Interventions for mycosis fungoides.

BACKGROUND

Mycosis fungoides is the most common type of cutaneous T-cell lymphoma, a malignant, chronic disease initially affecting the skin. Several therapies are available, which may induce clinical remission for a time.

OBJECTIVES

To assess the effects of interventions for mycosis fungoides in all stages of the disease.

SEARCH METHODS

We searched the following databases up to January 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), and LILACS (from 1982). We also checked reference lists of included studies for further references to relevant RCTs. We searched online trials registries for further references to unpublished trials and undertook a separate search for adverse effects of interventions for mycosis fungoides in non-RCTs in MEDLINE in May 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of interventions for mycosis fungoides in people with any stage of the disease. At least 90% of participants in the trials must have been diagnosed with mycosis fungoides (Alibert-Bazin-type).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility and methodological quality for each study and carried out data extraction. We resolved any disagreement by discussion. Primary outcomes were the impact on quality of life and the safety of interventions. When available, we reported on our secondary outcomes, which were the improvement or clearance of skin lesions, disease-free intervals, survival rates, relapse rates, and rare adverse effects. When possible, we combined homogeneous studies for meta-analysis. We used The Cochrane Collaboration's 'Risk of bias' tool to assess the internal validity of all included studies in six different domains.

MAIN RESULTS

The review included 14 RCTs involving 675 participants, covering a wide range of interventions. Eleven of the included trials assessed participants in clinical stages IA to IIB only (please see Table 1 for definitions of these stages).Internal validity was considerably low in studies with a high or unclear risk of bias. The main reasons for this were low methodological quality or missing data, even after we contacted the study authors, and a mean dropout rate of 26% (0% to 72%). Study size was generally small with a minimum of 4 and a maximum of 103 participants. Only one study provided a long enough follow-up for reliable survival analysis.Included studies assessed topical treatments, such as imiquimod, peldesine, hypericin, nitrogen mustard, as well as intralesional injections of interferon-α (IFN-α). The light therapies investigated included psoralen plus ultraviolet A light (PUVA), extracorporeal photopheresis (photochemotherapy), and visible light. Oral treatments included acitretin, bexarotene, and methotrexate. Treatment with parenteral systemic agents consisted of denileukin diftitox; a combination of chemotherapy and electron beam radiation; and intramuscular injections of active transfer factor. Nine studies evaluated therapies by using an active comparator; five were placebo-controlled RCTs.Twelve studies reported on common adverse effects, while only two assessed quality of life. None of these studies compared the health-related quality of life of participants undergoing different treatments. Most of the reported adverse effects were attributed to the interventions. Systemic treatments, and here in particular a combined therapeutic regimen of chemotherapy and electron beam, bexarotene, or denileukin diftitox, showed more adverse effects than topical or skin-directed treatments.In the included studies, clearance rates ranged from 0% to 83%, and improvement ranged from 0% to 88%. The meta-analysis combining the results of 2 trials comparing the effect of IFN-α and PUVA versus PUVA alone showed no significant difference in the relative risk of clearance: 1.07 (95% confidence interval 0.87 to 1.31). None of the included studies demonstrated a significant increase in disease-free intervals, relapse, or overall survival.

AUTHORS' CONCLUSIONS: This review identified trial evidence for a range of different topical and systemic interventions for mycosis fungoides. Because of substantial heterogeneity in design, small sample sizes, and low methodological quality, the comparative safety and efficacy of these interventions cannot be established on the basis of the included RCTs. Taking into account the possible serious adverse effects and the limited availability of efficacy data, topical and skin-directed treatments are recommended first, especially in the early stages of disease. More aggressive therapeutic regimens may show improvement or clearance of lesions, but they also result in more adverse effects; therefore, they are to be considered with caution. Larger studies with comparable, clearly-defined end points for all stages of mycosis fungoides, and a focus on safety, quality of life, and duration of remission as part of the outcome measures, are necessary.