Integrating Clinical and Polygenic Factors to Predict Breast Cancer Risk in Women Undergoing Genetic Testing

PURPOSE

Screening and prevention decisions for women at increased risk of developing breast cancer depend on genetic and clinical factors to estimate risk and select appropriate interventions. Integration of polygenic risk into clinical breast cancer risk estimators can improve discrimination. However, correlated genetic effects must be incorporated carefully to avoid overestimation of risk.

MATERIALS AND METHODS

A novel Fixed-Stratified method was developed that accounts for confounding when adding a new factor to an established risk model. A combined risk score (CRS) of an 86-single-nucleotide polymorphism polygenic risk score and the Tyrer-Cuzick v7.02 clinical risk estimator was generated with attenuation for confounding by family history. Calibration and discriminatory accuracy of the CRS were evaluated in two independent validation cohorts of women of European ancestry (N = 1,615 and N = 518). Discrimination for remaining lifetime risk was examined by age-adjusted logistic regression. Risk stratification with a 20% risk threshold was compared between CRS and Tyrer-Cuzick in an independent clinical cohort (N = 32,576).

RESULTS

Simulation studies confirmed that the Fixed-Stratified method produced accurate risk estimation across patients with different family history. In both validation studies, CRS and Tyrer-Cuzick were significantly associated with breast cancer. In an analysis with both CRS and Tyrer-Cuzick as predictors of breast cancer, CRS added significant discrimination independent of that captured by Tyrer-Cuzick (P < 10-11 in validation 1; P < 10-7 in validation 2). In an independent cohort, 18% of women shifted breast cancer risk categories from their Tyrer-Cuzick-based risk compared with risk estimates by CRS.

CONCLUSION

Integrating clinical and polygenic factors into a risk model offers more effective risk stratification and supports a personalized genomic approach to breast cancer screening and prevention.

Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic focus primarily on assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, and pancreatic cancer and recommended approaches to genetic testing/counseling and management strategies in individuals with these pathogenic or likely pathogenic variants. This manuscript focuses on cancer risk and risk management for BRCA-related breast/ovarian cancer syndrome and Li-Fraumeni syndrome. Carriers of a BRCA1/2 pathogenic or likely pathogenic variant have an excessive risk for both breast and ovarian cancer that warrants consideration of more intensive screening and preventive strategies. There is also evidence that risks of prostate cancer and pancreatic cancer are elevated in these carriers. Li-Fraumeni syndrome is a highly penetrant cancer syndrome associated with a high lifetime risk for cancer, including soft tissue sarcomas, osteosarcomas, premenopausal breast cancer, colon cancer, gastric cancer, adrenocortical carcinoma, and brain tumors.

Contribution of Germline Predisposition Gene Mutations to Breast Cancer Risk in African American Women

BACKGROUND

The risks of breast cancer in African American (AA) women associated with inherited mutations in breast cancer predisposition genes are not well defined. Thus, whether multigene germline hereditary cancer testing panels are applicable to this population is unknown. We assessed associations between mutations in panel-based genes and breast cancer risk in 5054 AA women with breast cancer and 4993 unaffected AA women drawn from 10 epidemiologic studies.

METHODS

Germline DNA samples were sequenced for mutations in 23 cancer predisposition genes using a QIAseq multiplex amplicon panel. Prevalence of mutations and odds ratios (ORs) for associations with breast cancer risk were estimated with adjustment for study design, age, and family history of breast cancer.

RESULTS

Pathogenic mutations were identified in 10.3% of women with estrogen receptor (ER)-negative breast cancer, 5.2% of women with ER-positive breast cancer, and 2.3% of unaffected women. Mutations in BRCA1, BRCA2, and PALB2 were associated with high risks of breast cancer (OR = 47.55, 95% confidence interval [CI] = 10.43 to >100; OR = 7.25, 95% CI = 4.07 to 14.12; OR = 8.54, 95% CI = 3.67 to 24.95, respectively). RAD51D mutations were associated with high risk of ER-negative disease (OR = 7.82, 95% CI = 1.61 to 57.42). Moderate risks were observed for CHEK2, ATM, ERCC3, and FANCC mutations with ER-positive cancer, and RECQL mutations with all breast cancer.

CONCLUSIONS

The study identifies genes that predispose to breast cancer in the AA population, demonstrates the validity of current breast cancer testing panels for use in AA women, and provides a basis for increased referral of AA patients for cancer genetic testing.

Ovarian and Breast Cancer Risks Associated With Pathogenic Variants in RAD51C and RAD51D

BACKGROUND

The purpose of this study was to estimate precise age-specific tubo-ovarian carcinoma (TOC) and breast cancer (BC) risks for carriers of pathogenic variants in RAD51C and RAD51D.

METHODS

We analyzed data from 6178 families, 125 with pathogenic variants in RAD51C, and 6690 families, 60 with pathogenic variants in RAD51D. TOC and BC relative and cumulative risks were estimated using complex segregation analysis to model the cancer inheritance patterns in families while adjusting for the mode of ascertainment of each family. All statistical tests were two-sided.

RESULTS

Pathogenic variants in both RAD51C and RAD51D were associated with TOC (RAD51C: relative risk [RR] = 7.55, 95% confidence interval [CI] = 5.60 to 10.19; P = 5 × 10-40; RAD51D: RR = 7.60, 95% CI = 5.61 to 10.30; P = 5 × 10-39) and BC (RAD51C: RR = 1.99, 95% CI = 1.39 to 2.85; P = 1.55 × 10-4; RAD51D: RR = 1.83, 95% CI = 1.24 to 2.72; P = .002). For both RAD51C and RAD51D, there was a suggestion that the TOC relative risks increased with age until around age 60 years and decreased thereafter. The estimated cumulative risks of developing TOC to age 80 years were 11% (95% CI = 6% to 21%) for RAD51C and 13% (95% CI = 7% to 23%) for RAD51D pathogenic variant carriers. The estimated cumulative risks of developing BC to 80 years were 21% (95% CI = 15% to 29%) for RAD51C and 20% (95% CI = 14% to 28%) for RAD51D pathogenic variant carriers. Both TOC and BC risks for RAD51C and RAD51D pathogenic variant carriers varied by cancer family history and could be as high as 32-36% for TOC, for carriers with two first-degree relatives diagnosed with TOC, or 44-46% for BC, for carriers with two first-degree relatives diagnosed with BC.

CONCLUSIONS

These estimates will facilitate the genetic counseling of RAD51C and RAD51D pathogenic variant carriers and justify the incorporation of RAD51C and RAD51D into cancer risk prediction models.

Upper Gastrointestinal Cancer Risk and Surveillance Outcomes in Li-Fraumeni Syndrome

INTRODUCTION

To assess the upper gastrointestinal (UGI) cancer risk and surveillance outcomes in Li-Fraumeni syndrome (LFS).

METHODS

Analysis of the International Agency for Research on Cancer database and a single-center adult LFS cohort.

RESULTS

UGI cancer was present in 7.2% of families and 3.9% of individuals with a pathogenic/likely pathogenic TP53 mutation in International Agency for Research on Cancer; 29% occurred before age 30. Our institutional cohort had 35 individuals (31% of the LFS cohort) with 48 cumulative upper endoscopies; 3 (8.5%) individuals had concerning UGI findings.

DISCUSSION

UGI cancer is observed in LFS. Upper endoscopy should be part of a comprehensive LFS surveillance program.

Polygenic risk scores and breast and epithelial ovarian cancer risks for carriers of BRCA1 and BRCA2 pathogenic variants

PURPOSE

We assessed the associations between population-based polygenic risk scores (PRS) for breast (BC) or epithelial ovarian cancer (EOC) with cancer risks for BRCA1 and BRCA2 pathogenic variant carriers.

METHODS

Retrospective cohort data on 18,935 BRCA1 and 12,339 BRCA2 female pathogenic variant carriers of European ancestry were available. Three versions of a 313 single-nucleotide polymorphism (SNP) BC PRS were evaluated based on whether they predict overall, estrogen receptor (ER)-negative, or ER-positive BC, and two PRS for overall or high-grade serous EOC. Associations were validated in a prospective cohort.

RESULTS

The ER-negative PRS showed the strongest association with BC risk for BRCA1 carriers (hazard ratio [HR] per standard deviation = 1.29 [95% CI 1.25-1.33], P = 3×10-72). For BRCA2, the strongest association was with overall BC PRS (HR = 1.31 [95% CI 1.27-1.36], P = 7×10-50). HR estimates decreased significantly with age and there was evidence for differences in associations by predicted variant effects on protein expression. The HR estimates were smaller than general population estimates. The high-grade serous PRS yielded the strongest associations with EOC risk for BRCA1 (HR = 1.32 [95% CI 1.25-1.40], P = 3×10-22) and BRCA2 (HR = 1.44 [95% CI 1.30-1.60], P = 4×10-12) carriers. The associations in the prospective cohort were similar.

CONCLUSION

Population-based PRS are strongly associated with BC and EOC risks for BRCA1/2 carriers and predict substantial absolute risk differences for women at PRS distribution extremes.

Association of germline variation with the survival of women with BRCA1/2 pathogenic variants and breast cancer

Germline genetic variation has been suggested to influence the survival of breast cancer patients independently of tumor pathology. We have studied survival associations of genetic variants in two etiologically unique groups of breast cancer patients, the carriers of germline pathogenic variants in BRCA1 or BRCA2 genes. We found that rs57025206 was significantly associated with the overall survival, predicting higher mortality of BRCA1 carrier patients with estrogen receptor-negative breast cancer, with a hazard ratio 4.37 (95% confidence interval 3.03-6.30, P = 3.1 × 10-9). Multivariable analysis adjusted for tumor characteristics suggested that rs57025206 was an independent survival marker. In addition, our exploratory analyses suggest that the associations between genetic variants and breast cancer patient survival may depend on tumor biological subgroup and clinical patient characteristics.

A Rare TP53 Mutation Predominant in Ashkenazi Jews Confers Risk of Multiple Cancers

Germline mutations in TP53 cause a rare high penetrance cancer syndrome, Li-Fraumeni syndrome (LFS). Here, we identified a rare TP53 tetramerization domain missense mutation, c.1000G>C;p.G334R, in a family with multiple late-onset LFS-spectrum cancers. Twenty additional c.1000G>C probands and one c.1000G>A proband were identified, and available tumors showed biallelic somatic inactivation of TP53. The majority of families were of Ashkenazi Jewish descent, and the TP53 c.1000G>C allele was found on a commonly inherited chromosome 17p13.1 haplotype. Transient transfection of the p.G334R allele conferred a mild defect in colony suppression assays. Lymphoblastoid cell lines from the index family in comparison with TP53 normal lines showed that although classical p53 target gene activation was maintained, a subset of p53 target genes (including PCLO, PLTP, PLXNB3, and LCN15) showed defective transactivation when treated with Nutlin-3a. Structural analysis demonstrated thermal instability of the G334R-mutant tetramer, and the G334R-mutant protein showed increased preponderance of mutant conformation. Clinical case review in comparison with classic LFS cohorts demonstrated similar rates of pediatric adrenocortical tumors and other LFS component cancers, but the latter at significantly later ages of onset. Our data show that TP53 c.1000G>C;p.G334R is found predominantly in Ashkenazi Jewish individuals, causes a mild defect in p53 function, and leads to low penetrance LFS. SIGNIFICANCE: TP53 c.1000C>G;p.G334R is a pathogenic, Ashkenazi Jewish-predominant mutation associated with a familial multiple cancer syndrome in which carriers should undergo screening and preventive measures to reduce cancer risk.

Mutation Rates in Cancer Susceptibility Genes in Patients With Breast Cancer With Multiple Primary Cancers

PURPOSE

Women with breast cancer have a 4%-16% lifetime risk of a second primary cancer. Whether mutations in genes other than BRCA1/2 are enriched in patients with breast and another primary cancer over those with a single breast cancer (S-BC) is unknown.

PATIENTS AND METHODS

We identified pathogenic germline mutations in 17 cancer susceptibility genes in patients with BRCA1/2-negative breast cancer in 2 different cohorts: cohort 1, high-risk breast cancer program (multiple primary breast cancer [MP-BC], n = 551; S-BC, n = 449) and cohort 2, familial breast cancer research study (MP-BC, n = 340; S-BC, n = 1,464). Mutation rates in these 2 cohorts were compared with a control data set (Exome Aggregation Consortium [ExAC]).

RESULTS

Overall, pathogenic mutation rates for autosomal, dominantly inherited genes were higher in patients with MP-BC versus S-BC in both cohorts (8.5% v 4.9% [P = .02] and 7.1% v 4.2% [P = .03]). There were differences in individual gene mutation rates between cohorts. In both cohorts, younger age at first breast cancer was associated with higher mutation rates; the age of non-breast cancers was unrelated to mutation rate. TP53 and MSH6 mutations were significantly enriched in patients with MP-BC but not S-BC, whereas ATM and PALB2 mutations were significantly enriched in both groups compared with ExAC.

CONCLUSION

Mutation rates are at least 7% in all patients with BRCA1/2 mutation-negative MP-BC, regardless of age at diagnosis of breast cancer, with mutation rates up to 25% in patients with a first breast cancer diagnosed at age < 30 years. Our results suggest that all patients with breast cancer with a second primary cancer, regardless of age of onset, should undergo multigene panel testing.

Comparison of up-front cash cards and checks as incentives for participation in a clinician survey: a study within a trial

Background

Evidence is needed regarding effective incentive strategies to increase clinician survey response rates. Cash cards are increasingly used as survey incentives; they are appealing because of their convenience and because in some cases their value can be reclaimed by investigators if not used. However, their effectiveness in clinician surveys is not known. In this study within the BRCA Founder OutReach (BFOR) study, a clinical trial of population-based BRCA1/2 mutation screening, we compared the use of upfront cash cards requiring email activation versus checks as clinician survey incentives.

Methods

Participants receiving BRCA1/2 testing in the BFOR study could elect to receive their results from their primary care provider (PCP, named by the patient) or from a geneticist associated with the study. In order to understand PCPs’ knowledge, attitudes, experiences and willingness to disclose results we mailed paper surveys to the first 501 primary care providers (PCPs) in New York, Boston, Los Angeles and Philadelphia who were nominated by study participants to disclose their BRCA1/2 mutation results obtained through the study. We used alternating assignment stratified by city to assign the first 303 clinicians to receive a $50 up-front incentive as a cash card (N = 155) or check (N = 148). The cash card required PCPs to send an activation email in order to be used. We compared response rates by incentive type, adjusting for PCP characteristics and study site.

Results

In unadjusted analyses, PCPs who received checks were more likely to respond to the survey than those who received cash cards (54.1% versus 41.9%, p = 0.046); this remained true when we adjusted for provider characteristics (OR for checks 1.61, 95% CI 1.01, 2.59). No other clinician characteristics had a statistically significant association with response rates in adjusted analyses. When we included an interaction term for incentive type and city, the favorable impact of checks on response rates was evident only in Los Angeles and Philadelphia.

Conclusions

An up-front cash card incentive requiring email activation may be less effective in eliciting clinician responses than up-front checks. However, the benefit of checks for clinician response rates may depend on clinicians’ geographic location.

Trial registration

ClinicalTrials.gov (NCT03351803), November 24, 2017.

Current Insights: Evolving Principles and Controversies of Cancer Risk Assessment and Management of Hereditary Cancers

With the introduction of panel and direct-to-consumer testing, genetic testing has become commonplace in recent years, paving the way for both increased awareness around prevalent genetic cancer risks, and also an onslaught of misinformation. At the NCCN 2020 Virtual Annual Conference, Dr. Tuya Pal led a panel of experts in discussing the utility and difficulties associated with multigene testing, the emerging role of moderate-penetrance genes in defining risks for hereditary cancer, and the controversies associated with direct-to-consumer genetic testing services.

Association of a Polygenic Risk Score With Breast Cancer Among Women Carriers of High- and Moderate-Risk Breast Cancer Genes

Importance

To date, few studies have examined the extent to which polygenic single-nucleotide variation (SNV) (formerly single-nucleotide polymorphism) scores modify risk for carriers of pathogenic variants (PVs) in breast cancer susceptibility genes. In previous reports, polygenic risk modification was reduced for BRCA1 and BRCA2 PV carriers compared with noncarriers, but limited information is available for carriers of CHEK2, ATM, or PALB2 PVs.

Objective

To examine an 86-SNV polygenic risk score (PRS) for BRCA1, BRCA2, CHEK2, ATM, and PALB2 PV carriers.

Design, Setting, and Participants

A retrospective case-control study using data on 150 962 women tested with a multigene hereditary cancer panel between July 19, 2016, and January 11, 2019, was conducted in a commercial testing laboratory. Participants included women of European ancestry between the ages of 18 and 84 years.

Main Outcomes and Measures

Multivariable logistic regression was used to examine the association of the 86-SNV score with invasive breast cancer after adjusting for age, ancestry, and personal and/or family cancer history. Effect sizes, expressed as standardized odds ratios (ORs) with 95% CIs, were assessed for carriers of PVs in each gene as well as for noncarriers.

Results

The median age at hereditary cancer testing of the population was 48 years (range, 18-84 years); there were 141 160 noncarriers in addition to carriers of BRCA1 (n = 2249), BRCA2 (n = 2638), CHEK2 (n = 2564), ATM (n = 1445), and PALB2 (n = 906) PVs included in the analysis. The 86-SNV score was associated with breast cancer risk in each of the carrier populations (P < 1 × 10-4). Stratification was more pronounced for noncarriers (OR, 1.47; 95% CI, 1.45-1.49) and CHEK2 PV carriers (OR, 1.49; 95% CI, 1.36-1.64) than for carriers of BRCA1 (OR, 1.20; 95% CI, 1.10-1.32) or BRCA2 (OR, 1.23; 95% CI, 1.12-1.34) PVs. Odds ratios for ATM (OR, 1.37; 95% CI, 1.21-1.55) and PALB2 (OR, 1.34; 95% CI, 1.16-1.55) PV carrier populations were intermediate between those for BRCA1/2 and CHEK2 noncarriers.

Conclusions and Relevance

In this study, the 86-SNV score was associated with modified risk for carriers of BRCA1, BRCA2, CHEK2, ATM, and PALB2 PVs. This finding supports previous reports of reduced PRS stratification for BRCA1 and BRCA2 PV carriers compared with noncarriers. Modification of risk in CHEK2 carriers associated with the 86-SNV score appeared to be similar to that observed in women without a PV. Larger studies are needed to provide more refined estimates of polygenic modification of risk for women with PVs in other moderate-penetrance genes.

Transcriptome-wide association study of breast cancer risk by estrogen-receptor status

Previous transcriptome-wide association studies (TWAS) have identified breast cancer risk genes by integrating data from expression quantitative loci and genome-wide association studies (GWAS), but analyses of breast cancer subtype-specific associations have been limited. In this study, we conducted a TWAS using gene expression data from GTEx and summary statistics from the hitherto largest GWAS meta-analysis conducted for breast cancer overall, and by estrogen receptor subtypes (ER+ and ER-). We further compared associations with ER+ and ER- subtypes, using a case-only TWAS approach. We also conducted multigene conditional analyses in regions with multiple TWAS associations. Two genes, STXBP4 and HIST2H2BA, were specifically associated with ER+ but not with ER- breast cancer. We further identified 30 TWAS-significant genes associated with overall breast cancer risk, including four that were not identified in previous studies. Conditional analyses identified single independent breast-cancer gene in three of six regions harboring multiple TWAS-significant genes. Our study provides new information on breast cancer genetics and biology, particularly about genomic differences between ER+ and ER- breast cancer.

Abstract A72: Combination ATR and PARP inhibitor (CAPRI) for recurrent, platinum-resistant ovarian cancer

Background: Platinum-resistant (PR) ovarian cancer (OC) is a lethal disease for which effective therapies are limited. Preclinical data suggest that inhibitors of poly(ADP-ribose) polymerase (PARP) and ataxia telangiectasia and Rad3-related kinase (ATR) have synergistic antitumor activity in these tumors. We hypothesize that targeting two unique DNA repair pathways with combination therapy may increase response rates, durability of response, and lower off-target toxicities compared to standard treatments. This clinical trial examines PARP and ATR inhibition (PARPi-ATRi) in patients (pts) with recurrent OC (NCT03462342). Data from the PR arm of this trial are presented.

Methods: Twelve patients were enrolled with PROC in the first stage of a Simon optimal two-stage design with alpha=0.10 and beta=0.10. Eligible pts had recurrent, PR high-grade serous OC, measurable disease, and no prior treatment with a targeted inhibitor of DNA repair. Pts may or may not have a somatic or germline mutation of BRCA1 or BRCA2. Pts received olaparib (O) 300mg orally twice daily on days 1-28 and AZD6738 (A) 160mg orally daily on days 1-7 of a 28-day cycle. Endpoints were safety (toxicity based on CTCAE v5.0), objective response rate (RECIST v1.1), and PFS (RECIST v1.1). If ≥1 patient of 12 treated has a partial or complete response, then 25 additional patients will be treated; if no responses are seen, the PR arm of this trial will be terminated.

Results: Nine patients have been treated and 8 pts have had on-study imaging thus far. Median (M) age is 63 years (53-73); M ECOG, 0 (0-1); M prior lines of chemotherapy, 2.5 (1-4); M prior therapies after acquiring platinum resistance, 0.5 (0-2). BRCA1/2m status (positive/negative/unknown) is: gBRCA1 (1/5/4); gBRCA2 (0/6/4); sBRCA1 (1/7/2); sBRCA2 (0/8/2). No complete or partial responses were seen. Six of 8 patients achieved SD with a mean duration on study of 6.7 cycles (range 4-10 cycles), including 1 pt with gBRCA1m. Three of these 6 pts demonstrated 20-27% tumor regression of target lesions. Two patients had disease progression. Toxicities occurring in ≥50% of pts that were at least possibly related to combination therapy were nausea (grade (G) 1/2: 6, G3: 1); anorexia (G1/2: 5, G3: 1); fatigue (G1/2: 4, G3: 1), anemia (G1/2: 4, G3: 1). No G4 toxicities were observed and no pts discontinued therapy due to toxicity.

Conclusions: Combination O and A is tolerable with mostly low-grade toxicity similar to that of olaparib single-agent. 75% of response-evaluable pts had stable disease, half of whom had substantial tumor regression. Duration of disease stability was clinically meaningful in this PR, largely g/sBRCA1/2 wild-type OC population. Biopsy samples will be evaluated by genomics and proteomics. Updated response data will be presented.

Citation Format: Payal D. Shah, Haley Zarrin, Stephanie Wethington, Nawar Latif, Lainie Martin, Diego Rodriguez, Katie Elkins, Robert Giuntoli, Robert Burger, Janos Tanyi, Mark Morgan, Susan M. Domchek, Stephanie Gailliard, Deborah K. Armstrong, Fiona Simpkins. Combination ATR and PARP inhibitor (CAPRI) for recurrent, platinum-resistant ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A72.

Genome-wide association study identifies 32 novel breast cancer susceptibility loci from overall and subtype-specific analyses

Breast cancer susceptibility variants frequently show heterogeneity in associations by tumor subtype1-3. To identify novel loci, we performed a genome-wide association study including 133,384 breast cancer cases and 113,789 controls, plus 18,908 BRCA1 mutation carriers (9,414 with breast cancer) of European ancestry, using both standard and novel methodologies that account for underlying tumor heterogeneity by estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 status and tumor grade. We identified 32 novel susceptibility loci (P < 5.0 × 10-8), 15 of which showed evidence for associations with at least one tumor feature (false discovery rate < 0.05). Five loci showed associations (P < 0.05) in opposite directions between luminal and non-luminal subtypes. In silico analyses showed that these five loci contained cell-specific enhancers that differed between normal luminal and basal mammary cells. The genetic correlations between five intrinsic-like subtypes ranged from 0.35 to 0.80. The proportion of genome-wide chip heritability explained by all known susceptibility loci was 54.2% for luminal A-like disease and 37.6% for triple-negative disease. The odds ratios of polygenic risk scores, which included 330 variants, for the highest 1% of quantiles compared with middle quantiles were 5.63 and 3.02 for luminal A-like and triple-negative disease, respectively. These findings provide an improved understanding of genetic predisposition to breast cancer subtypes and will inform the development of subtype-specific polygenic risk scores.

Integrating Genetic and Genomic Testing Into Oncology Practice

Genetic information, both germline and somatic, is an increasingly important consideration in therapeutic decision-making in cancer. Germline mutations in genes associated with increased cancer risk can identify those individuals without cancer who may benefit from enhanced screening and prevention strategies. In individuals with cancer, germline and somatic mutations may help to guide local and systemic management decisions. Here, we review considerations of these issues in selected cancer types.

Comprehensive breast cancer (BC) risk assessment for CHEK2 carriers incorporating a polygenic risk score (PRS) and the Tyrer-Cuzick (TC) model

1504

Background: Women with pathogenic variants in the moderate penetrance CHEK2 gene have on average an estimated > 20% lifetime risk for breast cancer, thereby meeting an established threshold for more aggressive screening, including consideration of breast magnetic resonance imaging (MRI). However, we previously showed that CHEK2 penetrance is modified by an 86-SNP PRS. CHEK2 risk is further modified by family history (FH) and other TC model variables. Here, we describe development of a comprehensive risk prediction model for women of European ancestry to more precisely estimate risk by incorporating CHEK2, PRS and TC V7.02. The number of CHEK2 carriers with low ( < 20%), moderate (20%-50%) and high ( > 50%) remaining lifetime risk based on the combined model was examined in an independent study cohort. Methods: This IRB-approved study included de-identified clinical records from 358,471 women of European ancestry who were tested clinically for hereditary cancer risk with a multi-gene panel. Model development was based on analysis of CHEK2 PV carriers ( N= 4,331) and women negative for BC gene PV ( N =353,681) who were tested between September 2013 and July 2019. Risk estimates incorporating CHEK2, PRS and TC were calculated using a fixed-stratified (FS) method that accounts for correlations between risk factors in a manner equivalent to multivariable co-estimation. Risk stratification was assessed in an independent cohort of CHEK2 carriers ( N= 459) who were tested after July 2019 and not included in model development. Results: We detected significant correlation of CHEK2 status with FH ( p= 4.1 × 10−17) and of PRS with FH among CHEK2 carriers ( p= 1.7× 10−5). For these factors, joint effects were co-estimated using the FS method. In an independent cohort, 24.0% of CHEK2 carriers were categorized as low risk ( < 20%), and 62.6% were categorized as moderate risk (20-50%). For 13.4% of CHEK2 carriers, risk estimation incorporating PRS and TC generated BC risks of greater than 50%, consistent with genes recognized as highly penetrant. Conclusions: In CHEK2 PV carriers, comprehensive risk assessment could inform individualized decision-making and may lead to improved targeting of screening and prevention strategies.

Burden of genetic testing in an academic biobank by pathological and family history-based criteria in prostate cancer (PCa)

1576

Background: Approximately 5% of localized PCa and 12% of metastatic PCa are associated with germline mutations in DNA repair genes. The National Comprehensive Cancer Network (NCCN) issued genetic testing guidelines to identify PCa patients (pts) likely to harbor a germline DNA repair mutation. The overall burden of this guideline-based, resource-intensive genetic testing is unknown. Using supervised phenotype-genotype information extraction algorithms, we determined the projected genetic testing burden at a single institution adhering to NCCN PCa genetic testing guidelines. Methods: A PCa cohort of 2127 pts was identified from the Penn Medicine BioBank via ICD 9/10 codes. Phenotypic data were extracted from the Penn Medicine Cancer Registry and electronic health record systems via natural language processing and manual chart review. Pts were classified based on 9 germline genetic testing criteria outlined in the NCCN PCa guidelines (Version 4.2019). Results: 895/2127 pts met at least 1 of the 9 NCCN genetic testing criteria, corresponding to a 42.1% overall genetic testing burden. 35.2% qualified for testing via high-risk localized PCa and 6.4% qualified via metastatic disease. Of the pts with localized PCa (n=2014), 15.1% qualified for genetic testing via high Gleason score, 5.1% via high-risk family history, 3.7% via PSA>20ng/mL, 8.7% via Ashkenazi Jewish descent, and 0.8% via intraductal/ductal histology. Conclusions: In this single-center PCa cohort, germline genetic testing was NCCN-guideline recommended for a larger proportion of pts than would otherwise be expected based on previously published reports. Future studies are needed to validate the sensitivity and specificity of these criteria for identifying germline mutations. Our study also highlights a need for novel methods to improve the efficiency of genetic testing for a large cohort. [Table: see text]

Randomized trial of web-based genetic education versus usual care in advanced cancer patients undergoing tumor genetic testing: Results from the ECOG-ACRIN NCI Community Oncology Research Program (NCORP; EAQ152) COMET trial

2008

Background: Enthusiasm for precision oncology may obscure the complex psychosocial and ethical considerations for tumor genetic testing. Low patient genetic knowledge has been documented and heightens the risk for adverse experiences. We developed a web-based intervention to increase genetic knowledge and decrease distress among advanced cancer patients undergoing tumor genetic testing. Methods: 594 patients (80% from NCORP Community Sites) were recruited and randomized to web-intervention (n = 293) or usual care (n = 301), prior to receipt of tumor genetic test results. Primary outcomes were genetic knowledge, anxiety, depression, and cancer-specific distress measured at T0 (prior to intervention), T1 (post-intervention), T2 (after receipt of tumor results) and T3 (3 months post receipt of tumor results). Secondary outcomes included satisfaction, regret and disappointment. The effect of web-intervention was evaluated using t-test, multiple linear regression and logistic regression, with an intent-to-treat approach. Results: Patients randomized to web-intervention had better knowledge improvement than those randomized to usual care (T1-T0, p < 0.0001; T2-T0, p = 0.003). No difference was observed in change scores for anxiety, depression or cancer-specific distress. To find the moderators of intervention effect (including sex, age, education, and literacy) two 2-way interactions were noted with statistical significance: higher depression among those in the intervention arm versus the control arm for patients with lower literacy (p = 0.03); and lower cancer-specific distress among women in the intervention arm than with usual care but no such effect noted in men (p = 0.01). 71% of patients reported receiving tumor test results and this did not differ by arm. Only 20% of patients reported regret and disappointment at T2, which was more likely for those without a mutation of interest (MOI) detected vs those with a MOI detected (OR = 2.08, 95% CI, 1.13 to 3.83, p = 0.02). Conclusions: Web-based education prior to receipt of tumor genetic test results increases patient understanding of tumor genetic testing. While the intervention did not significantly reduce distress, results suggest that women who received the intervention had lower cancer-specific distress than those with usual care. Future refinements to the web-intervention are needed to address low literacy groups, men and patients with no actionable results. Clinical trial information: NCT02823652.

Genetic testing experiences and emotional reactions among individuals with variant of uncertain significance results from cancer multiplex genetic testing

e13680

Background: Multiplex genetic testing (MGT) simultaneously analyzes multiple cancer susceptibility genes and can reveal genetic variants of uncertain significance (VUS) that have unclear associations with cancer risks. Little is known about how people are prepared for receiving VUS results from MGT, or whether their emotional reactions differ based on the levels of cancer risk to which they may be susceptible. Methods: We recruited participants from the online Prospective Registry of Multiplex Testing (PROMPT). Those with only a VUS in a cancer predisposition gene completed a survey including measures of their MGT experience, distress (range 0-30; α = .87), uncertainty (0-45; α = .83), and positive experiences (0-20; α = .75). We used generalized linear modeling to examine how demographics, awareness of the possibility of VUS before testing, and level of cancer risks associated with their VUS gene were related to emotional outcomes. Results: Data were available from 661 individuals (40% response rate, 95% female, 90% white, 78% college graduate, 69% cancer history, age 23-93) with VUS in a gene of high risk (47%), moderate/low risk (35%) or limited evidence of risk (18%). Among the sample, 80.8% reported ever receiving cancer genetic counseling, and only 50.8% reported being aware of the possibility of VUS when deciding about testing. Participants reported low current distress ( M± SD= 3.25±5.19), uncertainty (9.18±8.35) and positive experiences (7.83±5.98). Distress was associated with younger age, less family cancer history, and being unaware of the possibility of VUS before testing; distress was also higher among those with VUS in a gene of high risk than those with VUS in a gene of moderate/low risk or limited evidence of risk ( ps≤.023). Uncertainty was associated with younger age, non-white race, less education, and being unaware of the possibility of VUS; uncertainty was also higher among those with VUS in a gene of high risk than those with VUS in a gene with limited evidence of risk ( ps≤.05). Fewer positive experiences were associated with more education and more family cancer history; those with VUS in a gene of high risk had fewer positive experiences than those with VUS in a gene with limited evidence of risk ( ps≤.03). Conclusions: Many individuals undergoing MGT may not fully understand the prospect of receiving VUS. Clinicians should consider patients’ background, preparation, and level of cancer risk to which they are potentially susceptible, as these factors may affect their emotional adaptation.

Uptake of oophorectomy in women with findings on multigene panel testing: Results from the Prospective Registry of Multiplex Testing (PROMPT)

1508

Background: With the expansion of multigene panel testing for cancer susceptibility, increasing numbers of patients are identified with pathogenic/likely pathogenic variants (P/LP V) in genes which do not have a clearly actionable increased risk of ovarian cancer (OC) (lifetime risk of OC >5%). However, there is concern that patients and/or providers may ascribe OC risk to such genetic findings with the potential for unnecessary oophorectomy (ooph). Methods: The Prospective Registry of Multiplex Testing (PROMPT) is an online registry for individuals with a genetic alteration detected on multiplex panel testing for cancer susceptibility. Participants self-enroll and complete baseline and annual follow-up questionnaires. PROMPT has enrolled 7388 participants (6936; 93.9% women) since September 2014. Results: 1566 women in the PROMPT registry reported ooph, the indications for which were reported as either cancer treatment (n=481, 30.7%) or benign disease (n=432, 27.6%). An additional 186 (12.8%) reported PV in genes associated with lifetime OC risk >5% ( BRCA1, BRCA2, RAD51C, RAD51D, BRIP, or Lynch syndrome genes). The remaining 467 did not have guideline based indications for ooph due to OC risk and are described further here. 92 (19.7%) had a variant of uncertain significance (VUS) in genes associated with OC, 241 (51.6%) had a personal history of breast cancer (BC) and no VUS in OC genes, and 119 (25.5%) had no personal history of BC and no VUS in OC genes. The majority of women had no family history (FH) of OC in first or second degree relatives (Table). Most ooph occurred prior to age 50. Of the 405 women with CHEK2 P/LP, 11.4% reported ooph (59% under age 50 when age known), as did 13.2% (of 228) with CHEK2 VUS, 8.8% (of 261) with ATM P/LP (66.7% under age 50), and 8.3% (of 387) with ATM VUS. In addition, of the 184 women with PALB2 P/LP, 14.1% reported ooph (35.3% under age 50) as did 11.6% (of 198) with PALB2 VUS. Of those who reported provider discussions, 47.2% stated “my provider recommended this” (including >60% in the OC gene VUS group) and an additional 25.2% stated “my provider presented this as an option, but not a requirement”. In those with no FH of OC, 45.8% stated that their provider recommended ooph. Conclusions: 10-15% of women with PV/VUS in genes not associated with a high risk of OC reported ooph without a clear indication. [Table: see text]

TBCRC 048: A phase II study of olaparib monotherapy in metastatic breast cancer patients with germline or somatic mutations in DNA damage response (DDR) pathway genes (Olaparib Expanded)

1002

Background: Olaparib, a PARP inhibitor, is approved for HER2-negative MBC in g BRCA1/2 mutation carriers. Olaparib Expanded, an investigator-initiated study, assessed the response to olaparib in MBC patients with sBRCA1/2 mutations or g/s mutations in DDR-pathway genes other than BRCA1/2. Methods: Eligibility included: MBC with measurable disease; progression on < 2 metastatic chemotherapy regimens. Prior PARP inhibitor or progression on platinum was not allowed. Cohort 1 included patients with germline mutations in non- BRCA1/2 DDR-pathway genes. In Cohort 2 were those with somatic mutations in these genes or BRCA1/2; germline testing was required only to exclude a gBRCA mutation if a s BRCA mutation was present. Patients received olaparib 300 mg bid until progression or unacceptable toxicity. For each cohort, a single-arm Simon two-stage design was used with 13 then 14 patients in the 1st and 2nd stages, respectively. The null hypothesis within each cohort [≤ 5% objective response rate (ORR)] would be rejected if > 4 responses were seen at the end of stage 2. Secondary endpoints include clinical benefit rate, progression-free survival, and duration of response. Results: 54 patients enrolled from March 2018 to Jan 2020; 1 ineligible s BRCA2 was excluded. Median age was 59 yrs (range: 30-87). 40 patients had ER+ HER2-, 3 HER2+, and 10 TNBC. 87% had a mutation in PALB2, s BRCA1/2, ATM or CHEK2. ORR was 29.6% (8/27, 90%-CI: 15.6%-47.1%) in Cohort 1 and 38.5% (10/26, 90%-CI: 22.5%-56.4%) in Cohort 2. Responses were gene specific (Table): g PALB2 and s BRCA mutations predicted response; no responses were seen with only a CHEK2 or ATM mutation. To date, responses as long as 16.4 months have been observed. Responses were seen in all subtypes: 5/10 TNBC, 1/3 HER2+, 12/40 ER+ HER2-. 11 responses occurred after prior CDK4/6 inhibitor. In June 2020, final data for confirmed ORR and secondary endpoints will be reported. Conclusion: In this proof-of-principle study, single-agent olaparib successfully met its primary endpoint in both cohorts. Activity was seen largely in patients with MBC and s BRCA1/2 or g PALB2 mutations but not with ATM or CHEK2 mutations. Clinical trial information: NCT03344965 . [Table: see text]

The BRCA founder outreach study: Initial results of a digital health model

2007

Background: NCCN now endorses BRCA founder mutation genetic testing (GT) via longitudinal studies in all Ashkenazi Jewish (AJ) individuals. The BRCA Founder OutReach (BFOR) study offers pre-GT online education with posttest engagement of primary care providers (PCPs). Methods: The study in 4 US cities enrolls those age > 25 with > 1 AJ grandparent. Participants enroll online with chatbot and video education, have GT at local centers, receive results from their PCP or BFOR staff, and are surveyed 12 weeks post disclosure and annually for 5 years. Univariate analyses and multivariable (MV) logistic regression models were used to evaluate characteristics associated with not completing GT, selecting PCP to disclose GT, and positive GT. Results: As of January 2020, 4754 participants consented (77.5% female, median age 51); 37.7% never previously considered GT. Cancer family histories (FHx) were 56.4% low risk (LR), 36.4% high risk (HR), and 7.2% had a familial mutation (FM). To date, 3658 participants (76.9%) completed and 677 (14.2%) did not complete GT; the remainder are pending. Only 34.8% of participants selected PCP to disclose GT, and 42.6% of PCPs agreed. Of the 124 mutation carriers (3.4%) identified, 60.5% had a FM. At the 12-week survey, 65.4% of mutation carriers planned to proceed with recommended screening or scheduled risk reducing surgery; 3.5% of those with negative GT and HR FHx reported further GT. Satisfaction was high (mean 9.58/10, SD 1.12) and unrelated to result (p>.05). Conclusions: A digital model for founder mutation testing engaged those with LR FHx and no prior experience with GT. Older participants were more likely to complete the study. Males were less likely to enroll but more likely to carry mutations. The majority of those who tested positive had a FM. A minority of results were disclosed by PCPs. Continued follow up is needed to determine long term outcomes. [Table: see text]

Longitudinal follow-up after telephone disclosure in the randomized COGENT study

Purpose

To better understand the longitudinal risks and benefits of telephone disclosure of genetic test results in the era of multi-gene panel testing.

Patients and Methods

Adults who were proceeding with germline cancer genetic testing were randomized to telephone disclosure (TD) with a genetic counselor or in-person disclosure (IPD) of test results (i.e., usual care). All participants who received TD were recommended to return to meet with a physician to discuss medical management recommendations.

Results

473 participants were randomized to TD and 497 to IPD. There were no differences between arms for any cognitive, affective or behavioral outcomes at 6 and 12 months. Only 50% of participants in the TD arm returned for the medical follow-up appointment. Returning was associated with site (p<0.0001), being female (p=0.047), and not having a true negative result (p<0.002). Mammography was lower at 12 months among those who had TD and did not return for medical follow-up (70%) as compared to those who had TD and returned (86%) and those who had IPD (87%, adjusted p <0.01).

Conclusion

Telephone disclosure of genetic test results is a reasonable alternative to in-person disclosure, but attention to medical follow-up may remain important for optimizing appropriate use of genetic results.