Validation of a clinical breast cancer risk assessment tool combining a polygenic score for all ancestries with traditional risk factors.

PURPOSE: We previously described a combined risk score (CRS) that integrates a multiple-ancestry polygenic risk score (MA-PRS) with the Tyrer-Cuzick (TC) model to assess breast cancer (BC) risk. Here, we present a longitudinal validation of CRS in a real-world cohort. METHODS: This study included 130,058 patients referred for hereditary cancer genetic testing and negative for germline pathogenic variants in BC-associated genes. Data were obtained by linking genetic test results to medical claims (median follow-up 12.1 months). CRS calibration was evaluated by the ratio of observed to expected BCs. RESULTS: Three hundred forty BCs were observed over 148,349 patient-years. CRS was well-calibrated and demonstrated superior calibration compared with TC in high-risk deciles. MA-PRS alone had greater discriminatory accuracy than TC, and CRS had approximately 2-fold greater discriminatory accuracy than MA-PRS or TC. Among those classified as high risk by TC, 32.6% were low risk by CRS, and of those classified as low risk by TC, 4.3% were high risk by CRS. In cases where CRS and TC classifications disagreed, CRS was more accurate in predicting incident BC. CONCLUSION: CRS was well-calibrated and significantly improved BC risk stratification. Short-term follow-up suggests that clinical implementation of CRS should improve outcomes for patients of all ancestries through personalized risk-based screening and prevention.

Identifying homologous recombination deficiency in breast cancer: genomic instability score distributions differ among breast cancer subtypes.

PURPOSE: A 3-biomarker homologous recombination deficiency (HRD) score is a key component of a currently FDA-approved companion diagnostic assay to identify HRD in patients with ovarian cancer using a threshold score of ≥ 42, though recent studies have explored the utility of a lower threshold (GIS ≥ 33). The present study evaluated whether the ovarian cancer thresholds may also be appropriate for major breast cancer subtypes by comparing the genomic instability score (GIS) distributions of BRCA1/2-deficient estrogen receptor-positive breast cancer (ER + BC) and triple-negative breast cancer (TNBC) to the GIS distribution of BRCA1/2-deficient ovarian cancer. METHODS: Ovarian cancer and breast cancer (ER + BC and TNBC) tumors from ten study cohorts were sequenced to identify pathogenic BRCA1/2 mutations, and GIS was calculated using a previously described algorithm. Pathologic complete response (pCR) to platinum therapy was evaluated in a subset of TNBC samples. For TNBC, a threshold was set and threshold validity was assessed relative to clinical outcomes. RESULTS: A total of 560 ovarian cancer, 805 ER + BC, and 443 TNBC tumors were included. Compared to ovarian cancer, the GIS distribution of BRCA1/2-deficient samples was shifted lower for ER + BC (p = 0.015), but not TNBC (p = 0.35). In the subset of TNBC samples, univariable logistic regression models revealed that GIS status using thresholds of ≥ 42 and ≥ 33 were significant predictors of response to platinum therapy. CONCLUSIONS: This study demonstrated that the GIS thresholds used for ovarian cancer may also be appropriate for TNBC, but not ER + BC. GIS thresholds in TNBC were validated using clinical response data to platinum therapy.

Germline Genetic Testing After Cancer Diagnosis.

Importance: Germline genetic testing is recommended by practice guidelines for patients diagnosed with cancer to enable genetically targeted treatment and identify relatives who may benefit from personalized cancer screening and prevention. Objective: To describe the prevalence of germline genetic testing among patients diagnosed with cancer in California and Georgia between 2013 and 2019. Design, Setting, and Participants: Observational study including patients aged 20 years or older who had been diagnosed with any type of cancer between January 1, 2013, and March 31, 2019, that was reported to statewide Surveillance, Epidemiology, and End Results registries in California and Georgia. These patients were linked to genetic testing results from 4 laboratories that performed most germline testing for California and Georgia. Main Outcomes and Measures: The primary outcome was germline genetic testing within 2 years of a cancer diagnosis. Testing trends were analyzed with logistic regression modeling. The results of sequencing each gene, including variants associated with increased cancer risk (pathogenic results) and variants whose cancer risk association was unknown (uncertain results), were evaluated. The genes were categorized according to their primary cancer association, including breast or ovarian, gastrointestinal, and other, and whether practice guidelines recommended germline testing. Results: Among 1 369 602 patients diagnosed with cancer between 2013 and 2019 in California and Georgia, 93 052 (6.8%) underwent germline testing through March 31, 2021. The proportion of patients tested varied by cancer type: male breast (50%), ovarian (38.6%), female breast (26%), multiple (7.5%), endometrial (6.4%), pancreatic (5.6%), colorectal (5.6%), prostate (1.1%), and lung (0.3%). In a logistic regression model, compared with the 31% (95% CI, 30%-31%) of non-Hispanic White patients with male breast cancer, female breast cancer, or ovarian cancer who underwent testing, patients of other races and ethnicities underwent testing less often: 22% (95% CI, 21%-22%) of Asian patients, 25% (95% CI, 24%-25%) of Black patients, and 23% (95% CI, 23%-23%) of Hispanic patients (P < .001 using the χ2 test). Of all pathogenic results, 67.5% to 94.9% of variants were identified in genes for which practice guidelines recommend testing and 68.3% to 83.8% of variants were identified in genes associated with the diagnosed cancer type. Conclusions and Relevance: Among patients diagnosed with cancer in California and Georgia between 2013 and 2019, only 6.8% underwent germline genetic testing. Compared with non-Hispanic White patients, rates of testing were lower among Asian, Black, and Hispanic patients.

The landscape of BRCA1 and BRCA2 large rearrangements in an international cohort of over 20 000 ovarian tumors identified using next-generation sequencing.

BACKGROUND: Approximately half of ovarian tumors have defects within the homologous recombination repair pathway. Tumors carrying pathogenic variants (PVs) in BRCA1/BRCA2 are more likely to respond to poly-ADP ribose polymerase (PARP) inhibitor treatment. Large rearrangements (LRs) are a challenging class of variants to identify and characterize in tumor specimens and may therefore be underreported. This study describes the prevalence of pathogenic BRCA1/BRCA2 LRs in ovarian tumors and discusses the importance of their identification using a comprehensive testing strategy. METHODS: Sequencing and LR analyses of BRCA1/BRCA2 were conducted in 20 692 ovarian tumors received between March 18, 2016 and February 14, 2023 for MyChoice CDx testing. MyChoice CDx uses NGS dosage analysis to detect LRs in BRCA1/BRCA2 genes using dense tiling throughout the coding regions and limited flanking regions. RESULTS: Of the 2217 PVs detected, 6.3% (N = 140) were LRs. Overall, 0.67% of tumors analyzed carried a pathogenic LR. The majority of detected LRs were deletions (89.3%), followed by complex LRs (5.7%), duplications (4.3%), and retroelement insertions (0.7%). Notably, 25% of detected LRs encompassed a single or partial single exon. This study identified 84 unique LRs, 2 samples each carried 2 unique LRs in the same gene. We identified 17 LRs that occurred in multiple samples, some of which were specific to certain ancestries. Several cases presented here illustrate the intricacies involved in characterizing LRs, particularly when multiple events occur within the same gene. CONCLUSIONS: Over 6% of PVs detected in the ovarian tumors analyzed were LRs. It is imperative for laboratories to utilize testing methodologies that will accurately detect LRs at a single exon resolution to optimize the identification of patients who may benefit from PARP inhibitor treatment.

The association between age at breast cancer diagnosis and prevalence of pathogenic variants.

PURPOSE: Young age at breast cancer (BC) diagnosis and family history of BC are strongly associated with high prevalence of pathogenic variants (PVs) in BRCA1 and BRCA2 genes. There is limited evidence for such associations with moderate/high penetrance BC-risk genes such as ATM, CHEK2, and PALB2. METHODS: We analyzed multi-gene panel testing results (09/2013-12/2019) for women unaffected by any cancer (N = 371,594) and those affected with BC (N = 130,151) ascertained for suspicion of hereditary breast and/or ovarian cancer. Multivariable logistic regression was used to test association between PV status and age at BC diagnosis (≤ 45 vs. > 45 years) or family history of BC after controlling for personal/family non-BC histories and self-reported ancestry. RESULTS: An association between young age (≤ 45 years) at diagnosis and presence of PVs was strong for BRCA1 (OR 3.95, 95% CI 3.64-4.29) and moderate for BRCA2 (OR 1.98, 95% CI 1.84-2.14). Modest associations were observed between PVs and young age at diagnosis for ATM (OR 1.22, 95% CI 1.08-1.37) and CHEK2 (OR 1.34, 95% CI 1.21-1.47) genes, but not for PALB2 (OR 1.12, 95% CI 0.98-1.27). For women with BC, earliest age of familial BC diagnosis followed a similar pattern. For unaffected women, earliest age of family cancer diagnosis was significantly associated with PV status only for BRCA1 (OR 2.34, 95% CI 2.13-2.56) and BRCA2 (OR 1.25, 95% CI 1.16-1.35). CONCLUSIONS: Young age at BC diagnosis is not a strong risk factor for carrying PVs in BC-associated genes ATM, CHEK2, or PALB2.

Development and Validation of a Breast Cancer Polygenic Risk Score on the Basis of Genetic Ancestry Composition.

PURPOSE: Polygenic risk scores (PRSs) for breast cancer (BC) risk stratification have been developed primarily in women of European ancestry. Their application to women of non-European ancestry has lagged because of the lack of a formal approach to incorporate genetic ancestry and ancestry-dependent variant frequencies and effect sizes. Here, we propose a multiple-ancestry PRS (MA-PRS) that addresses these issues and may be useful in the development of equitable PRSs across other cancers and common diseases. MATERIALS AND METHODS: Women referred for hereditary cancer testing were divided into consecutive cohorts for development (n = 189,230) and for independent validation (n = 89,126). Individual genetic composition as fractions of three reference ancestries (African, East Asian, and European) was determined from ancestry-informative single-nucleotide polymorphisms. The MA-PRS is a combination of three ancestry-specific PRSs on the basis of genetic ancestral composition. Stratification of risk was evaluated by multivariable logistic regression models controlling for family cancer history. Goodness-of-fit analysis compared expected with observed relative risks by quantiles of the MA-PRS distribution. RESULTS: In independent validation, the MA-PRS was significantly associated with BC risk in the full cohort (odds ratio, 1.43; 95% CI, 1.40 to 1.46; P = 8.6 × 10-308) and within each major ancestry. The top decile of the MA-PRS consistently identified patients with two-fold increased risk of developing BC. Goodness-of-fit tests showed that the MA-PRS was well calibrated and predicted BC risk accurately in the tails of the distribution for both European and non-European women. CONCLUSION: The MA-PRS uses genetic ancestral composition to expand the utility of polygenic risk prediction to non-European women. Inclusion of genetic ancestry in polygenic risk prediction presents an opportunity for more personalized treatment decisions for women of varying and mixed ancestries.

Clinical Validation of EndoPredict in Pre-Menopausal Women with ER-Positive, HER2-Negative Primary Breast Cancer.

PURPOSE: The EndoPredict prognostic assay is validated to predict distant recurrence and response to chemotherapy primarily in post-menopausal women with estrogen receptor-positive (ER+), HER2- breast cancer. This study evaluated the performance of EndoPredict in pre-menopausal women. EXPERIMENTAL DESIGN: Tumor samples from 385 pre-menopausal women with ER+, HER2- primary breast cancer (pT1-3, pN0-1) who did not receive chemotherapy in addition to endocrine therapy were tested with EndoPredict to produce a 12-gene EP molecular score and an integrated EPclin score that includes pathologic tumor size and nodal status. Associations of molecular and EPclin scores with 10-year distant recurrence-free survival (DRFS) were evaluated by Cox proportional hazards models and Kaplan-Meier analysis. RESULTS: After a median follow-up of 9.7 years, both the EP molecular score and the molecular-clinicopathologic EPclin score were associated with increased risk of distant recurrence [HR, 1.33; 95% confidence interval (CI), 1.18-1.50; P = 7.2 × 10-6; HR, 3.58; 95% CI, 2.26-5.66; P = 9.8 × 10-8, respectively]. Both scores remained significant after adjusting for clinical factors in multivariate analysis. Patients with low-risk EPclin scores (64.7%) had significantly improved DRFS compared with high-risk patients (HR, 4.61; 95% CI, 1.40-15.17; P = 4.2 × 10-3). At 10 years, patients with low-risk and high-risk EPclin scores had a DRFS of 97% (95% CI, 93%-99%) and 76% (95% CI, 67%-82%), respectively. CONCLUSIONS: The EPclin score is strongly associated with DRFS in pre-menopausal women who received adjuvant endocrine therapy alone. On the basis of these data, pre-menopausal women with EPclin low-risk breast cancer may be treated with endocrine therapy only and safely forgo adjuvant chemotherapy.

Clonal Hematopoiesis and Mosaicism Revealed by a Multi-Tissue Analysis of Constitutional TP53 Status.

BACKGROUND: Though germline TP53 pathogenic/likely pathogenic variants (PV) are associated with Li-Fraumeni syndrome, many detected by multigene panels represent aberrant clonal expansion (ACE), most due to clonal hematopoiesis (CH). Discerning ACE/CH from germline variants and postzygotic mosaicism (PZM) is critically needed for risk assessment and management. METHODS: Participants in the Li-Fraumeni & TP53 Understanding & Progress (LiFT UP) study with a TP53 PV were eligible. Demographics, personal/family cancer history, and clinical laboratory test reports were obtained. DNA from multiple tissues was analyzed using a custom QIAseq assay (ACE panel) that included TP53 and other CH-associated genes; the ACE panel and eyebrow follicles were assessed in a workflow to discern TP53 PV clinical categories. RESULTS: Among 134 participants there was a significant difference for the age at diagnosis (P < 0.001), component cancers (P = 0.007), and clinical testing criteria (P < 0.001), comparing germline with PZM or ACE. ACE panel analysis of DNA from 55 sets of eyebrow follicles (mean 1.4 ug) and 36 formalin-fixed, paraffin imbedded tissues demonstrated low variance (SE, 3%; P = 0.993) for TP53 variant allele fraction, with no significant difference (P = 0.965) between tissue types, and detected CH gene PVs. Of 55 multi-tissue cases, germline status was confirmed for 20, PZM in seven, ACE for 25, and three were indeterminate. Additional CH variants were detected in six ACE and two germline cases. CONCLUSIONS: We demonstrated an effective approach and tools for discerning germline TP53 status. IMPACT: Discernment of PZM and TP53-driven CH increases diagnostic accuracy and enables risk-appropriate care.

Cross-sectional clinical cancer genomics community of practice survey analysis of provider attitudes and beliefs regarding the use of deceased family member tissue to guide living family member genetic cancer risk assessment.

Next-generation tumor tissue sequencing techniques may result in the detection of putative germline pathogenic variants (PVs), raising the possibility that germline cancer predisposition could be identified from archival medical tissue samples of deceased relatives. The approach, termed traceback, is designed to inform risk management recommendations for living family members. Provider perspectives regarding traceback testing have not yet been explored, so we conducted a cross-sectional survey of Clinical Cancer Genomics Community of Practice providers regarding their attitudes and beliefs toward traceback testing. Self-reported demographics, provider characteristics, attitudes and perceived barriers were collected. We evaluated responses in the context of whether providers had previous experience with traceback testing. Data were analyzed using chi-square and Fisher's exact testing. Among 207 respondents (of 816 eligible), most were women (89.4%), white (85.5%), and not Hispanic or Latino (89.7%). US-based providers represented the majority of respondents (87.4%). Relatively, few providers 32 of 207 (15.5%) had previous experience with traceback. Among the individuals without experience in traceback, 84.0% thought there would be barriers to implementation; however, only 68.8% of individuals with previous traceback experience agreed (p = .04). Respondents in both groups thought that traceback would be valuable in their practice (82.6%, p = .22) and that they would feel comfortable discussing the concept (83.6%, p = .83), interpreting the results (72.2%, p = .24), and discussing the results with their patients (80.7%, p = .38). Patient interest and cost were seen as less of a barrier by those with experience with traceback testing. Recurrent themes obtained in open-ended responses are also presented. Overall, providers believe that traceback would be a valuable tool in their practice. Individuals with previous experience identified less barriers with implementation of this testing, highlighting an area for future research and education.

Hereditary cancer risk assessment and genetic testing in the community urology practice setting.

OBJECTIVES: To evaluate the feasibility of integrating a hereditary cancer risk assessment (HCRA) process in the community urology practice setting for patients with prostate cancer (PCa). METHODS: In this prospective intervention, an HCRA process was implemented across six different community urology clinics between May 2019 and April 2020. The intervention included a process integration during which the workflow at each site was refined, a post-integration period during which HCRA was conducted in all patients with PCa, and a follow-up period during which healthcare providers and patients reported their satisfaction with the HCRA and genetic testing process. RESULTS: Among patients who completed a family history assessment during the post-integration period, 23.6% met guideline criteria for genetic testing. Of all patients seen at the clinic during the post-integration period, 8.7% completed genetic testing; this was a twofold increase over the period immediately preceding process integration (4.2%), and a sevenfold increase over the same period 1 year prior (1.2%). The majority of providers reported that the HCRA was as important as other regularly performed assessments (61.0%) and planned to continue using the process in their practice (68.3%). Most patients believed that the genetic test results were important for their future cancer care (84.7%) and had already shared their test results with at least one family member (63.2%). CONCLUSIONS: This study demonstrated that implementing an HCRA process in the community urology practice setting was feasible, generally favored by providers and patients, and resulted in an increase in the number of patients with PCa who completed genetic testing.

Comprehensive Breast Cancer Risk Assessment for CHEK2 and ATM Pathogenic Variant Carriers Incorporating a Polygenic Risk Score and the Tyrer-Cuzick Model.

PURPOSE: Breast cancer risks for CHEK2 and ATM pathogenic variant (PV) carriers are modified by an 86-single nucleotide polymorphism polygenic risk score (PRS) and individual clinical factors. Here, we describe comprehensive risk prediction models for women of European ancestry combining PV status, PRS, and individual clinical variables. MATERIALS AND METHODS: This study included deidentified clinical records from 358,095 women of European ancestry who received testing with a multigene panel (September 2013 to November 2019). Model development included CHEK2 PV carriers (n = 4,286), ATM PV carriers (n = 2,666), and women negative for other breast cancer risk gene PVs (n = 351,143). Odds ratios (ORs) were calculated using multivariable logistic regression with adjustment for familial cancer history. Risk estimates incorporating PV status, PRS, and Tyrer-Cuzick v7.02 were calculated using a Fixed-Stratified method that accounts for correlations between risk factors. Stratification of PV carriers into risk categories on the basis of remaining lifetime risk (RLR) was assessed in independent cohorts of PV carriers. RESULTS: ORs for association of PV status with breast cancer were 2.01 (95% CI, 1.88 to 2.16) and 1.83 (95% CI, 1.68 to 2.00) for CHEK2 and ATM PV carriers, respectively. ORs for PRS per one standard deviation were 1.51 (95% CI, 1.37 to 1.66) and 1.45 (95% CI, 1.30 to 1.64) in CHEK2 and ATM PV carriers, respectively. Using the combined model (PRS plus Tyrer-Cuzick plus PV status), RLR was low (≤ 20%) for 24.2% of CHEK2 PV carriers, medium (20%-50%) for 63.8%, and high (> 50%) for 12.0%. Among ATM PV carriers, RLR was low for 31.5% of patients, medium for 58.5%, and high for 9.7%. CONCLUSION: In CHEK2 and ATM PV carriers, risk assessment including PRS, Tyrer-Cuzick, and PV status has the potential for more precise direction of screening and prevention strategies.

Performance of the IBIS/Tyrer-Cuzick model of breast cancer risk by race and ethnicity in the Women's Health Initiative.

BACKGROUND: The IBIS/Tyrer-Cuzick model is used clinically to guide breast cancer screening and prevention, but was developed primarily in non-Hispanic White women. Little is known about its long-term performance in a racially/ethnically diverse population. METHODS: The Women's Health Initiative study enrolled postmenopausal women from 1993-1998. Women were included who were aged <80 years at enrollment with no prior breast cancer or mastectomy and with data required for IBIS/Tyrer-Cuzick calculation (weight; height; ages at menarche, first birth, and menopause; menopausal hormone therapy use; and family history of breast or ovarian cancer). Calibration was assessed by the ratio of observed breast cancer cases to the number expected by the IBIS/Tyrer-Cuzick model (O/E; calculated as the sum of cumulative hazards). Differential discrimination was tested for by self-reported race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, Asian or Pacific Islander, and American Indian or Alaskan Native) using Cox regression. Exploratory analyses, including simulation of a protective single-nucleotide polymorphism (SNP), rs140068132 at 6q25, were performed. RESULTS: During follow-up (median 18.9 years, maximum 23.4 years), 6783 breast cancer cases occurred among 90,967 women. IBIS/Tyrer-Cuzick was well calibrated overall (O/E ratio = 0.95; 95% CI, 0.93-0.97) and in most racial/ethnic groups, but overestimated risk for Hispanic women (O/E ratio = 0.75; 95% CI, 0.62-0.90). Discrimination did not differ by race/ethnicity. Exploratory simulation of the protective SNP suggested improved IBIS/Tyrer-Cuzick calibration for Hispanic women (O/E ratio = 0.80; 95% CI, 0.66-0.96). CONCLUSIONS: The IBIS/Tyrer-Cuzick model is well calibrated for several racial/ethnic groups over 2 decades of follow-up. Studies that incorporate genetic and other risk factors, particularly among Hispanic women, are essential to improve breast cancer-risk prediction.

Germline mutations and age at onset of lung adenocarcinoma.

BACKGROUND: To identify additional at-risk groups for lung cancer screening, which targets persons with a long history of smoking and thereby misses younger or nonsmoking cases, the authors evaluated germline pathogenic variants (PVs) in patients with lung adenocarcinoma for an association with an accelerated onset. METHODS: The authors assembled a retrospective cohort (1999-2018) of oncogenetic clinic patients with lung adenocarcinoma. Eligibility required a family history of cancer, data on smoking, and a germline biospecimen to screen via a multigene panel. Germline PVs (TP53/EGFR, BRCA2, other Fanconi anemia [FA] pathway genes, and non-FA DNA repair genes) were interrogated for associations with the age at diagnosis via an accelerated failure time model. RESULTS: Subjects (n = 187; age, 28-89 years; female, 72.7%; Hispanic, 11.8%) included smokers (minimum of 5 pack-years; n = 65) and nonsmokers (lighter ever smokers [n = 18] and never smokers [n = 104]). Overall, 26.7% of the subjects carried 1 to 2 germline PVs: TP53 (n = 5), EGFR (n = 2), BRCA2 (n = 6), another FA gene (n = 11), or another DNA repair gene (n = 28). After adjustment for smoking, sex, and ethnicity, the diagnosis of lung adenocarcinoma was accelerated 12.2 years (95% confidence interval [CI], 2.5-20.6 years) by BRCA2 PVs, 9.0 years (95% CI, 0.5-16.5 years) by TP53/EGFR PVs, and 6.1 years (95% CI, -1.0 to 12.6 years) by PVs in other FA genes. PVs in other DNA repair genes showed no association. Germline associations did not vary by smoking. CONCLUSIONS: Among lung adenocarcinoma cases, germline PVs (TP53, EGFR, BRCA2, and possibly other FA genes) may be associated with an earlier onset. With further study, the criteria for lung cancer screening may need to include carriers of high-risk PVs, and findings could influence precision therapy and reduce lung cancer mortality by earlier stage diagnosis.

Multigene assessment of genetic risk for women for two or more breast cancers.

PURPOSE: The prevalence, penetrance, and spectrum of pathogenic variants that predispose women to two or more breast cancers is largely unknown. METHODS: We queried clinical and genetic data from women with one or more breast cancer diagnosis who received multigene panel testing between 2013 and 2018. Clinical data were obtained from provider-completed test request forms. For each gene on the panel, a multivariable logistic regression model was constructed to test for association with risk of multiple breast cancer diagnoses. Models accounted for age of diagnosis, personal and family cancer history, and ancestry. Results are reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: This study included 98,979 patients: 88,759 (89.7%) with a single breast cancer and 10,220 (10.3%) with ≥ 2 breast cancers. Of women with two or more breast cancers, 13.2% had a pathogenic variant in a cancer predisposition gene compared to 9.4% with a single breast cancer. BRCA1, BRCA2, CDH1, CHEK2, MSH6, PALB2, PTEN, and TP53 were significantly associated with two or more breast cancers, with ORs ranging from 1.35 for CHEK2 to 3.80 for PTEN. Overall, pathogenic variants in all breast cancer risk genes combined were associated with both metachronous (OR 1.65, 95% CI 1.53-1.79, p = 7.2 × 10-33) and synchronous (OR 1.33, 95% CI 1.19-1.50, p = 2.4 × 10-6) breast cancers. CONCLUSIONS: This study demonstrated that several high and moderate penetrance breast cancer susceptibility genes are associated with ≥ 2 breast cancers, affirming the association of two or more breast cancers with diverse genetic etiologies.

Specifications of the ACMG/AMP variant interpretation guidelines for germline TP53 variants.

Germline pathogenic variants in TP53 are associated with Li-Fraumeni syndrome, a cancer predisposition disorder inherited in an autosomal dominant pattern associated with a high risk of malignancy, including early-onset breast cancers, sarcomas, adrenocortical carcinomas, and brain tumors. Intense cancer surveillance for individuals with TP53 germline pathogenic variants is associated with reduced cancer-related mortality. Accurate and consistent classification of germline variants across clinical and research laboratories is important to ensure appropriate cancer surveillance recommendations. Here, we describe the work performed by the Clinical Genome Resource TP53 Variant Curation Expert Panel (ClinGen TP53 VCEP) focused on specifying the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) guidelines for germline variant classification to the TP53 gene. Specifications were developed for 20 ACMG/AMP criteria, while nine were deemed not applicable. The original strength level for the 10 criteria was also adjusted due to current evidence. Use of TP53-specific guidelines and sharing of clinical data among experts and clinical laboratories led to a decrease in variants of uncertain significance from 28% to 12% compared with the original guidelines. The ClinGen TP53 VCEP recommends the use of these TP53-specific ACMG/AMP guidelines as the standard strategy for TP53 germline variant classification.

Mutation screening of germline TP53 mutations in high-risk Chinese breast cancer patients.

BACKGROUND: Germline TP53 mutations are associated with Li-Fraumeni syndrome, a severe and rare hereditary cancer syndrome. Despite the rarity of germline TP53 mutations, the clinical implication for mutation carriers and their families is significant. The risk management of TP53 germline mutation carriers is more stringent than BRCA carriers, and radiotherapy should be avoided when possible. METHODS: TP53 gene mutation screening was performed in 2538 Chinese breast cancer patients who tested negative for BRCA mutations. RESULTS: Twenty TP53 mutations were identified with high next-generation sequencing concerning for germline mutations in Chinese breast cancer families. The majorities of the TP53 carriers had early-onset, hormone receptor-positive breast cancer, and had strong family history of cancer. Among all, 11 patients carried a germline mutation and 6 of which were likely de novo germline mutations. In addition, 1 case was suspected to be induced by chemotherapy or radiation, as this patient had no significant family history of cancer and aberrant clonal expansion can commonly include TP53 mutations. Furthermore, we have identified one mosaic LFS case. Two novel mutations (c.524_547dup and c.529_546del) were identified in patients with early-onset. CONCLUSIONS: In view of the high lifetime risk of malignancy, identification of patients with germline TP53 mutations are important for clinicians to aid in accurate risk assessment and offer surveillance for patients and their families.

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.

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.

Abnormal body composition is a predictor of adverse outcomes after autologous haematopoietic cell transplantation.

BACKGROUND: The number of patients undergoing autologous haematopoietic cell transplant (HCT) is growing, but little is known about the factors that predict adverse outcomes. Low muscle mass and obesity are associated with disability and premature mortality in individuals with non-malignant diseases and may predict outcomes after autologous HCT. METHODS: This was a retrospective cohort study of 320 patients who underwent autologous HCT for Hodgkin or non-Hodgkin lymphoma between 2009 and 2014. Sarcopenia {skeletal muscle index male: <43 cm/m2 [body mass index (BMI) < 25 kg/m2 ] or < 53 cm/m2 [BMI ≥ 25 kg/m2 ] and female: <41 cm/m2 [regardless of BMI]) and obesity [total abdominal adiposity ≥450.0 cm2 (male), ≥396.4 cm2 (female)] were assessed from single-slice abdominal pre-HCT computed tomography images. Length of hospital stay, first unplanned intensive care unit admission, and 30-day unplanned readmission were evaluated based on body composition using multivariable regression analysis, and mortality was evaluated with Kaplan-Meier analysis and Gray's test. RESULTS: Median age at HCT was 53.3 years (range, 18.5 to 78.1 years); 26.3% were sarcopenic and an additional 7.8% were sarcopenic obese pre-HCT. Sarcopenic obesity was associated with increased risk of prolonged hospitalization [odds ratio (OR) = 3.6, 95% confidence interval (CI) 1.3-9.8], intensive care unit admission (OR = 4.7, 95% CI 1.5-16.1), and unplanned readmission after HCT (OR = 13.6, 95% CI 2.5-62.8). Patients who were sarcopenic obese also had the highest mortality risk at 1 year [hazard ratio (HR): 3.9, 95% CI 1.1-11.0] and 5 years (HR: 2.5, 95% CI 1.1-5.5), compared with patients with normal body composition. Sarcopenia alone, but not obesity alone, was associated with an increased risk of these outcomes, albeit with a lower magnitude of risk than in patients who were sarcopenic obese. CONCLUSIONS: Sarcopenic obesity was an important predictor of outcomes in patients undergoing autologous HCT. These findings could inform targeted prevention strategies in patients at highest risk of complications after HCT.

Genetic cancer predisposition syndromes among older adults.

Earlier age at onset is one characteristic of hereditary cancer syndromes, so most studies of genetic testing have focused on young patients with cancer. However, recent studies of multigene panel tests in unselected cancer populations have detected a considerable proportion of older patients with germline pathogenic variants (PVs) in cancer susceptibility genes. As the number of older patients with cancer continues to rise, clinicians should be aware of genetic/genomic cancer risk assessment (GCRA) criteria in both young and older adults. Identifying individuals with a germline PV in a cancer susceptibility gene may be important for precision therapy of current cancers and screening and prevention of new primary cancers, as well as cascade testing to identify high cancer risks for family members. Typically, hereditary predisposition germline genetic testing has been recommended for patients with early onset cancers and/or a family history of cancer. However, more recently international guidelines recommend testing for potential therapeutic intervention regardless of age for some tumors frequently seen in older patients, such as epithelial ovarian, pancreatic, and metastatic prostate and breast cancers. GCRA in older patients may present challenges including: clonal hematopoiesis (CH) confounding test interpretation, ethical aspects (autonomy, nonmaleficence, beneficence), patient health status, comorbidities, as well as lack of insurance coverage. These factors should be considered during genetic counseling and when considering cancer screening and risk reduction procedures. This manuscript reviews available data on common hereditary cancer syndromes in older patients and provides tools to help providers perform GCRA in this population.