High-dose chemotherapy for relapsed and refractory diffuse large B-cell lymphoma: mediastinal localization predicts for a favorable outcome.

This study was performed to evaluate the outcome of high-dose chemotherapy and autologous transplantation in patients with diffuse B-cell large-cell lymphoma, and, specifically, to evaluate the impact of primary mediastinal localization on the outcome of high-dose chemotherapy. A retrospective review was performed of all patients with diffuse large B-cell lymphoma who underwent autologous marrow or peripheral-blood stem-cell transplantation at our institution between January 1 986 and December 1995. Ninety patients were identified, of whom 31 (34%) had a primary mediastinal B-cell large-cell lymphoma (PML). Cumulative probabilities of disease-free survival, overall survival, and disease progression are 40% (95% confidence interval [CI], 29 to 51), 42% (95% CI, 31 to 53), and 52% (95% CI, 40 to 64), respectively. By univariate analysis, low lactate dehydrogenase (LDH) level and low Ann Arbor stage at transplant were associated with improved survival and disease-free survival. There was a trend for improved disease-free survival and survival for patients with PML. Multivariate stepwise Cox regression analysis showed that LDH level, Ann Arbor stage, and primary mediastinal localization were independent favorable prognostic factors for disease-free survival and survival. LDH level and Ann Arbor stage were also predictive for the risk of disease progression. Our results indicate that patients with PML may display an increased susceptibility to high-dose chemotherapy compared with other types of B-cell large-cell lymphoma. These findings, if confirmed, may have implications for the initial management of patients with PML.