The following article is a part of conference coverage from the American College of Rheumatology (ACR) Convergence 2021, being held virtually from November 3 to 10, 2021. The team at Rheumatology Advisor will be reporting on the latest news and research conducted by leading experts in rheumatology. Check back for more from the ACR Convergence 2021.

 

Risk for mortality was found to be higher among women with breast cancer and systemic lupus erythematosus (SLE) compared with women with breast cancer alone, according to research recently presented at the American College of Rheumatology (ACR) Convergence 2021, held November 3-10, 2021.


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Using information from the Surveillance, Epidemiology, and End Results (SEER) and the Texas Cancer Registry (TCR) dataset, this retrospective, observational study included 145,517 women with breast cancer but without SLE, 268 women with SLE but without breast cancer, and 494 women with both breast cancer and SLE. Study participants were at least 66 years of age, and those with breast cancer were diagnosed between 2005 and 2015.

Women with SLE but without breast cancer were matched with women with both breast cancer and SLE by race and birth year. Overall survival and breast cancer-specific survival were recorded from index date or date of diagnosis. The correlation between group and survival outcomes was assessed using multivariable Cox proportional hazards models and Kaplan-Meier methods with adjustments for treatment/cancer characteristics (breast cancer groups), comorbidities, and disease severity (women with SLE but without breast cancer).

Women with early (stage 0-II) breast cancer and SLE had a 5-year overall survival rate of 74% (95% CI, 68-78) compared with 86% for women with breast cancer but without SLE (95% CI, 85-86; P <.001). After adjusting for cancer treatment, characteristics, and comorbidities, women with breast cancer and SLE were found to be at significantly higher risk for mortality than women with breast cancer but without SLE (hazard ratio [HR] 1.65; 95% CI, 1.38-1.98). The investigators found no correlation between mortality and breast cancer­-specific survival. After adjusting for SLE disease severity, women with breast cancer and SLE were found to have a significantly higher mortality risk compared with women with SLE but without cancer (HR 1.42; 95% CI, 1.05-1.92).

The study authors conclude that women “with [breast cancer] and SLE are at risk of earlier mortality compared to patients with [breast cancer] alone, even after adjusting for SLE disease activity and comorbidities.”

Disclosure: Multiple authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

 

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Reference

Bruera S, Lei X, Pundole X, et al. Systemic lupus erythematosus is a risk factor for mortality in older patients with early-stage breast cancer. Presentation at ACR Convergence 2021; November 3-10, 2021. Abstract 134.