Systemic lupus erythematous and malignancy risk: a meta-analysis

Area of Science:

• Rheumatology
• Oncology
• Epidemiology

Background:

• Previous studies on cancer incidence in systemic lupus erythematosus (SLE) patients yielded inconclusive results.
• A comprehensive meta-analysis was needed to precisely determine the association between SLE and malignancy.
• This study synthesizes existing observational data to clarify cancer risks in SLE patients.

Purpose of the Study:

• To conduct a meta-analysis to ascertain the correlation between SLE and malignancy.
• To quantify the relative risks (RRs) for various cancers in SLE patients.
• To identify specific cancer types with significantly altered incidence in SLE.

Main Methods:

• Searched PubMed, Cochrane Library, and Embase databases up to June 2014 for relevant observational studies.
• Calculated pooled relative risks (RRs) using random or fixed effects models based on heterogeneity.
• Assessed between-study heterogeneity using the I2 index and publication bias using Egger's test.

Main Results:

• Included 16 studies with 59,662 SLE patients; analyzed RRs for overall malignancy and specific cancers.
• Found significantly increased RRs for non-Hodgkin lymphoma (NHL; 5.40), Hodgkin lymphoma (HL; 3.26), leukemia (2.01), liver cancer (3.21), and vaginal/vulvar cancer (3.67).
• Observed increased risks for laryngeal (4.19), lung (1.59), and thyroid (1.78) cancers, but a reduced risk for skin melanoma (0.65).

Conclusions:

• Data support a significant association between SLE and increased risk for NHL, HL, leukemia, and several non-hematologic malignancies.
• A reduced risk for skin melanoma was noted in SLE patients.
• Increased risks for multiple myeloma, esophageal, bladder, and non-melanoma skin cancers warrant further investigation and confirmation.