Yadav, Siddhartha

PURPOSE Among patients with metastatic breast cancer (mBC), the frequency of germline mutations in cancer susceptibility genes and the clinical relevance of these mutations are unclear. In this study, a prospective cohort of patients with mBC was used to determine mutation rates for breast cancer (BC) predisposition genes, to evaluate the clinical characteristics of patients with mutations, and to assess the influence of mutations on patient outcome. PATIENTS AND METHODS Germline DNA from 2,595 patients with mBC enrolled in the prospective PRAEGNANT registry was evaluated for mutations in cancer predisposition genes. The frequencies of mutations in known BC predisposition genes were compared with results from a prospective registry of patients with nonmetastatic BC sequenced using the same QIAseq method and with public reference controls. Associations between mutation status and tumor characteristics, progression-free survival, and overall survival were assessed. RESULTS Germline mutations in 12 established BC predisposition genes (including BRCA1 and BRCA2) were detected in 271 (10.4%) patients. A mutation in BRCA1 or BRCA2 was seen in 129 patients (5.0%). BRCA1 mutation carriers had a higher proportion of brain metastasis (27.1%) compared with nonmutation carriers (12.8%). Mutations were significantly enriched in PRAEGNANT patients with mBC compared with patients with nonmetastatic BC (10.4% v 6.6%, P < .01). Mutations did not significantly modify progression-free survival or overall survival for patients with mBC. CONCLUSION Multigene panel testing may be considered in all patients with mBC because of the high frequency of germline mutations in BRCA1/2 and other BC predisposition genes. Although the prognosis of mutation carriers and nonmutation carriers with mBC was similar, differences observed in tumor characteristics have implications for treatment and for future studies of targeted therapies.

Aspirin and statin drugs have been associated with reduced risk of several gastrointestinal cancers, but their association with gallbladder cancer (GBC) has not been well established. We evaluated the association of aspirin and statins with the risk of GBC. Patients with GBC managed at Mayo Clinic between 2000 and 2019 were matched 1:2 with a general patient pool by age and sex. Univariable and multivariable logistic regression models were used to assess associations between GBC and aspirin or statin use. The analysis included 795 cases and 1590 controls, with a median age of 67 years. Aspirin or statin use alone or in combination was higher in controls (p < 0.001). Univariate analysis showed that the use of aspirin [odds ratio (OR): 0.11; 95%CI: 0.08–0.15] or statins (OR: 0.29; 95%CI: 0.20–0.40) and their combined use (OR: 0.18; 95%CI: 0.13–0.24) was associated with lower risk of GBC. Multivariable analysis revealed that aspirin (OR: 0.12; 95%CI: 0.09–0.16) and combined statins and aspirin (OR: 0.46; 95%CI: 0.31–0.67) were associated with lower risk of GBC. Aspirin alone or in combination with statins is associated with a strongly reduced risk of GBC. Further prospective studies are needed to confirm these results and to elucidate their mechanisms.

Approximately 5% to 10% of women diagnosed with breast cancer will have a pathogenic variant (PV) in a hereditary cancer susceptibility gene, and this has significant implications for the management of these patients and their relatives. Despite the benefits of genetic testing, many eligible patients with breast cancer never undergo testing because of various barriers, including complicated testing criteria such as those from the National Comprehensive Cancer Network (NCCN). In 2019, the American Society of Breast Surgeons (ASBrS) proposed germline genetic testing for all patients with breast cancer to increase the identification of PV carriers. In 2020, a Mayo Clinic study highlighted the limitations of these 2 genetic testing guidelines (NCCN and ASBrS) and proposed a hybrid approach of testing all women diagnosed with breast cancer by the age of 65 years and using NCCN criteria for older patients. This commentary presents an updated analysis of the Mayo Clinic data and discusses the rationale for using the age of 60 years rather than 65 years as the cutoff for this hybrid approach. Using an age at diagnosis of ≤60 or ≤65 years for the universal testing of patients with breast cancer detected more PVs (11.9% [16 of 134] and 15.7% [21 of 134], respectively) in comparison with using the NCCN criteria. Lowering the age for universal testing from 65 to 60 years maintained the sensitivity of detecting a PV at >90% while sparing testing for an additional 10% of women. Compared with the testing of all patients, the hybrid approach would allow 31% of all women with breast cancer to forgo testing and result in fewer variants of uncertain significance identified and, therefore, would decrease the chance of harm from misinterpretation of these variants.

Abstract To evaluate the racial and ethnic differences in prevalence of germline pathogenic variants (PVs) and the effect of race and ethnicity on breast cancer (BC) risk among carriers, results of multigene testing of 77 900 women with BC (non-Hispanic White [NHW] = 57 003; Ashkenazi-Jewish = 4798; Black = 6722; Hispanic = 5194; and Asian = 4183) were analyzed, and the frequency of PVs in each gene were compared between BC patients (cases) and race- and ethnicity-matched gnomAD reference controls. Compared with NHWs, BRCA1 PVs were enriched in Ashkenazi-Jews and Hispanics, whereas CHEK2 PVs were statistically significantly lower in Blacks, Hispanics, and Asians (all 2-sided P &lt; .05). In case-control studies, BARD1 PVs were associated with high risks (odds ratio &gt; 4.00) of BC in Blacks, Hispanics, and Asians; ATM PVs were associated with increased risk of BC among all races and ethnicities except Asians, whereas CHEK2 and BRIP1 PVs were associated with increased risk of BC among NHWs and Hispanics only. These findings suggest a need for personalized management of BC risk in PV carriers based on race and ethnicity.

Abstract Purpose: To compare the clinical characteristics and overall survival (OS) of germline mutation carriers in homologous recombination repair (HRR) genes and noncarriers with pancreatic ductal adenocarcinoma (PDAC). Experimental Design: Germline DNA from 3,078 patients with PDAC enrolled in a prospective registry at Mayo Clinic between 2000 and 2017 was analyzed for mutations in 37 cancer predisposition genes. Characteristics and OS of patients with mutations in eight genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, PALB2, RAD51C, and RAD51D) involved in HRR were compared with patients testing negative for mutations in all 37 genes. Results: The 175 HRR mutation carriers and 2,730 noncarriers in the study had a median duration of follow-up of 9.9 years. HRR mutation carriers were younger (median age at diagnosis: 63 vs. 66 years, P &lt; 0.001) and more likely to have metastatic disease at diagnosis (46% vs. 36%, P = 0.004). In a multivariable model adjusting for sex, age at diagnosis, and tumor staging, patients with germline HRR mutations had a significantly longer OS compared with noncarriers [HR, 0.83; 95% confidence interval (CI), 0.70–0.97; P = 0.02]. Further gene-level analysis demonstrated that germline ATM mutation carriers had longer OS compared with patients without germline mutations in any of the 37 genes (HR, 0.72; 95% CI, 0.55–0.94; P = 0.01). Conclusions: This study demonstrates that germline mutation carrier status in PDAC is associated with longer OS compared with noncarriers. Further research into tumor biology and response to platinum-based chemotherapy in germline mutation carriers with PDAC are needed to better understand the association with longer OS.

Abstract Purpose: Blood-based candidate biomarkers of disease can be monitored by analyzing CTCs and/or circulating cfDNA isolated from the peripheral blood. Our primary objective is to understand the relative contributions of these circulating factors (i.e., CTCs and cfDNA) to the overall disease profile in MBC. Methods: Clinically archived FFPE tumor tissue and prospective blood samples are collected through a minimal risk protocol approved by the Mayo Clinic IRB (#16-001540) from patients with MBC and objective evidence of disease progression. Blood samples include 20 mL whole blood in Streck blood collection tubes (BCTs) for platelet poor plasma (PPP); 20 mL whole blood in AccuCyte BCTs for CTCs, WBCs, and PPP; and 10 mL whole blood in EDTA BCTs for PPP. Nucleated, EpCAM+/cytokeratin+/CD45- CTCs are identified, assessed for ER/HER2 status, and isolated using a centrifugation and direct imaging platform that allows for single cell retrieval (RareCyte). DNA is extracted from PPP, CTCs, WBCs, and FFPE tumor tissue using established methods. Targeted sequencing for SNVs/indels is performed on paired WBCs and CTC-DNA, AccuCyte-cfDNA, Streck-cfDNA, EDTA-cfDNA, and tumor tissue derived DNA using the same NGS panel and informatics pipeline (65 genes; CleanPlex OncoZoom; Paragon Genomics). Results: Tissue and blood samples were collected from 40 patients with metastatic breast cancer. 10 cases were selected for initial analyses on the basis of CTC yield (range 3-113 per 3.75 mL blood); up to 5 CTCs per subject were isolated and pooled for DNA extraction. Plasma cfDNA yields and variant allele frequencies were highly comparable between AccuCyte and Streck collected blood samples. Mutations (range 1-3) were identified in CTC-DNA and/or cfDNA in 9 of 10 cases for a total of 18 detected mutations: 10 in CTC-DNA and cfDNA (BRCA2 N372H, PIK3CA E542K, PIK3CA E545K (x3), PIK3CA H1047R, PTEN R130P, RET G691S, TP53 C135W, TP53 Q192*); 5 in CTC-DNA only (EGFR R521K, EGFR T790M, PIK3CA H1047R, SMAD4 C363Y, TP53 N263D); and 3 in cfDNA only (DNMT3A W893S, DNMT3A S714C, TP53 Q136E). Parallel analyses of samples from 10 more subjects are in progress. Analysis of tumor tissue for all 20 subjects and of EDTA-cfDNA and single CTCs for a subset of cases is ongoing. Updated results will be presented at the meeting. Conclusions: It is feasible to isolate high quality CTCs and cfDNA from the same blood collection tube to perform targeted sequencing; this streamlines specimen processing, decreases overall costs, and minimizes required blood volumes. Importantly, there is overlap in the majority of mutations identified in CTC-DNA and cfDNA, but actionable mutations (e.g., PIK3CA, EGFR) were detected in CTC-DNA only. The clinical and theranostic relevance of these findings is unclear and warrants further investigation. Citation Format: Minetta C. Liu, Karthik V. Giridhar, Roberto A. Leon Ferre, Jamie L. Carroll, Matthew P. Goetz, Tufia C. Haddad, Deanne R. Smith, Siddhartha Yadav, Vidushi Kapoor, Guoying Liu, Tad George, Nolan Ericson, Arturo B. Ramirez, Eric Kaldjian, Keegan E. Haselkorn. Comparison of circulating tumor cell (CTC) derived DNA and circulating cell-free DNA (cfDNA) from simultaneous blood sampling of patients with metastatic breast cancer (MBC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3119.

Abstract Background: Sex differences in non-small cell lung cancer (NSCLC) outcomes have been described. Immune-related adverse events (IRAEs) have emerged as a serious clinical problem in the use of immune checkpoint inhibitors (ICI). Risk factors for IRAEs and their association with response to therapy remain controversial. Sex differences in innate and adaptive immune responses have been observed but the association of these differences with IRAEs remains unclear. Therefore, we studied sex differences in IRAEs and their association with response to therapy. Methods: All patients with metastatic NSCLC treated with anti-PD1 and anti-PDL1 therapy at Mayo Clinic Rochester and Florida from 2015 to 2018 were reviewed. Patients receiving treatment at an outside facility with history autoimmune disorders or radiation-induced pneumonitis were excluded. Chi-square test was used to estimate differences in categorical data. Kaplan-Meier method was used for time-to-event analysis. Results: A total of 231 patients were identified; 120 (52%) were women and 111 (48%) were men. Baseline characteristics and ICI distribution were similar among groups. Women were more likely to experience IRAEs compared to men (48% vs. 31%, p&lt;0.008). Among patients with IRAEs, women were more likely to be prescribed systemic steroids (63% vs. 41%, p&lt;0.02). On the other hand, no significant differences were observed in the administration of intravenous steroids. Women were more likely to develop pneumonitis (23% vs. 12%, p&lt;0.03) and arthralgias (17% vs. 3%, p&lt;0.04). However, dermatologic toxicities (35% vs. 9%, p&lt;0.002) were more commonly seen in men. In 17% of women the ICI was discontinued due to toxicity (men 7%). Besides sex, no other clinical characteristic was associated with increased IRAEs. Women with IRAEs were more likely to have a radiographic response compared with women without IRAEs (78% vs. 23%, p&lt;0.0001), although this was not observed in men (37% vs. 26%, p&gt;0.22). Better PFS was observed in women with IRAEs (10 months vs. 3.3 months, p&lt;0.0006) compared to women without IRAEs. Conclusions: Women with metastatic NSCLC are more likely to experience IRAEs compared to men. We also observed sex differences in the frequency of certain IRAEs. In addition, an association between IRAEs and response to therapy was observed in women. Larger studies are needed to investigate the mechanisms underlying these associations. Citation Format: Narjust Duma, Abdel-Ghani Azzouqa, Siddhartha Yadav, Kahterine Hoversten, Clay Reed, Andrea Sitek, Elizabeth Enninga, Jonas Paludo, Lisa Kottschade, Aaron Mansfield, Rami Manochakian, Roxana Dronca, Alex Adjei. Sex differences in tolerability and response to immune checkpoint inhibitors in non-small cell lung cancer patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A120.