“This is an unbiased national health insurance epidemiology study looking at cancer risk and MS. It appears that Taiwanese woman with MS have a higher risk of breast cancer than control subjects. What could this mean? Is the link causal or is simply due to association between MS, cancer and another risk factor, for example vitamin D deficiency. The latter has been linked to increased cancer risk in the general population.”
“What does this mean? It may be simply be association and have something to do with environmental factors.”
BACKGROUND: Studies have suggested that MS might be linked to an overall reduced cancer rate, but a positive relationship is also found for several types of cancer. This study determines whether MS is associated with cancer risk in Taiwan.
METHODS: Data from the National Health Insurance System of Taiwan were used to assess this issue. The MS cohort included 1292 MSers, and each MSer was randomly frequency-matched with four participants without MS, based on their age, sex and index year (control cohort). Cox proportional hazards regression analysis was conducted to estimate the influence of MS on cancer risk.
RESULTS: A significantly higher risk of developing overall cancer was found amongst the MS cohort compared with the control cohort [adjusted hazard ratio (HR) 1.85, 95% confidence interval (CI) 1.26-2.74], as well as breast cancer (adjusted HR 2.23, 95% CI 1.11-4.46).
CONCLUSIONS: The nationwide population-based cohort study revealed that Taiwanese patients with MS have a higher risk of developing overall cancer types and breast cancer in particular.