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The drug's activity at the target tissue could help to define the minimal effective dose to promote cancer preventive therapy. Here we present exemestane and sex hormone concentrations within breast tissue from a pre-surgical study of alternative exemestane schedules. Postmenopausal women candidate for breast surgery for estrogen receptor-positive breast cancer were randomized to exemestane 25 mg once daily (QD), 25 mg three times/week (TIW), or 25 mg per/week (QW) for 4-6 weeks before surgery. Drug and sex hormones were analyzed from homogenized frozen tissue using a QTRAP 6500+ LC-MS/MS System. Tissue drug concentrations were detectable only in the QD arm with higher concentrations in non-malignant tissue. Estradiol was nearly suppressed in all groups in the non-malignant tissue (QD vs TIW p = .364 and QD vs QW p = .693). In contrast, a dose-response trend was observed in cancer tissue. Based on estradiol suppression in non-malignant tissue, lower exemestane schedules should be explored for breast cancer preventive therapy., (© The Author(s) 2024. Published by Oxford University Press.)

Importance: The effects of breast cancer incidence changes and advances in screening and treatment on outcomes of different screening strategies are not well known., Objective: To estimate outcomes of various mammography screening strategies., Design, Setting, and Population: Comparison of outcomes using 6 Cancer Intervention and Surveillance Modeling Network (CISNET) models and national data on breast cancer incidence, mammography performance, treatment effects, and other-cause mortality in US women without previous cancer diagnoses., Exposures: Thirty-six screening strategies with varying start ages (40, 45, 50 years) and stop ages (74, 79 years) with digital mammography or digital breast tomosynthesis (DBT) annually, biennially, or a combination of intervals. Strategies were evaluated for all women and for Black women, assuming 100% screening adherence and "real-world" treatment., Main Outcomes and Measures: Estimated lifetime benefits (breast cancer deaths averted, percent reduction in breast cancer mortality, life-years gained), harms (false-positive recalls, benign biopsies, overdiagnosis), and number of mammograms per 1000 women., Results: Biennial screening with DBT starting at age 40, 45, or 50 years until age 74 years averted a median of 8.2, 7.5, or 6.7 breast cancer deaths per 1000 women screened, respectively, vs no screening. Biennial DBT screening at age 40 to 74 years (vs no screening) was associated with a 30.0% breast cancer mortality reduction, 1376 false-positive recalls, and 14 overdiagnosed cases per 1000 women screened. Digital mammography screening benefits were similar to those for DBT but had more false-positive recalls. Annual screening increased benefits but resulted in more false-positive recalls and overdiagnosed cases. Benefit-to-harm ratios of continuing screening until age 79 years were similar or superior to stopping at age 74. In all strategies, women with higher-than-average breast cancer risk, higher breast density, and lower comorbidity level experienced greater screening benefits than other groups. Annual screening of Black women from age 40 to 49 years with biennial screening thereafter reduced breast cancer mortality disparities while maintaining similar benefit-to-harm trade-offs as for all women., Conclusions: This modeling analysis suggests that biennial mammography screening starting at age 40 years reduces breast cancer mortality and increases life-years gained per mammogram. More intensive screening for women with greater risk of breast cancer diagnosis or death can maintain similar benefit-to-harm trade-offs and reduce mortality disparities.

Breast cancer prevention only requires local exposure of the breast to active drug. However, oral preventive agents entail systemic exposure, causing adverse effects that limit acceptance by high-risk women. Drug-delivery through the breast skin is an attractive option, but requires demonstration of dermal safety and drug distribution throughout the breast. We formulated the tamoxifen metabolite (E/Z)-endoxifen for transdermal delivery and tested it in a placebo-controlled, double-blinded Phase I trial with dose escalation from 10 to 20 mg daily. The primary endpoint was dermal toxicity. Thirty-two women planning mastectomy were randomized (2:1) to endoxifen-gel or placebo-gel applied to both breasts for 3-5 weeks. Both doses of endoxifen-gel incurred no dermal or systemic toxicity compared to placebo. All endoxifen-treated breasts contained the drug at each of five sampling locations; the median per-person tissue concentration in the treated participants was 0.6 ng/g (IQR 0.4-1.6), significantly higher (p < 0.001) than the median plasma concentration (0.2 ng/mL, IQR 0.2-0.2). The median ratio of the more potent (Z)-isomer to (E)-isomer at each breast location was 1.50 (IQR 0.96-2.54, p < 0.05). No discernible effects of breast size or adiposity on tissue concentrations were observed. At the endoxifen doses and duration used, and the tissue concentration achieved, we observed a non-significant overall reduction of tumor proliferation (Ki67 LI) and significant downregulation of gene signatures known to promote cancer invasion (FN1, SERPINH1, PLOD2, PDGFA, ITGAV) (p = 0.03). Transdermal endoxifen is an important potential breast cancer prevention agent but formulations with better dermal penetration are needed., Competing Interests: Declaration of Competing Interest No potential conflicts of interest were disclosed by all authors., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

In a 3-arm presurgical trial, four-six weeks exemestane 25 mg three times/week (TIW) was non-inferior to 25 mg/day (QD) in suppressing circulating estradiol in postmenopausal women with ER-positive breast cancer. Since obesity may decrease exemestane efficacy, we analyzed changes in sex steroids, adipokines, Ki-67, and drug levels in relation to obesity. Postmenopausal women with early-stage ER-positive breast cancer were randomized to either exemestane 25 mg QD (n = 57), 25 mg TIW (n = 57), or 25 mg/week (QW, n = 62) for 4-6 weeks before breast surgery. Serum and tissue pre- and post-treatment biomarkers were stratified by body mass index (BMI)< or ≥30 kg/m 2 . Post-treatment median exemestane and 17-OH exemestane levels were 5-6 times higher in the QD arm compared to the TIW arm. For obese women, TIW maintained comparable reductions to QD in systemic estradiol levels, although the reduction in estrone was less with the TIW regimen. There was less suppression of SHBG with the TIW versus the QD dose schedule in obese women which should result in less systemic bioavailable estrogens. Metabolically, the effect of the TIW regimen was similar to the QD regimen for obese women in terms of leptin suppression and increase in the adiponectin-leptin ratio. Reduction in tissue Ki-67 was less for obese women on the TIW regimen than QD, although changes were similar for non-obese women. Our findings suggest that TIW exemestane should be explored further for primary cancer prevention in both normal weight and obese cohorts., (© 2024. The Author(s).)

Importance: Oral tamoxifen citrate benefits women with ductal carcinoma in situ (DCIS), but concern about toxic effects has limited acceptance. Previous pilot studies have suggested transdermal 4-hydroxytamoxifen gel has equivalent antiproliferative efficacy to oral tamoxifen, with low systemic exposure., Objective: To demonstrate that 4-hydroxytamoxifen gel applied to the breast skin is noninferior to oral tamoxifen in its antiproliferative effect in DCIS lesions., Design, Setting, and Participants: This randomized, double-blind, phase 2 preoperative window trial was performed at multicenter breast surgery referral practices from May 31, 2017, to January 27, 2021. Among 408 women with estrogen receptor-positive DCIS who were approached, 120 consented and 100 initiated study treatment. The most common reasons for nonparticipation were surgical delay, disinterest in research, and concerns about toxic effects. Data were analyzed from January 26, 2021, to October 5, 2022., Intervention: Random assignment to oral tamoxifen citrate, 20 mg/d, and gel placebo or 4-hydroxytamoxifen gel, 2 mg/d per breast, and oral placebo, for 4 to 10 weeks, followed by DCIS resection., Main Outcomes and Measures: The primary end point was absolute change in DCIS Ki-67 labeling index (Ki67-LI). Secondary end points included 12-gene DCIS Score, breast tissue tamoxifen metabolite concentrations, tamoxifen-responsive plasma protein levels, and patient-reported symptoms. Noninferiority of Ki67-LI reduction by 4-hydroxytamoxifen gel was tested using analysis of covariance; within- and between-arm comparisons were performed with paired t tests for mean values or the Wilcoxon rank sum test for medians., Results: Of 90 participants completing treatment (mean [SD] age, 55 [11] years; 8 [8.9%] Asian, 16 [17.8%] Black, 8 [8.9%] Latina, and 53 [58.9%] White), 15 lacked residual DCIS in the surgical sample, leaving 75 evaluable for the primary end point analysis (40 in the oral tamoxifen group and 35 in the 4-hydroxytamoxifen gel group). Posttreatment Ki67-LI was 3.3% higher (80% CI, 2.1%-4.6%) in the 4-hydroxytamoxifen gel group compared with the oral tamoxifen group, exceeding the noninferiority margin (2.6%). The DCIS Score decreased more with oral tamoxifen treatment (-16 [95% CI, -22 to -9.4]) than with 4-hydroxytamoxifen gel (-1.8 [95% CI, -5.8 to 2.3]). The median 4-hydroxytamoxifen concentrations deep in the breast were nonsignificantly higher in the oral tamoxifen group (5.7 [IQR, 4.0-7.9] vs 3.8 [IQR, 1.3-7.9] ng/g), whereas endoxifen was abundant in the oral tamoxifen group and minimal in the 4-hydroxytamoxifen gel group (median, 13.0 [IQR, 8.9-20.6] vs 0.3 [IQR, 0-0.3] ng/g; P < .001). Oral tamoxifen caused expected adverse changes in plasma protein levels and vasomotor symptoms, with minimal changes in the transdermal group., Conclusions and Relevance: In this randomized clinical trial, antiproliferative noninferiority of 4-hydroxytamoxifen gel to oral tamoxifen was not confirmed, potentially owing to endoxifen exposure differences. New transdermal approaches must deliver higher drug quantities and/or include the most potent metabolites., Trial Registration: ClinicalTrials.gov Identifier: NCT02993159.

NeuVax is a vaccine comprised of the HER2-derived MHC class I peptide E75 (nelipepimut-S, NPS) combined with GM-CSF. We completed a randomized trial of preoperative vaccination with NeuVax versus GM-CSF alone in patients with ductal carcinoma in situ (DCIS). The primary objective was to evaluate for NPS-specific cytotoxic T lymphocyte (CTL) responses. Patients with human leukocyte antigen (HLA)-A2-positive DCIS were enrolled and randomized 2:1 to NeuVax versus GM-CSF alone and received two inoculations prior to surgery. The number of NPS-specific CTL was measured pre-vaccination, at surgery, and 1 and 3 to 6 months post-operation by dextramer assay. Differences in CTL responses between groups and between pre-vaccination and 1-month post-operation were analyzed using a two-sample t test or Wilcoxon rank sum test. The incidence and severity of adverse events were compared between groups. Overall, 45 patients were registered; 20 patients were HLA-A2 negative, 7 declined participation, 1 withdrew, and 4 failed screening for other reasons. The remaining 13 were randomized to NeuVax (n = 9) or GM-CSF alone (n = 4). Vaccination was well-tolerated with similar treatment-related toxicity between groups with the majority (>89%) of adverse events being grade 1. The percentage of NPS-specific CTLs increased in both arms between baseline (pre-vaccination) and 1-month post-operation. The increase was numerically greater in the NPS+GM-CSF arm, but the difference was not statistically significant. NPS+GM-CSF is safe and well-tolerated when given preoperatively to patients with DCIS. In patients with HLA-A2-positive DCIS, two inoculations with NPS+GM-CSF can induce in vivo immunity and a continued antigen-specific T-cell response 1-month postsurgery., Prevention Relevance: This trial showed that vaccination of patients with HLA-A2-positive DCIS with NeuVax in the preoperative setting can induce a sustained antigen-specific T-cell response. This provides proof of principle that vaccination in the preoperative or adjuvant setting may stimulate an adaptive immune response that could potentially prevent disease recurrence., (©2023 American Association for Cancer Research.)

Importance: Successful therapeutic cancer prevention requires definition of the minimal effective dose. Aromatase inhibitors decrease breast cancer incidence in high-risk women, but use in prevention and compliance in adjuvant settings are hampered by adverse events., Objective: To compare the noninferiority percentage change of estradiol in postmenopausal women with estrogen receptor-positive breast cancer given exemestane, 25 mg, 3 times weekly or once weekly vs a standard daily dose with a noninferiority margin of -6%., Design, Setting, and Participants: This multicenter, presurgical, double-blind phase 2b randomized clinical trial evaluated 2 alternative dosing schedules of exemestane. Postmenopausal women with estrogen receptor-positive breast cancer who were candidates for breast surgery were screened from February 1, 2017, to August 31, 2019. Blood samples were collected at baseline and final visit; tissue biomarker changes were assessed from diagnostic biopsy and surgical specimen. Biomarkers were measured in different laboratories between April 2020 and December 2021., Interventions: Exemestane, 25 mg, once daily, 3 times weekly, or once weekly for 4 to 6 weeks before surgery., Main Outcomes and Measures: Serum estradiol concentrations were measured by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry detection. Toxic effects were evaluated using the National Cancer Institute terminology criteria, and Ki-67 was assessed by immunohistochemistry., Results: A total of 180 women were randomized into 1 of the 3 arms; median (IQR) age was 66 (60-71) years, 63 (60-69) years, and 65 (61-70) years in the once-daily, 3-times-weekly, and once-weekly arms, respectively. In the intention-to-treat population (n = 171), the least square mean percentage change of serum estradiol was -89%, -85%, and -60% for exemestane once daily (n = 55), 3 times weekly (n = 56), and once weekly (n = 60), respectively. The difference in estradiol percentage change between the once-daily and 3-times-weekly arms was -3.6% (P for noninferiority = .37), whereas in compliant participants (n = 153), it was 2.0% (97.5% lower confidence limit, -5.6%; P for noninferiority = .02). Among secondary end points, Ki-67 and progesterone receptor were reduced in all arms, with median absolute percentage changes of -7.5%, -5.0%, and -4.0% for Ki-67 in the once-daily, 3-times-weekly, and once-weekly arms, respectively (once daily vs 3 times weekly, P = .31; once daily vs once weekly, P = .06), and -17.0%, -9.0%, and -7.0% for progesterone receptor, respectively. Sex hormone-binding globulin and high-density lipoprotein cholesterol had a better profile among participants in the 3-times-weekly arm compared with once-daily arm. Adverse events were similar in all arms., Conclusions and Relevance: In this randomized clinical trial, exemestane, 25 mg, given 3 times weekly in compliant patients was noninferior to the once-daily dosage in decreasing serum estradiol. This new schedule should be further studied in prevention studies and in women who do not tolerate the daily dose in the adjuvant setting., Trial Registration: ClinicalTrials.gov Identifier: NCT02598557; EudraCT: 2015-005063-16.

Background: Diabetes mellitus has been associated with increased breast cancer (BC) risk; however, the magnitude of this effect is uncertain. This study focused on BC risk for women with type 2 diabetes mellitus (T2DM)., Methods: Two separate meta-analyses were conducted (1) to estimate the relative risk (RR) of BC for women with T2DM and (2) to evaluate the risk of BC for women with T2DM associated with the use of metformin, a common diabetes treatment. In addition, subgroup analyses adjusting for obesity as measured by body mass index (BMI) and menopausal status were also performed. Studies were identified via PubMed/Scopus database and manual search through April 2021., Results: A total of 30 and 15 studies were included in the first and second meta-analyses, respectively. The summary RR of BC for women with T2DM was 1.15 (95% confidence interval [CI], 1.09-1.21). The subgroup analyses adjusting BMI and adjusting BMI and menopause resulted in a summary RR of 1.22 (95% CI, 1.15-1.30) and 1.20 (95% CI, 1.05-1.36), respectively. For women with T2DM, the summary RR of BC was 0.82 (95% CI, 0.60-1.12) for metformin users compared with nonmetformin users., Conclusions: Women with T2DM were more likely to be diagnosed with BC and this association was strengthened by adjusting for BMI and menopausal status. No statistically significant reduction of BC risk was observed among metformin users., Impact: These two meta-analyses can inform decision-making for women with type 2 diabetes regarding their use of metformin and the use of screening mammography for early detection of breast cancer., (© 2022 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Prevention Relevance: Bexarotene is a rexinoid that has been shown to prevent mammary tumors in mouse models but oral dosing has toxicities. This phase I study evaluates topical bexarotene, as a potential chemoprevention agent, for safety and toxicity in high-risk women for breast cancer., (©2022 American Association for Cancer Research.)

Female carriers of pathogenic/likely pathogenic (P/LP) BRCA1/2 variants are at increased risk of developing breast and ovarian cancer. Currently, the only effective strategy for ovarian cancer risk reduction is risk-reducing bilateral salpingo-oophorectomy (RR-BSO), which carries adverse effects related to early menopause. There is ongoing investigation of inhibition of the RANK ligand (RANKL) with denosumab as a means of chemoprevention for breast cancer in carriers of BRCA1 P/LP variants. Through the NCI Division of Cancer Prevention (DCP) Early Phase Clinical Trials Prevention Consortia, a presurgical pilot study of denosumab was developed in premenopausal carriers of P/LP BRCA1/2 variants scheduled for RR-BSO with the goal of collecting valuable data on the biologic effects of denosumab on gynecologic tissue. The study was terminated early due to the inability to accrue participants. Challenges which impacted the conduct of this study included a study design with highly selective eligibility criteria and requirements and the COVID-19 pandemic. It is critical to reflect on these issues to enhance the successful completion of future prevention studies in individuals with hereditary cancer syndromes., (©2022 American Association for Cancer Research.)

Background: The 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) 3rd expert report highlights up-to-date Cancer Prevention Recommendations that may reduce burdens of many chronic diseases, including diabetes. This study examined if following a lifestyle that aligns with the recommendations - assessed via the 2018 WCRF/AICR Score - was associated with lower risk of type 2 diabetes in high-risk adults participating in the Diabetes Prevention Program Outcomes Study (DPPOS)., Methods: The Diabetes Prevention Program (DPP) randomized adults at high risk for diabetes to receive a lifestyle intervention (ILS), metformin (MET) or a placebo (PLB) (mean: 3.2 years), with additional follow-up in DPPOS for 11 years (mean: 15 years total). 2018 WCRF/AICR Scores included seven components: body weight, physical activity, plant-based foods, fast foods, red and processed meat, sugar-sweetened beverages, and alcohol; the optional breastfeeding component was excluded. Scores ranged 0-7 points (with greater scores indicating greater alignment with the recommendations) and were estimated at years 0, 1, 5, 6, 9, and 15 (N=3,147). Fasting glucose and HbA1c were measured every six months and oral glucose tolerance tests were performed annually. Adjusted Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) were used to examine the association of both Score changes from years 0-1 and time-dependent Score changes on diabetes risk through DPP and year 15., Results: Scores improved within all groups over 15 years (p<0.001); ILS Scores improved more than MET or PLB Scores after 1 year (p<0.001). For every 1-unit improvement from years 0-1, there was a 31% and 15% lower diabetes risk in ILS (95% CI: 0.56-0.84) and PLB (95% CI: 0.72-0.97) through DPP, and no significant association in MET. Associations were greatest among American Indian participants, followed by non-Hispanic White and Hispanic participants. Score changes from years 0-1 and time-dependent Score changes in ILS and PLB remained associated with lower risk through year 15., Conclusions: Score improvements were associated with long-term, lower diabetes risk among high-risk adults randomized to ILS and PLB, but not MET. Future research should explore impact of the Score on cancer risk., Trial Registration: Diabetes Prevention Program: NCT00004992 ; Diabetes Prevention Program Outcomes Study: NCT00038727., (© 2022. The Author(s).)

The Division of Cancer Prevention in the NCI sponsored a Roundtable with primary care providers (PCP) to determine barriers for integrating cancer prevention within primary care and discuss potential opportunities to overcome these barriers. The goals were to: (i) assess the cancer risk assessment tools available to PCPs; (ii) gather information on use of cancer prevention resources; and (iii) understand the needs of PCPs to facilitate the implementation of cancer prevention interventions beyond routine screening and interventions. The Roundtable discussion focused on challenges and potential research opportunities related to: (i) cancer risk assessment and management of high-risk individuals; (ii) cancer prevention interventions for risk reduction; (iii) electronic health records/electronic medical records; and (iv) patient engagement and information dissemination. Time constraints and inconsistent/evolving clinical guidelines are major barriers to effective implementation of cancer prevention within primary care. Social determinants of health are important factors that influence patients' adoption of recommended preventive interventions. Research is needed to determine the best means for implementation of cancer prevention across various communities and clinical settings. Additional studies are needed to develop tools that can help providers collect clinical data that can enable them to assess patients' cancer risk and implement appropriate preventive interventions., (©2022 The Authors; Published by the American Association for Cancer Research.)

Metabolic syndrome consists of a constellation of clinical factors associated with an increased risk of cardiovascular disease, type 2 diabetes, and cancer. Preclinical studies demonstrate that restricting the time during a 24-hour period when an obese animal eats (time-restricted feeding) leads to metabolic benefits. These benefits, which may or may not be associated with weight loss, often lead to improvements in glucose tolerance and insulin sensitivity. Studies seeking to determine whether similar benefits result when humans restrict daily eating time (time-restricted eating) are less mature and less consistent in their findings. In this commentary, we outline some of the exciting preclinical findings, the challenges that preliminary studies in humans present, and efforts of the US National Institutes of Health and specifically the National Cancer Institute to address the role of time-restricted eating in cancer., (Published by Oxford University Press 2022.)

Precision cancer prevention as it is currently envisioned is a targeted, molecular-based approach to intercept carcinogenesis before cancer develops or before it becomes untreatable. Unfortunately, due to systemic biases, current precision cancer prevention interventions might not be effective in all populations, especially in minoritized communities. In addition, not all cancer risk is attributable to genetic or even biological factors, but includes social determinants of health (SDH). Here, we propose a broader framework for precision cancer prevention, anchored in optimizing the benefits to harms for all people. We propose that precision cancer prevention considers not only what is being delivered, but also for whom, where, and how, with a goal of achieving cancer prevention health equity., Competing Interests: Declaration of interests None declared by the authors., (Published by Elsevier Inc.)

As clinical guidelines for cancer prevention refer individuals to primary care physicians (PCP) for risk assessment and clinical management, PCPs may be expected to play an increasing role in cancer prevention. It is crucial that PCPs are adequately supported to assess an individual's cancer risk and make appropriate recommendations. The objective of this study is to assess use, familiarity, attitude, and behaviors of PCPs regarding breast and ovarian cancer risk and prevention, to better understand the factors that influence their prescribing behaviors. We conducted a cross-sectional, web-based survey of PCPs in the United States, recruited from an opt-in healthcare provider panel. Invitations were sent in batches until the target sample size of 750 respondents (250 each for obstetrics/gynecology, internal medicine, and family medicine) was met. Self-reported use of breast/ovarian cancer risk assessments was low (34.7%-59.2%) compared with discussion of cancer family history (96.9%), breast exams (87.1%), and mammograms (92.8%). Although most respondents (48.0%-66.8%) were familiar with cancer prevention interventions, respondents who reported to be less familiar were more likely to report cautious attitudes. When presented with hypothetical cases depicting patients at different breast/ovarian cancer risks, up to 34.0% of respondents did not select any of the clinically recommended course(s) of action. This survey suggests that PCP use of breast/ovarian cancer risk assessment tools and ability to translate the perceived risks to clinical actions is variable. Improving implementation of cancer risk assessment and clinical management guidelines within primary care may be necessary to improve the appropriate prescribing of cancer prevention interventions. Prevention Relevance: Primary care physicians are becoming more involved in cancer prevention management, so it is important that cancer risk assessment and medical society guideline recommendations for cancer prevention are better integrated into primary care to improve appropriate prescribing of cancer prevention interventions and help reduce cancer risk., (©2020 American Association for Cancer Research.)

Background: A previous study found evidence that a breast cancer risk prediction model preferentially selected for less aggressive tumors in Swedish women. In the US, the Gail model has been widely used and was used for entry criteria in two large breast cancer prevention trials. We assessed if higher risk levels from the Gail model were associated with less aggressive tumor characteristics and if risk levels were predictive of mortality and survival., Methods: We used questionnaire data from women in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to calculate Gail risk levels (low < 1.66%; moderate 1.66-2.99%; high ≥ 3.00%). Women aged 55-74 were enrolled between 1993 and 2001 and had detailed information on breast cancer incidence and tumors collected. We calculated breast cancer incidence and mortality rates among all women by risk levels and examined breast cancer survival and tumor characteristics among women diagnosed with breast cancer. We used Chi-squared tests and multivariable logistic regression to assess the association between risk levels and tumor characteristics., Results: The study population for this analysis included 45,402 women with 1908 cases of breast cancer. Women at high risk were associated with higher risk of breast cancer mortality compared to women with low risk [rate ratio (RR) = 2.29 95% confidence interval (CI) 1.37-3.84)]. Higher risk levels were associated with lobular-type tumors [moderate: adjusted odds ratio (aOR) = 1.57 95% CI 1.13-2.17; high: aOR = 1.78 95% CI 1.25-2.54] but were not associated with any other tumor characteristics or breast cancer survival., Conclusions: We did not find evidence that higher risk levels from the Gail model are predictive of less aggressive breast cancer tumors.

Purpose: Acceptability and uptake of cancer preventive interventions is associated with physician recommendation, which is dependent on physician familiarity with available preventive options. The goal of this study is to evaluate cancer prevention perceptions, understanding of breast and ovarian cancer risk factors, and prescribing behaviors of primary care physicians., Methods: We conducted cross-sectional. Web-based survey of 750 primary care physicians (250 each for obstetrics/gynecology, internal medicine, and family medicine) in the United States. Survey respondents were recruited from an opt-in health care provider panel., Results: Perception of importance and the practice of recommending general and cancer-specific preventive screenings and interventions significantly differed by provider type. These perceptions and behaviors reflected the demographics of the population that the primary care physicians see within their respective practices. The majority of respondents recognized genetic/hereditary risk factors for breast or ovarian cancer, while epidemiologic or clinical risk factors were less frequently recognized. Prescribing behaviors were related to familiarity with the interventions, with physicians indicating that they more frequently reinforced a specialist's recommendation rather than prescribed a preventive intervention., Conclusions: Cancer prevention perceptions, recognition of cancer risk factors, and prescribing behaviors differ among practice types and were related to familiarity with preventive options. Cancer prevention education and risk assessment resources should be more widely available to primary care physicians., (Published by Elsevier Inc.)

Background: The incidence of ductal carcinoma in situ (DCIS) has increased substantially since the introduction of mammography screening. Nevertheless, little is known about the natural history of preclinical DCIS in the absence of biopsy or complete excision., Methods: Two well-established population models evaluated six possible DCIS natural history submodels. The submodels assumed 30%, 50%, or 80% of breast lesions progress from undetectable DCIS to preclinical screen-detectable DCIS; each model additionally allowed or prohibited DCIS regression. Preclinical screen-detectable DCIS could also progress to clinical DCIS or invasive breast cancer (IBC). Applying US population screening dissemination patterns, the models projected age-specific DCIS and IBC incidence that were compared to Surveillance, Epidemiology, and End Results data. Models estimated mean sojourn time (MST) in the preclinical screen-detectable DCIS state, overdiagnosis, and the risk of progression from preclinical screen-detectable DCIS., Results: Without biopsy and surgical excision, the majority of DCIS (64-100%) in the preclinical screen-detectable state progressed to IBC in submodels assuming no DCIS regression (36-100% in submodels allowing for DCIS regression). DCIS overdiagnosis differed substantially between models and submodels, 3.1-65.8%. IBC overdiagnosis ranged 1.3-2.4%. Submodels assuming DCIS regression resulted in a higher DCIS overdiagnosis than submodels without DCIS regression. MST for progressive DCIS varied between 0.2 and 2.5 years., Conclusions: Our findings suggest that the majority of screen-detectable but unbiopsied preclinical DCIS lesions progress to IBC and that the MST is relatively short. Nevertheless, due to the heterogeneity of DCIS, more research is needed to understand the progression of DCIS by grades and molecular subtypes.

In both estrogen receptor/progesterone receptor-positive (ER + /PR + ) human breast cancer and in ER + /PR + cancers in the methylnitrosourea (MNU)-induced rat model, short-term modulation of proliferation in early cancers predicts preventive/therapeutic efficacy. We determined the effects of known effective/ineffective chemopreventive agents on proliferative index (PI) in both rat mammary epithelium and small cancers. Female Sprague-Dawley rats were treated with MNU at 50 days of age. Five days later, the rats were treated with the individual compounds for a period of 14 days. At that time, normal mammary tissue from the inguinal gland area was surgically removed. After removal, the rats remained on the agents for an additional 5 months. This cancer prevention study confirmed our prior results of striking efficacy with tamoxifen, vorozole, Targretin, and gefitinib, and no efficacy with metformin, naproxen, and Lipitor. Employing a separate group of rats, the effects of short-term (7 days) drug exposure on small palpable cancers were examined. The PI in both small mammary cancers and in normal epithelium from control rats was >12%. In agreement with the cancer multiplicity data, tamoxifen, vorozole, gefitinib, and Targretin all strongly inhibited proliferation (>65%; P < 0.025) in the normal mammary epithelium. The ineffective agents metformin, naproxen, and Lipitor minimally affected PI. In the small cancers, tamoxifen, vorozole, and Targretin all reduced the PI, while metformin and Lipitor failed to do so. Thus, short-term changes in the PI in either normal mammary epithelium or small cancers correlated with long-term preventive efficacy in the MNU-induced rat model., (©2019 American Association for Cancer Research.)

Raloxifene reduces breast cancer incidence. However, it is unclear whether it also reduces mortality from breast cancer. For raloxifene to reduce incidence but not mortality, breast cancer survival would have to be worse for raloxifene users than nonusers. Surveillance Epidemiology and End Results-Medicare was used to identify women with invasive breast cancer diagnosed from 2007 to 2015 at ages 65-89 who had prior Medicare Part D (prescription drug) enrollment; breast cancer characteristics and survival were assessed among raloxifene regular users (≥180 days in past year) versus nonusers. Logistic regression was used to assess cancer characteristics. Two methods utilizing proportional hazards models were employed to assess breast cancer-specific survival. In method 1, survival was assessed adjusting for demographics, mammography use, and chronic conditions in the subset with Medicare fee-for-service enrollment. In method 2, predicted survival as a function of breast cancer characteristics was modeled in nonusers and the model applied to users to predict survival. A total of 116,317 raloxifene nonusers and 1,223 regular users were identified. Users were significantly more likely to have hormone receptor (HR)-negative cancers, but less likely to have T2+, N1+, and metastatic disease. There were 10,869 and 101 breast cancer-related deaths in nonusers and regular users, respectively. The HR (users vs. nonusers) for breast cancer-specific survival in method 1 was 0.94 (95% confidence interval, 0.73-1.22). In method 2, predicted survival was higher in users than nonusers (8-year survival 84.9% vs. 83.4%). Breast cancer-specific survival in raloxifene users was not worse than in nonusers, providing indirect evidence that raloxifene reduces breast cancer-related mortality., (©2019 American Association for Cancer Research.)

Novel biomarkers of type 2 diabetes (T2D) and response to preventative treatment in individuals with similar clinical risk may highlight metabolic pathways that are important in disease development. We profiled 331 metabolites in 2,015 baseline plasma samples from the Diabetes Prevention Program (DPP). Cox models were used to determine associations between metabolites and incident T2D, as well as whether associations differed by treatment group (i.e., lifestyle [ILS], metformin [MET], or placebo [PLA]), over an average of 3.2 years of follow-up. We found 69 metabolites associated with incident T2D regardless of treatment randomization. In particular, cytosine was novel and associated with the lowest risk. In an exploratory analysis, 35 baseline metabolite associations with incident T2D differed across the treatment groups. Stratification by baseline levels of several of these metabolites, including specific phospholipids and AMP, modified the effect that ILS or MET had on diabetes development. Our findings highlight novel markers of diabetes risk and preventative treatment effect in individuals who are clinically at high risk and motivate further studies to validate these interactions., (© 2019 by the American Diabetes Association.)

9cUAB30 is a synthetic analogue of 9-cis retinoic acid with chemoprevention activity in cell lines and animal models. The purpose of this phase I placebo-controlled, double-blinded, dose escalation study of 9cUAB30 was to evaluate its safety, pharmacokinetics, and determine a dose for future phase II studies. Participants received a single dose of study drug (placebo or 9cUAB30) on day 1 followed by a 6-day drug-free period and then 28 days of continuous daily dosing starting on day 8. Fifty-three healthy volunteers were enrolled into five dose cohorts (20, 40, 80, 160, and 240 mg). Participants were randomized within each dose level to receive either 9cUAB30 ( n = 8) or placebo ( n = 2). 9cUAB30 was well tolerated, with no dose limiting toxicities reported and no evidence of persistent elevations in serum triglycerides or cholesterol. Treatment-emergent grade 3 hypertension occurred in 1 of 8 participants at the 20 mg dose level and in 2 of 8 at the 240 mg dose level, all considered unlikely related to study agent; no other grade 3 adverse events were observed. The AUC increased, as expected, between day 1 (single dose) and day 36 (steady state). Pharmacokinetics were linear in dose escalation through 160 mg. 9cUAB30 administered by daily oral dosing has a favorable safety and pharmacokinetic profile. On the basis of the observed safety profile and lack of linearity in pharmacokinetics at doses greater than 160 mg, the recommended phase II dose with the current formulation is 160 mg once daily., (©2019 American Association for Cancer Research.)

Individuals at high risk for cancer, including those already diagnosed with premalignant lesions, can potentially benefit from chemopreventive interventions to reduce cancer risk. However, uptake and acceptability have been hindered due to the risk of systemic toxicity and other adverse effects. Locally delivered chemopreventive agents, where direct action on the primary organ may limit systemic toxicity, are emerging as an option for high-risk individuals. While a number of clinical trials support the development of chemopreventive agents, it is crucial to understand the factors and barriers that influence their acceptability and use. We conducted 36 focus groups with 198 individuals at average and high risk of breast/ovarian, gynecologic, and head/neck/oral and lung cancers to examine the perceptions and acceptability of chemopreventive agents. Participants' willingness to use chemopreventive agents was influenced by several factors, including perceived risk of cancer, skepticism around prevention, previous knowledge of chemopreventive agents, support from trusted sources of health information, participation in other cancer-related risk-reduction activities, previous experience with similar modalities, cost, regimen, side effects, and perceived effectiveness of the preventive intervention. Our findings indicate that individuals may be more receptive to locally delivered chemopreventive agents if they perceive themselves to be at high risk for cancer and are given the necessary information regarding regimen and side effects to make an informed decision. Clinical trials that collect additional patient-centered data including side effects and how these interventions fit into an individual's lifestyle are imperative to improve uptake of chemopreventive agents., (©2019 American Association for Cancer Research.)

Obesity, a cause of subclinical inflammation, is a risk factor for the development of postmenopausal breast cancer and is associated with poorer cancer outcomes. Docosahexaenoic acid (DHA), an omega-3 fatty acid, possesses anti-inflammatory properties. We hypothesized that treatment with DHA would reduce the expression of proinflammatory genes and aromatase, the rate-limiting enzyme for estrogen biosynthesis, in benign breast tissue of overweight/obese women. A randomized, placebo-controlled, double-blind phase II study of DHA given for 12 weeks to overweight/obese women with a history of stage I-III breast cancer, DCIS/LCIS, Paget's disease, or proliferative benign breast disease was carried out. In this placebo controlled trial, the primary objective was to determine whether DHA (1,000 mg by mouth twice daily) reduced breast tissue levels of TNFα. Secondary objectives included evaluation of the effect of DHA on breast tissue levels of COX-2, IL1β, aromatase, white adipose tissue inflammation, and gene expression by RNA-seq. Red blood cell fatty acid levels were measured to assess compliance. From July 2013 to November 2015, 64 participants were randomized and treated on trial (32 women per arm). Increased levels of omega-3 fatty acids in red blood cells were detected following treatment with DHA ( P < 0.001) but not placebo. Treatment with DHA did not alter levels of TNFα ( P = 0.71), or other biomarkers including the transcriptome in breast samples. Treatment with DHA was overall well-tolerated. Although compliance was confirmed, we did not observe changes in the levels of prespecified biomarkers in the breast after treatment with DHA when compared with placebo. Cancer Prev Res; 11(4); 203-14. ©2018 AACR See related editorial by Fabian and Kimler, p. 187 ., (©2018 American Association for Cancer Research.)

The largest and longest clinical trial of metformin for the prevention of diabetes is the Diabetes Prevention Program/Diabetes Prevention Program Outcomes Study (DPP/DPPOS). In this review, we summarise data from the DPP/DPPOS, focusing on metformin for diabetes prevention, as well as its long-term glycaemic and cardiometabolic effects and safety in people at high-risk of developing diabetes. The DPP (1996-2001) was a RCT of 3234 adults who, at baseline, were at high-risk of developing diabetes. Participants were assigned to masked placebo (n = 1082) or metformin (n = 1073) 850 mg twice daily, or intensive lifestyle intervention (n = 1079). The masked metformin/placebo intervention phase ended approximately 1 year ahead of schedule because of demonstrated efficacy. Primary outcome was reported at 2.8 years. At the end of the DPP, all participants were offered lifestyle education and 88% (n = 2776) of the surviving DPP cohort continued follow-up in the DPPOS. Participants originally assigned to metformin continued to receive metformin, unmasked. The DPP/DPPOS cohort has now been followed for over 15 years with prospective assessment of glycaemic, cardiometabolic, health economic and safety outcomes. After an average follow-up of 2.8 years, metformin reduced the incidence of diabetes by 31% compared with placebo, with a greater effect in those who were more obese, had a higher fasting glucose or a history of gestational diabetes. The DPPOS addressed the longer-term effects of metformin, showing a risk reduction of 18% over 10 and 15 years post-randomisation. Metformin treatment for diabetes prevention was estimated to be cost-saving. At 15 years, lack of progression to diabetes was associated with a 28% lower risk of microvascular complications across treatment arms, a reduction that was no different among treatment groups. Recent findings suggest metformin may reduce atherosclerosis development in men. Originally used for the treatment of type 2 diabetes, metformin, now proven to prevent or delay diabetes, may serve as an important tool in battling the growing diabetes epidemic. Long-term follow-up, currently underway in the DPP/DPPOS, is now evaluating metformin's potential role, when started early in the spectrum of dysglycaemia, on later-stage comorbidities, including cardiovascular disease and cancer., Trial Registration: ClinicalTrials.gov NCT00038727 and NCT00004992.

Multiple epidemiological studies have documented an association between metformin, used for treatment of type 2 diabetes, and reduced cancer incidence and mortality. Cell line models may not accurately reflect the effects of metformin in the clinical setting. Moreover, findings from animal model studies have been inconsistent, whilst those from more recent epidemiological studies have tempered the overall effect size. The purpose of this review is to examine metformin's chemopreventive potential by outlining relevant mechanisms of action, the most recent epidemiologic evidence, and recently completed and ongoing clinical trials. Although repurposing drugs with excellent safety profiles is an appealing strategy for cancer prevention and treatment in the adjuvant setting, there is no substitute for well-executed, large randomised clinical trials to define efficacy and determine the populations that are most likely to benefit from an intervention. Thus, enthusiasm remains for understanding the role of metformin in cancer through ongoing clinical research.

Selective estrogen receptor modulators (SERMs), tamoxifen, and raloxifene that reduce the risk of breast cancer are limited to only estrogen receptor-positive (ER(+)) breast cancer. In addition, patient acceptance of SERMs is low due to toxicity and intolerability. New agents with improved toxicity profile that reduce risk of ER-negative breast cancer are urgently needed. Observational studies show that statins can reduce breast cancer incidence and recurrence. The objective of this prospective short-term prevention study was to evaluate the effect of a lipophilic statin, atorvastatin, on biomarkers in breast tissue and serum of women at increased risk. Eligible participants included women with previous history of carcinoma in situ, or atypical hyperplasia, or 5 year breast cancer projected Gail risk >1.67 %, or lifetime breast cancer risk >20 % calculated by models including Claus, Tyrer-Cuzick, Boadicea, or BRCAPRO. Patients underwent baseline fine needle aspiration (FNA) of the breast, blood collection for biomarker analysis, and were randomized to either no treatment or atorvastatin at 10, 20, or 40 mg/day dose for 3 months. At 3 months, blood collection and breast FNA were repeated. Biomarkers included C-reactive protein (CRP), lipid profile, atorvastatin, and its metabolites, Ki-67, bcl-2, EGFR, and pEGFR. Baseline genotype for 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) was also measured. Among 60 patients evaluated, a significant reduction in serum CRP, cholesterol and low-density lipoprotein (LDL), and increase in atorvastatin metabolites in serum and breast FNAs was demonstrated. No changes were observed in other tissue biomarkers. This study shows that atorvastatin and its metabolites are detectable in breast samples and may lower serum CRP among women without hyperlipidemia.

This phase II trial evaluated clinical markers of efficacy and safety of exemestane in postmenopausal women at increased risk for breast cancer. Postmenopausal women (n = 42) at risk for invasive breast cancer received 25 mg exemestane daily for 2 years along with calcium and vitamin D. The primary outcome was change in mammographic density (MD) after one year. Secondary outcomes included change in serum steroid hormones as well as change in trefoil protein 1 (TFF1) and proliferating cell nuclear antigen (PCNA) in breast tissue. Safety and tolerability were also assessed. MD decreased at 1 year and was significant at 2 years [mean change = -4.1%; 95% confidence intervals (CI), -7.2 to -1.1; P = 0.009]. Serum estradiol and testosterone levels significantly decreased at 3 months and remained suppressed at 12 months. After 1 year of treatment, TFF1 intensity decreased (mean change -1.32; 95% CI, -1.87 to -0.76; P < 0.001). Exemestane was safe and well tolerated. Exemestane decreased MD and expression of breast tissue TFF1. It was well tolerated with few clinically relevant side effects. MD and breast tissue TFF1 are potential biomarkers of breast cancer-preventive effects of exemestane in high-risk postmenopausal women., (©2016 American Association for Cancer Research.)

Multiple epidemiologic studies have documented an association between the anti-diabetic agent metformin and reduced cancer incidence and mortality. However, this effect has not been consistently demonstrated in animal models or more recent epidemiological studies. The purpose of this paper is to examine metformin's chemopreventive potential by reviewing relevant mechanisms of action, preclinical evidence of efficacy, updated epidemiologic evidence after correction for potential biases and confounders, and recently completed and ongoing clinical trials. Although repurposing drugs with well described mechanisms of action and safety profiles is an appealing strategy for cancer prevention, there is no substitute for well executed late phase clinical trials to define efficacy and populations that are most likely to benefit from an intervention., (Published by Elsevier Inc.)

The purpose of this study was to assess the feasibility of using the selective estrogen receptor modulator (SERM) acolbifene as a breast cancer prevention agent in premenopausal women. To do so, we assessed change in proliferation in benign breast tissue sampled by random periareolar fine-needle aspiration (RPFNA) as a primary endpoint, along with changes in other risk biomarkers and objective and subjective side effects as secondary endpoints. Twenty-five women with cytologic hyperplasia ± atypia and ≥2% of breast epithelial cells staining positive for Ki-67, received 20 mg acolbifene daily for 6-8 months, and then had benign breast tissue and blood risk biomarkers reassessed. Ki-67 decreased from a median of 4.6% [interquartile range (IQR), 3.1%-8.5%] at baseline to 1.4% (IQR, 0.6%-3.5%) after acolbifene (P < 0.001; Wilcoxon signed-rank test), despite increases in bioavailable estradiol. There were also significant decreases in expression (RT-qPCR) of estrogen-inducible genes that code for pS2, ERα, and progesterone receptor (P ≤ 0.026). There was no significant change in serum IGF1, IGFBP3, IGF1:IGFBP3 ratio, or mammographic breast density. Subjective side effects were minimal with no significant increase in hot flashes, muscle cramps, arthralgias, or fatigue. Objective measures showed a clinically insignificant decrease in lumbar spine bone density (DEXA) and an increase in ovarian cysts but no change in endometrial thickness (sonography). In summary, acolbifene was associated with favorable changes in benign breast epithelial cell proliferation and estrogen-inducible gene expression but minimal side effects, suggesting a phase IIB placebo-controlled trial evaluating it further for breast cancer prevention., (©2015 American Association for Cancer Research.)

Previous meta-analyses have shown that the antidiabetic agent metformin is associated with reduced cancer incidence and mortality. However, this effect has not been consistently demonstrated in animal models and recent epidemiologic studies. We performed a meta-analysis with a focus on confounders and biases, including body mass index (BMI), study type, and time-related biases. We identified 71 articles published between January 1, 1966, and May 31, 2013, through Pubmed, ISI Web of Science (Science Citation Index Expanded), Embase, and the Cochrane library that were related to metformin and cancer incidence or mortality. Study characteristics and outcomes were abstracted for each study that met inclusion criteria. We included estimates from 47 independent studies and 65,540 cancer cases in patients with diabetes. Overall cancer incidence was reduced by 31% [summary relative risk (SRR), 0.69; 95% confidence interval (CI), 0.52-0.90], although between-study heterogeneity was considerable (I(2) = 88%). Cancer mortality was reduced by 34% (SRR, 0.66; 95% CI, 0.54-0.81; I(2) = 21%). BMI-adjusted studies and studies without time-related biases also showed significant reduction in cancer incidence (SRR, 0.82; 95% CI, 0.70-0.96 with I(2) = 76% and SRR, 0.90; 95% CI, 0.89-0.91 with I(2) = 56%, respectively), albeit with lesser magnitude (18% and 10% reduction, respectively). However, studies of cancer mortality and individual organ sites did not consistently show significant reductions across all types of analyses. Although these associations may not be causal, our results show that metformin may reduce cancer incidence and mortality in patients with diabetes However, the reduction seems to be of modest magnitude and not affecting all populations equally. Clinical trials are needed to determine if these observations apply to nondiabetic populations and to specific organ sites., (©2014 American Association for Cancer Research.)

Background: Breast cancer risk is partially determined by several hormone-related factors. Preclinical and clinical studies suggested that resveratrol may modulate these hormonal factors., Methods: We conducted a pilot study in postmenopausal women with high body mass index (BMI ≥ 25 kg/m2) to determine the clinical effect of resveratrol on systemic sex steroid hormones. Forty subjects initiated the resveratrol intervention (1 gm daily for 12 weeks) with six withdrawn early due to adverse events (AEs). Thirty-four subjects completed the intervention., Results: Resveratrol intervention did not result in significant changes in serum concentrations of estradiol, estrone, and testosterone but led to an average of 10% increase in the concentrations of sex steroid hormone binding globulin (SHBG). Resveratrol intervention resulted in an average of 73% increase in urinary 2-hydroxyestrone (2-OHE1) levels leading to a favorable change in urinary 2-OHE1/16α-OHE1 ratio. One participant had asymptomatic Grade 4 elevation of liver enzymes at the end of study intervention. Two subjects had Grade 3 skin rashes. The remaining adverse events were Grade 1 or 2 events. The most common adverse events were diarrhea and increased total cholesterol, reported in 30% and 27.5% of the subjects, respectively., Conclusion: We conclude that among overweight and obese postmenopausal women, daily 1 gm dose of resveratrol has favorable effects on estrogen metabolism and SHBG. Further placebo-controlled studies are needed to confirm our findings on these hormone-related breast cancer risk factors and the attribution of the adverse effects observed in the study population., Trial Registration: ClinicalTrials.gov: NCT01370889.

Purpose: Local transdermal therapy to the breast may achieve effective target-organ drug delivery, while diminishing systemic effects. We conducted a randomized, double-blind, placebo-controlled phase II trial comparing transdermal 4-hydroxytamoxifen gel (4-OHT) to oral tamoxifen (oral-T) in women with ductal carcinoma in situ (DCIS)., Methods: Twenty-seven pre- and postmenopausal women were randomized to 4-OHT (4 mg/day) or oral-T (20 mg/day) for 6 to 10 weeks before surgery. Plasma, nipple aspirate fluid, and breast adipose tissue concentrations of tamoxifen and its major metabolites were determined by liquid chromatography/tandem mass spectrometry. The primary endpoint was Ki67 labeling in DCIS lesions, measured by immunohistochemistry. In plasma, insulin-like growth factor-1 (IGFI), sex hormone-binding globulin (SHBG), and coagulation protein concentrations were determined., Results: Posttherapy Ki67 decreased by 3.4% in the 4-OHT and 5.1% in the oral-T group (P ≤ 0.03 in both, between-group P = 0. 99). Mean plasma 4-OHT was 0.2 and 1.1 ng/mL in 4-OHT and oral groups, respectively (P = 0.0003), whereas mean breast adipose tissue concentrations of 4-OHT were 5.8 ng/g in the 4-OHT group and 5.4 ng/g in the oral group (P = 0.88). There were significant increases in plasma SHBG, factor VIII, and von Willebrand factor and a significant decrease in plasma IGFI with oral-T, but not with 4-OHT. The incidence of hot flashes was similar in both groups., Conclusions: The antiproliferative effect of 4-OHT gel applied to breast skin was similar to that of oral-T, but effects on endocrine and coagulation parameters were reduced. These findings support the further evaluation of local transdermal therapy for DCIS and breast cancer prevention., (©2014 American Association for Cancer Research.)

Objectives: To discuss the role of clinical trials in the changing landscape of cancer care resulting in individualized cancer treatment plans including a discussion of several innovative randomized studies designed to evaluate multiple targeted therapies in molecularly defined subsets of individuals., Data Sources: Medical and nursing literature, research articles, and clinicaltrials.gov., Conclusion: Recent advancements in cancer biomarkers and biomedical technology have begun to transform fundamentals of cancer therapeutics and clinical trials through innovative adaptive trial designs. The goal of these studies is to learn not only if a drug is safe and effective but also how it is best delivered and who will derive the most benefit., Implications for Nursing Practice: Implementation of clinical trials in the cancer biomarker era requires knowledge, skills, and expertise related to the use of biomarkers and molecularly defined processes underlying a malignancy, as well as an understanding of associated ethical, legal, and social issues to provide competent, safe, and effective health care and patient communication., (Published by Elsevier Inc.)

Introduction: The National Cancer Institute Principles and Practice of Cancer Prevention and Control course is a 4-week course encompassing a variety of cancer prevention and control topics that is open to attendees from medical, academic, government, and related institutions around the world. Themes related to the challenges health disparities present to cancer prevention efforts and potential solutions to these issues emerged from facilitated group discussions among the 2012 course participants., Materials and Methods: Small-group discussion sessions with participants (n = 85 from 33 different countries) and facilitators (n = 9) were held once per week throughout the 4-week course. Facilitators prepared open-ended questions related to course topics. Participants provided responses reflecting their opinions of topics on the basis of experiences in their countries. A thematic analysis was conducted to explore themes emerging from the discussion groups., Results: The varied influences of health disparities on cancer prevention efforts among > 30 countries represented prominent themes across discussion groups. Participants discussed the interplay of individual characteristics, including knowledge and culture, interpersonal relationships such as family structure and gender roles, community and organizational factors such as unequal access to health care and access to treatment, and national-level factors including policy and government structure., Conclusion: The ideas and solutions presented here are from a geographically and professionally diverse group of individuals. The collective discussion highlighted the pervasiveness of health disparities across all areas represented by course participants and suggested that disparities are the largest impediment to achieving cancer prevention goals.

Tamoxifen is a drug that has been in worldwide use for the treatment of estrogen receptor (ER)-positive breast cancer for over 30 years; it has been used in both the metastatic and adjuvant settings. Tamoxifen's approval for breast cancer risk reduction dates back to 1998, after results from the Breast Cancer Prevention Trial, co-sponsored by the National Cancer Institute and the National Surgical Adjuvant Breast and Bowel Project, showed a 49% reduction in the incidence of invasive, ER-positive breast cancer in high-risk women. Despite these positive findings, however, the public's attitude toward breast cancer chemoprevention remains ambivalent, and the toxicities associated with tamoxifen, particularly endometrial cancer and thromboembolic events, have hampered the drug's uptake by high-risk women who should benefit from its preventive effects. Among the strategies to overcome such obstacles to preventive tamoxifen, two novel and potentially safer modes of delivery of this agent are discussed in this paper. Low-dose tamoxifen, expected to confer fewer adverse events, is being investigated in both clinical biomarker-based trials and observational studies. A series of systemic biomarkers (including lipid and insulin-like growth factor levels) and tissue biomarkers (including Ki-67) are known to be favorably affected by conventional tamoxifen dosing and have been shown to be modulated in a direction consistent with a putative anti-cancer effect. These findings suggest possible beneficial clinical preventive effects by low-dose tamoxifen regimens and they are supported by observational studies. An alternative approach is topical administration of active tamoxifen metabolites directly onto the breast, the site where the cancer is to be prevented. Avoidance of systemic administration is expected to reduce the distribution of drug to tissues susceptible to tamoxifen-induced toxicity. Clinical trials of topical tamoxifen with biological endpoints are still ongoing whereas pharmacokinetic studies have already shown that appropriate formulations of drug successfully penetrate the skin to reach breast tissue, where a preventive effect is sought.

The Principles and Practice of Cancer Prevention and Control course (Principles course) is offered annually by the National Cancer Institute Cancer Prevention Fellowship Program. This 4-week postgraduate course covers the spectrum of cancer prevention and control research (e.g., epidemiology, laboratory, clinical, social, and behavioral sciences) and is open to attendees from medical, academic, government, and related institutions across the world. In this report, we describe a new addition to the Principles course syllabus, which was exclusively a lecture-based format for over 20 years. In 2011, cancer prevention fellows and staff designed and implemented small group discussion sessions as part of the curriculum. The goals of these sessions were to foster an interactive environment, discuss concepts presented during the Principles course, exchange ideas, and enhance networking among the course participants and provide a teaching and leadership opportunity to current cancer prevention fellows. Overall, both the participants and facilitators who returned the evaluation forms (n=61/87 and 8/10, respectively) reported a high satisfaction with the experience for providing both an opportunity to explore course concepts in a greater detail and to network with colleagues. Participants (93%) and facilitators (100%) stated that they would like to see this component remain a part of the Principles course curriculum, and both groups provided recommendations for the 2012 program. The design, implementation, and evaluation of this initial discussion group component of the Principles course are described herein. The findings in this report will not only inform future discussion group sessions in the Principles course but may also be useful to others planning to incorporate group learning into large primarily lecture-based courses.

Objectives: To discuss the discovery, validation, and clinical use of multiple types of biomarkers., Data Sources: Medical literature and published guidelines., Conclusion: Formal validation of biomarkers should include both retrospective analyses of well-characterized samples as well as a prospective clinical trial in which the biomarker is tested for its ability to predict the presence of disease or the efficacy of a cancer therapy., Implications for Nursing Practice: Biomarker development is complicated, with very few biomarker discoveries leading to clinically useful tests. Nurses should understand how a biomarker was developed, including the sensitivity and specificity before applying new biomarkers in the clinical setting., (Copyright © 2012. Published by Elsevier Inc.)

Background: Policymakers need estimates of the impact of tobacco control (TC) policies to set priorities and targets for reducing tobacco use. We systematically reviewed the independent effects of TC policies on smoking behavior., Methods: We searched MEDLINE (through January 2012) and EMBASE and other databases through February 2009, looking for studies published after 1989 in any language that assessed the effects of each TC intervention on smoking prevalence, initiation, cessation, or price participation elasticity. Paired reviewers extracted data from studies that isolated the impact of a single TC intervention., Findings: We included 84 studies. The strength of evidence quantifying the independent effect on smoking prevalence was high for increasing tobacco prices and moderate for smoking bans in public places and antitobacco mass media campaigns. Limited direct evidence was available to quantify the effects of health warning labels and bans on advertising and sponsorship. Studies were too heterogeneous to pool effect estimates., Interpretations: We found evidence of an independent effect for several TC policies on smoking prevalence. However, we could not derive precise estimates of the effects across different settings because of variability in the characteristics of the intervention, level of policy enforcement, and underlying tobacco control environment.

P190A and p190B Rho GTPase activating proteins (GAPs) are essential genes that have distinct, but overlapping roles in the developing nervous system. Previous studies from our laboratory demonstrated that p190B is required for mammary gland morphogenesis, and we hypothesized that p190A might have a distinct role in the developing mammary gland. To test this hypothesis, we examined mammary gland development in p190A-deficient mice. P190A expression was detected by in situ hybridization in the developing E14.5day embryonic mammary bud and within the ducts, terminal end buds (TEBs), and surrounding stroma of the developing virgin mammary gland. In contrast to previous results with p190B, examination of p190A heterozygous mammary glands demonstrated that p190A deficiency disrupted TEB morphology, but did not significantly delay ductal outgrowth indicating haploinsufficiency for TEB development. To examine the effects of homozygous deletion of p190A, embryonic mammary buds were rescued by transplantation into the cleared fat pads of SCID/Beige mice. Complete loss of p190A function inhibited ductal outgrowth in comparison to wildtype transplants (51% vs. 94% fat pad filled). In addition, the transplantation take rate of p190A deficient whole gland transplants from E18.5 embryos was significantly reduced compared to wildtype transplants (31% vs. 90%, respectively). These results suggest that p190A function in both the epithelium and stroma is required for mammary gland development. Immunostaining for p63 demonstrated that the myoepithelial cell layer is disrupted in the p190A deficient glands, which may result from the defective cell adhesion between the cap and body cell layers detected in the TEBs. The number of estrogen- and progesterone receptor-positive cells, as well as the expression levels of these receptors was increased in p190A deficient outgrowths. These data suggest that p190A is required in both the epithelial and stromal compartments for ductal outgrowth and that it may play a role in mammary epithelial cell differentiation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Introduction: Rho GTPases are overexpressed and hyperactivated in human breast cancers. Deficiency of p190B RhoGAP, a major inhibitor of the Rho GTPases, inhibits mouse mammary tumor virus long terminal repeat (MMTV)-Neu/ErbB2 mammary tumor formation and progression in part through effects within the stromal environment, suggesting that p190B function is pro-tumorigenic. To further investigate the potential pro-tumorigenic actions of p190B, we examined the effects of exogenous p190B expression within the mammary epithelium on MMTV-Neu tumor formation and progression., Methods: Tetracycline-regulatable p190B transgenic mice were bred to MMTV-Neu mice, and the effects of exogenous p190B expression on tumor latency, multiplicity, growth rates, angiogenesis, and metastasis were examined. The effects of exogenous p190B expression on cell-matrix adhesion and invasion were tested using non-transformed primary mammary epithelial cells (MECs). Rho GTPase activity, oxidative stress as an indicator of reactive oxygen species (ROS) production, and downstream signaling pathways were analyzed., Results: Altered p190B expression resulted in a 2-fold increase in tumor multiplicity and a 3-fold increase in metastases compared to control mice indicating that exogenous p190B expression in the mammary epithelium promotes MMTV-Neu mammary tumor formation and progression. Interestingly, non-transformed primary MECs expressing exogenous p190B displayed increased adhesion to laminin and type IV collagen and formed invasive structures in a three-dimensional culture assay. Ras related C3 botulinum toxin 1 (Rac1)-GTP levels were elevated in p190B transgenic tumors whereas Ras homologous A (RhoA) and cell division cycle 42 (Cdc42)-GTP levels were not significantly altered. Rac1 activity affects production of ROS, which regulate transformation, metastasis, and oxidative stress. Protein carbonylation, which is indicative of oxidative stress, was elevated 1.75-fold in p190B transgenic tumors as compared to control tumors suggesting that exogenous p190B expression may affect Rac1-dependent ROS production., Conclusions: These studies indicate that paradoxically, p190B RhoGAP, a major inhibitor of the Rho GTPases in vitro, has pro-tumorigenic functions that enhance MMTV-Neu induced mammary tumor formation and metastasis. Furthermore, exogenous p190B expression enhances cell adhesion and invasion, which may facilitate metastasis. Rac1 activity and oxidative stress are elevated in tumors expressing exogenous p190B suggesting that p190B may promote tumorigenesis through a Rac1/ROS dependent mechanism.