Genetic Basis of Breast and Ovarian Cancer: Approaches and Lessons Learnt from Three Decades of Inherited Predisposition Testing.

Germline variants occurring in BRCA1 and BRCA2 give rise to hereditary breast and ovarian cancer (HBOC) syndrome, predisposing to breast, ovarian, fallopian tube, and peritoneal cancers marked by elevated incidences of genomic aberrations that correspond to poor prognoses. These genes are in fact involved in genetic integrity, particularly in the process of homologous recombination (HR) DNA repair, a high-fidelity repair system for mending DNA double-strand breaks. In addition to its implication in HBOC pathogenesis, the impairment of HR has become a prime target for therapeutic intervention utilizing poly (ADP-ribose) polymerase (PARP) inhibitors. In the present review, we introduce the molecular roles of HR orchestrated by BRCA1 and BRCA2 within the framework of sensitivity to PARP inhibitors. We examine the genetic architecture underneath breast and ovarian cancer ranging from high- and mid- to low-penetrant predisposing genes and taking into account both germline and somatic variations. Finally, we consider higher levels of complexity of the genomic landscape such as polygenic risk scores and other approaches aiming to optimize therapeutic and preventive strategies for breast and ovarian cancer.

Biological Role and Clinical Implications of microRNAs in BRCA Mutation Carriers.

Women with pathogenic germline mutations in BRCA1 and BRCA2 genes have an increased risk to develop breast and ovarian cancer. There is, however, a high interpersonal variability in the modality and timing of tumor onset in those subjects, thus suggesting a potential role of other individual's genetic, epigenetic, and environmental risk factors in modulating the penetrance of BRCA mutations. MicroRNAs (miRNAs) are small noncoding RNAs that can modulate the expression of several genes involved in cancer initiation and progression. MiRNAs are dysregulated at all stages of breast cancer and although they are accessible and evaluable, a standardized method for miRNA assessment is needed to ensure comparable data analysis and accuracy of results. The aim of this review was to highlight the role of miRNAs as potential biological markers for BRCA mutation carriers. In particular, biological and clinical implications of a link between lifestyle and nutritional modifiable factors, miRNA expression and germline BRCA1 and BRCA2 mutations are discussed with the knowledge of the best available scientific evidence.

A Phase 1 Study of mTORC1/2 Inhibitor BI 860585 as a Single Agent or with Exemestane or Paclitaxel in Patients with Advanced Solid Tumors.

This phase 1 trial (NCT01938846) determined the maximum tolerated dose (MTD) of the mTOR serine/threonine kinase inhibitor, BI 860585, as monotherapy and with exemestane or paclitaxel in patients with advanced solid tumors. This 3+3 dose-escalation study assessed BI 860585 monotherapy (5-300 mg/day; Arm A), BI 860585 (40-220 mg/day; Arm B) with 25 mg/day exemestane, and BI 860585 (80-220 mg/day; Arm C) with 60-80 mg/m2/week paclitaxel, in 28-day cycles. Primary endpoints were the number of patients with dose-limiting toxicities (DLTs) in cycle 1 and the MTD. Forty-one, 25, and 24 patients were treated (Arms A, B, and C). DLTs were observed in four (rash (n = 2), elevated alanine aminotransferase/aspartate aminotransferase, diarrhea), four (rash (n = 3), stomatitis, and increased gamma-glutamyl transferase), and two (diarrhea, increased blood creatine phosphokinase) patients in cycle 1. The BI 860585 MTD was 220 mg/day (Arm A) and 160 mg/day (Arms B and C). Nine patients achieved an objective response (Arm B: Four partial responses (PRs); Arm C: Four PRs; one complete response). The disease control rate was 20%, 28%, and 58% (Arms A, B, and C). The most frequent treatment-related adverse events (AEs) were hyperglycemia (54%) and diarrhea (39%) (Arm A); diarrhea (40%) and stomatitis (40%) (Arm B); fatigue (58%) and diarrhea (58%) (Arm C). The MTD was determined in all arms. Antitumor activity was observed with BI 860585 monotherapy and in combination with exemestane or paclitaxel.

Role of innate and adaptive immunity in the efficacy of anti-HER2 monoclonal antibodies for HER2-positive breast cancer.

Anti-HER2 monoclonal antibodies (mAbs) such as trastuzumab are effective for all stages of HER2-positive breast cancer (BC). However, intrinsic or acquired resistance to these drugs may occur in a significant number of patients (pts) and, except for HER2 status, no validated predictive factors of response/resistance have been identified to date. This lack is in part due to the not yet fully elucidated mechanism of action of mAbs in vivo. Increasing evidence suggests a significant contribution of both innate and adaptive immunity to the antitumor effects of mAbs. The aim of this review was to describe the role of innate and adaptive immunity in the efficacy of anti-HER2 mAbs and to report known and novel strategies to be used for optimizing immune effects of anti-HER2 therapies for HER2-positive BC.

Mechanism of Action and Clinical Efficacy of CDK4/6 Inhibitors in BRCA-Mutated, Estrogen Receptor-Positive Breast Cancers: Case Report and Literature Review.

Sensitivity to endocrine therapy of patients with estrogen receptor (ER)-positive metastatic breast cancer and germline BRCA1/2 mutations is not yet fully elucidated. Furthermore, the registration trials of CDK 4/6 inhibitors in combination with endocrine therapy lacked of a pre-specified subgroup analysis in BRCA1/2 mutation carriers. We report clinical history of two patients with BRCA-mutated, ER-positive metastatic breast cancer treated with letrozole plus the CDK 4/6 inhibitor palbociclib. Biological and clinical implications of the treatment outcome observed in the two cases are discussed with the knowledge of scientific evidence to date available. Overall, biological rationale, preclinical, and clinical data support the prominent role of CDK 4/6 inhibitors plus endocrine therapy, even in combination with PARP inhibitors, in the treatment of BRCA-mutated, ER-positive breast cancers. However, the interaction between Cyclin/CDK pathway, ER and BRCA is complex and evidences reported so far, albeit reliable, await confirmation in the context of future randomized clinical trials.

Nab-paclitaxel after docetaxel hypersensitivity reaction: case report and literature review.

Taxanes, including paclitaxel and docetaxel, are one of the most active cytotoxic agents in breast cancer  treatment  including  Her-2  positive  subtype characterized  by  aggressive  clinical  and pathological features since the early stage. However, their use is sometimes limited by the occurrence of hypersensivity reactions (HSRs) characterized by erythematous rashes, bronchospasm, respiratory distress, hypotension, and pulmonary edema. Cross-reactions between paclitaxel and docetaxel are described in literature with a rate ranging from 49% to 90%. Abraxane (nab-paclitaxel), an albumin-bound form of paclitaxel, has a different toxicity profile from solvent-based paclitaxel and a lower rate of HSRs. Interestingly, several authors have recently reported cases of patients who developed HSRs to taxanes, principally paclitaxel, and were then safety treated with Abraxane, suggesting the absence of cross-reactivity between these drugs. Based on these considerations, we report our clinical experience and perform a literature review on this topic with the aim to investigate the cross-reactivity between nab-paclitaxel and other taxanes, in particular with docetaxel.

Triple negative status and BRCA mutations in contralateral breast cancer: a population-based study.

BACKGROUND AND AIM OF THE WORK: BRCA1/2 mutation carriers diagnosed with breast cancer have a strong life-time risk of developing contralateral breast cancer (CBC). We performed a population-based study with the aim of estimating the proportion of CBC associated with BRCA1/BRCA2 mutations, and the contribution of germline mutations to both molecular and clinical features of these tumors. METHODS: Fifty-five women with invasive CBC consecutively seen at the at the Genetic Oncology Service of the University Hospital of Parma from 2000 to 2011 were subjected to BRCA1/2 testing. Fifty-five case-matched, unilateral breast cancer (UBC)  patients (pts), which tested negative for BRCA1/2 mutations, were selected as control group. RESULTS: BRCA mutations were detected in 13 (24%) of 55 CBC pts. Women with BRCA1 mutations, and to a lesser extent BRCA2 mutations, were significantly more likely to present with high histologic grade, negative hormone receptor status and high proliferation rate in both first and second primary breast cancers than BRCA-negative, CBC tumors. A diagnosis of triple-negative breast cancer (TNBC) was significantly more frequent in women with BRCA mutations in comparison with BRCA-negative, UBC controls. There were no survival differences between BRCA-positive and non-BRCA tumors. CONCLUSIONS: Results of the present study indicate that both first primary and second primary breast cancers in BRCA carriers are qualitatively distinct from BRCA negative CBC, and from sporadic UBC controls. These findings highlight relevant clinical considerations about the potential value of BRCA testing in women with CBC as well as therapeutic, preventive, and surveillance implications for patients carrying a mutation.

Prognostic risk factors for treatment decision in pT1a,b N0M0 HER2-positive breast cancers.

Although outcomes for women with breast cancers may vary by biologic subtype, patients with T1a,b N0M0 tumors have an excellent prognosis across all subgroups. HER2 overexpression occurs in 15-20% of primary breast tumors, and is associated with diminished disease-free and overall survival. The anti-HER2 monoclonal antibody trastuzumab in combination with chemotherapy is an effective treatment for all stages of HER2 positive breast cancer (bc). However, the absolute benefit decreases as the risk of recurrence lessens and no available randomized adjuvant trial has evaluated the role of trastuzumab in women with pT1a,b N0M0, HER2-positive breast tumors. These findings may explain the debate about the appropriate indication for adjuvant chemotherapy plus trastuzumab in this setting of patients. The aim of this review was to describe known and novel prognostic risk factors to be used for tailored treatment decision in pT1a,b N0M0 HER2-positive tumors. Whether patients with small HER2-positive bc may be suitable for (chemo)therapy reduction strategies, the current available data cannot exclude the need for a more aggressive treatment in a small subset of these subjects. Novel clinical prognostic factors such as interval cancer (IC) detection may help to address this clinically important controversy. A multicenter population-based cancer registry study is currently evaluating whether IC detection may identify patients with pT1a N0M0 HER2-positive tumors in whom the rate of recurrence justifies consideration for use of conventional, trastuzumab-based chemotherapy regimens.

Human epidermal growth factor receptor 2 status and interval breast cancer in a population-based cancer registry study.

PURPOSE: To determine whether human epidermal growth factor receptor 2 (HER2) -positive status is associated with risk of breast cancer diagnosis in the interval between mammographic screening, we estimated the distribution of features of aggressive tumor behavior in a general population with newly diagnosed breast cancer and known screening status. PATIENTS AND METHODS: We evaluated all invasive breast cancers (N = 641) that were systematically collected by the Parma Province Cancer Registry and diagnosed in women age 50 to 69 years from 2004 to 2007. From this population, 292 screen-detected cancers and 48 interval cases with negative screening mammograms on expert rereading (true interval cancers) were selected for study purposes. Unconditional logistic regression adjusted for age and tumor size was used to determine whether interval cancers were associated with selected clinicobiologic characteristics. RESULTS: Tumors with a high histologic grade (odds ratio [OR], 1.8; 95% CI, 1.2 to 3.8), high proliferative rate (OR, 2.4; 95% CI, 1.2 to 4.5), negative estrogen receptor status (OR, 1.6; 95% CI, 1.1 to 3.1), or HER2-positive status (OR, 3.4; 95% CI, 1.7 to 7.1) were more likely to be diagnosed in the interval between screening. Women age less than 60 years with HER2-positive breast cancer were four times more likely to be diagnosed in the interval between screening compared with only a two-fold increased risk for older women. CONCLUSION: This population-based cancer registry study demonstrated that HER2-positive tumors account for a substantial proportion of mammographic screening failure. The distribution of biologic characteristics in screen-detected cancers differs from that observed in interval cancers and may account in part for the more aggressive behavior of interval-detected cases.

Activity and safety of dose-adjusted infusional cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy with rituximab in very elderly patients with poor-prognostic untreated diffuse large B-cell non-Hodgkin lymphoma.

BACKGROUND: This study was designed to assess the activity and safety of dose-adjusted infusional cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy with rituximab (DA-POCH-R) in elderly patients with poor-prognostic untreated diffuse large B-cell non-Hodgkin lymphoma (DLBCL). METHODS: From April 2006 to November 2009, 23 patients, aged ≥70 years, with an age-adjusted International Prognostic Index (IPI) of 2 or 3, were enrolled. Only patients with left ventricular ejection fraction (LVEF) ≥50% were allowed. The DA-POCH-R regimen was administered every 3 weeks for a minimum of 6 and a maximum of 8 cycles. RESULTS: Median patient age was 77 years (range, 70-90 years); 83% of patients had Ann Arbor stage III to IV disease. Median LVEF at baseline was 62%. Four (17%) patients had a history of abnormal cardiovascular conditions. Twenty-one (91%) patients were evaluable for response. The overall response rate was 90%, with a complete response rate of 57%. The 3-year overall survival and event-free survival rates were 56% and 54%, respectively. Neutropenia (48%) was the most frequent grade 3 to 4 adverse event (AE); no grade 3 to 4 cardiac AEs were observed. CONCLUSIONS: DA-POCH-R was an active and safe combination therapy for patients aged ≥70 years with poor-prognostic untreated DLBCL. This regimen was a reasonable alternative for elderly patients who were not considered to tolerate standard R-CHOP treatment.