Intralesional vincristine as first-line therapy for nodular lesions in classic Kaposi sarcoma: a prospective study in 151 patients.

Summary Background  Classic Kaposi sarcoma is a rare angioproliferative neoplasm with varying biological behaviour. Depending on the clinical stage, local or systemic therapy can be used. Vincristine has proven to be effective as systemic chemotherapy and in very few reports as intralesional treatment. Objectives  Our aim was to determine the efficacy and safety of intralesional vincristine in the treatment of classic Kaposi sarcoma nodular lesions. Methods  We conducted a prospective, open-label, single-centre clinical trial in 151 patients with stage IB classic Kaposi sarcoma. Vincristine was injected in a single nodule (0·3–0·8 mm) on the lower limb. Another similar lesion on the same limb, at a distance of ≥ 10 cm, or on the contralateral limb, was kept under clinical observation as control. Adverse effects were evaluated after 1 week, and efficacy after 4 and 12 weeks. Results  One hundred and fifty-one patients were enrolled. At final evaluation, 115 patients presented complete response (76·1%), 28 had partial response (18·5%), six had improvement (4%), one had stable disease (0·7%) and only one patient had tumour progression (0·7%). Therefore the total response rate was 98·7% (149 patients). Therapy was generally well tolerated. The most frequently registered adverse events, observed in 21 patients (13·9%), were erythema and itching. Conclusions  Intralesional vincristine is an effective and safe treatment for nodular lesions in classic Kaposi sarcoma and can be recommended as first-line therapy in initial stages and as support therapy in advanced stages.