Strengths and limitations of breast cancer risk assessment

Pesticide exposure and increased breast cancer risk in women population studies

Pesticide exposure is emerging as a risk factor for various human diseases. Breast cancer (BC) is a multifactorial disease with known genetic and non-genetic risk factors. Most BC cases are attibutable to non-genetic risk factors, with a history of adverse environmental exposures playing a significant role. Pesticide exposure can occur at higher levels in female populations participating in rural activities such as spraying of pesticides in the field, unprotected handling of pesticides at home, and washing of contaminated clothes. Exposure can also be significant in the drinking water of certain populations. Here, we reviewed the literature on women's exposure to pesticides and the risk of BC. We summarize the main links between pesticide exposure and BC and discuss the role of dose and exposure context, as well as potential mechanisms of toxicity. Overall, reports reviewed here have documented stronger associations between higher levels of exposure and BC risk, including documenting direct and acute pesticide exposure in certain female populations. However, discrepancies among studies regarding dose and mode of exposure may result in misunderstandings about the risks posed by pesticide exposure. Plausible mechanisms linking pesticides to breast cancer risk include their impacts as endocrine disruptors, as well as their roles as genotoxic agents, and modulators of the epigenome. Besides establishing links between pesticide exposure and breast cancer, the literature also highlights the critical need to understand the routes and doses of women's exposure to pesticides and the specific associations and mechanisms that are determinants of disease etiology and prognosis.

Zn(II) 5,5-Diethylbarbiturate Complex Selectively Induces Apoptosis in Breast Cancer and Breast Cancer Stem-Like Cells

The biological activities of Zn(II) compounds have been extensively studied in recent years. In this study, the growth suppressive effect of Zn(II) 5,5-diethylbarbiturate complex on MCF-7 and MDA-MB-231 human breast cancer cells was determined by SRB and ATP viability assays and apoptosis-inducing effect by double staining method. Significant increase in cytokeratin 18 level, caspase 3/7 activity and annexin-V upregulation prove that Zn(II) complex has apoptotic effect in breast cancer cells. Intrinsic apoptosis pathway in MCF-7 cells and extrinsic apoptosis pathway in MDA-MB-231 cells was determined by Western blot (PARP, Cleave PARP, BAX, COX4, RIP, Caspase 8, Split Caspase 8, DR4 and B-Actin) and RT-PCR (PARP, Fas, Bcl-2, TNF10A, P53) analysis. No reduction of viability was found in MCF-710A healthy breast cells treated with Zn(II) complex. In breast cancer stem-like cells (MCF-7s), the Zn(II) complex was found to have a cytotoxic effect and to activate the apoptotic pathway. As a result, it was concluded that Zn(II) complex has anti-proliferative and apoptotic effects on breast cancer and breast cancer stem-like cells. Also this complex prevents the metastatic effect of cancer cells and does not effect to healthy cells so this complex has a specific effect on cancer cells. These findings might shed light on the discovery of new chemotherapeutic agents.

Evaluation of the Impact of Nurses' Healthy Lifestyle Behaviors on Utilization from Breast Cancer Early Diagnosis Methods

OBJECTIVE

This descriptive study was designed to determine the impact of nurses' healthy lifestyle behaviors on utilization from breast cancer early diagnosis methods.

MATERIALS AND METHODS

The study was carried out with 236 (41.7%) nurses who agreed to participate out of 565 nurses who work in a university hospital from February 12th to February 15th 2011. Healthy Lifestyle Behaviors Scale was collected by using a questionnaire consisting of 41 questions. The Healthy Lifestyle Behaviors Scale was improved by Walker, Sechrist and Pender (1987) and was adapted to Turkish by Esin (1997). The data was evaluated by percentage calculation, one -way ANOVA, t-test and Tukey's test.

RESULTS

The mean Healthy Lifestyle Behaviors Scale score was 129.09±19.82, the mean scores subscale scores of self-actualization, health responsibility, exercise, nutrition, interpersonal support and stress management were 38.52±6.28, 24.95±5.39, 9.41±3.24, 16.99±3.29, 21.22±3.39 and 17.99±3.66 respectively. It was found that Healthy Lifestyle Behaviors Scale total score was higher in nurses with sufficient level of breast cancer knowledge (F=13.115, p=0.000), who perform regular BSE (t=3.191, p=0.002) and who attended training on breast cancer (t=3030, p=0.003).

CONCLUSION

It was determined that although the mean total score of nurse's Healthy Lifestyle Behaviors Scale and their information on breast cancer prevention were above average, the utilization of breast cancer early detection services was not at the expected levels.

Reported mammographic density: film-screen versus digital acquisition

PURPOSE

To test the hypothesis that American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) categories for breast density reported by radiologists are lower when digital mammography is used than those reported when film-screen (FS) mammography is used.

MATERIALS AND METHODS

This study was institutional review board approved and HIPAA compliant. Demographic data, risk factors, and BI-RADS breast density categories were collected from five mammography registries that were part of the Breast Cancer Surveillance Consortium. Active, passive, or waiver of consent was obtained for all participants. Women aged 40 years and older who underwent at least two screening mammographic examinations less than 36 months apart between January 1, 2000, and December 31, 2009, were included. Women with prior breast cancer, augmentation, or use of agents known to affect density were excluded. The main sample included 89 639 women with both FS and digital mammograms. The comparison group included 259 046 women with two FS mammograms and 87 066 women with two digital mammograms. BI-RADS density was cross-tabulated according to the order in which the two types of mammogram were acquired and by the first versus second interpretation.

RESULTS

Regardless of acquisition method, the percentage of women with a change in density from one reading to the next was similar. Breast density was lower in 19.8% of the women who underwent FS before digital mammography and 17.1% of those who underwent digital before FS mammography. Similarly, lower density classifications were reported on the basis of the second mammographic examination regardless of acquisition method (15.8%-19.8%). The percentage of agreement between density readings was similar regardless of mammographic types paired (67.3%-71.0%).

CONCLUSION

The study results showed no difference in reported BI-RADS breast density categories according to acquisition method. Reported BI-RADS density categories may be useful in the development of breast cancer risk models in which FS, digital, or both acquisition methods are used.

Successful use of multi-detector row computed tomography for detecting contralateral breast cancer

OBJECTIVE

We retrospectively evaluated whether multi-detector row computed tomography (MDCT) could contribute to the early detection of contralateral breast cancer in women with a diagnosis of breast cancer and no suspicious lesions on a mammogram or an ultrasonogram of the contralateral breast.

METHODS

A total of 518 women with newly diagnosed unilateral breast cancer underwent MDCT. Multi-detector row CT was performed using a 16-detector row CT scanner set for 2-mm collimation, 120 kilovolt (peak), and 180 mA. Axial images of the contralateral breast were evaluated.

RESULTS

Four hundred fifty-nine women were eligible for this study. There were suspicious malignant lesions only on MDCT in 21. Multi-detector row CT contributed to the diagnosis of contralateral occult breast cancer in 12 women (2.6%), including 1 in whom breast cancer was later diagnosed at another institution.

CONCLUSIONS

Multi-detector row CT has a potential role in detecting contralateral breast cancer in women who are at high risk.

Breast Cancer Risk and Immune Responses in Healthy Women

PURPOSE/OBJECTIVES

To summarize the findings of objective and subjective breast cancer risk assessments and their association with psychological distress and immune responses in healthy women with a family history of breast cancer.

DATA SOURCES

Published articles and book chapters.

DATA SYNTHESIS

Healthy women with a family history of breast cancer have shown decreased immune responses (i.e., low natural killer cell activity and low Th1 cytokine production), exaggerated biophysiologic reactivity to stimuli, and increased psychological distress.

CONCLUSIONS

Objective and subjective breast cancer risk is associated with impaired immune responses and exaggerated biophysiologic responses in healthy women with a family history of breast cancer. Increased psychological distress can contribute further to negative immune responses. Additional studies are warranted to substantiate and extend the findings based on more comprehensive assessments of objective and subjective breast cancer risk.

IMPLICATIONS FOR NURSING

Biophysiologic assessment is a useful approach for nurses in early identification of women at risk for breast cancer and developing appropriate strategies to reduce the risk.