Risk of cancer among rheumatoid arthritis patients in California

Abstract

Objective The objective of this retrospective cohort study was to evaluate cancer risk among rheumatoid arthritis (RA) patients in California. Methods The study cohort derived from statewide patient discharge records was followed via linkage with cancer registry data over the period 1991–2002. Age and sex adjusted standardized incidence ratios (SIRs) and 95% confidence intervals were calculated to compare observed to expected numbers of cancers based on age, race, and sex specific incidence rates in the California population. Results Among the 84,475 RA patients, who were observed for 405,540 person-years, 5,533 incident cancers were diagnosed during the observation interval. The risk of developing lymphohematopoietic cancer was significantly higher in the cohort for both sexes. Males had significantly higher risks of lung, liver, and esophageal cancer, but a lower risk of prostate cancer. Females were at significantly decreased risk for several cancers including breast, ovary, uterus, cervix, and melanoma, with the risk reduction ranging from 15 to 57% lower than the general population. Hispanics had increased risks of leukemia, vagina/vulva, lung, and liver cancers. Conclusion Studies investigating the mechanisms that underlie the reported associations between RA and specific cancer types are needed.

Melanoma and rheumatoid arthritis (brief report)

“…The remaining 124 were further reviewed, and of these, 11 met our inclusion criteria for analysis and are presented in Table 1 [3][4][5][6][7][8][9][10][11][12][13]. Askling et al [5] and Setoguchi et al [6] included cancer incidence information separately for those exposed to biologics, as is indicated in the table.…”

Effect of autoimmune diseases on risk and survival in female cancers

“…However, mechanisms for such increases are not clear and a chance association is possible as the study involved numerous comparisons. The mechanisms for the overall protective effects in breast, endometrial and ovarian cancers could be the interference in the gonadal steroid synthesis by immunosuppressive therapy, leading to earlier menopause [11,15]. In support of this mechanism was also the stronger protective effect observed for endometrial than for breast cancer, as endometrial cancer is thought to be most responsive to estrogens [22].…”

“…Usually the published studies have addressed one particular AI disease and one or a few female cancers. For example for rheumatoid arthritis most studies suggest decreased or no risks in most female cancers [9][10][11]; in these patients, the survival in breast cancer has been favorable [12]. Similarly most female cancers were decreased in patients with systemic lupus erythematosus, with the exception of cervical cancer which appeared to be increased [13][14][15].…”

Acute myeloid leukemia developing in patients with autoimmune diseases

“…A significant association between rheumatoid arthritis and the risk of AML was observed in the inpatient prevalent and early-arthritis incident cohorts. 36 In the second study, the rheumatoid arthritis cohort, derived from California's statewide discharge data set, both inpatient men and women with rheumatoid arthritis patients had a significant risk of being diagnosed with leukemia, with males at a substantially greater risk 37 compared to the general population. The Swedish Cancer registry was used in the third study which examined 42,262 hospitalized rheumatoid arthritis patients between 1980 and 2004.…”