Purpose: To evaluate the
infection incidence in
breast cancer patients whether they have a major
autoimmune disease or not. Methods: This retrospective cohort study compared the
infection incidence of 174
breast cancer patients with an
autoimmune disease, including
Sjogren's Syndrome (SS),
Rheumatoid Arthritis (RA), and
Systemic Lupus Erythematosus (SLE), along with 4429 patients without an
autoimmune disease, for the period 2000 to 2016. Six-hundred and ninety six, age-, stage-, and diagnosis era-matched patients without any
autoimmune disease were analyzed to eliminate the effects of these confounding factors may have on the results. Results: After adjusting for age, stage and diagnosis era,
breast cancer patients with an
autoimmune disease had a higher
Infection Incidence Ratio (
IRR: 2.62) than the patients without any
autoimmune disease. In the univariate analysis, patients who had an
autoimmune disease (p<0.001), underwent
chemotherapy (p<0.001),
radiotherapy (p=0.004), and
monoclonal antibody therapy (p<0.001) had a higher
infection rate. In the multivariate analysis,
autoimmune disease was shown to be an independent factor for
infection incidence. Conclusion:
Autoimmune disease was a potential predictor of
infection incidence in
breast cancer patients post-treatment after adjusting for clinical confounding factors.