Sustained complete remissions have been achieved with whole body continuous topical applications of aqueous solutions of mechlorethamine (HN2), and supplemental intralesional injections of tumors. Of 76 patients entered into the treatment study over a 4‐year period, approximately 50% are free of detectable disease, 13 of whom have had remissions extending now beyond 2 years. Most patients experiencing complete remissions had disease confined to skin, without lymph node or visceral involvement, when topical therapy was initiated. Delayed hypersensitivity to HN2, a frequent occurrence, has been abolished in sensitized patients by means of daily minute I.V. doses of the drug. Induction of specific immunologic tolerance to HN2, prior to topical treatment, has been achieved by means of several weekly I.V. injections of similarly minute doses of the drug.

Recent studies suggest that cells elaborating type 1 cytokines are important mediators of anti-tumor cell-mediated immunity in cutaneous T cell lymphoma. Type 1 cell-mediated immune responsiveness was assessed in 276 patients with cutaneous T cell lymphoma (mycosis fungoides and Sézary syndrome) using 2,4-dinitrochlorobenzene (DNCB) skin testing as part of the initial evaluation. The overall rate of sensitization after one and two DNCB challenges was 32% and 67%, respectively, which is much decreased compared with the expected rate of more than 95% for normal individuals. Moreover, the frequency of DNCB sensitization and allergic contact dermatitis to topically applied mechlorethamine decreased with advancing stage of disease. In addition to the expected strong correlation with stage, we observed that patients who were DNCB test positive were significantly less likely to experience disease progression and had a better overall prognosis compared with DNCB-negative patients. These results support the concept that cell-mediated responses are important in cutaneous T cell lymphoma, and that augmentation of these responses would be therapeutically beneficial.

Ninety-two courses of daily low-dose intravenous nitrogen mustard were administered to 46 patients with advanced cutaneous lymphomas (mycosis fungoides, Sezary syndrome and lymphoma cutis). Seventy-eight % of patients showed objective clinical remission, and 35% reached a clinically disease-free state following 1 or more courses. The response rate was greater in patients with the plaque-tumor type of mycosis fungoides than in those with erythrodermic variants. Therapy was free of significant side effects.