Is the biology of breast cancer changing? A study of hormone receptor status 1984-1986 and 1996-1997

Endocrine disrupting chemicals and breast cancer cells

Many hundreds of endocrine disrupting chemicals (EDCs) have been measured as entering human breast tissue from a range of environmental sources, and this review focuses on discussion of mechanisms by which such EDCs may be contributing to the globally rising incidence of breast cancer. Many of the distinguishing features of breast cancer may be accounted for by EDC exposure, including, but not limited to, the fact that many EDCs possess estrogenic activity and exposure to estrogen is a main risk factor for breast cancer. Studies of the actions of EDCs in human breast cancer cells are aided by use of the conceptual framework of the hallmarks of cancer, and, acting by a variety of genomic and nongenomic mechanisms, EDCs have now been shown to enable all the hallmarks of cancer to develop in human breast cancer cells. Many studies report that hallmarks can develop at concentrations which are within the range of those measured in human breast tissues, especially when added as mixtures. The varied levels of different EDCs measured in individual breast tissue samples together with the overlapping and complementary mechanisms of action of the EDCs imply that thematic mechanisms will be driven inevitably by different chemical mixtures. Despite the complexity, EDCs do need to now be acknowledged as a risk factor for breast cancer in order for preventative strategies to include reduction in EDC exposure.

Breast Cancer Estrogen Receptor Status According to Biological Generation: US Black and White Women Born 1915-1979

Evidence suggests that contemporary population distributions of estrogen-receptor (ER) status among breast cancer patients may be shaped by earlier major societal events, such as the 1965 abolition of legal racial discrimination in the United States (state and local "Jim Crow" laws) and the Great Famine in China (1959-1961). We analyzed changes in ER status in relation to Jim Crow birthplace among the 46,417 black and 339,830 white US-born, non-Hispanic women in the Surveillance, Epidemiology, and End Results (SEER) 13 Registry Group who were born between 1915 and 1979 and diagnosed (ages 25-84 years, inclusive) during 1992-2012. We grouped the cases according to birth cohort and quantified the rate of change using the haldane (which scales change in relation to biological generation). The percentage of ER-positive cases rose according to birth cohort (1915-1919 to 1975-1979) only among women diagnosed before age 55. Changes according to biological generation were greater among black women than among white women, and among black women, they were greatest among those born in Jim Crow (versus non-Jim Crow) states, with this group being the only group to exhibit high haldane values (>|0.3|, indicating high rate of change). Our study's analytical approach and findings underscore the need to consider history and societal context when analyzing ER status among breast cancer patients and racial/ethnic inequities in its distribution.

Tumor Specimen Biobanks: Data Gaps for Analyzing Health Inequities-the Case of Breast Cancer

Biobanks are increasingly recognized to be vital for analyzing tumor properties, treatment options, and clinical prognosis, yet few data exist on whether they are equipped to enable research on cancer inequities, that is, unfair and unnecessary social group differences in health. We conducted a systematic search of global biobanks, identified 46 that have breast tumor tissue and share data externally with academic researchers, and e-mailed and called to obtain data on the sociodemographic, socioeconomic, and geospatial data included, plus time span encompassed. Among the 32 biobank respondents, 91% housed specimens solely from the Global North, only 31% obtained socioeconomic data, 63% included racial/ethnic data (of which 55% lacked socioeconomic data), 44% included limited geographic data, and 55% had specimens dating back at most to 2000. To enable research to address cancer inequities, including trends over time, biobanks will need to address the data gaps documented by our study.

Trends in progression-free survival (PFS) and time to progression (TTP) over time within first-line aromatase inhibitors trials in hormone receptor-positive advanced breast cancer

BACKGROUND

Over the last 20 years, aromatase inhibitors (AI) have been tested in clinical trials as first-line therapy for hormone receptor-positive (HR-positive) advanced breast cancer (ABC), firstly as experimental arms, when they proved to be effective, and recently as control arms. This analysis aims to evaluate trends in progression-free survival (PFS) and time to progression (TTP) over time.

PATIENTS AND METHODS

A literature review was conducted using the MEDLINE database to identify randomized controlled phase II or III trials which reported PFS or TTP of at least one arm using first-line AI HR-positive ABC patients. A linear correlation was used to access the association between the year of the first patient enrolled and the observed PFS/TTP.

RESULTS

The search retrieved 19 trials, accounting for 4552 postmenopausal patients divided into 21 separate AI treatment arms. The PFS/TTP increased from 6 to 9 months in the earlier trials to 13-16 months in the current era, representing an absolute gain of approximately 7 months, without the addition of any other drug. Our analysis showed a positive correlation between the year of the first patient enrolled in these trials and median PFS/TTP reported (R ² = 0.34; p < 0.01). No correlation was found between the year of the first patient included in these trials and other potential prognostic factors such as visceral metastasis at baseline (R ² = 0.26; p = 0.20) or exposure to adjuvant therapy (R ² = 0.05; p = 0.18).

CONCLUSION

Patients treated with first-line AIs in the more recently conducted trials have longer PFS/TTP when compared to their counterparts treated with the same drugs in older studies. These findings have important implications for the estimation of sample size and follow-up periods for the planning of future trials as well as in the translation of the results into clinical practice decisions.

The DEK oncogene is a target of steroid hormone receptor signaling in breast cancer

Expression of estrogen and progesterone hormone receptors indicates a favorable prognosis due to the successful use of hormonal therapies such as tamoxifen and aromatase inhibitors. Unfortunately, 15-20% of patients will experience breast cancer recurrence despite continued use of tamoxifen. Drug resistance to hormonal therapies is of great clinical concern so it is imperative to identify novel molecular factors that contribute to tumorigenesis in hormone receptor positive cancers and/or mediate drug sensitivity. The hope is that targeted therapies, in combination with hormonal therapies, will improve survival and prevent recurrence. We have previously shown that the DEK oncogene, which is a chromatin remodeling protein, supports breast cancer cell proliferation, invasion and the maintenance of the breast cancer stem cell population. In this report, we demonstrate that DEK expression is associated with positive hormone receptor status in primary breast cancers and is up-regulated in vitro following exposure to the hormones estrogen, progesterone, and androgen. Chromatin immunoprecipitation experiments identify DEK as a novel estrogen receptor α (ERα) target gene whose expression promotes estrogen-induced proliferation. Finally, we report for the first time that DEK depletion enhances tamoxifen-induced cell death in ER+ breast cancer cell lines. Together, our data suggest that DEK promotes the pathogenesis of ER+ breast cancer and that the targeted inhibition of DEK may enhance the efficacy of conventional hormone therapies.

Effects of multidisciplinary team working on breast cancer survival: retrospective, comparative, interventional cohort study of 13 722 women

OBJECTIVES

To describe the effect of multidisciplinary care on survival in women treated for breast cancer.

DESIGN

Retrospective, comparative, non-randomised, interventional cohort study.

SETTING

NHS hospitals, health boards in the west of Scotland, UK.

PARTICIPANTS

14,358 patients diagnosed with symptomatic invasive breast cancer between 1990 and 2000, residing in health board areas in the west of Scotland. 13,722 (95.6%) patients were eligible (excluding 16 diagnoses of inflammatory cancers and 620 diagnoses of breast cancer at death).

INTERVENTION

In 1995, multidisciplinary team working was introduced in hospitals throughout one health board area (Greater Glasgow; intervention area), but not in other health board areas in the west of Scotland (non-intervention area).

MAIN OUTCOME MEASURES

Breast cancer specific mortality and all cause mortality.

RESULTS

Before the introduction of multidisciplinary care (analysed time period January 1990 to September 1995), breast cancer mortality was 11% higher in the intervention area than in the non-intervention area (hazard ratio adjusted for year of incidence, age at diagnosis, and deprivation, 1.11; 95% confidence interval 1.00 to 1.20). After multidisciplinary care was introduced (time period October 1995 to December 2000), breast cancer mortality was 18% lower in the intervention area than in the non-intervention area (0.82, 0.74 to 0.91). All cause mortality did not differ significantly between populations in the earlier period, but was 11% lower in the intervention area than in the non-interventional area in the later period (0.89, 0.82 to 0.97). Interrupted time series analyses showed a significant improvement in breast cancer survival in the intervention area in 1996, compared with the expected survival in the same year had the pre-intervention trend continued (P=0.004). This improvement was maintained after the intervention was introduced.

CONCLUSION

Introduction of multidisciplinary care was associated with improved survival and reduced variation in survival among hospitals. Further analysis of clinical audit data for multidisciplinary care could identify which aspects of care are most associated with survival benefits.

Health Services Research and Health Economy - Quality Care Training in Gynaecology, with Focus On Gynaecological Oncology

In the era of cost increases and reduced resources in the German healthcare system, the value of health services research and health economics is increasing more and more. Health services research attempts to develop concepts for the most effective ways to organise, manage, finance and deliver high-quality care and evaluates the implementation of these concepts with regard to daily routine conditions. Goals are the assessment of benefits and the economic advantages and disadvantages of new and established diagnostic methods, drugs and vaccines. Regarding these goals, it is clear that health services research goes hand in hand with health economics, which evaluates the benefits of diagnostic and therapeutic procedures in relation to the costs. Both scientific fields have focus principally on gynaecology and particularly on gynaecological oncology in Germany, as can be seen by numerous publications. These present several advantages compared with clinical trials - they uncover gaps in health care, question the material, staffing and consequently the financial resources required and they allow the estimation of value and the comparison of different innovations to identify the best options for our patients.

Determining tamoxifen sensitivity using primary breast cancer tissue in collagen-based three-dimensional culture

We developed a three-dimensional assay prepared from primary breast cancer tissue and quantified tumor response to tamoxifen therapy. Freshly harvested breast cancer biopsies obtained at the time of curative surgical resection were fragmented and embedded into collagen I cushions. Changes in proliferation, apoptosis and tumor volume in response to tamoxifen treatment were quantified using image analysis software and optical projection tomography. Individual and collective invasion of epithelial cells into the surrounding collagen I was observed over the course of the experiment using phase contrast light microscopy and histopathological methods. Addition of tamoxifen to preparations derived from ER+ tumors demonstrated a range of response as measured by proliferative and apoptotic markers. In keeping with published data, tamoxifen reduced the percentage of apoptotic cells expressing cleaved caspase-3 (p = 0.02, Poisson regression analysis). Tamoxifen also reduced residual epithelial volume in ER+ tumors (p = 0.001, Mann-Whitney test), but not in ER low/- tumors (p = 0.78). Changes in tumor volume, as measured by optical projection tomography, allowed stratification into responsive and non-responsive tumors. The model mirrors observations of breast cancer response and histopathological changes to tamoxifen in neo-adjuvant trials. This assay provides a method of screening a battery of therapeutics against individual cancers, informing subsequent design of neo-adjuvant trials.

Cost-Benefit Analysis of Endocrine Therapy in the Adjuvant Setting for Postmenopausal Patients with Hormone Receptor-Positive Breast Cancer, Based on Survival Data and Future Prices for Generic Drugs in the Context of the German Health Care System

BACKGROUND: Cost-effectiveness analyses have focused on aromatase inhibitors (AIs), but the results are inconsistent and disease-free survival has often been extrapolated to overall survival. The present study calculates the cost-effectiveness of 5 years of letrozole versus tamoxifen versus anastrozole in the context of the German health care system, using survival data from the Breast International Group (BIG) 1-98 study and the Arimidex, Tamoxifen, Alone or in Combination (ATAC) study and generic prices. MATERIALS AND METHODS: A hybrid model was developed that incorporates recurrence rates, overall survival, treatment costs and treatment-associated adverse events and the resulting costs. The basic assumption was that generic anastrozole would lead to a price reduction to 75% of the original price. Further analyses were carried out with 50% and 25% of the original prices for anastrozole and letrozole. RESULTS: The cost-benefit model showed a gain of 0.3124 or 0.0659 quality-adjusted life years (QALYs) for letrozole or anastrozole. Incremental costs of € 29,375.15/QALY for letrozole (100% of original price) were calculated and € 94,648.03/QALY for anastrozole (75% of original price). Marked increases in cost-effectiveness are observed with further decreases in price (anastrozole: 50% price € 54,715.17/QALY, 25% price € 14,779.57/QALY; letrozole 75% price € 20,988.59/QALY, 50% price € 12,602.03/QALY, 25% price € 4,215.46/QALY). CONCLUSION: The present model including the inverse probability of censoring weighted analysis (IPCW) for letrozole and generic prices for both AIs shows that letrozole is cost effective.

Metastatic breast cancer or multiple myeloma? Camouflage by lytic lesions

We report a case of a female with stage I infiltrating ductal carcinoma who received adjuvant therapy including trastuzumab. One year later she developed lytic lesions and was retreated with trastuzumab that was held after she developed symptomatic heart failure. Lytic lesions were attributed to relapse of breast cancer, and cardiac failure attributed to prior trastuzumab therapy. After complications necessitated multiple hospitalizations, a further workup revealed that the lytic lesions were not metastatic breast cancer but multiple myeloma. Her advanced multiple myeloma was associated with systemic amyloidosis involving gut and heart, which ultimately led to her demise. This report addresses the pitfalls of overlapping symptoms and the question of which patients with suspected metastatic disease should undergo a biopsy.