Risk of malignancy in patients with systemic lupus erythematosus: Systematic review and meta-analysis

Malignancy is a potential comorbidity in patients with systemic lupus erythematosus (SLE). However, risk by malignancy type remains to be fully elucidated. We evaluated the risk of malignancy type in SLE patients in a systematic review and meta-analysis.MEDLINE and EMBASE were searched from inception to July 2018 to identify observational studies that evaluated malignancy risk in adult SLE patients compared with the general population. Random-effects models were used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). Heterogeneity was quantified using the I2 test.Forty-one studies reporting on 40 malignancies (one overall, 39 site-specific) were included in the meta-analysis. The pooled RR for all malignancies from 3694 events across 80 833 patients was 1.18 (95% CI: 1.00-1.38). The risk of 24 site-specific malignancies (62%) was increased in SLE patients. For malignancies with ≥6 studies, non-Hodgkin lymphoma and Hodgkin lymphoma risk was increased >3-fold; myeloma and liver >2-fold; cervical, lung, bladder, and thyroid ≥1.5-fold; stomach and brain >1.3-fold. The risk of four malignancies (breast, uterine, melanoma, prostate) was decreased, whereas risk of 11 other malignancies did not differ between SLE patients and the general population. Heterogeneity ranged between 0% and 96%, and 63% were non-significant.The risk of overall and some site-specific malignancies is increased in SLE compared with the general population. However, the risk for some site-specific malignancies is decreased or did not differ. Further examination of risk profiles and SLE patient phenotypes may support guidelines aimed at reducing malignancy risk.AstraZeneca.PROSPERO number: CRD42018110433.