Treatment benefit of electrochemotherapy for superficial squamous cell carcinoma: a systematic review and single-arm meta-analysis

Objective Treating aggressive superficial squamous cell carcinoma (SCC) poses challenges due to invasiveness. Palliative care is recommended for inoperable cases with extensive tumors near vital organs, risking disfigurement or functional impairment. Electrochemotherapy (ECT) is an emerging cutaneous tumor treatment, but its efficacy against superficial SCC remains uncertain. This study conducts a systematic review and single-arm meta-analysis to evaluate ECT's effectiveness against superficial SCC and provide current evidence for clinical practice. Methods Embase, PubMed and Cochrane Library were searched for studies up to May 2023. The random effects model analyzed complete response (CR) and partial response (PR), with subgroup assessment based on drug dosage, treatment response evaluation, tumor size, primary/recurrent status, and tumor location. Results Ten studies involving 162 patients and 208 tumors were included. Pooled CR and PR rates for ECT-treated superficial SCC were 66.5% (95% CI 48.4%-82.5%; I-2 = 84%) and 20.3% (95% CI 10.5%-32.3%; I-2 = 70%), respectively. Subgroup analysis indicated ECT's superiority in treating primary tumors (PR: 70%, CR: 30%) and tumors <= 3 cm (PR: 81.3%, CR: 10.1%) compared to recurrent tumors (PR: 56.7%, CR: 36.5%) and tumors > 3 cm (PR: 45.2%, CR: 34.4%). Conclusion This single-arm meta-analysis confirms ECT's efficacy against superficial SCC, especially in primary tumors and those <= 3 cm in diameter. The study highlights the impact of tumor location and response evaluation on ECT's benefits, warranting further investigation through additional research.