The impact of autoimmune diseases on the incidence and prognosis of cutaneous malignant melanoma.
BACKGROUND
Persons being treated with IFNalpha-2b for advanced cutaneous malignant melanoma (CMM) have been reported to have a greatly improved prognosis if they develop autoantibodies or clinical signs of autoimmunity during therapy. Consequently, we examined whether autoimmune diseases might also be associated with lower CMM incidence and better prognosis.


METHODS
We established a study cohort based on the entire Danish population, obtaining information on CMM and autoimmune diseases from the Danish national registers. Using log-linear regression models adjusting for age, period, and sex, we compared CMM incidence and CMM-specific mortality rates in persons with and without a history of autoimmune disease.


RESULTS
Between 1977 and 2003, 20,482 cases of CMM were registered in the Danish Cancer Register. Previously diagnosed autoimmune diseases did not affect the incidence of CMM (incidence rate ratio, 1.0; 95% confidence interval, 0.9-1.1). In the first 5 years after CMM diagnosis, we observed 8,957 deaths in individuals with CMM (5,181 expected). CMM-specific mortality rates 1 to 5 years after diagnosis were similar in CMM patients with and without autoimmune diseases (mortality rate ratio, 0.9; 95% confidence interval, 0.7-1.2).


CONCLUSIONS
Autoimmune conditions were not associated with CMM incidence or prognosis. The better CMM prognosis previously observed when autoantibodies or clinical signs of autoimmunity developed during IFNalpha-2b therapy may have been related to variation in individual responses to this therapy, with individuals sensitive to treatment exhibiting more signs of autoimmunity but also (independently) experiencing greater antitumor responses as a result of treatment.
Kaae
Jeanette
J
Department of Epidemiology Research Statens Serum Institut Artillerivej 5, 2300 Copenhagen S, Denmark. jtk@ssi.dk
Wohlfahrt
Jan
J
Boyd
Heather A
HA
Wulf
Hans Christian
HC
Biggar
Robert J
RJ
Melbye
Mads
M
D015551:Autoimmunity; D015331:Cohort Studies; D003718:Denmark; D006801:Humans; D015994:Incidence; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000276:immunology / Q000627:therapeutic use; D008545:Melanoma / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology; D011379:Prognosis; D011994:Recombinant Proteins; D012878:Skin Neoplasms / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins