Roisin M. Connolly

Beta Blockers and Breast Cancer Mortality: A Population- Based Study

PURPOSE Preclinical studies have demonstrated that antagonism of β₂-adrenergic signaling inhibits several pathways necessary for breast tumor progression and metastasis. A series of population-based observational studies were conducted to examine associations between beta blocker use and breast tumor characteristics at diagnosis or breast cancer-specific mortality. PATIENTS AND METHODS Linked national cancer registry and prescription dispensing data were used to identify women with a diagnosis of stage I to IV invasive breast cancer between January 1, 2001, and December 31, 2006. Women taking propranolol (β₁/β₂ antagonist; n = 70) or atenolol (β₁ antagonist; n = 525), in the year before breast cancer diagnosis were matched (1:2) to women not taking a beta blocker (n = 4,738). Associations between use of propranolol or atenolol and risk of local tumor invasion at diagnosis (T4 tumor), nodal or metastatic involvement at diagnosis (N2/N3/M1 tumor), and time to breast cancer-specific mortality were assessed. RESULTS Propranolol users were significantly less likely to present with a T4 (odds ratio [OR], 0.24, 95% CI, 0.07 to 0.85) or N2/N3/M1 (OR, 0.20; 95% CI, 0.04 to 0.88) tumor compared with matched nonusers. The cumulative probability of breast cancer-specific mortality was significantly lower for propranolol users compared with matched nonusers (hazard ratio, 0.19; 95% CI, 0.06 to 0.60). There was no difference in T4 or N2/N3/M1 tumor incidence or breast cancer-specific mortality between atenolol users and matched nonusers. CONCLUSION The results provide evidence in humans to support preclinical observations suggesting that inhibiting the β₂-adrenergic signaling pathway can reduce breast cancer progression and mortality.

Early discontinuation of tamoxifen: a lesson for oncologists.

Five years of treatment provides the optimum duration of tamoxifen therapy for the prevention of breast cancer recurrence and mortality. Durations of adjuvant tamoxifen therapy less than 5 years are associated with poorer outcomes for breast cancer patients. The purpose of the study was to assess rates of tamoxifen nonpersistence (early discontinuation) in women aged 35 years or older using prescription refill data from a national prescribing database.

Molecular Pathways: Current Role and Future Directions of the Retinoic Acid Pathway in Cancer Prevention and Treatment

Retinoids and their naturally metabolized and synthetic products (e.g., all-trans retinoic acid, 13-cis retinoic acid, bexarotene) induce differentiation in various cell types. Retinoids exert their actions mainly through binding to the nuclear retinoic acid receptors (α, β, γ), which are transcriptional and homeostatic regulators with functions that are often compromised early in neoplastic transformation. The retinoids have been investigated extensively for their use in cancer prevention and treatment. Success has been achieved with their use in the treatment of subtypes of leukemia harboring chromosomal translocations. Promising results have been observed in the breast cancer prevention setting, where fenretinide prevention trials have provided a strong rationale for further investigation in young women at high risk for breast cancer. Ongoing phase III randomized trials investigating retinoids in combination with chemotherapy in non–small cell lung cancer aim to definitively characterize the role of retinoids in this tumor type. The limited treatment success observed to date in the prevention and treatment of solid tumors may relate to the frequent epigenetic silencing of RARβ. Robust evaluation of RARβ and downstream genes may permit optimized use of retinoids in the solid tumor arena. Clin Cancer Res; 19(7); 1651–9. ©2013 AACR.

Treatment of HER2-positive breast cancer

The human epidermal growth factor receptor 2 gene (HER2) is overexpressed and/or amplified in ~15% of breast cancer patients and was identified a quarter century ago as a marker of poor prognosis. By 1998, antibody therapy targeting the HER2 pathway was shown to demonstrably improve progression-free and overall survival in metastatic disease, and in 2005 evidence of improvement in disease-free and overall survival from the first generation of trastuzumab adjuvant trials became available. However, not all patients with HER2 overexpression benefit from trastuzumab. Second-generation studies in metastatic disease led to the approval of several new HER2-targeted therapies using small molecule tyrosine kinase inhibitors such as lapatinib, new HER2/HER3 antibodies such as pertuzumab, and the new antibody chemotherapy conjugate ado-trastuzumab emtansine. These successes supported the launch of second-generation adjuvant trials testing single and dual HER2-targeted agents, administered concomitantly or sequentially with chemotherapy that will soon complete accrual. HER2-positive breast cancer in the setting of HER2-targeted therapy is no longer associated with poor prognosis, and recent guidance by the US Food and Drug Administration suggests that pathologic response to HER2-targeted therapy given preoperatively may allow an earlier assessment of their clinical benefit in the adjuvant setting. An adjuvant trial of trastuzumab in patient whose tumors express normal levels of HER2 and trials of single/dual HER2-targeting without chemotherapy are also ongoing. In this article, we review the current data on the therapeutic management of HER2-positive breast cancer.

Epigenetics as a Therapeutic Target in Breast Cancer

Epigenetics refers to alterations in gene expression due to modifications in histone acetylation and DNA methylation at the promoter regions of genes. Unlike genetic mutations, epigenetic alterations are not due to modifications in the gene primary nucleotide sequence. The importance of epigenetics in the initiation and progression of breast cancer has led many investigators to incorporate this novel and exciting field in breast cancer drug development. Several drugs that target epigenetic alterations, including inhibitors of histone deacetylase (HDAC) and DNA methyltransferase (DNMT), are currently approved for treatment of hematological malignancies and are available for clinical investigation in solid tumors. In this manuscript, we review the critical role of epigenetics in breast cancer including the potential for epigenetic alterations to serve as biomarkers determining breast cancer prognosis and response to therapy. We highlight initial promising results to date with use of epigenetic modifiers in patients with breast cancer and the ongoing challenges involved in the successful establishment of these agents for the treatment of breast cancer.

Translational breast cancer research consortium (TBCRC) 022: A phase II trial of neratinib for patients with human epidermal growth factor receptor 2-positive breast cancer and brain metastases

PURPOSE Evidence-based treatments for metastatic, human epidermal growth factor receptor 2 (HER2)-positive breast cancer in the CNS are limited. Neratinib is an irreversible inhibitor of erbB1, HER2, and erbB4, with promising activity in HER2-positive breast cancer; however, its activity in the CNS is unknown. We evaluated the efficacy of treatment with neratinib in patients with HER2-positive breast cancer brain metastases in a multicenter, phase II open-label trial. PATIENTS AND METHODS Eligible patients were those with HER2-positive brain metastases (≥ 1 cm in longest dimension) who experienced progression in the CNS after one or more line of CNS-directed therapy, such as whole-brain radiotherapy, stereotactic radiosurgery, and/or surgical resection. Patients received neratinib 240 mg orally once per day, and tumors were assessed every two cycles. The primary endpoint was composite CNS objective response rate (ORR), requiring all of the following: ≥ 50% reduction in volumetric sum of target CNS lesions and no progression of non-target lesions, new lesions, escalating corticosteroids, progressive neurologic signs/symptoms, or non-CNS progression--the threshold for success was five of 40 responders. RESULTS Forty patients were enrolled between February 2012 and June 2013; 78% of patients had previous whole-brain radiotherapy. Three women achieved a partial response (CNS objective response rate, 8%; 95% CI, 2% to 22%). The median number of cycles received was two (range, one to seven cycles), with a median progression-free survival of 1.9 months. Five women received six or more cycles. The most common grade ≥ 3 event was diarrhea (occurring in 21% of patients taking prespecified loperamide prophylaxis and 28% of those without prophylaxis). Patients in the study experienced a decreased quality of life over time. CONCLUSION Although neratinib had low activity and did not meet our threshold for success, 12.5% of patients received six or more cycles. Studies combining neratinib with chemotherapy in patients with CNS disease are ongoing.

TBCRC 008: Early Change in 18F-FDG Uptake on PET Predicts Response to Preoperative Systemic Therapy in Human Epidermal Growth Factor Receptor 2–Negative Primary Operable Breast Cancer

Epigenetic modifiers, including the histone deacetylase inhibitor vorinostat, may sensitize tumors to chemotherapy and enhance outcomes. We conducted a multicenter randomized phase II neoadjuvant trial of carboplatin and nanoparticle albumin-bound paclitaxel (CP) with vorinostat or placebo in women with stage II/III, human epidermal growth factor receptor 2 (HER2)–negative breast cancer, in which we also examined whether change in maximum standardized uptake values corrected for lean body mass (SULmax) on 18F-FDG PET predicted pathologic complete response (pCR) in breast and axillary lymph nodes. Methods: Participants were randomly assigned to 12 wk of preoperative carboplatin (area under the curve of 2, weekly) and nab-paclitaxel (100 mg/m2 weekly) with vorinostat (400 mg orally daily, days 1–3 of every 7-d period) or placebo. All patients underwent 18F-FDG PET and research biopsy at baseline and on cycle 1 day 15. The primary endpoint was the pCR rate. Secondary objectives included correlation of change in tumor SULmax on 18F-FDG PET by cycle 1 day 15 with pCR and correlation of baseline and change in Ki-67 with pCR. Results: In an intent-to-treat analysis (n = 62), overall pCR was 27.4% (vorinostat, 25.8%; placebo, 29.0%). In a pooled analysis (n = 59), we observed a significant difference in median change in SULmax 15 d after initiating preoperative therapy between those achieving pCR versus not (percentage reduction, 63.0% vs. 32.9%; P = 0.003). Patients with 50% or greater reduction in SULmax were more likely to achieve pCR, which remained statistically significant in multivariable analysis including estrogen receptor status (odds ratio, 5.1; 95% confidence interval, 1.3–22.7; P = 0.023). Differences in baseline and change in Ki-67 were not significantly different between those achieving pCR versus not. Conclusion: Preoperative CP with vorinostat or placebo is associated with similar pCR rates. Early change in SULmax on 18F-FDG PET 15 d after the initiation of preoperative therapy has potential in predicting pCR in patients with HER2-negative breast cancer. Future studies will further test 18F-FDG PET as a potential treatment-selection biomarker.

Current approaches for neoadjuvant chemotherapy in breast cancer

Compared to adjuvant chemotherapy, the administration of the same regimen in the neoadjuvant setting provides women with identical improvements in disease free and overall survival. Neoadjuvant chemotherapy may offer benefits to properly selected women such as broadening surgical options and enhancing the likelihood of breast conservation. Assessment of response to neoadjuvant chemotherapy provides women with an individualized estimate of prognosis. For example, a woman who achieves a complete pathological response following neoadjuvant chemotherapy has a very low risk of recurrence compared to a woman with similar tumor characteristics and a large residual disease. In this review we will provide a historical perspective and discuss the aims of neoadjuvant chemotherapy in primary operable breast cancer; as well as appropriate patient selection, treatment strategies, response monitoring, and postoperative care. We will also discuss the attractiveness of this approach to study the mechanism of action of standard and novel agents, and the role of predictive biomarkers of response to treatment and outcomes.

Combination Epigenetic Therapy in Advanced Breast Cancer with 5-Azacitidine and Entinostat: A Phase II National Cancer Institute/Stand Up to Cancer Study.

Purpose: In breast cancer models, combination epigenetic therapy with a DNA methyltransferase inhibitor and a histone deacetylase inhibitor led to reexpression of genes encoding important therapeutic targets, including the estrogen receptor (ER). We conducted a multicenter phase II study of 5-azacitidine and entinostat in women with advanced hormone-resistant or triple-negative breast cancer (TNBC). Experimental Design: Patients received 5-azacitidine 40 mg/m2 (days 1–5, 8–10) and entinostat 7 mg (days 3, 10) on a 28-day cycle. Continuation of epigenetic therapy was offered with the addition of endocrine therapy at the time of progression [optional continuation (OC) phase]. Primary endpoint was objective response rate (ORR) in each cohort. We hypothesized that ORR would be ≥20% against null of 5% using Simon two-stage design. At least one response was required in 1 of 13 patients per cohort to continue accrual to 27 per cohort (type I error, 4%; power, 90%). Results: There was one partial response among 27 women with hormone-resistant disease (ORR = 4%; 95% CI, 0–19), and none in 13 women with TNBC. One additional partial response was observed in the OC phase in the hormone-resistant cohort (n = 12). Mandatory tumor samples were obtained pre- and posttreatment (58% paired) with either up- or downregulation of ER observed in approximately 50% of posttreatment biopsies in the hormone-resistant, but not TNBC cohort. Conclusions: Combination epigenetic therapy was well tolerated, but our primary endpoint was not met. OC phase results suggest that some women benefit from epigenetic therapy and/or reintroduction of endocrine therapy beyond progression, but further study is needed. Clin Cancer Res; 23(11); 2691–701. ©2016 AACR.

Abstract 4666: A phase 2 study investigating the safety, efficacy and surrogate biomarkers of response of 5-azacitidine (5-AZA) andentinostat (MS-275) in patients with triple-negative advanced breast cancer.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: In preclinical breast cancer models, combination epigenetic therapy with a DNA methyltransferase inhibitor (DNMTI) and a histone deacetylase inhibitor (HDACI) yield superior estrogen receptor (ER) re-expression and greater restoration of tamoxifen responsiveness than either agent alone. We conducted a multicenter phase II clinical trial to evaluate the DNMTI 5-azacitidine (5-AZA) and the HDACI entinostat in women with advanced breast cancer. Methods: Women with advanced HER2-negative, either triple-negative (TN; ER/progesterone receptor [PR]/HER2-negative) or hormone-resistant breast cancer received 5-AZA 40 mg/m2 (SQ, days 1-5, 8-10) and entinostat 7 mg (PO, days 3,10) every 28 days. Primary endpoint: objective response rate (ORR) in each group. Secondary endpoints: safety, tolerability, survival, clinical benefit rate. Exploratory endpoints: pharmacokinetics, pharmacogenetics, change in candidate gene re-expression/methylation in circulating DNA and mandatory tumor samples. Patients are offered ongoing study therapy at progression with addition of hormonal therapy (optional continuation phase). Sample size: Simon two-stage design with interim analysis after 13 patients per cohort (1st stage). If ≥1 response, accrual will continue for total of 27 per cohort (2nd stage). Null hypothesis: ORR at most 5% against alternative hypothesis that is at least 20% with type I error 4% and power 90%. Preclinical TN/ ER-positive xenograft studies assessing 5-AZA impact were also performed. Results: Thirteen evaluable patients were enrolled in 1st stage of TN cohort. Median age was 47 (31-67), median prior chemotherapies 3 (1-5), 77% white/33% black, 77% visceral disease. Median cycles received 2 (1-4). Therapy was well tolerated, most common grade 3/4 treatment related adverse events leucopenia and neutropenia (23% each). No responses observed following 1st stage and this cohort was closed. Median 1.5 additional cycles (optional continuation phase) received by 4 patients with no responses to date. Exposure to 5-AZA (Cmax=1134±1670ng/mL; AUCINF=939±724 ng*h/mL) was slightly higher than previous studies, entinostat (Cmin=0.78±0.65ng/mL) was similar. Hormone-resistant cohort proceeded to 2nd stage as 1 partial response observed. Final results will be reported once accrual complete. Ongoing preclinical studies suggest that ER-positive is more sensitive than TN breast cancer to 5-AZA. Conclusion: Combination epigenetic therapy with agents, dose and schedule described was well tolerated but not associated with clinical activity in advanced TN breast cancer. Correlative analyses will be presented at meeting. Promising preclinical findings suggest epigenetic therapy may be efficacious in ER-positive breast cancer. Citation Format: Roisin M. Connolly, Rachel C. Jankowitz, Cynthia A. Zahnow, Zhe Zhang, Michelle A. Rudek, Stacie C. Jeter, Shannon Slater, Penny Powers, Antonio C. Wolff, John Fetting, Adam M. Brufsky, Richard Piekarz, Nita Ahuja, George Somlo, Augustin Garcia, Steven Baylin, Nancy E. Davidson, Vered Stearns. A phase 2 study investigating the safety, efficacy and surrogate biomarkers of response of 5-azacitidine (5-AZA) andentinostat (MS-275) in patients with triple-negative advanced breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4666. doi:10.1158/1538-7445.AM2013-4666