Cisplatin With Gemcitabine With Dexamethasone in Patients With Aggressive Non-Hodgkin's Lymphoma

Inclusion Criteria: * The patients must have a histological diagnosis of aggressive non-Hodgkin's lymphoma including the following sub-categories of the WHO classification: * Diffuse large B-cell lymphoma and its variants (immunoblastic, Burkitt-like, sclerosis of mediastinum, large B-cell MALT, rich in T-cells and anaplastic B-cell lymphoma) * Peripheral T-cell lymphoma * Anaplastic lymphoma of large T-cells /null cells * Patients are eligible if they have documented evidence of progression after prior first-line chemotherapy containing anthracyclines associated or not with Rituximab. Patients with refractory disease to first line of treatment are also eligible. * ECOG PS (performance status) less than or equal to 2 * Presence of bidimensionally measurable disease in accordance with WHO criteria. Exclusion Criteria: * Involvement of the CNS. * Any medical condition which contraindicates the degree of hydration required for the safe use of cisplatin. * Intermediate degree lymphoma derived from the malignant transformation of a previous low-grade lymphoma. * Active infection (in the opinion of the investigator).