Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
RA, Anti-TNF Therapy, and Risk of Malignant Melanoma-a Nationwide Population-Based Study From Sweden.
Raaschou1, Pauline, Simard2, Julia F., Neovius2, Martin, Holmqvist2, Marie, Eriksson2, Jonas, Askling2, Johan, the ARTIS studygroup,
States of immune suppression, such as post-transplant therapy, have recently emerged as a possible risk factor not only for non-melanoma skin cancer but also for malignant melanoma (Vajdic CM et al, JAMA 2006). An increased risk of melanoma associated with anti-TNF therapy has been reported (Wolfe F et al, Arthritis Rheum. 2007; Askling J. EULAR Conference Abstract 2009). We aimed to investigate the risk of malignant melanoma in patients with RA compared to the general population, and to investigate whether anti-TNF treatment influences melanoma risk in RA.
A nationwide and population-based cohort of patients with RA were identified using data from the Swedish outpatient register from 2001 through 2009 (n=56,336). Patients starting anti-TNF therapy were identified through linkage to the Swedish Biologics Register ARTIS and to the national Prescribed Drug Register (n=8,453) To each RA patient, 5 general population comparators were matched for sex, year of birth and county of residence. Occurrence of first-ever invasive malignant melanoma, as well as occurrence of first-ever cancer, irrespective of type (all-site), was assessed through linkage to the national Swedish Cancer Register. Relative risks (RRs) for malignant melanoma and all-site cancer were calculated using Cox regression with age as time-scale and anti-TNF therapy treated as a time-dependent variable, adjusted for selected co-morbidities. RRs were assessed overall and by time since start of anti-TNF therapy.
Based on 135 incident melanomas during 253,572 person-years of follow-up among biologics-naïve patients with RA vs. 718 melanomas during 1,460,120 person-years of follow-up in the general population comparator, the RR for malignant melanoma in biologics-naïve patients with RA was 1.1 (95% CI 0.91.3). Based on 32 incident malignant melanomas during 44,858 person-years of follow-up from start of anti-TNF therapy, compared to biologics-naïve RA patients, the RR was 1.8 (95% CI 1.22.7). Based on 418 incident all site cancers during 42,418 person-years of follow-up among the anti-TNF exposed, the RR was 1.0 (0.91.1) compared to biologics-naïve RA patients (Table). Sensitivity analyses also including in situ melanomas resulted in a relative risk of 1.5 (95% CI 1.12.1).
Table. Relative risks adjusted for age, sex and co-morbidities (95% confidence intervals) and number of cases among patients treated with anti-TNF, comparing Swedish patients with RA treated with anti-TNF (n=8,453) to biologics-naïve patients with RA (n=47,883).
|Anti-TNF-exposed vs. Biologics-naïve RA||Time since first anti-TNF treatment start|
|Overall||< 1 year||12 years||>=2 years|
|Relative risk (95%CI), Cases||1.8 (1.22.7), 32||1.5 (0.64.1), 4||2.9 (1.45.9), 8||1.7 (1.02.7), 20|
|Relative risk (95%CI), Cases||1.0 (0.91.1), 418||1.0 (0.81.3), 74||0.9 (0.71.2), 63||1.1 (1.01.3), 281|
In the absence of anti-TNF therapies, RA patients are not at elevated risk of malignant melanoma. Patients selected for and treated with anti-TNF have a higher risk of malignant melanoma than biologics-naïve RA patients.
To cite this abstract, please use the following information:
Raaschou, Pauline, Simard, Julia F., Neovius, Martin, Holmqvist, Marie, Eriksson, Jonas, Askling, Johan, et al; RA, Anti-TNF Therapy, and Risk of Malignant Melanoma-a Nationwide Population-Based Study From Sweden. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :2523