Autoimmune diseases and breast cancer risk by tumor hormone‐receptor status among elderly women

Abstract

The female preponderance of many autoimmune diseases suggests a possible hormonal etiology. Little research exists on systemic and organ-specific autoimmune diseases and risk of breast cancer by tumor estrogen receptor (ER)- and progesterone receptor (PR)- status. Here, we evaluate associations between selected systemic and organ-specific autoimmune diseases and breast cancer risk overall and by tumor ER- and PR-status. We used linked Surveillance, Epidemiology and End Results (SEER)-Medicare data, with first female breast cancer cases ages ≥66 years identified by SEER registries (years 1992-2011; N = 209,929). We selected female controls (N = 200,000) from a stratified 5% random sample of Medicare recipients who were alive and breast cancer-free. We assessed exposures until 12 months before breast cancer diagnosis/selection using Medicare claims data. We estimated odds ratios (OR) and 99.9% confidence intervals (CI) using unconditional and multinomial logistic regression. We found reduced breast cancer risk among those with rheumatoid arthritis (OR = 0.84; 99.9% CI 0.79-0.89), systemic lupus erythematosus (OR = 0.82; 99.9% CI 0.70-0.97) and pernicious anemia (OR = 0.90; 99.9% CI 0.83-0.97) and increased risk among those with psoriasis (OR = 1.16; 99.9% CI 1.06-1.27). Statistically significant alterations in risk for rheumatoid arthritis were limited to ER-positive (+) breast cancer, whereas those for the other three conditions were further limited to ER+/PR+ breast cancer. However, only differences for rheumatoid arthritis by ER-status were statistically significant (p-heterogeneity = 0.0001). The reasons for these associations need to be investigated in future studies accounting for host characteristics and autoimmune disease treatment.

Contribution of viral infection to risk for cancer in systemic lupus erythematosus and multiple sclerosis

“…We confirmed previous findings that suggest that SLE itself confers a lower risk for breast and prostate cancer [ 34 – 36 ]. It is likely that SLE affects hormones or hormone regulation important for the development or proliferation of these cancers [ 37 ]. As expected by general population studies, viral infection did not affect the rate of these types of malignancies in the SLE population.…”

Potential association between rosacea and cancer: A study in a medical center in southern China

“…The observation of upregulation of pro‐inflammatory cytokines IL‐6, IL‐1 and TNF in ER‐positive tumors demonstrated that these cytokines play an important role in the activation of ER . Activated ER promotes the release of vasodilators, leading to vasomotor disorders and neovascularization . Moreover, studies have shown that several autoimmune disorders are associated with ER‐positive breast cancer, suggesting a potential relationship between immune abnormalities and breast cancer.…”

“…50,51 Activated ER promotes the release of vasodilators, leading to vasomotor disorders and neovascularization. 52 Moreover, studies have shown that several autoimmune disorders are associated with ER-positive breast cancer, 52 suggesting a potential relationship between immune abnormalities and breast cancer. However, PR and HER-2 status make no difference between two groups, and more research is needed to further elucidate the underlying pathogenesis.…”

Inflammatory Biomarkers and Breast Cancer Risk: A Systematic Review of the Evidence and Future Potential for Intervention Research

“…A growing number of studies have examined whether different medical conditions that are related to chronic inflammation are also associated with breast cancer risk by comparing women with these conditions to women without, in terms of the incidence of breast cancer [47]. However, many different conditions, including rheumatoid arthritis, have been inconsistently associated with breast cancer risk and do not support a strong association between chronic inflammatory conditions and breast cancer risk.…”