LAHAINA, HAWAII – from South Korea, Iltefat Hamzavi, MD, said at the Hawaii Dermatology Seminar provided by Global Academy for Medical Education/Skin Disease Education Foundation.
Bruce Jancin/MDedge News
Dr. Iltefat Hamzavi
Previous studies by Dr. Hamzavi and others have established that vitiligo patients have a reduced risk of melanoma and perhaps nonmelanoma skin cancers as well. But the South Korean national study of 101,078 vitiligo patients matched by age and sex to twice as many vitiligo-free controls was the first large examination of the association between vitiligo and internal malignancies. The findings suggest that immunosurveillance in patients with the disease is not merely a skin-deep phenomenon, noted Dr. Hamzavi, of the MultiCultural Dermatology Center at Henry Ford Hospital in Detroit.
“Vitiligo is probably a systemic disease in which there may be increased immunosurveillance. The point here is that as we suppress the disease, we have to be careful that we’re not going to increase cancer rates,” the dermatologist explained in an interview. “This is big data, and something to be aware of, but don’t act on it yet in clinical practice. I just want people to be aware that all of these autoimmune diseases are there for a reason. There are lower rates of melanoma and internal cancers in patients who have vitiligo, but what that means for our new therapies that are coming up we don’t know yet.”
He predicted that the study will open up an active new research domain, but it will take time to find definitive answers as to whether emerging immunomodulatory therapies for patients with vitiligo might, in some instances, increase their current favorably lower risk of internal malignancies. In the meantime, physicians interested in treating vitiligo off label with, for example, Janus kinase (JAK) inhibitors will want to be particularly cautious in patients with a strong history of skin cancer or internal malignancies.
The retrospective, population-based study utilized data from the Korean National Health Insurance claims database. The investigators found that the incidence rate of internal malignancies was 612.9 per 100,000 person-years in the vitiligo group and 708.9 per 100,000 person-years in controls, for a statistically significant and clinically meaningful 14% relative risk reduction after adjustment for age, sex, and comorbid conditions.
Among the most striking organ-specific findings: the vitiligo group had a 38% relative risk reduction in colorectal cancer, a 25% reduction in the risk of lung cancer, and a 38% decrease in ovarian cancer. In contrast, they had a 20% increase in the risk of thyroid cancer (J Clin Oncol. 2019 Apr 10;37[11]:903-11).
Despite the fact that vitiligo is a common disease that affects 0.5%-1% of the population worldwide, for decades it has been something of a pharmacotherapeutic backwater. That’s changed recently and in dramatic fashion as a result of new understanding of the disease pathogenesis. The JAK inhibitors are now under active investigation for the treatment of vitiligo. Indeed, ruxolitinib cream, a potent JAK-1 and -2 inhibitor, is now in phase 3 investigation following a highly successful phase 2 trial. Interleukin-15 blockade is another promising avenue.
Dr. Hamzavi reported serving as a consultant to AbbVie, Aclaris, Novartis, and Pfizer, and receiving research funding from Estee Lauder, Clinuvel Pharmaceuticals, Incyte, and Pfizer. SDEF/Global Academy for Medical Education and this news organization are owned by the same parent company.