Different Anatomical Distribution of Basal Cell Carcinoma Subtypes in Iranian Population: Association between Site and Subtype

BACKGROUND Basal cell carcinoma (BCC) is the most common type of human cancer. Despite the high prevalence of these tumors, there is a lack of reliable epidemiological data in some regions including Iran. OBJECTIVE To assess the relationship between BCC subtypes and anatomical distribution in the Iranian population. METHODS There were 876 patients with a single BCC enrolled in this study (March 2007 to March 2010; Razi Dermatology Center, Tehran, Iran). RESULTS Among 876 patients, 544 were males and 332 females. Of the lesions, 43% were nodular, 32.4% mixed type, 3% superficial and rest of other subtypes. In the lesion location, 58.2% were on the face, 29.2% on scalp, 6.2% on ears, 2.3% on neck, 1.7% on trunk and 1.3% on the extremities. There was no significant difference between male and female in the BCC subtypes, but anatomical distribution of the tumor was different (p=0.002). Most of the trunk-arising BCCs were superficial, and most of the facial BCCs were nodular subtype. Also, most of the BCC subtypes occurred in patients between 40 to 80 years old and mostly on the face and scalp (p=0.04). However, superficial BCCs mostly occurred in younger patients over others (p=0.001). CONCLUSION Subtype is associated with a site, independent of gender or age. Also BCCs occurring on the trunk are mostly of the superficial subtype.