Long-term efficacy, curative potential, and prognostic factors of radiotherapy in primary cutaneous B-cell lymphoma

Primary cutaneous B-cell lymphomas (PCBCL) are rare and constitute approximately 5-10% of all cutaneous lymphomas. In the literature, conflicting data exist on the optimal treatment modality regarding the efficacy and the relapse rate after radiotherapy (RT) or polychemotherapy. To evaluate the efficacy of RT, patient data from two centers were analyzed and compared with recent reports in the literature.

Between April 1984 and June 2001, 35 patients with PCBCL, 17 men and 18 women ages 27-86 years, were treated with RT alone (29/35 patients) or postoperative RT (6/35 patients). According to the European Organization for Research and Treatment of Cancer classification for PCBCL, this study group included 21 patients (60%) with primary cutaneous follicle center-cell lymphoma, 7 (20%) with primary cutaneous immunocytoma, 4 (11%) with primary cutaneous large B-cell lymphoma (PCLBCL) of the leg, and 3 (9%) provisional types.

A total of 34/35 patients achieved an initial complete response after RT. In one additional patient, RT was interrupted after 16 Gy because of fulminant pneumonia. A total of 11/35 (31%) patients developed cutaneous relapse after a median of 11 months. Three patients developed an in-field response and 8 patients an out-field relapse. After a median follow-up of 52 months, 27/35 patients are alive, whereas 8/35 patients died (three deaths resulting from PCBCL and five unrelated to PCBCL). The 5-year overall survival rate was 75% (95% CI: 55-95%). The 5-year relapse-free survival was 50% (95% CI: 32-68%). Univariate and multivariate analysis revealed disseminated primary lesions in at least two noncontiguous anatomic sites and the histologic subtype PCLBCL as unfavorable prognostic factors.

RT of all visible skin lesions is an effective treatment for localized PCBCL. In patients with cutaneous relapses, RT is an effective treatment option as well.