Non-Hodgkin's Lymphoma

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Lymphoblastic lymphoma

Lymphoblastic lymphoma (precursor T-cell) is a very aggressive form of NHL. It often occurs in young patients but not exclusively.[199] It is commonly associated with large mediastinal masses and has a high predilection for disseminating to bone marrow and to the CNS. Treatment is usually patterned after that for acute lymphoblastic leukemia. Intensive combination chemotherapy with or without BMT is the standard treatment of this aggressive histologic type of NHL.[200,201,202] Radiation therapy is sometimes given to areas of bulky tumor masses. Since these forms of NHL tend to progress so quickly, combination chemotherapy is instituted rapidly once the diagnosis has been confirmed. Careful review of the pathologic specimens, bone marrow aspirate, biopsy specimen, cerebrospinal fluid cytology, and lymphocyte marker constitute the most important aspects of the pretreatment staging workup. (Refer to the PDQ summary on Adult Acute Lymphoblastic Leukemia Treatment for more information.)

Adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma is caused by infection with the retrovirus HTLV-1 and is frequently associated with lymphadenopathy, hypercalcemia, circulating leukemic cells, bone and skin involvement, hepatosplenomegaly, a rapidly progressive course, and poor response to combination chemotherapy.[203,204] (Refer to the PDQ summary on Hypercalcemia for more information.) Using combination chemotherapy, only 10% to 20% of patients survived even 3 years in a trial of 118 patients.[205] The combination of zidovudine and interferon-alpha has activity against adult T-cell leukemia/lymphoma, even for patients who failed previous cytotoxic therapy. Durable remissions are seen in 66% of presenting patients with this combination, but long-term disease-free survival rates are not yet available.[206,207,208]

Mantle cell lymphoma

Mantle cell lymphoma is found in lymph nodes, the spleen, bone marrow, blood, and sometimes the gastrointestinal system (lymphomatous polyposis).[4,209,210] Mantle cell lymphoma is characterized by CD5-positive follicular mantle B cells, a translocation of chromosomes 11 and 14, and an overexpression of the cyclin D1 protein.[211] Like the low-grade lymphomas, mantle cell lymphoma appears incurable with anthracycline-based chemotherapy and occurs in older patients with generally asymptomatic advanced-stage disease.[212] The median survival, however, is significantly shorter (3–5 years) than that of other lymphomas, and this histology is now considered to be an aggressive lymphoma.[213,214] A diffuse pattern and the blastoid variant have an aggressive course with shorter survival, while the mantle zone type may have a more indolent course.[56,215] A high cell proliferation rate (increased Ki-67, mitotic index, beta-2-microglobulin) may be associated with a poorer prognosis.[211,216] It is unclear which chemotherapeutic approach offers the best long-term survival in this clinicopathologic entity; refractoriness to chemotherapy is a usual feature.[213,217,218,219,220,221,222] Patients with low risk on the IPI may do well when initial therapy is deferred.[223][Level of evidence: 3iiiDiv] Many investigators are exploring high-dose chemoradioimmunotherapy with stem cell/marrow support or nonmyeloablative allogeneic stem cell transplantation.[219,220,221,224,225,226,227,228,229,230,231,232,233] Thus far, randomized trials have not shown OS benefits from these newer approaches.[230] Bortezomib shows response rates close to 50% in relapsed patients, prompting clinical trials combining this proteasome inhibitor with rituximab and cytotoxic agents in first-line therapy.[234,235][Level of evidence: 3iiiDiv]