This investigation compared the histologic features of basal cell carcinoma (BCC) between organ transplant recipients and the general population.
Development and progression of basal cell carcinoma (BCC) were more common among organ transplant recipients (OTRs) compared with the general population, and the former also had a higher rate of deep invasion, according to new study findings published in Archives of Dermatological Research.
The study authors note that their data point to immunosuppression as the culprit, which echoes previous research and highlights the greater skin cancer risk these patients face.
“The most frequently occurring skin cancers in OTRs are squamous cell carcinomas (SCCs), and because they are responsible for high morbidity and mortality, SCCs in OTRs have been studied extensively,” the investigators wrote. “BCCs occur less frequently than SCCs and rarely metastasize, and thus BCCs in OTRs have received relatively little attention despite their increased incidence compared with the general population.”
Data for their analysis were provided by histopathology reports from 2 prospective skin cancer studies, 1 each being conducted among the general population (QSkin Sun and Health Study) and OTRs (Skin Tumors in Allograft Recipients). These data were on BCC tumor site, size, level of invasion, subtype, and biopsy procedure. Age- and sex-adjusted prevalence ratios were also uncovered.
Overall, prevalence results show an average of 3.51 cases of BCCs per OTR, or 702 BCCs from among 200 OTRs. This rate was significantly higher than the 2.15 BCC cases per general population, or 1725 BCCS seen in 804 cases.
Cases were more often seen among male patients in both groups, but men accounted for more of the OTR vs general population cases: 76% vs 56%. Also among the OTR group, more than twice as many patients with BCC had their skin checked more than once each year: 53% vs 21%.
No matter the biopsy method, excision or punch/shave biopsy or curettage, respectively, the head/neck region was the most common site for a BCC among both patient cohorts: 46.4% and 41.9% in the OTR group and 43.4% and 33.4% in the general population. Excision was the most common surgical method overall for tumors of 2 cm or smaller, but tumor size data were lacking from a sizeable portion of each group who had punch/shave biopsy or curettage: 75.5% of the OTR group and 67.1% of the general population group.
The authors note this is because, “Substantial proportions of BCC tumors in each group were diagnosed and treated only by partial biopsies, thus tumor size and depth of invasion were unknown for over two-thirds of partially excised BCCs in both case groups.”
There were also more instances of unknown tumor depth in the OTR group, but this group also had a higher rate of nonaggressive tumors for those who underwent excision vs the general pop patients: 82.0% vs 68.6%. Nonaggressive rates were similar for punch/shave biopsy or curettage, at 83.1% and 83.2%, respectively. Aggressive tumor results were more often seen in the general patient excision cohort (31.4%) compared with the OTR excision cohort (18.1%).
A greater number of higher-risk BCCs per person were seen in the OTR group, among whom more tumors were larger and invaded skin beyond the dermis layer:
Adjusting for age and sex produced higher prevalence ratios for BCCs on the scalp or ear, higher-risk BCCs that were 2 cm or larger, and BCCs that extended beyond the dermis among the OTR group compared with the general population.
“This is among the largest clinicopathological series of BCCs in OTRs reported to date, and one of the few to compare BCCs in OTRs and the general population,” the authors concluded. “Patient care and future research to confirm these findings may both benefit from enhanced communication between treating clinicians and dermatopathologists, not only via the pathology requisition but also by comprehensive histopathologic reporting of BCCs.”
Pandeya N, Huang N, Jiyad Z, et al. Basal cell carcinomas in organ transplant recipients versus the general population: clinicopathologic study. Arch Dermatol Res. Published online October 25, 2022. doi:10.1007/s00403-022-02403-6