Purpose: Patients with mycosis fungoides [cutaneous T-cell lymphoma (CTCL)] may benefit from adjuvant therapy after completing total skin electron beam therapy (TSEBT). We report the results for T1/T2 CTCL patients treated with adjuvant oral psoralen plus ultraviolet light (PUVA) with respect to overall survival (OS), disease-free survival (DFS), salvage of recurrence, and toxicity.
Methods and materials: Between 1974 and 1993, TSEBT was administered to a total of 213 patients with CTCL. Records were reviewed retrospectively, and a total of 114 patients were identified as having T1 or T2 disease. Radiotherapy was provided via a 6-MeV linac to a total of 36 Gy, 1 Gy/day, 4 days/week, for 9 weeks. Beginning in 1988, patients were offered adjuvant PUVA within 2 months of completing TSEBT. This was started at 0.5-2 J/m2, 1-2 treatments/week, with a taper over 3-6 months. Therapy then continued once per month. There were 39 T1 and 75 T2 patients. Six T1 (15%) and eight T2 (11%) patients were treated with adjuvant PUVA. A further 49% of the 114 patients received adjuvant systemic therapy, 3% received spot external beam, 4% received adjuvant ECP, 2% received topical nitrogen mustard, 22% received a combination of therapies exclusive of PUVA, and 9% received no adjuvant therapy. Patients were balanced in all subgroups based on pre-TSEBT therapy. The median age of the cohort was 58 (range 20-88), with a median follow-up time of 62 months (range 3-179).
Results: Within 1 month after completing of TSEBT, 97% of T1, and 87% of T2 patients had achieved a complete remission. Stratified by adjuvant therapy, none of six T1 and one of eight T2 patients who received adjuvant PUVA failed within the first 3 years after completion of TSEBT. A total of 43% of the T1 and T2 patients receiving other or no adjuvant treatment failed within the same time course. The 5-year OS for the entire cohort was 85%. Those who received PUVA had a 5-year OS of 100% versus a 5-year OS for the non-PUVA group of 82% (p < 0.10). The 5-year DFS for the entire cohort was 53%. Those who received PUVA had a 5-year DFS of 85% versus a 5-year DFS for the non-PUVA group of 50% (p < 0.02). By T stage, those with T1 receiving PUVA exhibited no relapses, whereas those with T1 not treated with PUVA had a crude relapse rate of 36%. Median DFS was not reached at 103 months for the T1 adjuvant PUVA patients versus 66 months for the non-PUVA patients (p < 0.01). For those with T2, crude relapse rates were 25% and 55%, respectively, with DFS of 60 (median DFS not reached) and 20 months (p < 0.03). The 5-year DFS for patients salvaged with PUVA was 50%. Toxicity of adjuvant and salvage PUVA therapy was acceptable, with only two patients requiring a reduction in PUVA dosage.
Conclusion: PUVA can maintain remissions in patients with CTCL after TSEBT. There is a significant benefit in DFS but no statistically significant improvement in OS. Prospective, randomized data are needed to confirm these results. PUVA is also effective as a salvage therapy after TSEBT in early-stage patients with recurrence, with acceptable toxicity.