A long-term cohort study of acitretin for prevention of keratinocyte carcinoma in solid organ transplant recipients.

Background: Solid organ transplant recipients (SOTR) are at high risk of keratinocyte carcinoma (KC). Long-term evidence for acitretin as chemoprophylaxis in this population is lacking.

Objective: To determine the benefit of long-term acitretin for KC chemoprevention in SOTR.

Methods: A retrospective cohort study of SOTR treated with acitretin at an Australian transplant dermatology clinic was performed. General estimating equations were used to evaluate change in rates of histologically confirmed KC in the 6-12 months prior to acitretin and following a minimum 6 months of treatment. A control group of patients within the same service was included, comprising SOTR who were not treated with acitretin.

Results: Twenty-two patients received acitretin treatment for at least 6 months, eighteen for at least 5 years and four for at least 9 years. The median KC rate pretreatment was 3.31 per year (IQR 1.93, 5.40). There was a significant reduction in the rate of KC in the first year of acitretin treatment (IRR 0.41, 95% CI 0.22, 0.76, P = 0.005), and this effect was observed for 5 years (IRR at 5 years 0.34, 95% CI 0.17, 0.67, P = 0.002). The control group had no statistically significant change in KC rate over time in the study.

Conclusions: Acitretin appears to be well-tolerated and effective in reducing KC in SOTR for at least 5 years. Study limitations include its retrospective nature, small sample size and lack of blinding.