Basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma are frequently distributed on areas of the face with high UV exposure, but they do not share commonly affected sites, indicating the presence of disease-specific etiologic factors aside from UV radiation, researchers reported in the British Journal of Dermatology.
The investigators retrospectively analyzed data regarding facial lesions in Japanese patients with BCC (292 lesions; 139 men and 153 women; mean age, 75 years); invasive SCC (118 lesions; 56 men and 62 women; mean age, 85 years); and melanoma (51 lesions; 23 men and 28 women; mean age, 78 years). The patients were treated at a hospital in Japan from January 2000 to December 2017, and the diagnosis in all cases was histopathologically confirmed.
For each case, the lesion area was projected onto a pixeled facial model. Lesion centroids were recorded, and a pixel was counted as lesion-positive when more than half of its area was occupied.
The researchers found that all 3 cancers were distributed frequently on the median face of the patients. A significant correlation was observed between lesion number and the affected region of the median face (all P <.01).
The most predominantly affected region for BCC was the central area of the median face (195 lesion centers [66.8%] vs 16 for SCC [13.6%] and 10 for melanoma [19.6%]). The most predominantly affected region for SCC was the external area of the median face (45 lesion centers [38.1%] vs 17 for BCC [5.8%] and 4 for melanoma [7.8%]). For melanoma, the most predominantly affected region was the internal area of the median face (29 lesion centers [56.9%] vs 40 for BCC [13.7%] and 15 for SCC [12.7%]).
The highly prevalent lesion areas of BCC, SCC, and melanoma were mutually exclusive and without remarkable overlap. A subanalysis showed that melanoma significantly more frequently aggregated at the internal area of the median face in women (20 cases [71.4%] vs 9 cases [39.1%] in men, P =.0261), and SCC was observed significantly more predominantly on the external area of the median face in men (28 cases [50.0%] vs 17 cases [27.4%] in women, P =.0141).
BCC was highly focused on the center of the face, possibly owing to embryologic factors or Malassezia yeast localization, according to the study authors. Patients with Parkinson disease had an increased incidence of BCC but a low incidence of other malignancies.
The investigators noted that their study was limited by its descriptive design, the limited number of cases from a single center, and a lack of adjustment for confounders.
“The unique nonoverlapping distributions of BCC, SCC, and melanoma on the face surface indicated the presence of disease-specific etiologic factors other than UV exposure,” the researchers concluded.
Omodaka T, Minagawa A, Okuyama R. Ultraviolet-related skin cancers distribute differently on the face surface. Br J Dermatol. Published online February 10, 2021. doi:10.1111/bjd.19875