A multidisciplinary approach to the management of breast cancer, part 2: therapeutic considerations

Analysis of Outcomes in Patients With BRCA1/2 Breast Cancer Mutations Treated With Accelerated Partial Breast Irradiation (APBI)

OBJECTIVE

To analyze outcomes and survival for BRCA1/2+ patients treated with accelerated partial breast irradiation (APBI).

MATERIALS AND METHODS

Retrospective review was performed on 341 women treated with intracavitary APBI (Mammosite or Contura) postlumpectomy from 2002 to 2013. Patients were treated to 34.0 Gy in 10 BID fractions. Of 341 treated patients, 11 (3.2%) had BRCA1/2 mutations, 5 of whom had an oophorectomy. Ipsilateral breast tumor recurrence (IBTR), contralateral breast tumor recurrence (CBTR), and breast tumor recurrence progression-free survival were analyzed using SPSS-17. BRCA1/2+ patient outcomes were compared with a general population treated cohort.

RESULTS

Median age at diagnosis was 66 years, for BRCA1/2+ women it was 61 years. Median follow-up was 8.4 years and for BRCA1/2+ patients it was 8.8 years. IBTR for the entire cohort was 3.5%, while CBTR was 1.2%. Both IBTR and CBTR for the BRCA1/2+ group were 0%. The 5-year IBTR-free survival was 97.3% (95% confidence interval [CI]=94.9%, 98.6%), and the CBTR-free survival was 99.4% (95% CI=97.6%, 99.9%). The 5-year breast tumor recurrence-free survival was 96.7% (95% CI=94.1%, 98.2%). As no patients with BRCA1/2+ mutation died of metastatic breast cancer or recurrence during follow-up and review, overall survival could not be evaluated.

CONCLUSIONS

To date, BRCA1/2+ patients treated with APBI sustained no recurrences, or second cancers. Most patients had an ER+ status and underwent oophorectomy, which may be a protective mechanism for recurrence. This is the first outcomes report in the literature of BRCA1/2 mutations treated with APBI technique.

Interaction of WBP2 with ERα increases doxorubicin resistance of breast cancer cells by modulating MDR1 transcription

BACKGROUND

Surgery combined with new adjuvant chemotherapy is the primary treatment for early stage invasive and advanced stage breast cancer. Growing evidence indicates that patients with ERα-positive breast cancer show poor response to chemotherapeutics. However, ERα-mediated drug-resistant mechanisms remain unclear.

METHODS

Levels of WW domain-binding protein 2 (WBP2) and drug-resistant gene were determined by western blotting and RT-PCR, respectively. Cell viability was measured by preforming MTT assay. CD243 expression and apoptosis rate were evaluated by flow cytometry. Interactions of WBP2/ERα and ERα/MDR1 were detected by co-immunoprecipitation and chromatin immunoprecipitation (ChIP) assay, respectively.

RESULTS

There was an intrinsic link between WBP2 and ERα in drug-resistant cancer cells. Upregulation of WBP2 in MCF7 cells increased the chemoresistance to doxorubicin, while RNAi-mediated knockdown of WBP2 in MCF7/ADR cells sensitised the cancer cells to doxorubicin. Further investigation in in vitro and in vivo models demonstrated that WBP2 expression was directly correlated with MDR1, and WBP2 could directly modulate MDR1 transcription through binding to ERα, resulting in increased chemotherapy drug resistance.

CONCLUSIONS

Our finding provides a new mechanism for the chemotherapy response of ERα-positive breast tumours, and WBP2 might be a key molecule for developing new therapeutic strategies to treat chemoresistance in breast cancer patients.

Immunohistochemical Analysis of ER, PR, HER-2, CK 5/6, p63 and EGFR Antigen Expression in Medullary Breast Cancer

Aims and Background

Recent publications of breast cancer classification based on gene expression profile analyses indicate that medullary breast carcinomas (MBC) may be considered part of the basal-like carcinoma spectrum made up of ER-negative, PR-negative and HER-2-negative cells (“triple-negative phenotype”). On the other hand, there are also data showing that a proportion of MBC and atypical MBC (AMBC) is ER, PR and/or HER-2 positive. Therefore, we have decided to immunohistochemically analyze ER, PR, HER-2 and basal/myoepithelial markers CK5/6, p63 and EGFR expression in our archival paraffin-embedded MBC and AMBC samples from 48 patients.

Methods

Immunohistochemical evaluation of samples which were derived from patients operated on at our two hospitals between 1999 and 2005.

Results

Typical MBC was found in 39 patients and AMBC in 9 patients. The patients ranged in age from 32 to 84 years (median 55). Modified radical mastectomy with axillary dissection was performed in 30/48 patients (63%) while breast segmentectomy with axillary dissection was performed in 18/48 patients (37%). Metastases in axillary lymph nodes were observed in 15/48 patients (31%). ER positivity was present in 3/48 patients (6%), PR positivity in 8/48 (17%), and a positive HER-2 reaction was present in 14/48 patients (29%). CK 5/6 was positive in 20/48, p63 in 24/48 and EGFR in 8/48 patients. Adjuvant therapy was applied in all but 2 patients. Alive were 45/48 (94%) of patients. With the exception of PR expression, 39 patients with typical MBC and 9 patients with AMBC were comparable in the analyzed parameters. Positive HER-2 antigen expression in the analyzed sample was not found to be associated to a statistically significant degree with the MBC or AMBC histological tumor type, tumor size, axillary lymph node metastases, ER and PR status nor with patient survival.

Conclusions

The data from our study seem to be generally comparable with the relatively scarce published data on clinicopathological parameters of MBC and AMBC.

ERα propelled aberrant global DNA hypermethylation by activating the DNMT1 gene to enhance anticancer drug resistance in human breast cancer cells

Drug-induced aberrant DNA methylation is the first identified epigenetic marker involved in chemotherapy resistance. Understanding how the aberrant DNA methylation is acquired would impact cancer treatment in theory and practice. In this study we systematically investigated whether and how ERα propelled aberrant global DNA hypermethylation in the context of breast cancer drug resistance. Our data demonstrated that anticancer drug paclitaxel (PTX) augmented ERα binding to the DNMT1 and DNMT3b promoters to activate DNMT1 and DNMT3b genes, enhancing the PTX resistance of breast cancer cells. In support of these observations, estrogen enhanced multi-drug resistance of breast cancer cells by up-regulation of DNMT1 and DNMT3b genes. Nevertheless, the aberrant global DNA hypermethylation was dominantly induced by ERα-activated-DNMT1, since DNMT1 over-expression significantly increased global DNA methylation and DNMT1 knockdown reversed the ERα-induced global DNA methylation. Altering DNMT3b expression had no detectable effect on global DNA methylation. Consistently, the expression level of DNMT1 was positively correlated with ERα in 78 breast cancer tissue samples shown by our immunohistochemistry (IHC) analysis and negatively correlated with relapse-free survival (RFS) and distance metastasis-free survival (DMFS) of ERα-positive breast cancer patients. This study provides a new perspective for understanding the mechanism underlying drug-resistance-facilitating aberrant DNA methylation in breast cancer and other estrogen dependent tumors.

ERα directly activated the MDR1 transcription to increase paclitaxel-resistance of ERα-positive breast cancer cells in vitro and in vivo

Chemotherapy is commonly used to treat early-stage invasive and advanced-stage breast cancer either before or after surgery. Increasing evidence from clinical analysis and in vitro studies has shown that ER-positive breast cancer cells are insensitive to chemotherapy. Complete understanding of how ERα mediates drug resistance is prerequisite to improvement of the chemotherapeutic efficacy. Over-expression of P-glycoprotein (P-gp) encoded by MDR1 gene is one of the major causes of drug resistance. The association between ERα and MDR1 in breast cancer is still unclear and the limited reports are conflict. This study systematically explored intrinsic link between ERα and the P-gp over-expression in paclitaxel-resistant ERα(+) breast cancer cell lines and mouse model in molecular details. Our data showed that ERα activated the MDR1 transcription in MCF-7/PTX breast cancer cells by binding to ERE1/2 and interacting with Sp1 that bridged to the downstream CG-rich element within the MDR1 promoter. Knockdown of MDR1 restrained the effect of ERα in MCF-7 cells and sensitized the cells to paclitaxel. Treatment of ICI 182,780 that selectively suppressed ERα significantly decreased the MDR1 expression and increased the sensitivity of drug resistant breast cancer cells and xenograft tumors to paclitaxel. Our data strongly demonstrated that ERα was able to increase drug resistance of breast cancer cells through activating MDR1 transcription. This novel mechanism provides new insight to how the ERα signaling regulates response of ERα(+) breast tumors to chemotherapy, which may be exploited for developing novel therapeutic strategies for breast cancer in the future.

Megestrol acetate for treatment of anorexia-cachexia syndrome

BACKGROUND

This is an updated version of a previously published review in The Cochrane Library (2005, Issue 2) on 'Megestrol acetate for the treatment of anorexia-cachexia syndrome'. Megestrol acetate (MA) is currently used to improve appetite and to increase weight in cancer-associated anorexia. In 1993, MA was approved by the US Food and Drug Administration for the treatment of anorexia, cachexia or unexplained weight loss in patients with AIDS. The mechanism by which MA increases appetite is unknown and its effectiveness for anorexia and cachexia in neoplastic and AIDS (acquired immunodeficiency syndrome) patients is under investigation.

OBJECTIVES

To evaluate the efficacy, effectiveness and safety of MA in palliating anorexia-cachexia syndrome in patients with cancer, AIDS and other underlying pathologies.

SEARCH METHODS

We sought studies through an extensive search of electronic databases, journals, reference lists, contact with investigators and other search strategies outlined in the methods. The most recent search for this update was carried out in May 2012.

SELECTION CRITERIA

Studies were included in the review if they assessed MA compared to placebo or other drug treatments in randomised controlled trials of patients with a clinical diagnosis of anorexia-cachexia syndrome related to cancer, AIDS or any other underlying pathology.

DATA COLLECTION AND ANALYSIS

Two independent review authors conducted data extraction and evaluated methodological quality. We performed quantitative analyses using appetite and quality of life as a dichotomous variable, and analysed weight gain as continuous and dichotomous variables.

MAIN RESULTS

We included 35 trials in this update, the same number but not the same trials as in the previous version of the review. The trials comprised 3963 patients for effectiveness and 3180 for safety. Sixteen trials compared MA at different doses with placebo, seven trials compared different doses of MA with other drug treatments and 10 trials compared different doses of MA. Meta-analysis showed a benefit of MA compared with placebo, particularly with regard to appetite improvement and weight gain in cancer, AIDS and other underlying conditions, and lack of benefit in the same patients when MA was compared to other drugs. There was insufficient information to define the optimal dose of MA, but higher doses were more related to weight improvement than lower doses. Quality of life improvement in patients was seen only when comparing MA versus placebo but not other drugs in both subcategories: cancer and AIDS. Oedema, thromboembolic phenomena and deaths were more frequent in the patients treated with MA. More than 40 side effects were studied.

AUTHORS' CONCLUSIONS

This review shows that MA improves appetite and is associated with slight weight gain in cancer, AIDS and in patients with other underlying pathology. Despite the fact that these patients are receiving palliative care they should be informed of the risks involved in taking MA.

Racial and ethnic differences in adjuvant hormonal therapy use

BACKGROUND

In the United States, 5-year breast cancer survival is highest among Asian American women, followed by non-Hispanic white, Hispanic, and African American women. Breast cancer treatment disparities may play a role. We examined racial/ethnic differences in adjuvant hormonal therapy use among women aged 18-64 years, diagnosed with hormone receptor-positive breast cancer, using data collected by the Northern California Breast Cancer Family Registry (NC-BCFR), and explored changes in use over time.

METHODS

Odds ratios (OR) comparing self-reported ever-use by race/ethnicity (African American, Hispanic, non-Hispanic white vs. Asian American) were estimated using multivariable adjusted logistic regression. Analyses were stratified by recruitment phase (phase I, diagnosed January 1995-September 1998, phase II, diagnosed October 1998-April 2003) and genetic susceptibility, as cases with increased genetic susceptibility were oversampled.

RESULTS

Among 1385 women (731 phase I, 654 phase II), no significant racial/ethnic differences in use were observed among phase I or phase II cases. However, among phase I cases with no susceptibility indicators, African American and non-Hispanic white women were less likely than Asian American women to use hormonal therapy (OR 0.20, 95% confidence interval [CI]0.06-0.60; OR 0.40, CI 0.17-0.94, respectively). No racial/ethnic differences in use were observed among women with 1+ susceptibility indicators from either recruitment phase.

CONCLUSIONS

Racial/ethnic differences in adjuvant hormonal therapy use were limited to earlier diagnosis years (phase I) and were attenuated over time. Findings should be confirmed in other populations but indicate that in this population, treatment disparities between African American and Asian American women narrowed over time as adjuvant hormonal treatments became more commonly prescribed.

Do pharmacokinetic polymorphisms explain treatment failure in high-risk patients with neuroblastoma?

PURPOSE

Neuroblastoma is the most common extracranial solid tumour in childhood. It accounts for 15% of all paediatric oncology deaths. In the last few decades, improvement in treatment outcome for high-risk patients has not occurred, with an overall survival rate <30-40%. Many reasons may account for such a low survival rate. The aim of this review is to evaluate whether pharmacogenetic factors can explain treatment failure in neuroblastoma.

METHODS

A literature search based on PubMed's database Medical Subject Headings (MeSH) was performed to retrieve all pertinent publications on current treatment options and new classes of drugs under investigation. One hundred and fifty-eight articles wer reviewed, and relevant data were extracted and summarised.

RESULTS AND CONCLUSIONS

Few of the large number of polymorphisms identified thus far showed an effect on pharmacokinetics that could be considered clinically relevant. Despite their clinical relevance, none of the single nucleotide polymorphisms (SNPs) investigated can explain treatment failure. These findings seem to reflect the clinical context in which anti-tumour drugs are used, i.e. in combination with multimodal therapy. In addition, many pharmacogenetic studies did not assess (differences in) drug exposure, which could contribute to explaining pharmacogenetic associations. Furthermore, it remains unclear whether the significant activity of new drugs on different neuroblastoma cell lines translates into clinical efficacy, irrespective of resistance or myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN) amplification. Elucidation of the clinical role of pharmacogenetic factors in the treatment of neuroblastoma demands an integrated pharmacokinetic-pharmacodynamic approach to the analysis of treatment response data.

Perceptions of care coordination in a population-based sample of diverse breast cancer patients

OBJECTIVE

To identify factors associated with perceptions of care coordination in a diverse sample of breast cancer patients.

METHODS

Breast cancer patients reported to the metropolitan SEER registries of Detroit or Los Angeles from 6/05 to 2/07 were surveyed after diagnosis (N=2268, RR=72.4%). Outcomes were two dichotomous measures reflecting patient appraisal of care coordination during their treatment experience. Primary independent variables were race/ethnicity (white, African American, Latina-high acculturated, Latina-low acculturated) and health literacy (low, moderate, high). Logistic regression was used to evaluate factors associated with both measures of care coordination.

RESULTS

2148 subjects were included in the analytic dataset. 16.4% of women perceived low care coordination and 12.5% reported low satisfaction. Race/ethnicity was not significantly associated with care coordination. Women with low subjective health literacy were 3-4 times as likely as those with high health literacy to perceive low care coordination and low satisfaction with care coordination (OR=3.88; 95% CI: 2.78-5.41; OR=3.19 95% CI: 2.25-4.52, respectively).

CONCLUSIONS

Many breast cancer patients positively appraised their care coordination, but patients with low health literacy perceived low care coordination.

PRACTICE IMPLICATIONS

Providers should be aware of the health literacy deficits that may contribute to their patients' attitudes towards their breast cancer care coordination.

Pharmacogenetics in breast cancer: steps toward personalized medicine in breast cancer management

There is wide individual variability in the pharmacokinetics, pharmacodynamics, and tolerance to anticancer drugs within the same ethnic group and even greater variability among different ethnicities. Pharmacogenomics (PG) has the potential to provide personalized therapy based on individual genetic variability in an effort to maximize efficacy and reduce adverse effects. The benefits of PG include improved therapeutic index, improved dose regimen, and selection of optimal types of drug for an individual or set of individuals. Advanced or metastatic breast cancer is typically treated with single or multiple combinations of chemotherapy regimens including anthracyclines, taxanes, antimetabolites, alkylating agents, platinum drugs, vinca alkaloids, and others. In this review, the PG of breast cancer therapeutics, including tamoxifen, which is the most widely used therapeutic for the treatment of hormone-dependent breast cancer, is reviewed. The pharmacological activity of tamoxifen depends on its conversion by cytochrome P450 2D6 (CYP2D6) to its abundant active metabolite, endoxifen. Patients with reduced CYP2D6 activity, as a result of either their genotype or induction by the coadministration of other drugs that inhibit CYP2D6 function, produce little endoxifen and hence derive limited therapeutic benefit from tamoxifen; the same can be said about the different classes of therapeutics in breast cancer. PG studies of breast cancer therapeutics should provide patients with breast cancer with optimal and personalized therapy.

Mammographic density as a predictor of breast cancer outcome

Evaluation of: Cil T, Fishell E, Hanna W et al.: Mammographic density and the risk of breast cancer recurrence after breast-conserving surgery. Cancer 115, 5780–5787 (2009). This clinical investigation explored mammographic density, a strong etiologic risk factor for breast cancer, as a predictor of local breast cancer recurrence. The authors reported that women with intermediate and high breast density had a significantly elevated risk of developing a local breast cancer recurrence. However, this effect was observed only among patients who had not received radiotherapy. Only two previous reports have shown that mammographic density may be a prognostic factor, but the studies disagree on the role of radiotherapy as an effect modifier. Future studies that incorporate additional risk factors, such as obesity, need to examine the role of mammographic density in larger patient populations before including breast density in treatment decision models.

Management of newly diagnosed symptomatic multiple myeloma: updated Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus guidelines

Multiple myeloma is a malignant plasma cell neoplasm that affects more than 20,000 people each year and is the second most common hematologic malignancy. It is part of a spectrum of monoclonal plasma cell disorders, many of which do not require active therapy. During the past decade, considerable progress has been made in our understanding of the disease process and factors that influence outcome, along with development of new drugs that are highly effective in controlling the disease and prolonging survival without compromising quality of life. Identification of well-defined and reproducible prognostic factors and introduction of new therapies with unique modes of action and impact on disease outcome have for the first time opened up the opportunity to develop risk-adapted strategies for managing this disease. Although these risk-adapted strategies have not been prospectively validated, enough evidence can be gathered from existing randomized trials, subgroup analyses, and retrospective studies to develop a working framework. This set of recommendations represents such an effort-the development of a set of consensus guidelines by a group of experts to manage patients with newly diagnosed disease based on an interpretation of the best available evidence.

TNM: therapeutically not mandatory

Cancer survival may be inversely related to the speed at which a primary tumour grows and disseminates. Assessment of prognosis using surgical and/or radiological definition of disease extent, i.e. staging, has thus become a standard intervention in newly diagnosed patients, with the most popular framework being the tumour-node-metastasis (TNM) system. However, increasing use of biomarkers--non-TNM factors that predict therapeutic benefit, rather than adverse disease outcome--has weakened the decision-making dominance of TNM. This shift from risk-led to benefit-led practice is now starting to blur the time-honoured qualitative distinction between curable (M(0), early stage, adjuvant) and incurable (M(1), early metastatic, palliative) disease treatment strategies; the same biologic drug strategy may improve average survival outcomes by similar increments for two patients, one of whom is 'adjuvant' and the other 'metastatic'. Plausibly, then, biomarker-positive patients presenting with high-TNM (M(1)) disease may enjoy the same, if not more, disease-free and/or overall survival benefit as conventional low-TNM (M(0)) patients when treated with standard adjuvant interventions. Conversely, M(0) patients concerned by quality-of-life issues such as alopecia may in future be able to choose better-tolerated personalized drug regimens similar to those now used with survival benefit in palliative settings, even if such adjuvant regimens have not yet been validated by level 1 data. To these ends, a modernised decision-oriented disease staging system called METS (molecular/extra-primary/tumour/symptoms) is presented here.

Molecular targeted therapies for breast cancer treatment

Targeting the oestrogen receptor, HER2 (human epidermal growth factor receptor 2) and vascular endothelial growth factor has markedly improved breast cancer therapy. New targeted therapeutic approaches to induction of apoptosis or inhibition of anti-apoptosis, cell cycle progression, signal transduction and angiogenesis are described. The molecular pathways and their inhibitory or repair mechanisms are discussed in the preclinical and clinical settings.