Multiple sclerosis (MS) has been linked to reduced rates of cancer prior to the era of immunomodulating treatments. We assessed the incidence of cancer in a cohort of 1338 MS patients and evaluated the effect of exposure to immunomodulatory treatment. Cancer incidence in the MS population was compared with the expected age- and gender-matched incidence rates in the Israeli population for the period 1960-2003. Time-dependant Cox model analysis was used to estimate hazard ratios for glatiramer acetate, beta-interferons (1a and 1-b) and intravenous immunoglobulins (IVIg). Among 892 female MS patients, 15 (1.7%) developed breast cancer, and 31 (3.5%) developed cancers of any type. Seventeen of 446 (3.8%) male MS patients developed cancer. The standardized incidence ratios (SIRs) computed until the time of first immunomodulatory treatment were 0.60 (95% CI, 0.38-0.92, p = 0.02) for all female cancer, and 1.11 (95% CI, 0.64-1.91) for all male cancer. Time-dependent covariate analyses for female breast cancer yielded a relative risk for glatiramer acetate of 3.10 (95% CI, 0.86-11.1) and 0.52 (95% CI, 0.07-4.05) for beta-interferons. For IVIg, the analyses were uninformative. Our findings indicate that cancer incidence is significantly lower in female MS patients than in the general population. Female MS patients treated with glatiramer acetate showed an elevated rate of breast cancer and all MS patients treated with beta-interferons showed an elevated risk of non-breast cancers though not statistically significant (p = 0.122 and 0.072, respectively. REMEMBER THIS MEANS NOT DIFFERENT FOR EITHER). Further study is needed to assess possible associations between long-term exposure to the novel immunomodulatory treatments in MS and rate of cancer.
Lebrun C, Debouverie M, Vermersch P, Clavelou P, Rumbach L, de Seze J, Wiertlevski S, Defer G, Gout O, Berthier F, Danzon A. Cancer risk and impact of disease-modifying treatments in patients with multiple sclerosis. Mult Scler. 2008 ;14(3):399-405
RESULTS: Thirty one patients (1.75%) with confirmed MS had a history of cancer: mean age at MS diagnosis of 37.9 years and a mean age atcancer diagnosis of 46.4 years. The most frequent cancers were breast (34.5%), gynecological (12.5%), skin (10.2%), acute leukemia and lymphoma (5.9%), digestive (8.8%), kidney and bladder (5.1%), lung (3.4%) and central nervous system (3%). Calculated standardized incidence rates were 0.29 (0.17-0.45) for men and 0.53 (0.42-0.66) for women. The incidence of cancer in this MS population was lower than that expected for the general population. Matched to age, gender and histology, cancers in MS were associated with a young age and exposure to IS treatments. When considering all patients, treated patients had a 3-fold higher risk of developing cancer, if they had a history of IS (P = 0.0035). For treated patients, the cancer sites were more likely the breast, the urinary tract, the digestive system and the skin.
CONCLUSION: Our data suggest that MS patients do not have an increased risk of cancer. Rather for several types of cancer a significantly reduced risk was observed, except for breast cancer in women treated with IS. The relative increased risk of breast cancer in MS women under IS treatment warrants further attention.