Malignancy in systemic lupus erythematosus: a nationwide cohort study in Taiwan

an increased risk of malignancy in patients with systemic lupus erythematosus has been reported, but rarely in Asian populations. We aimed to investigate the relative risk of cancer and to identify the high-risk group for cancer in patients with lupus.

we conducted a retrospective, nationwide cohort study that included 11,763 patients with lupus without a history of malignancies, using the national health insurance database of Taiwan from 1996 to 2007. Standardized incidence ratios (SIRs) of cancers were analyzed.

a total of 259 cancers were observed in patients with lupus. An elevated risk of cancer among those with systemic lupus erythematosus was noted (SIR 1.76; 95% confidence interval [CI] 1.74-1.79), especially for hematologic malignancies (SIR 4.96; 95% CI 4.79-5.14). Younger patients had a greater risk ratio of cancer than the general population, and the risk ratio decreased with age. The risk ratio of cancer decreased with time, yet remained elevated compared with that of the general population. The risk of non-Hodgkin lymphoma was greatest (SIR 7.27) among hematologic cancers. Among solid tumors, the risk was greatest for cancers of the vagina/vulva (SIR 4.76), nasopharynx (SIR 4.18), and kidney (SIR 3.99). An elevated risk for less common cancers, including those of the brain, oropharynx, and thyroid glands, was also observed.

patients with lupus are at increased risk of cancers and should receive age- and gender-appropriate malignancy evaluations, with additional assessment for vulva/vagina, kidney, nasopharynx, and hematologic malignancy. Continued vigilance for development of cancers in follow-up is recommended.