Alopecia

Prevalence of Sun-induced Skin Cancers in Patients With Alopecia Areata, Alopecia Totalis, and Alopecia Universalis

Alopecia areata (AA) is a T-lymphocyte-mediated autoimmune disease characterized by round patches of nonscarring hair loss on the scalp and body. The pathophysiologic mechanism is unclear, but it is thought to be due to peribulbar T-cell inflammation, which results in premature induction of anagen follicles to catagen and telogen, without causing destruction of the hair follicle.¹ This mechanism is similar to that of vitiligo, in which there is autoimmune destruction of melanocytes and a decreased risk of sun-induced skin cancers.²⁻³ There has long been speculation whether the hyper-reactive autoimmune state during AA has a protective effect against skin cancers; and if it does, is it undermined by hair loss and subsequent greater body surface of direct sun exposure?

Institute researchers conducted a retrospective case control study using the electronic medical records of patients >18 diagnosed with AA (N = 498) at Cleveland Clinic Department of Dermatology from 2005–2014. Patients were age and gender matched to a group of patients with a diagnosis of seborrheic keratosis (SK) and no hair loss. The study population consisted of 563 AA patients, and a matched group of control patients. Further, the prevalence of melanoma and nonmelanoma skin cancers (NMSC), subdivided into basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) in the AA group was compared with controls.

Demographic Characteristics, Incidence and Distribution of Sun-Induced Cancers Among Alopecia Areata Patients and Control Group (N = 563)

2005 – 2014

The odds of developing NMSCs were 86% lower among AA patients compared with controls (OR 0.14, 95% CI 0.09-0.20, P <0.001).

Decreased Risk of Melanoma and Nonmelanoma Skin Cancers Among Patients with Alopecia Areata (N = 563)

2005 – 2014

One prior study examined these findings and concluded similarly that the rates of NMSCs were lower among AA patients; however they did not find differences between melanoma rates in AA compared with controls that were shown in our study.³ These findings suggest the need for larger studies of sun-induced skin cancers among AA patients.

References
  1. Jabbari A, Petukhova L, Cabral RM, Clynes R, Christiano AM. Genetic basis of alopecia areata: a roadmap for translational research. Dermatol Clin. 2013;31:109-117.
  2. Paradisi A, Tabolli S, Didona B, Sobrino L, Russo N, Abeni D. Markedly reduced incidence of melanoma and nonmelanoma skin cancer in a nonconcurrent cohort of 10,040 patients with vitiligo. J Am Acad Dermatol. 2014 Dec;71(6):1110-1116. doi: 10.1016/j.jaad.2014.07.050. Epub 2014 Sep 19.
  3. Mostaghimi A, Qureshi S, Joyce C, Guo Y, Huang KP. Reduced incidence of skin cancer in patients with alopecia areata: a retrospective cohort study. Cancer Epidemiol. 2016; 41:129-131.