Basal cell carcinomas in organ transplant recipients versus the general population: clinicopathologic study

Organ transplant recipients (OTRs) are at greater risk of basal cell carcinomas (BCCs) than non-OTRs, but histopathologic differences between BCCs in OTRs and the general population are largely unknown. We compared clinicopathologic features of BCCs in OTRs vs the general population in Queensland, Australia. Details of BCC tumors (site, size, level of invasion, subtype, biopsy procedure) were collected from histopathology reports in two prospective skin cancer studies, one in OTRs and one general-population-based. We used log-binomial regression models to estimate age- and sex-adjusted prevalence ratios (PR) with 95% confidence intervals (CIs) for BCC features. Overall, there were 702 BCCs in 200 OTRs and 1725 BCCs in 804 population cases. Of these, 327 tumors in 128 OTRs were higher risk BCCs (any head and neck BCC; >= 2 cm on trunk/extremities), more per person than 703 higher risk BCCs in 457 cases in the general population (chi-square p = 0.008). Among head/neck BCCs, OTRs were more likely than general population cases to have BCCs on scalp/ear than on face/lip/neck (PR = 1.5, 95%CI 1.2-1.8). Although aggressive subtypes were less common among higher risk BCCs in OTRs, BCCs invading beyond the dermis were almost twice as prevalent in OTRs (PR = 1.8, 95% CI 1.3-2.6) than the general population.