Background and Objectives
Rising incidences of basal cell carcinoma (BCC) have increased the need for effective topical therapies. By enhancing cutaneous uptake of the chemotherapeutic agents, cisplatin and 5-fluorouracil (5-FU), laser-assisted delivery may provide a new combination treatment for BCC. Accordingly, this study aimed to evaluate tumor response, safety, and drug biodistribution in tumors and blood after topical laser-assisted 5-FU + CIS treatment in BCC patients.

Study Design/Materials and Methods
This open-label, proof-of-concept trial investigated laser-assisted combination cisplatin + 5-FU treatment in 20 patients with histologically verified, low-risk superficial or nodular BCCs on the face (<20 mm) or trunk/extremities (<50 mm). After tumor demarcation guided by optical coherence tomography (OCT), BCCs were exposed to ablative fractional CO2 laser followed by 60 minutes topical cisplatin solution and 7-day exposure to 5% 5-FU cream under occlusion. After 30 days, treatment was repeated if any tumor residual was identified. Tumor response at day 30 and month 3 was assessed clinically as well as by OCT, reflectance confocal microscopy, and ultrasound, supplemented by histological verification at 3 months. Local skin reactions (LSRs) and side effects were evaluated on days 1, 3–5, 14, 30, and month 3. Drug detection in tumors and blood was performed in a subset of patients 1- and 24 hours after treatment.

Results
Nineteen patients completed the trial, with 32% (6/19) receiving a single treatment and 68% (13/19) treated twice. At 3 months, clinical clearance was seen in 18/19 patients with a corresponding 94% (17/18) achieving histological clearance. Baseline tumor thickness and subtype did not influence treatment number or clearance rate (P ≥ 0.61). LSRs were well-tolerated and consisted of erythema, edema, and erosion, followed by crusting by day 14. Erythema declined gradually by month 3, with 94% of patients and 79% of physicians rating cosmesis as “good” or “excellent.” Scarring or hyperpigmentation was noted in 50% and 56%, respectively, while pain and infection were not observed during the follow-up period. Although chemotherapy uptake was visualized extending to deep skin layers, no systemic exposure to cisplatin or 5-FU was detected in patient blood.

Conclusion
Laser-assisted cisplatin + 5-FU shows potential as an effective and tolerable treatment option for low-risk BCC, particularly in instances where self-application is not possible or where in-office, non-surgical therapy is preferred.