Researchers have found that patients with a history of atopic diseases may be less likely to develop melanoma than patients with a history of nonatopic diseases, according to a new study published by Komulainen et al in Melanoma Research. The findings also revealed that patients with atopic diseases had a considerably lower overall risk of skin cancer and extracutaneous malignancies.
Background
Atopic diseases—such as allergic asthma, allergic rhinitis, and atopic dermatitis—have become increasingly prevalent in industrialized countries in recent decades. The prevalence of skin cancers has also increased, which has raised questions about a possible association between the two. Indeed, the link between atopic diseases and skin cancer has been studied before, but with somewhat inconclusive results. Studies have suggested that the chronic inflammation that accompanies atopic diseases, or an abnormal immune response, may either contribute to the development of cancer—or prevent it.
“The latest theory is that the skin has a naturally occurring autoreactive immunoglobulin E response that could protect against carcinogens and skin damage leading to cancer. This theory makes sense because atopic diseases typically involve an [immunoglobulin E]–mediated allergy, so the protective mechanism may be even more pronounced in [the] skin [of patients with atopic diseases],” explained senior study author Ilkka Harvima, MD, PhD, Professor and Chief Physician in the Department of Dermatology at the University of Eastern Finland and Kuopio University Hospital.
Study Methods and Results
Conducted under the North-Savo Skin Cancer program, researchers in the new study recruited 496 adult patients estimated to have an increased risk of skin cancers—such as basal cell carcinoma, squamous cell carcinoma, or melanoma—and analyzed the patients’ background information, history of atopic diseases, overall medical history, and skin. The researchers also classified the patients into different skin cancer risk classes: low risk, moderate risk, and high risk. The patients who had atopic diseases were divided into groups based on whether they had mucous membrane atopy or atopic dermatitis.
After conducting a logistic regression analysis, the researchers discovered that in the group consisting of 171 patients with atopic diseases, there were about 50% fewer cases of melanoma and extracutaneous malignancies, and a considerably better general skin cancer risk classification than in the nonatopic group. When 94 patients who were immunosuppressed were removed from the analysis, the reduced melanoma risk was found to be particularly pronounced in the mucous membrane atopy group—where the risk was more than 50% lower than in the nonatopic group.
However, there was no statistically significant association between atopy and the severity of photoaging, actinic keratoses, nevus count, basal cell carcinoma, and squamous cell carcinoma. In addition, serum total immunoglobulin E levels were not associated with these skin changes nor with extracutaneous malignancies. Since the research design was cross-sectional, the researchers were unable to demonstrate a causal relationship.
Conclusions
“The cellular mechanism between atopy and melanoma needs to be studied further, and skin biopsies taken from the [study participants] are currently under analysis,” noted lead study author Jenni Komulainen, MD, a doctoral researcher at the University of Eastern Finland and Kuopio University Hospital.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.
