Efalizumab and Progression of Undiagnosed Follicular Mycosis Fungoides—Reply

In reply

We respectfully disagree with Di Lernia's comment that patients with pilar MF, F-MF, or folliculotropic cutaneous T-cell lymphoma (CTCL) “should always be considered to have tumor-stage disease.”

We are familiar with the 2002 article by van Doorn et al¹ that describes 51 patients with F-MF who had disease-specific survival rates of 68% at 5 years and 26% at 10 years and posits that the prognosis for F-MF is similar to that for epidermotropic tumor-stage disease.¹ However, Di Lernia did not cite 2 more recent reports that give much better survival rates for F-MF. In a 2005 report,² the European Organization for Research on the Treatment of Cancer classifies F-MF as a distinct subgroup. The 5-year survival rate of 86 patients with F-MF is reported to be 80%, while that of 800 patients with classic MF is 88%.² A 2008 report by Gerami et al³ comparing a United States group of 43 patients with F-MF to age- and stage-matched patients with epidermotropic MF found that those with early F-MF (up to and including stage IIA) had a 10-year survival of 82% and a 15-year survival rate of 41%. The 43 control patients who had epidermotropic MF had a 91% survival rate at both 10 and 15 years. However, patients with later-stage F-MF (stage IIB or higher) had outcomes similar to those with conventional epidermotropic MF of a similar stage. And the 10-year progression-free survival rate was 25% in the patients with stage IIB or higher F-MF compared with 8% in the epidermotropic MF group. While the authors conclude that F-MF is a more aggressive variant of CTCL, especially in the early stages, there was no evidence of worse prognosis in stage IIB or more advanced disease.

The patient we described⁴ presented to his community dermatologist with a pruritic, erythematous dermatitis of 2 years' duration. His physician did not intentionally treat him as a patient with CTCL using efalizumab. During the 4 months of efalizumab treatment, the patient developed additional plaques on his scalp, face, and back; these then progressed to tumors. We first saw him in our cutaneous lymphoma clinic 2 months later, and on our retrospective review found that a skin biopsy specimen taken before efalizumab therapy had begun was consistent with folliculotropic CTCL. This skin specimen was taken 4 months prior to efalizumab therapy, not 2 years prior, so there is no evidence that the patient's skin problem had been CTCL for 2 years.

It is recognized that patients with CTCL who have been treated with cyclosporine and biological immunosuppressants have experienced serious adverse effects.^{5 - 6} Four months of efalizumab exposure occurred in our patient prior to his tumor progression, which was the same duration of cyclosporine exposure seen in reported patients with CTCL who then developed much more aggressive CTCL disease.⁶ With only a single patient, we cannot assert that efalizumab exposure shortens the time in which follicular and/or folliculotropic and/or pilar CTCL progresses to severe tumor-stage disease, but we are concerned that it might.

Dr Worobec, Department of Dermatology (MC 624), College of Medicine, University of Illinois at Chicago, 840 S Wood St, Chicago, IL 60612 (sworobec@uic.edu).