genes have significantly increased lifetime risks of breast and ovarian cancer. To manage both the ovarian and breast cancer risks the current recommendation is undergo a risk reducing salpingo-oophorectomy (RRSO) prior to natural menopause. To date, studies have focussed on quality of life and sexual dysfunction in women who undergo RRSO, but few have reported on the wider physical consequences. We performed a questionnaire study in women with BRCA 1 or 2 gene mutations known to the Peter MacCallum Familial Cancer Centre. We gathered information about ovarian surgery, ongoing follow-up, management of risk factors including osteoporosis, and current severity of menopausal symptoms. Two hundred and nineteen women were surveyed. One hundred and forty-three of 157 responding participants (91 %) reported having RRSO. Sixty one were pre-menopausal at RRSO. Post surgical follow-up rates were generally low, and a minority of women reported recent bone density imaging or pharmaceutical prevention or treatment of osteoporosis. Menopausal symptoms appeared generally mild. No significant differences in symptom severity were observed in women who underwent a pre-menopausal RRSO compared to RRSO after natural menopause. These data indicate that a formalised follow-up protocol is necessary to optimally manage the consequences of a RRSO.

Predictors of breast cancer screening behavior in women with a strong family history of the disease.

This study applied the self-regulation model to examine cognitive and emotional predictors of screening in unaffected women with a strong family history of breast cancer. 748 unaffected female members of an Australian registry of multiple-case breast cancer families formed the sample. Participants completed a baseline psychosocial questionnaire and a screening questionnaire 3 years later. Multinomial logistic regression was employed to determine predictors of under- and over-screening according to national guidelines. At follow-up 16% of women under-screened and 10% over-screened with mammography; 55% under-screened with clinical breast examination (CBE); and 9% over-screened with breast self-examination (BSE). Of the women found screening according to guidelines for mammography 72% reported ever having received specific recommendations for mammography screening from a health professional. Compared to appropriate screeners, under-screeners on mammography were less likely to have received a screening recommendation (as were under-screeners on CBE), were younger and reported lower perceived breast cancer risk, but were at higher relative risk (RR) of breast cancer and were more likely to report elevated depression. Over-screeners on mammography were more likely to be younger and have a lower RR of breast cancer. Over-screeners on BSE reported elevated cancer-specific anxiety, were less likely to be university educated and more likely to have received a recommendation for BSE. Under- and over-screening is common in women with a strong family history of breast cancer. Evaluation of interventions targeting perceived risk of breast cancer, anxiety and depression are needed to ensure women obtain accurate advice from relevant specialists and enact screening recommendations.

Contralateral risk-reducing mastectomy in BRCA1 and BRCA2 mutation carriers and other high-risk women in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab).

The purpose of this study is to determine the prevalence and predictors of contralateral risk-reducing mastectomy (CRRM) in Australasian women at high familial risk of a second primary breast cancer (BC). Participants were women with unilateral BC and a strong family history of the disease, including BRCA1/2 mutation carriers. Data were collected through interview, self-administered questionnaire and review of pathology and surgical reports. Associations between CRRM and potential predictors were assessed using multivariate logistic regression. Of 1,018 women (median follow-up 11.1 years), 154 (15%) underwent CRRM, 43% of these within 12 months of initial BC surgery. More likely to undergo CRRM were women who were younger at BC diagnosis (odds ratio [OR] = 0.94 per year of age, P < 0.001), were diagnosed more recently (OR = 1.16 per calendar year, P < 0.001), underwent mastectomy as initial definitive BC treatment (OR = 5.2, P < 0.001) and underwent risk-reducing salpingo-oophorectomy (OR = 3.4, P < 0.001). BRCA1/2 mutation status, axillary nodal status and receipt of chemotherapy were not independently associated with CRRM uptake. A contralateral BC event (invasive or in situ) occurred in 177 (20.5%) of the 864 women who did not have CRRM, compared with one chest wall event (0.6%) in the 154 women post-CRRM. The contralateral event rate was 15.1 per 1,000 women-years for non-CRRM women and 0.7 per 1,000 women-years for CRRM women; P < 0.0001. Younger women with more recently diagnosed BC treated with mastectomy are more likely to elect CRRM. Neither BRCA1/2 mutation status, nor the competing risk of BC recurrence and death, appears to influence decision making.

Cancer risk management practices of noncarriers within BRCA1/2 mutation positive families in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer.

PURPOSE: Women from BRCA mutation-positive families who do not carry the family-specific mutation are generally at average cancer risk and therefore do not require intensive risk management. METHODS: Participants were female noncarriers from BRCA mutation-positive families who had responded to 3 yearly follow-up questionnaires and had chosen to either receive or not receive their genetic test result. In the former group, undertaking mammography younger than age 40 years or more than once every 2 years, clinical breast examination (CBE) more than yearly, breast self-examination (BSE) more than monthly, or any transvaginal ultrasound (TVU) or CA-125 was considered overscreening. Screening behaviors of women who did and did not know their genetic test result were compared. Logistic regression and nonparametric analyses were performed to identify demographic and psychosocial factors (respectively) associated with overscreening. RESULTS: Of 325 eligible women, 116 knew their mutation status and 209 did not. For the first group, proportions overscreening were mammography, 53%; CBE, 10%; BSE, 11%; TVU, 7%; and CA-125, 10%. There were no significant differences in screening behaviors between the groups. In those aware of their mutation status, parous women were more likely to overuse mammography (odds ratio [OR] = 4.4; 95% CI, 1.1 to 17; P = .03) and women with one or more first-degree relative with ovarian cancer (OC) were more likely to overuse OC screening (TVU: OR = 6.00; 95% CI, 1.0 to 35.1; P = .047, and CA-125: OR = 6.50; 95% CI, 1.49 to 28.4; P = .013). CONCLUSION: The reasons for overuse of screening (particularly mammography) by mutation noncarriers require additional elucidation given the potential for harm.

Prostate screening uptake in Australian BRCA1 and BRCA2 carriers.

Men who carry mutations in BRCA1 or BRCA2 are at increased risk for prostate cancer. However the efficacy of prostate screening in this setting is uncertain and limited data exists on the uptake of prostate screening by mutation carriers. This study prospectively evaluated uptake of prostate cancer screening in a multi-institutional cohort of mutation carriers. Subjects were unaffected male BRCA1 and BRCA2 mutation carriers, aged 40-69 years, enrolled in the Kathleen Cuningham Consortium for Research into Familial Breast Cancer (kConFab) and who had completed a mailed, self-report follow-up questionnaire 3 yearly after study entry. Of the 75 male carriers in this study, only 26 (35%) had elected to receive their mutation result. Overall, 51 (68%) did not recall having received a recommendation to have prostate screening because of their family history, but 41 (55%) had undergone a prostate specific antigen (PSA) test and 32 (43%) a digital rectal examination (DRE) in the previous 3 years. Those who were aware of their mutation result were more likely to have received a recommendation for prostate screening (43 vs. 6%, p = 0.0001), and to have had a PSA test (77 vs. 43%, p = 0.005) and a DRE (69 vs. 29%, p = 0.001) in the previous 3 years. The majority of unaffected males enrolled in kConFab with a BRCA1/2 mutation have not sought out their mutation result. However, of those aware of their positive mutation status, most have undergone at least one round of prostate screening in the previous 3 years.