Three-Year Follow-Up Results of Photodynamic Therapy vs. Imiquimod vs. Fluorouracil for Treatment of Superficial Basal Cell Carcinoma: A Single-Blind, Noninferiority, Randomized Controlled Trial

A randomized controlled trial including 601 patients previously showed that the effectiveness of imiquimod and fluorouracil cream were not inferior to methyl aminolevulinate photodynamic therapy (MAL-PDT) in patients with superficial basal cell carcinoma after 1 year of follow-up. We now present the 3-year follow-up results. The probability of tumor-free survival at 3 years post-treatment was 58.0% for MAL-PDT (95% confidence interval [CI] = 47.8-66.9), 79.7% for imiquimod (95% CI = 71.6-85.7), and 68.2% for fluorouracil (95% CI = 58.1-76.3). The hazard ratio for treatment failure comparing imiquimod with MAL-PDT was 0.50 (95% CI = 0.33-0.76, P = 0.001). Comparison of fluorouracil with MAL-PDT and fluorouracil with imiquimod showed hazard ratios of 0.73 (95% CI = 0.51-1.05, P = 0.092) and 0.68 (95% CI = 0.44-1.06, P = 0.091), respectively. Subgroup analysis showed a higher probability of treatment success for imiquimod versus MAL-PDT in all subgroups with the exception of elderly patients with superficial basal cell carcinoma on the lower extremities. In this subgroup, the risk difference in tumor-free survival was 57.6% in favor of MAL-PDT. In conclusion, according to results at 3 years post-treatment, imiquimod is superior and fluorouracil not inferior to MAL-PDT in treatment of superficial basal cell carcinoma

Risk of Invasive Cutaneous Squamous Cell Carcinoma After Different Treatments for Actinic Keratosis: A Secondary Analysis of a Randomized Clinical Trial

Importance: Treatment of actinic keratosis (AK) aims to prevent cutaneous squamous cell carcinoma (cSCC). However, whether AK can progress into invasive cSCC is a matter of debate, and little is known about the effect of treatment on preventing cSCC. Objectives: To evaluate the risk of invasive cSCC and factors that may contribute to increased risk in patients with multiple AKs. Design, Setting, and Participants: In this secondary analysis of a multicenter randomized clinical trial, 624 patients with a minimum of 5 AKs within an area of 25 to 100 cm2 on the head were recruited from the Department of Dermatology of 4 hospitals in the Netherlands. Long-term follow-up was performed from July 1, 2019, to December 31, 2020. Interventions: Patients were randomized to treatment with 5% fluorouracil, 5% imiquimod cream, methylaminolevulinate photodynamic therapy, or 0.015% ingenol mebutate gel. Main Outcomes and Measures: The primary outcome was the proportion of patients with invasive cSCC in the target area during follow-up. Secondary outcomes were the associations between risk of invasive cSCC and a priori defined potential prognostic factors, including type of treatment, severity of AK (Olsen grade), history of nonmelanoma skin cancer, and additional treatment. Results: Of the 624 patients (558 [89.4%] male; median age, 73 years [range, 48-94 years]) in the study, 26 were diagnosed with a histologically proven invasive cSCC in the target area during follow-up. The total 4-year risk of developing cSCC in a previously treated area of AK was 3.7% (95% CI, 2.4%-5.7%), varying from 2.2% (95% CI, 0.7%-6.6%) in patients treated with fluorouracil to 5.8% (95% CI, 2.9%-11.3%) in patients treated with imiquimod. In patients with severe AK (Olsen grade III), the risk was 20.9% (95% CI, 10.8%-38.1%), and the risk was especially high (33.5%; 95% CI, 18.2%-56.3%) in patients with severe AK who needed additional treatment. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, risk of invasive cSCC was highest in patients with Olsen grade III AK and was substantially increased in patients who received additional treatment. These patients should be closely followed up after treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02281682

Risk of Invasive Cutaneous Squamous Cell Carcinoma After Different Treatments for Actinic Keratosis:A Secondary Analysis of a Randomized Clinical Trial

Importance: Treatment of actinic keratosis (AK) aims to prevent cutaneous squamous cell carcinoma (cSCC). However, whether AK can progress into invasive cSCC is a matter of debate, and little is known about the effect of treatment on preventing cSCC. Objectives: To evaluate the risk of invasive cSCC and factors that may contribute to increased risk in patients with multiple AKs. Design, Setting, and Participants: In this secondary analysis of a multicenter randomized clinical trial, 624 patients with a minimum of 5 AKs within an area of 25 to 100 cm2 on the head were recruited from the Department of Dermatology of 4 hospitals in the Netherlands. Long-term follow-up was performed from July 1, 2019, to December 31, 2020. Interventions: Patients were randomized to treatment with 5% fluorouracil, 5% imiquimod cream, methylaminolevulinate photodynamic therapy, or 0.015% ingenol mebutate gel. Main Outcomes and Measures: The primary outcome was the proportion of patients with invasive cSCC in the target area during follow-up. Secondary outcomes were the associations between risk of invasive cSCC and a priori defined potential prognostic factors, including type of treatment, severity of AK (Olsen grade), history of nonmelanoma skin cancer, and additional treatment. Results: Of the 624 patients (558 [89.4%] male; median age, 73 years [range, 48-94 years]) in the study, 26 were diagnosed with a histologically proven invasive cSCC in the target area during follow-up. The total 4-year risk of developing cSCC in a previously treated area of AK was 3.7% (95% CI, 2.4%-5.7%), varying from 2.2% (95% CI, 0.7%-6.6%) in patients treated with fluorouracil to 5.8% (95% CI, 2.9%-11.3%) in patients treated with imiquimod. In patients with severe AK (Olsen grade III), the risk was 20.9% (95% CI, 10.8%-38.1%), and the risk was especially high (33.5%; 95% CI, 18.2%-56.3%) in patients with severe AK who needed additional treatment. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, risk of invasive cSCC was highest in patients with Olsen grade III AK and was substantially increased in patients who received additional treatment. These patients should be closely followed up after treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02281682