OBJECTIVES: People with autoimmune (AI) diseases are diagnosed with increased frequencies of some cancers, which may depend on the underlying dysregulation of the immune system or treatment. Data on female cancers are limited.
METHODS: The investihgators analyzed systematically risk and survival of female cancers of the breast, uterus, ovary and other genital organs in close to 200,000 patients diagnosed with any of 33 different AI diseases. Standardized incidence ratios (SIR) for risk and hazard ratios (HRs) for survival were calculated for subsequent incident cancers or cancer deaths up to year 2008.
RESULTS: For all breast cancer after any AI diseases, the SIR was 0.94; SIRs were modestly increased after two AI diseases and decreased after nine AI diseases, including Sjogren syndrome (0.46). For cervical cancer, the risk was increased after discoid lupus erythematosus (3.34) and systemic sclerosis (2.43). The HR was 2.12 in chronic rheumatic heart disease patients. The overall SIR for endometrial cancer was 0.85, with low SIR in ankylosing spondylitis (0.37); the HR was 4.05 for Sjogren syndrome. The SIR for ovarian cancer was increased for polymyositis/dermatomyositis (3.26) while the HR was increased for multiple sclerosis (2.43). The overall SIR for other genital cancers was increased to 1.54 and a very high risk of 35.88 was observed in localized scleroderma.
CONCLUSIONS: Breast, endometrial and ovarian cancers were decreased after all AI diseases and most significant changes after individual AI diseases were towards lower risks. Probably treatment related factors explain the findings. For cervical and other genital cancers all significant changes were increased risks.
“These results indicated that female MSers are at increased risk of ovarian cancer. I suggest this data is confirmed or refuted in another population before we start speculating about potential mechanisms. It is interesting nevertheless.”