A retrospective study comparing PUVA therapy with and without maintenance therapy in patients with mycosis fungoides in a real-word clinical practice

Abstract

PUVA therapy is recommended in all stages of mycosis fungoides (MF) and can be combined with other therapies depending on the stage.^1-4 Complete response rates for oral PUVA were calculated to be 85% for stage IA, 65% for stage IB, and 85% for stage IIA. A prospective study from 2019 revealed improved remission with 9 months of maintenance therapy after the induction phase (12–24 weeks) compared to no maintenance.^{5, 6} The aim of this retrospective study was to compare patients with MF receiving PUVA treatment with maintenance therapy (adapted to the above-mentioned prospective study) from the years 2020–2024 with patients receiving PUVA treatment without maintenance therapy from the years 2013–2019.

Twenty-five and 22 analysable patients with histologically confirmed MF were presented to the photodermatology unit for PUVA therapy in the years 2013–2019 (group 1) and 2020–2024 (group 2) respectively. Treatment in the PUVA induction phase was usually administered four times a week for up to 6 weeks with increasing UVA doses for both groups. Additionally, PUVA maintenance therapy was usually administered for 9 months (first month: every week; second and third month: every 2 weeks; fourth to ninth month: every 4 weeks) with the last UVA dose of the induction phase in group 2. The type of PUVA therapy, the number of treatments, the single dose and the cumulative doses were documented. Application of topical steroids was allowed, and systemic drugs were used in some patients (Table 1). Clinical evaluation of the response was performed every week during the induction phase, regularly during the maintenance therapy and afterwards every 3–6 months depending on the stage of the disease. The assessment with regard to remission (complete response, partial response) or progression (progressive disease, relapse) according to previously published criteria⁷ was determined 1 year after the start of the induction phase. Statistical analysis was performed with the chi-squared test. The threshold for statistical significance was set to p < 0.05. The odds ratio (OR) was calculated using MedCalc (MedCalc Software Ltd, Ostend, Belgium).

Details of sex, age, type of PUVA therapy, systemic treatments alongside PUVA therapy, mean cumulative dose and mean number of irradiations can be found in Table 1. Out of the 25 patients in group 1, 11 experienced remission, while 15 out of the 22 patients in group 2 had a remission (44% vs. 68%, n.s., p = 0.096). One patient of group 2 is shown in Figure 1. The OR for remission with PUVA maintenance therapy compared to induction PUVA only was 2.73 with a 95% confidence interval of 0.83–9.01 and a p-value of 0.10.

This retrospective study suggests a trend towards improved rates of remission using PUVA maintenance at year 1. This short follow-up period and the small sample size are limitations of the study. In a prospective study with 8 versus 11 patients the standardised 9-month PUVA maintenance phase significantly prolonged median (range) disease-free remission from 4 (1–20) months to 15 (1–54) months.⁵ Another prospective study with a 28-month follow-up in 40 patients with early-stage MF did not find a statistically significant difference between the groups according to receipt of PUVA maintenance therapy (p = 0.161) similar to this study.⁸ In another retrospective study there was also no significant difference between recurrence-free survival in five patients who received PUVA maintenance therapy compared to six patients without maintenance therapy (p = 0.63).⁹ Nevertheless, our data along with the results of the prospective study of 2019 and guidelines for phototherapy of MF lead to the assumption that there are likely patients who benefit from maintenance therapy.^{2, 3, 7, 10}

BE has full access to all of the data in the study and is the guarantors of this. She takes responsibility for the content of the manuscript, including the data and analysis. LF collected data of patients‘ files. BE wrote the manuscript. BE, RH, CP, ODP contributed to the supervision of the patients, data interpretation and revision of the manuscript.

CP has received honoraria and travel support from BMS, MSD, Pierre-Fabre, Almirall, AbbVie, Pelpharma, Novartis, Leo Pharma, Eli Lilly, Pfizer, Boehringer Ingelheim, Celgene, Takeda, Janssen, Sanofi, Galderma and Amazentis, all unrelated to the present study. All other authors state that they have no conflict of interest.

The patient in this manuscript has given written informed consent for participation in the study and the use of his deidentified, anonymized, aggregated data and his case details (including photographs) for publication. Ethical Approval: Not applicable.