Ethnic Differences in Germline Genetic Testing For Breast Cancer

Introduction: Ethnic variations in uptake of genetic testing and differences in findings of germline mutations within ethnic groups, are not well understood. The goal of this research is to assess for any such differences or similarities within a genetic counseling and testing program at an urban Cancer Center. Methods: This is a non-comparative, descriptive epidemiology study assessing individuals with a diagnosis of breast cancer undergoing genetic counseling at the TJUH Sidney Kimmel Cancer Center in Philadelphia between 2014 and 2019. Data were compiled onto Research Electronic Data Capture (REDCAP) and analyzed statistically. Results: Patients with Breast Cancer (n=1075) were included in the analysis, 807 of whom had genetic testing conducted. In total, 81 Caucasians had pathogenic/likely pathogenic mutations (13%) and 16% had VUS. African Americans had the highest prevalence of VUS (32%) and 16 pathogenic/likely pathogenic mutations (13%). Asians (n=44) had no pathogenic but 2 likely pathogenic mutations (6%), and 3 VUS (9%). Comparatively, no statistically significant differences were observed. Asians presented for genetic counseling younger (mean age 49) than African Americans (mean age 54) and Caucasians (mean age 58) (p\u3c0.001). Caucasians were more likely to undergo genetic testing (89%) than African Americans (78%) and Asians (79%) (p\u3c0.002). Discussion: These results point toward ethnic differences in utilization and followthrough with genetic testing, as well as variations in genetic mutations. The high prevalence of VUS mutations in African Americans and few mutations in Asians suggests that the mutational spectrum in these populations is not well understood and warrants further study

Transcriptomic profiling of 39 commonly-used neuroblastoma cell lines

Neuroblastoma cell lines are an important and cost-effective model used to study oncogenic drivers of the disease. While many of these cell lines have been previously characterized with SNP, methylation, and/or mRNA expression microarrays, there has not been an effort to comprehensively sequence these cell lines. Here, we present raw whole transcriptome data generated by RNA sequencing of 39 commonly-used neuroblastoma cell lines. These data can be used to perform differential expression analysis based on a genetic aberration or phenotype in neuroblastoma (e.g., MYCN amplification status, ALK mutation status, chromosome arm 1p, 11q and/or 17q status, sensitivity to pharmacologic perturbation). Additionally, we designed this experiment to enable structural variant and/or long-noncoding RNA analysis across these cell lines. Finally, as more DNase/ATAC and histone/transcription factor ChIP sequencing is performed in these cell lines, our RNA-Seq data will be an important complement to inform transcriptional targets as well as regulatory (enhancer or repressor) elements in neuroblastoma

Ipatasertib plus paclitaxel for PIK3CA/AKT1/PTEN-altered hormone receptor-positive HER2-negative advanced breast cancer: primary results from cohort B of the IPATunity130 randomized phase 3 trial

HER2 negative; Ipatasertib; PI3K/AKTHER2 negativo; Ipatasertib; PI3K/AKTHER2 negatiu; Ipatasertib; PI3K/AKTPurpose PI3K/AKT pathway alterations are frequent in hormone receptor-positive (HR+) breast cancers. IPATunity130 Cohort B investigated ipatasertib–paclitaxel in PI3K pathway-mutant HR+ unresectable locally advanced/metastatic breast cancer (aBC). Methods Cohort B of the randomized, double-blind, placebo-controlled, phase 3 IPATunity130 trial enrolled patients with HR+ HER2-negative PIK3CA/AKT1/PTEN-altered measurable aBC who were considered inappropriate for endocrine-based therapy (demonstrated insensitivity to endocrine therapy or visceral crisis) and were candidates for taxane monotherapy. Patients with prior chemotherapy for aBC or relapse < 1 year since (neo)adjuvant chemotherapy were ineligible. Patients were randomized 2:1 to ipatasertib (400 mg, days 1–21) or placebo, plus paclitaxel (80 mg/m2, days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed progression-free survival (PFS). Results Overall, 146 patients were randomized to ipatasertib–paclitaxel and 76 to placebo–paclitaxel. In both arms, median investigator-assessed PFS was 9.3 months (hazard ratio, 1.00, 95% CI 0.71–1.40) and the objective response rate was 47%. Median paclitaxel duration was 6.9 versus 8.8 months in the ipatasertib–paclitaxel versus placebo–paclitaxel arms, respectively; median ipatasertib/placebo duration was 8.0 versus 9.1 months, respectively. The most common grade ≥ 3 adverse events were diarrhea (12% with ipatasertib–paclitaxel vs 1% with placebo–paclitaxel), neutrophil count decreased (9% vs 7%), neutropenia (8% vs 9%), peripheral neuropathy (7% vs 3%), peripheral sensory neuropathy (3% vs 5%) and hypertension (1% vs 5%). Conclusion Adding ipatasertib to paclitaxel did not improve efficacy in PIK3CA/AKT1/PTEN-altered HR+ HER2-negative aBC. The ipatasertib–paclitaxel safety profile was consistent with each agent’s known adverse effects.This work was supported by Genentech/Roche. Medical writing assistance was provided by Jennifer Kelly, MA (Medi-Kelsey Ltd), funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland

Replication and Meta-analysis of the Association between BDNF Val66Met Polymorphism and Cognitive Impairment in Patients Receiving Chemotherapy.

Cancer-related cognitive impairment (CRCI) adversely affects cancer patients. We had previously demonstrated that the BDNF Val66Met genetic polymorphism is associated with lower odds of subjective CRCI in the multitasking and verbal ability domains among breast cancer patients receiving chemotherapy. To further assess our previous findings, we evaluated the association of BDNF Val66Met polymorphism with subjective and objective CRCI in a temporally separate cohort of patients and pooled findings from both the original (n = 145) and current (n = 193) cohorts in a meta-analysis. Subjective CRCI was assessed using FACT-Cog. Objective CRCI was evaluated using computerized neuropsychological tests. Genotyping was carried out using Sanger sequencing. The association of BDNF Val66Met genotypes and CRCI was examined with logistic regression. A fixed-effect meta-analysis was conducted using the inverse variance method. In the meta-analysis (n = 338), significantly lower odds of CRCI were associated with Met allele carriers based on the global FACT-Cog score (OR = 0.52, 95% CI 0.29-0.94). Furthermore, Met allele carriers were at lower odds of developing impairment in the domains of memory (OR = 0.34, 95% CI: 0.17-0.70), multitasking (OR = 0.33, 95% CI: 0.18-0.59), and verbal ability (OR = 0.46, 95% CI: 0.24-0.88). Consistent with the previous study, lower odds of subjective CRCI among patients with the BDNF Met allele was observed after adjusting for potential confounders in the multitasking (OR = 0.30, 95% CI: 0.14-0.67) domain. In conclusion, carriers of the BDNF Met allele were protected against global subjective CRCI, particularly in the domains of memory, multitasking, and verbal ability. Our findings further contribute to the understanding of CRCI pathophysiology

A negative feedback loop mediated by the Bcl6-cullin 3 complex limits Tfh cell differentiation

Induction of Bcl6 (B cell lymphoma 6) is essential for T follicular helper (Tfh) cell differentiation of antigen-stimulated CD4(+) T cells. Intriguingly, we found that Bcl6 was also highly and transiently expressed during the CD4(+)CD8(+) (double positive [DP]) stage of T cell development, in association with the E3 ligase cullin 3 (Cul3), a novel binding partner of Bcl6 which ubiquitinates histone proteins. DP stage-specific deletion of the E3 ligase Cul3, or of Bcl6, induced the derepression of the Bcl6 target genes Batf (basic leucine zipper transcription factor, ATF-like) and Bcl6, in part through epigenetic modifications of CD4(+) single-positive thymocytes. Although they maintained an apparently normal phenotype after emigration, they expressed increased amounts of Batf and Bcl6 at basal state and produced explosive and prolonged Tfh responses upon subsequent antigen encounter. Ablation of Cul3 in mature CD4(+) splenocytes also resulted in dramatically exaggerated Tfh responses. Thus, although previous studies have emphasized the essential role of Bcl6 in inducing Tfh responses, our findings reveal that Bcl6-Cul3 complexes also provide essential negative feedback regulation during both thymocyte development and T cell activation to restrain excessive Tfh responses

Moving From Poly (ADP-Ribose) Polymerase Inhibition to Targeting DNA Repair and DNA Damage Response in Cancer Therapy

The DNA damage response (DDR) pathway coordinates the identification, signaling, and repair of DNA damage caused by endogenous or exogenous factors and regulates cell-cycle progression with DNA repair to minimize DNA damage being permanently passed through cell division. Severe DNA damage that cannot be repaired may trigger apoptosis; as such, the DDR pathway is of crucial importance as a cancer target. Poly (ADP-ribose) polymerase (PARP) is the best-known element of the DDR, and several PARP inhibitors have been licensed. However, there are approximately 450 proteins involved in DDR, and a number of these other targets are being investigated in the laboratory and clinic. We review the most recent evidence for the clinical effect of PARP inhibition in breast and ovarian cancer and explore expansion into the first-line setting and into other tumor types. We critique the evidence for patient selection techniques and summarize what is known about mechanisms of PARP inhibitor resistance. We then discuss what is known about the preclinical rationale for targeting other members of the DDR pathway and the associated tumor cell genetics that may confer sensitivity to these agents. Examples include DNA damage sensors (MLH1), damage signaling molecules (ataxia-telangiectasia mutated; ataxia-telangiectasia mutated–related and Rad3-related; CHK1/2; DNA-dependent protein kinase, catalytic subunit; WEE1; CDC7), or effector proteins for repair (POLQ [also referred to as POLθ], RAD51, poly [ADP-ribose] glycohydrolase). Early-phase clinical trials targeting some of these molecules, either as a single agent or in combination, are discussed. Finally, we outline the challenges that must be addressed to maximize the therapeutic opportunity that targeting DDR provides

Poly(ADP-Ribose) Polymerase Inhibition: "Targeted" Therapy for Triple-Negative Breast Cancer

In contrast to endocrine-sensitive and HER2-positive breast cancer, novel agents capable of treating advanced triple negative breast cancer (TNBC) are lacking. PARP (Poly-(adenosine diphosphate [ADP]-ribose) polymerase) inhibitors are emerging as one of the most promising ‘targeted’ therapeutics to treat TNBC, with the intended ‘target’ being DNA repair. PARP's are a family of enzymes involved in multiple cellular processes including DNA repair. TNBC shares multiple clinico-pathologic features with BRCA-mutated breast cancers which harbor dysfunctional DNA repair mechanisms. Investigators hypothesized PARP inhibition, in conjunction with the loss of DNA-repair via BRCA-dependent mechanisms, would result in synthetic lethality and augmented cell death. This hypothesis has borne out in both preclinical models and in clinical trials testing PARP inhibitors in both BRCA-deficient and TNBC. The focus of this review will include an overview of the preclinical rationale for evaluating PARP inhibitors in TNBC, the presumed mechanism of action of this novel therapeutic class, promising results from several influential clinical trials of PARP inhibition in advanced breast cancer (both TNBC and BRCA-deficient), proposed mechanisms of acquired resistance to PARP inhibitors, and, finally, conclude with current challenges and future directions for the development of PARP inhibitors in the treatment of breast cancer