Systematic review of programmed cell death-1 inhibitor therapy for advanced-stage cutaneous squamous cell carcinoma in solid-organ transplant recipients.

BACKGROUND

Programmed cell death-1 (PD-1) inhibitors represent an effective treatment option for advanced cutaneous squamous cell carcinoma (cSCC). However, solid organ transplant (SOT) recipients with cSCC have traditionally been excluded from clinical trials.

OBJECTIVE

To assess the safety and efficacy of PD-1 inhibitors for stage III-IV cSCC in SOT recipients.

MATERIALS & METHODS: A systematic review was performed using the PubMed, EMBASE, and Scopus databases.

RESULTS

We identified 21 articles describing 33 SOT recipients (26 kidney, four liver, two lung, and one heart) with stage III-IV cSCC treated with PD-1 inhibitors. Eleven patients (33.3%) experienced allograft rejection. Of the 25 cases with iRECIST scores, twelve patients (48.0%) had a complete response (CR), eight (32.0%) showed a partial response (PR), three (12.0%) progressive disease, and two (8.0%) stable disease (SD). Including patients without available iRECIST scores, 21 patients (63.6%) showed tumor response. Eleven patients died, with six (54.5%) due to tumor progression and one (9.1%) due to allograft rejection after foregoing dialysis.

CONCLUSION

PD-1 inhibitors demonstrate efficacy for advanced cSCC and confer a risk of allograft rejection in SOT recipients, requiring careful assessment of risks and benefits. If anti-PD-1 therapy is pursued, use of mTOR inhibitors, prophylactic steroids, and donor-derived cell-free DNA monitoring may mitigate the risk of rejection.