1Comparison of Subtypes of Penile Squamous Cell Carcinoma From High and Low Incidence Geographical Regions

respectively.1,2 In the United States the national fig-ure is 0.5 but there are population subsets at greater risk for penile cancer in Kentucky, West Virginia, and the American Indian population (1.0, 0.8, and 1.8, respectively). There are several environmental risk factors involved in the pathogenesis of penile cancer, such as phimosis, smoking, hygienic habits, treatment with Psoralen and ultraviolet A (PUVA) photochemotherapy, and a history of genital warts.3-6 Lichen sclerosus have been found consistently asso-ciated with special subtypes of penile squamous cell carcinomas (SCC).7-12 Presence of human papillo-mavirus (HPV) was found to be a risk factor for There is a broad worldwide variation in the age standardized incidence (ASR) per 100 000 inhabitants of penile carcinoma ranging from about 2 to 4 per 100 000 in some countries of Africa, Asia, and South America to about 0.2 to 1 per 100 000 in North America and Europe.1 Lowest ASRs are from Israel, Korea, Japan, and the Chinese population in San Francisco at rates of 0.1 to 0.2. There is a worldwide geographical variation in the inci-dence of penile squamous cell carcinoma (PSCC); some subtypes are HPV-related (warty, basaloid) while others (keratinizing variants) are not. The aims of this study were to compare the distribution of different histological subtypes of PSCC from regions of low (Paraguay, 144 cases) and high (USA, 157 cases) inci-dence and to identify and compare tumors with and without warty and/or basaloid morphology. The distri-bution of subtypes in the Paraguayan and the American series was: usual, 49.3 and 46.5%; verrucous, 8.3 and 7.6%; papillary NOS, 7.6 and 5.7%; warty, 6.9 an