Mainstreaming in parallel with ovarian cancer tumor testing to improve genetic testing uptake.

OBJECTIVES: Although genetic testing (GT) is universally recommended for patients with epithelial ovarian cancer (EOC), rates are low (34%). In 1/2019, we implemented mainstreaming-GT in parallel with tumor testing via MSK-IMPACT within oncology clinics. We sought to determine GT rates pre/post-mainstreaming and patient characteristics associated with GT. METHODS: Patients with newly diagnosed EOC seen at our institution from 7/1/2015-3/31/2022 were included. Clinical data were abstracted including social determinants of health (SDOH) variables, race/ethnicity, marital status, insurance, language, comorbidities, employment, and Yost index, a measure of socioeconomic status. GT rates were calculated overall and pre-/post-mainstreaming (1/2019). Logistic regression models were fit to identify variables associated with GT. RESULTS: Of 1742 patients with EOC, 1591 (91%) underwent GT. Rates of GT increased from 87% to 95% after mainstreaming (p < 0.001). Among 151 patients not undergoing GT, major reasons were lack of provider recommendation (n = 76, 50%) and logistical issues (n = 38, 25%) with few declining (n = 14, 9%) or having medical complications preventing GT (n = 7, 4.6%). High-grade serous histology, advanced stage (III/IV), and having a spouse/partner were associated with increased GT uptake (p < 0.01). Among SDOH variables, there were no differences by insurance, Yost score, language, comorbidities, employment, or race/ethnicity. In multivariable models, likelihood of GT increased with mainstreaming, even after adjustment for histology, stage, and marital status (OR 3.77; 95% CI: 2.56-5.66). CONCLUSIONS: Mainstreaming increased the likelihood of GT in patients with EOC. We found lower testing rates in patients without partners/spouses, non-high-grade serous histology, and early-stage disease, representing potential areas for future interventions.

The Largest Chinese Cohort Study Indicates Homologous Recombination Pathway Gene Mutations as Another Major Genetic Risk Factor for Colorectal Cancer with Heterogeneous Clinical Phenotypes.

While genetic factors were associated with over 30% of colorectal cancer (CRC) patients, mutations in CRC-susceptibility genes were identified in only 5% to 10% of these patients. Besides, previous studies on hereditary CRC were largely designed to analyze germline mutations in patients with single genetic high-risk factor, which limited understanding of the association between genotype and phenotypes. From January 2015 to December 2018, we retrospectively enrolled 2,181 patients from 8,270 consecutive CRC cases, covering 5 categories of genetic high-risk factors. Leukocyte genomic DNA was analyzed for germline mutations in cancer predisposition genes. The germline mutations under each category were detected and analyzed in association with CRC susceptibility, clinical phenotypes, and prognoses. A total of 462 pathogenic variants were detected in 19.3% of enrolled CRC patients. Mismatch repair gene mutation was identified in 9.1% of patients, most prevalent across all high-risk groups. Homologous recombination (HR) gene mutations were detected in 6.5% of cases, penetrated in early-onset and extra-colonic cancer risk groups. Mutations in HR genes, including BARD1, RAD50, and ATM, were found to increase CRC risk with odds ratios of 2.8-, 3.1-, and 3.1-fold, respectively. CRC patients with distinct germline mutations manifested heterogeneous phenotypes in clinicopathology and long-term prognoses. Thus, germline mutation screenings should be performed for CRC patients with any of those genetic risk factors. This study also reveals that HR gene mutations may be another major driver for increased CRC risk.

Prevalence and Clinical Implications of Mismatch Repair-Proficient Colorectal Cancer in Patients With Lynch Syndrome.

PURPOSE: Lynch syndrome (LS)-associated colorectal cancer (CRC) is characterized by mismatch repair-deficiency (MMR-D) and/or microsatellite instability (MSI). However, with increasing utilization of germline testing, MMR-proficient (MMR-P) and/or microsatellite stable (MSS) CRC has also been observed. We sought to characterize MMR-P/MSS CRC among patients with LS. METHODS: Patients with solid tumors with germline MMR pathogenic/likely pathogenic (P/LP) variants were identified on a prospective matched tumor-normal next-generation sequencing (NGS) protocol. CRCs were evaluated for MMR-D via immunohistochemical (IHC) staining and/or MSI via NGS. Clinical variables were correlated with MMR status using nonparametric tests. RESULTS: Among 17,617 patients with solid tumors, 1.4% (n = 242) had LS. A total of 36% (86 of 242) of patients with LS had at least one CRC that underwent NGS profiling, amounting to 99 pooled CRCs assessed. A total of 10% (10 of 99) of CRCs were MMR-P, with 100% concordance between MSS status and retained MMR protein staining. A total of 89% (8 of 9) of patients in the MMR-P group had MSH6 or PMS2 variants, compared with 30% (23 of 77) in the MMR-D group (P = .001). A total of 46% (6 of 13) of PMS2+ patients had MMR-P CRC. The median age of onset was 58 and 43 years for MMR-P and MMR-D CRC, respectively (P = .07). Despite the later median age of onset, 40% (4 of 10) of MMR-P CRCs were diagnosed <50. A total of 60% (6 of 10) of MMR-P CRCs were metastatic compared with 13% (12 of 89) of MMR-D CRCs (P = .002). A total of 33% (3 of 9) of patients with MMR-P CRC did not meet LS testing criteria. CONCLUSION: Patients with LS remained at risk for MMR-P CRC, which was more prevalent among patients with MSH6 and PMS2 variants. MMR-P CRC was later onset and more commonly metastatic compared with MMR-D CRC. Confirmation of tumor MMR/MSI status is critical for patient management and familial risk estimation.

Comprehensive analysis of germline drivers in endometrial cancer.

BACKGROUND: We sought to determine the prevalence of germline pathogenic variants (gPVs) in unselected patients with endometrial cancer (EC), define biallelic gPVs within tumors, and describe their associations with clinicopathologic features. METHODS: Germline assessment of at least 76 cancer predisposition genes was performed in patients with EC undergoing clinical tumor-normal Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) sequencing from January 1, 2015, to June 30, 2021. In patients with gPVs, biallelic alterations in ECs were identified through analysis of loss of heterozygosity and somatic PVs. Clinicopathologic variables were compared using nonparametric tests. RESULTS: Of 1625 patients with EC, 216 (13%) had gPVs, and 15 patients had 2 gPVs. There were 231 gPVs in 35 genes (75 [32%] high penetrance; 39 [17%] moderate penetrance; and 117 [51%] low, recessive, or uncertain penetrance). Compared with those without gPVs, patients with gPVs were younger (P = .002), more often White (P = .009), and less obese (P = .025) and had differences in distribution of tumor histology (P = .017) and molecular subtype (P < .001). Among 231 gPVs, 74 (32%) exhibited biallelic inactivation within tumors. For high-penetrance gPVs, 63% (47 of 75) of ECs had biallelic alterations, primarily affecting mismatch repair (MMR) and homologous recombination related genes, including BRCA1,BRCA2, RAD51D, and PALB2. Biallelic inactivation varied across molecular subtypes with highest rates in microsatellite instability-high (MSI-H) or copy-number (CN)-high subtypes (3 of 12 [25%] POLE, 30 of 77 [39%] MSI-H, 27 of 60 [45%] CN-high, 9 of 57 [16%] CN-low; P < .001). CONCLUSIONS: Of unselected patients with EC, 13% had gPVs, with 63% of gPVs in high-penetrance genes (MMR and homologous recombination) exhibiting biallelic inactivation, potentially driving cancer development. This supports germline assessment in EC given implications for treatment and cancer prevention.

An updated counseling framework for moderate-penetrance colorectal cancer susceptibility genes.

PURPOSE: With the recent guideline change for individuals at average risk for colorectal cancer (CRC) to initiate colonoscopy at the age of 45 years, there is a need to provide an updated counseling framework for individuals with variants in moderate-penetrance CRC susceptibility genes. METHODS: Population age-specific incidence rates for CRC were obtained from the 2014-2018 US Surveillance, Epidemiology, and End Results Program cancer statistics. Average-risk multipliers derived from a systematic meta-analysis were used to calculate the 5-year and cumulative lifetime risks for specific genetic variants associated with a moderate risk for CRC: NM_007194.4(CHEK2):c.1100del (p.Thr367fs), NM_007194.4(CHEK2):c.470T>C (p.Ile157Thr), NM_000038.6(APC):c.3920T>A (p.Ile1307Lys) and monoallelic MUTYH. RESULTS: When an individual at average risk would initiate colonoscopy at age 45 years, a CRC risk of 0.39% is reached. For CHEK2 1100delC, CHEK2 I157T, and APC I1307K heterozygotes, this same level of risk is reached (or nearly reached) by age 40 to 45 years. For individuals with a monoallelic MUTYH variant, the CRC risk is 0.46% by age 45 to 49 years, similar to individuals at average risk. CONCLUSION: These updated calculations support recommendations to initiate earlier colonoscopy surveillance for CHEK2 and APC I1307K germline variant heterozygotes. However, earlier surveillance is not indicated for individuals with monoallelic MUTYH germline variants in the absence of family history.

Early age of onset and broad cancer spectrum persist in MSH6- and PMS2-associated Lynch syndrome.

PURPOSE: This study aimed to characterize MSH6/PMS2-associated mismatch repair-deficient (MMR-D)/microsatellite instability-high (MSI-H) tumors, given revised guidelines suggesting more modest phenotypes. METHODS: Patients who consented to Institutional Review Board-approved protocols of tumor/germline sequencing or Lynch syndrome registry at a single institution from February 2005 to January 2021 with germline, heterozygous MSH6/PMS2 pathogenic/likely pathogenic variants were identified. Clinical data were abstracted and correlated with MMR/microsatellite instability status using nonparametric tests. RESULTS: We identified 243 patients (133 sequencing, 110 registry) with germline MSH6/PMS2 pathogenic/likely pathogenic variants; 186 (77%) had >1 cancer. Of 261 pooled tumors, colorectal cancer (CRC) and endometrial cancer (EC) comprised 55% and 43% of cancers in MSH6 and PMS2, respectively; 192 tumors underwent molecular assessments and 122 (64%) were MMR-D/MSI-H (77 in MSH6, 45 in PMS2). MMR-D/MSI-H cancers included CRC (n = 56), EC (n = 35), small bowel cancer (n = 6), ovarian cancer (n = 6), urothelial cancer (n = 5), pancreas/biliary cancer (n = 4), gastric/esophageal cancer (n = 3), nonmelanoma skin tumors (n = 3), prostate cancer (n = 2), breast cancer (n = 1), and central nervous system/brain cancer (n = 1). Among MMR-D/MSI-H CRC and EC, median age of diagnosis was 51.5 (range = 27-80) and 55 (range = 39-74) years, respectively; 9 of 56 (16%) MMR-D/MSI-H CRCs were diagnosed at age <35 years. CONCLUSION: MSH6/PMS2 heterozygotes remain at risk for a broad spectrum of cancers, with 16% of MMR-D/MSI-H CRCs presenting before upper threshold of initiation of colonoscopy per guidelines.

ATM Germline-Mutated Gastroesophageal Junction Adenocarcinomas: Clinical Descriptors, Molecular Characteristics, and Potential Therapeutic Implications.

BACKGROUND: Gastroesophageal junction (GEJ) adenocarcinoma is a rare cancer associated with poor prognosis. The genetic factors conferring predisposition to GEJ adenocarcinoma have yet to be identified. METHODS: We analyzed germline testing results from 23 381 cancer patients undergoing tumor-normal sequencing, of which 312 individuals had GEJ adenocarcinoma. Genomic profiles and clinico-pathologic features were analyzed for the GEJ adenocarcinomas. Silencing of ATM and ATR was performed using validated short-interfering RNA species in GEJ, esophageal, and gastric adenocarcinoma cell lines. All statistical tests were 2-sided. RESULTS: Pathogenic or likely pathogenic ATM variants were identified in 18 of 312 patients (5.8%), and bi-allelic inactivation of ATM through loss of heterozygosity of the wild-type allele was detected in all (16 of 16) samples with sufficient tumor content. Germline ATM-mutated GEJ adenocarcinomas largely lacked somatic mutations in TP53, were more likely to harbor MDM2 amplification, and harbored statistically significantly fewer somatic single nucleotide variants (2.0 mutations/Mb vs 7.9 mutations/Mb; P < .001). A statistically significantly higher proportion of germline ATM-mutated than ATM-wild-type GEJ adenocarcinoma patients underwent a curative resection (10 [100%] vs 92 [86.8%], P = .04; Fisher's exact test.), A synthetic lethal interaction between short-interfering RNA silencing of ATM and ATR was observed in the models analyzed. CONCLUSIONS: Our results indicate that germline pathogenic variants in ATM drive oncogenesis in GEJ adenocarcinoma and might result in a distinct clinical phenotype. Given the high prevalence of germline ATM-mutated GEJ adenocarcinomas, genetic testing for individuals with GEJ adenocarcinomas may be considered to better inform prognostication, treatment decisions, and future cancer risk.

Risk-Reducing Bilateral Salpingo-Oophorectomy for Ovarian Cancer: A Review and Clinical Guide for Hereditary Predisposition Genes.

Pathogenic germline variants underlie up to 20% of ovarian cancer (OC) and are associated with varying degrees of risk for OC. For mutations in high-penetrance genes such as BRCA1/2, the role of risk-reducing bilateral salpingo-oophorectomy (RRSO) in cancer prevention is well-established and improves mortality. However, in moderate-penetrance genes where the degree of risk for OC is less precisely defined, the role of RRSO is more controversial. Although national guidelines have evolved to incorporate gene-specific recommendations, studies demonstrate significant variations in practice. Given this, our multidisciplinary group has reviewed the available literature on risk estimates for genes associated with OC, incorporated levels of evidence, and set thresholds for consideration of RRSO. We found that the benefit of RRSO is well-established for pathogenic variants in BRCA1/2 as well as BRIP1 and RAD51C/D where the risk of OC is elevated beyond our threshold for RRSO. In PALB2, RRSO is particularly controversial as newer studies consistently demonstrate an increased risk of OC that is dependent on family history, making uniform recommendations challenging. Additionally, new guidelines for Lynch syndrome provide gene-specific risks, questioning the role of RRSO, and even hysterectomy, for MSH6 and PMS2 mutation carriers. Given these uncertainties, shared decision making should be used around RRSO with discussion of individual risk factors, family history, and adverse effects of surgery and premature menopause. Herein, we provide a clinical guide and counseling points.

Prevalence and Characterization of Biallelic and Monoallelic NTHL1 and MSH3 Variant Carriers From a Pan-Cancer Patient Population.

NTHL1 and MSH3 have been implicated as autosomal recessive cancer predisposition genes. Although individuals with biallelic NTHL1 and MSH3 pathogenic variants (PVs) have increased cancer and polyposis risk, risks for monoallelic carriers are uncertain. We sought to assess the prevalence and characterize NTHL1 and MSH3 from a large pan-cancer patient population. MATERIALS AND METHODS: Patients with pan-cancer (n = 11,081) underwent matched tumor-normal sequencing with consent for germline analysis. Medical records and tumors were reviewed and analyzed. Prevalence of PVs was compared with reference controls (Genome Aggregation Database). RESULTS: NTHL1-PVs were identified in 40 patients including 39 monoallelic carriers (39/11,081 = 0.35%) and one with biallelic variants (1/11,081 = 0.009%) and a diagnosis of isolated early-onset breast cancer. NTHL1-associated mutational signature 30 was identified in the tumors of the biallelic patient and two carriers. Colonic polyposis was not identified in any NTHL1 patient. MSH3-PVs were identified in 13 patients, including 12 monoallelic carriers (12/11,081 = 0.11%) and one with biallelic MSH3 variants (1/11,081 = 0.009%) and diagnoses of later-onset cancers, attenuated polyposis, and abnormal MSH3-protein expression. Of the 12 MSH3 carriers, two had early-onset cancer diagnoses with tumor loss of heterozygosity of the wild-type MSH3 allele. Ancestry-specific burden tests demonstrated that NTHL1 and MSH3 prevalence was not significantly different in this pan-cancer population versus controls. CONCLUSION: NTHL1 and MSH3 germline alterations were not enriched in this pan-cancer patient population. However, tumor-specific findings, such as mutational signature 30 and loss of heterozygosity of the wild-type allele, suggest the potential contribution of monoallelic variants to tumorigenesis in a subset of patients.

Age of onset and behavioral manifestations in Huntington's disease: An Enroll-HD cohort analysis.

Huntington's disease is associated with motor, cognitive and behavioral dysfunction. Behavioral symptoms may present before, after, or simultaneously with clinical disease manifestation. The relationship between age of onset and behavioral symptom presentation and severity was explored using the Enroll-HD database. Manifest individuals (n = 4469) were initially divided into three groups for preliminary analysis: early onset (<30 years; n = 479); mid-adult onset (30-59 years; n = 3478); and late onset (>59 years; n = 512). Incidence of behavioral symptoms reported at onset was highest in those with early onset symptoms at 26% (n = 126), compared with 19% (n = 678) for mid-adult onset and 11% (n = 56) for late onset (P < 0.0001). Refined analysis, looking across the continuum of ages rather than between categorical subgroups found that a one-year increase in age of onset was associated with a 5.6% decrease in the odds of behavioral symptoms being retrospectively reported as the presenting symptom (P < 0.0001). By the time of study enrollment, the odds of reporting severe behavioral symptoms decreased by 5.5% for each one-year increase in reported age of onset. Exploring environmental, genetic and epigenetic factors that affect age of onset and further characterizing types and severity of behavioral symptoms may improve treatment and understanding of Huntington's disease's impact on affected individuals.