Tamoxifen vs Raloxifene vs Exemestane for Chemoprevention

Novel Treatment Strategies for Hormone Receptor (HR)-Positive, HER2-Negative Metastatic Breast Cancer

Estrogen receptor (ER)-positive breast cancer (BC) is the most common BC subtype. Endocrine therapy (ET) targeting ER signaling still remains the mainstay treatment option for hormone receptor (HR)-positive BC either in the early or in advanced setting, including different strategies, such as the suppression of estrogen production or directly blocking the ER pathway through SERMs-selective estrogen receptor modulators-or SERDs-selective estrogen receptor degraders. Nevertheless, the development of de novo or acquired endocrine resistance still remains challenging for oncologists. The use of novel ET combined with targeted drugs, such as cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, has significantly improved long-term outcome rates, thus changing the therapeutic algorithm for metastatic BC (MBC) and recently the therapeutic strategy in the adjuvant setting for early high-risk BC. Eluding the resistance to CDK4/6 inhibitors combined with ET is currently an unmet medical need, and there is disagreement concerning the best course of action for patients who continue to progress after this combination approach. Genetic changes in the tumor along its growth uncovered by genomic profiling of recurrent and/or metastatic lesions through tumor and/or liquid biopsies may predict the response or resistance to specific agents, suggesting the best therapeutic strategy for each patient by targeting the altered ER-dependent pathway (novel oral SERDs and a new generation of anti-estrogen agents) or alternative ER-independent signaling pathways such as PI3K/AKT/mTOR or tyrosine kinase receptors (HER2 mutations or HER2 low status) or by inhibiting pathways weakened through germline BRCA1/2 mutations. These agents are being investigated as single molecules and in combination with other target therapies, offering promising weapons to overcome or avoid treatment failure and propose increasingly more personalized treatment approaches. This review presents novel insights into ET and other targeted therapies for managing metastatic HR+/HER2- BC by exploring potential strategies based on clinical evidence and genomic profiling following the failure of the CDK4/6i and ET combination.

Dynamic Changes of Convolutional Neural Network-based Mammographic Breast Cancer Risk Score Among Women Undergoing Chemoprevention Treatment

INTRODUCTION

We investigated whether our convolutional neural network (CNN)-based breast cancer risk model is modifiable by testing it on women who had undergone risk-reducing chemoprevention treatment.

MATERIALS AND METHODS

We conducted a retrospective cohort study of patients diagnosed with atypical hyperplasia, lobular carcinoma in situ, or ductal carcinoma in situ at our institution from 2007 to 2015. The clinical characteristics, chemoprevention use, and mammography images were extracted from the electronic health records. We classified two groups according to chemoprevention use. Mammograms were performed at baseline and subsequent follow-up evaluations for input to our CNN risk model. The 2 chemoprevention groups were compared for the risk score change from baseline to follow-up. The change categories included stayed high risk, stayed low risk, increased from low to high risk, and decreased from high to low risk. Unordered polytomous regression models were used for statistical analysis, with P < .05 considered statistically significant.

RESULTS

Of 541 patients, 184 (34%) had undergone chemoprevention treatment (group 1) and 357 (66%) had not (group 2). Using our CNN breast cancer risk score, significantly more women in group 1 had shown a decrease in breast cancer risk compared with group 2 (33.7% vs. 22.9%; P < .01). Significantly fewer women in group 1 had an increase in breast cancer risk compared with group 2 (11.4% vs. 20.2%; P < .01). On multivariate analysis, an increase in breast cancer risk predicted by our model correlated negatively with the use of chemoprevention treatment (P = .02).

CONCLUSIONS

Our CNN-based breast cancer risk score is modifiable with potential utility in assessing the efficacy of known chemoprevention agents and testing new chemoprevention strategies.

Synthesis and molecular docking study of new pyrazole derivatives as potent anti-breast cancer agents targeting VEGFR-2 kinase

Based on the previous studies that revealed the valuable role of pyrazole scaffold in cancer management and VEGFR-2 inhibition, a new set of pyrazole conjugated with pyrazoline, triazolopyrimidine and pyrazolone moieties were synthesized and investigated for their anticancer efficiency against human breast cancer MCF-7. The anticancer screening revealed the significant sensitivity of breast carcinoma towards compounds 4b, 5c, 6c, 7b, 7c and 12c with IC₅₀ values ranging from 16.50 - 26.73 µM in comparison with tamoxifen (IC₅₀ = 23.31 µM). Moreover, the new analogues were further examined for their VEGFR-2 inhibitory activity, among the tested derivatives 5c, 6c, 7b, 7c and 12c displayed prominent inhibitory efficiency versus VEGFR-2 kinase with % inhibition ranging from 70 to 79%. Compounds 6c, 7c and 12c revealed inhibitory efficiency in nanomolar level with IC₅₀ (913.51, 225.17 and 828.23 nM, respectively) comparing to sorafenib (IC₅₀ = 186.54 nM). Flow cytometric analysis revealed that the promising compound 12c prompted pre-G1 apoptosis and cell growth cessation at G2/M phase and stimulated apoptosis via activation of caspase-3. Moreover, molecular docking study of the promising derivatives was performed to highlight their binding modes and interactions with the amino acid residues of VEGFR-2 enzyme.

Are we ready for the challenge of implementing risk-based breast cancer screening and primary prevention?

BACKGROUND

Increased knowledge of breast cancer risk factors provides opportunities to shift from a one-size-fits-all screening programme to a personalised approach, where screening and prevention is based on a woman's risk of developing breast cancer. However, potential implementation of this new paradigm could present considerable challenges which the present review aims to explore.

METHODS

Bibliographic databases were searched to identify studies evaluating potential implications of the implementation of personalised risk-based screening and primary prevention for breast cancer. Identified themes were evaluated using thematic analysis.

RESULTS

The search strategy identified 5699 unique publications, of which 59 were selected for inclusion. Significant changes in policy and practice are warranted. The organisation of breast cancer screening spans several healthcare delivery systems and clinical settings. Feasibility of implementation depends on how healthcare is funded and arranged, and potentially varies between countries. Piloting risk assessment and prevention counselling in primary care settings has highlighted implications relating to the need for extensive additional training on risk (communication) and prevention, impact on workflow, and professionals' personal discomfort breaching the topic with women. Additionally, gaps in risk estimation, psychological, ethical and legal consequences will need to be addressed.

CONCLUSION

The present review identified considerable unresolved issues and challenges. Potential implementation will require a more complex framework, in which a country's healthcare regulations, resources, and preferences related to screening and prevention services are taken into account. However, with the insights gained from the present overview, countries expecting to implement risk-based screening and prevention can start to inventory and address the issues that were identified.

Decision making for breast cancer prevention among women at elevated risk

Several medical management approaches have been shown to be effective in preventing breast cancer and detecting it early among women at elevated risk: 1) prophylactic mastectomy; 2) prophylactic oophorectomy; 3) chemoprevention; and 4) enhanced screening routines. To varying extents, however, these approaches are substantially underused relative to clinical practice recommendations. This article reviews the existing research on the uptake of these prevention approaches, the characteristics of women who are likely to use various methods, and the decision-making processes that underlie the differing choices of women. It also highlights important areas for future research, detailing the types of studies that are particularly needed in four key areas: documenting women's perspectives on their own perceptions of risk and prevention decisions; explicit comparisons of available prevention pathways and their likely health effects; the psychological, interpersonal, and social processes of prevention decision making; and the dynamics of subgroup variation. Ultimately, this research could support the development of interventions that more fully empower women to make informed and values-consistent decisions, and to move towards favorable health outcomes.

Uptake of exemestane chemoprevention in postmenopausal women at increased risk for breast cancer

Despite their efficacy, uptake of selective estrogen receptor modulators for breast cancer chemoprevention remains low. Exemestane, an aromatase inhibitor, has recently been identified as a potential chemopreventive option with fewer serious side effects compared with selective estrogen receptor modulators in postmenopausal women. The purpose of this study was to assess the uptake of exemestane in a breast cancer prevention clinic. A retrospective chart review was conducted to capture chemoprevention uptake by postmenopausal women presenting to the Yale Breast Cancer Prevention Clinic between November 2011 and November 2012. Descriptive statistics of the study population have been presented. Statistical analyses were carried out using SAS 9.3 (SAS Institute Inc., Cary, North Carolina, USA) between December 2012 and February 2013. Of 90 postmenopausal women, 56 were eligible for chemoprevention. Their mean age was 56.8 years. Among the women, 39% had osteopenia or osteoporosis. Thirteen women chose to start chemoprevention medication (23%). Although 31% of the chemopreventive medication administered included exemestane, only four of 56 postmenopausal women opted for exemestane (7%). Chemoprevention uptake rates of postmenopausal women in the setting of a breast cancer prevention clinic are higher than that reported in the general population; however, they remain low overall despite the inclusion of exemestane as an option. A significant proportion of postmenopausal women have decreased bone density, which is a potential barrier to exemestane uptake. The results provide practical implications suggesting that exemestane may have limited impact on breast cancer chemoprevention uptake. Further investigations should focus on understanding the factors that influence, predict, and increase chemoprevention uptake.

Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis

BACKGROUND

Preventive therapy is a risk reduction option for women who have an increased risk of breast cancer. The effectiveness of preventive therapy to reduce breast cancer incidence depends on adequate levels of uptake and adherence to therapy. We aimed to systematically review articles reporting uptake and adherence to therapeutic agents to prevent breast cancer among women at increased risk, and identify the psychological, clinical and demographic factors affecting these outcomes.

DESIGN

Searches were carried out in PubMed, CINAHL, EMBASE and PsychInfo, yielding 3851 unique articles. Title, abstract and full text screening left 53 articles, and a further 4 studies were identified from reference lists, giving a total of 57. This review was prospectively registered with PROSPERO (CRD42014014957).

RESULTS

Twenty-four articles reporting 26 studies of uptake in 21 423 women were included in a meta-analysis. The pooled uptake estimate was 16.3% [95% confidence interval (CI) 13.6-19.0], with high heterogeneity (I(2) = 98.9%, P < 0.001). Uptake was unaffected by study location or agent, but was significantly higher in trials [25.2% (95% CI 18.3-32.2)] than in non-trial settings [8.7% (95% CI 6.8-10.9)] (P < 0.001). Factors associated with higher uptake included having an abnormal biopsy, a physician recommendation, higher objective risk, fewer side-effect or trial concerns, and older age. Adherence (day-to-day use or persistence) over the first year was adequate. However, only one study reported a persistence of ≥ 80% by 5 years. Factors associated with lower adherence included allocation to tamoxifen (versus placebo or raloxifene), depression, smoking and older age. Risk of breast cancer was discussed in all qualitative studies.

CONCLUSION

Uptake of therapeutic agents for the prevention of breast cancer is low, and long-term persistence is often insufficient for women to experience the full preventive effect. Uptake is higher in trials, suggesting further work should focus on implementing preventive therapy within routine care.

Breast Cancer Chemoprevention among High-risk Women and those with Ductal Carcinoma In Situ

Chemoprevention with the anti-estrogens, tamoxifen, raloxifene, and aromatase inhibitors, reduce breast cancer incidence in high-risk women; however, uptake has been poor (<5%) in the prevention setting. We assessed use of anti-estrogens for breast cancer prevention, among high-risk women seen at an academic breast center, to observe how uptake rates compare in this setting. We collected data on demographics, breast cancer risk factors, and health behaviors via self-administered questionnaires and medical chart abstraction. Women eligible for chemoprevention with anti-estrogens had a 5-year predicted breast cancer risk according to the Gail model of ≥1.67%, history of lobular or ductal carcinoma in situ (LCIS/DCIS), and/or BRCA mutation. We dichotomized anti-estrogen use as ever or never. Predictors of use were evaluated using multivariable log-binomial regression. Of 412 high-risk women enrolled, 316 (77%) were eligible for chemoprevention. Among eligible women, 55% were non-Hispanic white, 29% Hispanic, 8% non-Hispanic black, and 7% Asian. Women were grouped based upon their highest category of breast cancer risk (in descending order): BRCA mutation carriers (3%), DCIS (40%), LCIS (22%), and 5-year Gail risk ≥1.67% (36%). Among those eligible for chemoprevention, 162 (51%) had ever initiated anti-estrogen therapy (71% tamoxifen, 23% raloxifene, 5% aromatase inhibitor). Anti-estrogen use was highest among women with DCIS (73%). In multivariable analysis, women with a 5-year Gail risk ≥1.67% had approximately a 20% lower likelihood of anti-estrogen use compared to women with DCIS (p = 0.01). In the primary prevention setting, excluding women diagnosed with DCIS, anti-estrogen use was 37%. Multivariable analysis showed differences in uptake by education and potentially by race/ethnicity. Among high-risk women seen at a breast center, anti-estrogen use for chemoprevention was relatively high as compared to the published literature. Clinicians can support high-risk women by effectively communicating breast cancer risk and enhancing knowledge about the risks and benefits of chemoprevention.

Synthesis and anti-breast cancer evaluation of novel N-(guanidinyl)benzenesulfonamides

A series of 4-(substituted)-N-(guanidinyl)benzenesulfonamides bearing biologically active pyrazole, pyrimidine and pyridine moieties were prepared and evaluated for their anticancer activity against human tumor breast cell line (MCF7). These sulfonamides showed promising activity with IC50 values ranging from 49.5 to 70.2 μM. The structure-activity relationship of the synthesized compounds was studied. Interestingly, it was found that the most potent compounds in this study were the corresponding 2-cyanoacrylate 3, 3-oxobutanoate 4, pyrazole 6, pyridine 9 and pyrazole 13. Compounds 7 and 8 are nearly as active as Doxorubicin as reference drug with (IC50 values=70.2, 68.1 μM), while compounds 5, 10 and 11 exhibited a moderate activity.

Are selective estrogen receptor modulators (SERMs) a therapeutic option for HPV-associated cervical lesions and cancers?

This Commentary highlights the article by Spurgeon et al which evaluates oral SERM raloxifene as a potential therapeutic agent for HPV-associated cancer.