Cytotoxic and Gamma-Delta Subtypes Of Peripheral T-Cell Lymphoma: A Single Center Experience

Peripheral T-cell lymphomas (TCLs) are uncommon neoplasms. TCLs in which gamma-delta T-cell receptors are expressed are extremely aggressive and rare, accounting for less than 1% of lymphoid neoplasms. The two main types of CTLs recognized in the 2008 WHO classification of lymphoid neoplasms are hepatosplenic T-cell lymphoma (HSTL) and primary cutaneous gamma-delta T-cell lymphoma (PCGD-TCL). Although rare, these diseases are associated with an aggressive clinical course, refractoriness to conventional therapies, and poor prognosis.

Patients with newly diagnosed cytotoxic or gamma-delta TCLs treated from 2005-2012 were retrospectively identified. Analyses included patient characteristics, clinical presentation, pathology, treatment and outcome.

Twenty-two patients (11 cutaneous gamma-delta TCL, 5 primary cutaneous aggressive epidermotropic CD8⁺TCL, 4 hepatosplenic gamma-delta TCL, 2 cytotoxic TCL involving the intestine) were identified. Median age was 48 (range: 18-70), 12% (12/22) were male, and 54.5% (12) presented with B symptoms. Initial therapy included CHOP based chemotherapy in 6, denileukin difititox with CHOP in 5, and single agent denileukin diftitox in 4.  One patient died with hemophagocytosis prior to initiation of chemotherapy. Fifteen of 21 pts responded to initial therapy but 10 of 15 required more than one regimen containing either etoposide or gemcitabine to achieve remission. The median number of regimens was 2 (range 0-4). In the salvage setting, two patients had partial responses with romidepsin, one had a PR with pralatrexate and one had a CR after pralatrexate salvage therapy. Thirteen patients underwent stem cell transplantation in first remission: autologous in 5 pts who had no donor, and allogeneic in 8 pts. At a median follow up of 3 years, 60% relapsed, and 14 (63%) are still alive. Of the patients who underwent transplant, one auto pt died from hemophagocytosis, 2 alloBMT patients died from acute GVHD, and 2 alloBMT pts died from disease progression. One alloBMT patient with cutaneous gamma delta TCL relapsed and responded to salvage therapy.

Cytotoxic and gamma-delta TCLs are rare diseases that have traditionally responded poorly to treatment. In our experience, many patients have a suboptimal response to CHOP alone and require additional therapy to achieve remission. We report a favorable outcome after stem cell transplantation and with implementation of novel agents. Advances in understanding biology and international collaborative efforts are required to improve outcome in these rare entities.

Off Label Use: sorafenib in t cell nhl. Foss:merck: Research Funding; spectrum: Research Funding; eisai: Membership on an entity’s Board of Directors or advisory committees; millenium: Honoraria, Membership on an entity’s Board of Directors or advisory committees; celgene: Honoraria, Research Funding; seattle genetics: Research Funding.