(HealthDay News) — Compared with the general population, there is an increased risk for certain cancers in patients with rheumatoid arthritis (RA) in Singapore, according to a study published online July 11 in the International Journal of Rheumatic Diseases.
Xin Rong Lim, M.B.B.S., from Tan Tock Seng Hospital in Singapore, and colleagues used the prospective Tan Tock Seng Hospital RA Registry (2001 to 2013; 1,117 patients) to identify patients who developed malignancies after the onset of RA. The expected numbers of malignancies were calculated based on the Singapore Cancer Registry.
The researchers noted 132 incident malignancies diagnosed during the study period (114 solid-organ tumors and 18 hematological malignancies). For all malignancies, the age- and sex-adjusted standardized incidence ratio (SIR) was 1.28 for men (95 percent confidence interval [CI], 0.88 to 1.87) and 1.21 for women (95 percent CI, 1.00 to 1.46). Among RA patients, there was a fourfold to fivefold increase in lymphoma compared with the general population (SIRs, 5.05 for men [95 percent CI, 1.90 to 13.46] and 3.75 for women [95 percent CI, 1.95 to 7.20]). In male RA patients, the SIR of lung malignancy was 2.36 (95 percent CI, 1.23 to 4.53). In female RA patients, the SIR of cervical malignancy was 3.72 (95 percent CI, 2.20 to 6.23).
“This paper adds information about RA-associated malignancy among Singaporean and Asian RA patients, which hitherto has been very sparse,” the authors write.