Tool shows continued efficacy in determining skin cancer risk among transplant recipients

A tool designed to assess skin cancer risk in solid organ transplant recipients proved to be efficacious in independent populations outside of the one used in its creation, according to a study.

“Between 14% and 37.5% of solid organ transplant recipients will develop skin cancer within 10 years of transplantation,” Álvaro Gómez-Tomás, MD, of the department of dermatology at the Vall d'Hebron University Hospital in Barcelona, Spain, and colleagues wrote. “Several skin cancer risk stratification instruments have been developed for the [solid organ transplant recipient (SOTR)] population ... but none was widely used or had large population-based studies backing their validity or usability.”

According to the study, the Skin and UV Neoplasia Transplant Risk Assessment Calculator (SUNTRAC) tool was proposed in 2019 and achieved good prognostic discrimination in the Transplant Skin Cancer Network population study at that time. The tool was designed to consider five variables: sex, race, age at transplantation, pretransplan history of skin cancer, and type of transplant.

Gómez-Tomás and colleagues sought to validate these results in an independent population. Using data from two European cohorts, this retrospective external validation prognostic study evaluated the validity of the SUNTRAC as a tool for identifying solid organ transplant recipients (SOTRs) at a higher risk of developing skin cancer.

Researchers analyzed data from 3,421 SOTRs (mean age at baseline, 53; age range, 42-62 years; 63.2% men) from cohorts in the Netherlands and Spain. Patients were 4% Black; 2.1% Asian; 8% “Latinx”; 3.2% Middle Eastern and North African; and 82.7% white.

SUNTRAC scores were calibrated at the time of transplant based on race, sex, age, pretransplant history of skin cancer and type of organ transplant. Patients were then assigned to their respective risk group based on their SUNTRAC score (low risk, 0-6 points; medium risk, 7-13 points; high risk, 14-17 points; very high risk, 18-22 points).

Results showed that higher SUNTRAC scores were associated with an increased risk of skin cancer. Compared with the low-risk group, significantly higher skin cancer rates were found for each increase in SUNTRAC group, including for medium risk (subdistribution HR [SHR] = 6.8; 95% CI, 3.8-12.1), high risk (SHR = 15.9; 95% CI, 8.9-28.4) and very high risk (SHR = 54.8; 95% CI, 29.1-102.9). Additionally, a 1-point increase on the SUNTRAC score constituted a 25% increase in skin cancer risk (SHR = 1.25; 95% CI, 1.22-1.28).

At 5 years after transplant, observed skin cancer incidence among medium-risk patients was 7%, which the researchers called “similar” to the SUNTRAC predicted percentage of 6.2%, although the SUNTRAC tool achieved greater discrimination in the Dutch cohort compared with the Spanish cohort.

While the SUNTRAC tool provided clinicians with an intuitive skin cancer risk measure, the authors suggested that prospective randomized clinical trials should be conducted to fully assess the tool’s effectiveness.

“Having a tool that can quickly and correctly stratify SOTRs according to their relative skin cancer risk is a great aid for the clinician and a fundamental step in defining guidelines to ensure adequate screening and dermatological follow-up of these patients,” Gómez-Tomás and colleagues concluded.