Insurance Status Predicts Survival in Women with Breast Cancer: Results of Breast and Cervical Cancer Treatment Program in California.

BACKGROUND AND PURPOSE: The Breast and Cervical Cancer Treatment Program (BCCTP) Act, passed by Congress in 2000, provides time-limited coverage to uninsured breast or cervical cancer patients. We examine survival differences between BCCTP cases and insured controls. METHODS: Stage I-III breast cancer patients, covered under California's BCCTP from 2005 to 2009 (N = 6343), were 1:1 matched with California Cancer Registry controls on age, race/ethnicity, and cancer stage. Overall and disease-specific (OS and DSS) survival were compared using multivariate regression. RESULTS: BCCTP cases were more often unmarried [odds ratio (OR) 2.47, 95% confidence interval (CI) 2.30-2.66], with poorly/undifferentiated tumors (OR 1.26, CI 1.13-1.40), classified as ER negative (OR 1.10, CI 1.02-1.20) and/or PR negative (OR 1.09, CI 1.01-1.17). Cases were more likely to undergo mastectomy (OR 1.13, CI 1.05-1.21) or no surgery (OR 1.64, CI 1.31-2.05) versus lumpectomy. Cases were also more likely to undergo radiation (OR 1.11, CI 1.03-1.19). Endocrine therapy rates were marginally lower in cases (OR 0.93, CI 0.86-1.00). OS and DSS were shorter in BCCTP cases on multivariate analysis (HR 1.29, CI 1.17-1.42 and HR 1.27, CI 1.14-1.42, respectively). When stratified by socioeconomic status (SES), cases had significantly shorter OS and DSS except in the lowest quintile. When stratified by stage, cases had significantly shorter OS and DSS, except for stage I. CONCLUSIONS: The BCCTP provides uninsured breast cancer patients with comprehensive and timely care. Although our results suggest that BCCTP delivers quality care, BCCTP patients have shorter survival rates, even after accounting for SES and stage differences. Further assistance to vulnerable populations is warranted, including longer duration of treatment coverage, and surveillance adhering to NCCN compliant surveillance programs.

Prolactin receptor attenuation induces zinc pool redistribution through ZnT2 and decreases invasion in MDA-MB-453 breast cancer cells.

Prolactin receptor (PRL-R) activation regulates cell differentiation, proliferation, cell survival and motility of breast cells. Prolactin (PRL) and PRL-R over-expression are strongly implicated in breast cancer, particularly contributing to tumor growth and invasion in the more aggressive estrogen-receptor negative (ER-) disease. PRL-R antagonists have been suggested as potential therapeutic agents; however, mechanisms through which PRL-R antagonists exert their actions are not well-understood. Zinc (Zn) is a regulatory factor for over 10% of the proteome, regulating critical cell processes such as proliferation, cell signaling, transcription, apoptosis and autophagy. PRL-R signaling regulates Zn metabolism in breast cells. Herein we determined effects of PRL-R attenuation on cellular Zn metabolism and cell function in a model of ER-, PRL-R over-expressing breast cancer cells (MDA-MB-453). PRL-R attenuation post-transcriptionally increased ZnT2 abundance and redistributed intracellular Zn pools into lysosomes and mitochondria. ZnT2-mediated lysosomal Zn sequestration was associated with reduced matrix metalloproteinase 2 (MMP-2) activity and decreased invasion. ZnT2-mediated Zn accumulation in mitochondria was associated with increased mitochondrial oxidation. Our results suggest that PRL-R antagonism in PRL-R over-expressing breast cancer cells may reduce invasion through the redistribution of intracellular Zn pools critical for cellular function.

Marginal zinc intake reduces the protective effect of lactation on mammary gland carcinogenesis in a DMBA-induced tumor model in mice.

Breastfeeding can reduce breast cancer risk; however, unknown factors modify this protective effect. Zinc (Zn) modulates an array of cellular functions including oxidative stress, cell proliferation, motility and apoptosis. Marginal Zn intake is common in women and is associated with breast cancer. We reported that marginal Zn intake in mice leads to mammary gland hypoplasia and hallmarks of pre-neoplastic lesions. In the present study, we tested the hypothesis that marginal Zn intake confounds the protective effect of lactation on breast cancer. Nulliparous mice fed control (ZA, 30 mg Zn/kg) or a marginal Zn diet (ZD, 15 mg Zn/kg), were bred and offspring were weaned naturally. Post-involution, mice were gavaged with corn oil or 7,12-dimethylbenz(a)anthracene (DMBA, 1 mg/wk for 4 weeks) and tumor development was monitored. A ZD diet led to insufficient involution, increased fibrosis and oxidative stress. Following DMBA treatment, mice fed ZD had higher oxidative stress in mammary tissue that correlated with reduced levels of peroxiredoxin-1 and p53 and tended to have shorter tumor latency and greater incidence of non-palpable tumors. In summary, marginal Zn intake creates a toxic mammary gland microenvironment and abrogates the protective effect of lactation on carcinogenesis.

Paradoxical zinc toxicity and oxidative stress in the mammary gland during marginal dietary zinc deficiency.

Zinc (Zn) regulates numerous cellular functions. Zn deficiency is common in females; ∼80% of women and 40% of adolescent girls consume inadequate Zn. Zn deficiency enhances oxidative stress, inflammation and DNA damage. Oxidative stress and inflammation is associated with breast disease. We hypothesized that Zn deficiency increases oxidative stress in the mammary gland, altering the microenvironment and architecture. Zn accumulated in the mammary glands of Zn deficient mice and this was associated with macrophage infiltration, enhanced oxidative stress and over-expression of estrogen receptor α. Ductal and stromal hypercellularity was associated with aberrant collagen deposition and disorganized e-cadherin. Importantly, these microenvironmental alterations were associated with substantial impairments in ductal expansion and mammary gland development. This is the first study to show that marginal Zn deficiency creates a toxic microenvironment in the mammary gland impairing breast development. These changes are consistent with hallmarks of potential increased risk for breast disease and cancer.