ℹ️ What are T-Cell Lymphomas (TCL)?

Peripheral T-Cell Lymphomas (PTCLs) are a heterogeneous group of aggressive malignancies. The most common subtypes in Western countries are: PTCL-NOS (not otherwise specified, ~25%), Angioimmunoblastic T-cell Lymphoma (AITL, ~20%), and Anaplastic Large Cell Lymphoma (ALCL, ~15%). ALCL exists in two biologically distinct forms: ALK-positive ALCL (excellent prognosis, ~90% long-term survival) and ALK-negative ALCL (poorer prognosis). CHOP-based chemotherapy is the backbone of most PTCL treatment, often enhanced with etoposide (CHOEP) or with brentuximab vedotin (in CD30+ tumors). Autologous stem cell transplant in first remission is recommended for eligible patients with most PTCL subtypes except ALK+ ALCL. Romidepsin, pralatrexate, belinostat, and brentuximab vedotin are available for relapsed disease. CAR T-cell therapy for T-cell lymphomas is an active area of clinical investigation.

💊 Primary Treatment Approaches

T-cell lymphoma treatment is anchored by CHOP-based regimens. BV-CHP has replaced CHOP for CD30+ tumors; autologous transplant consolidation is used in eligible patients:

🔬 Overview of T-Cell Lymphomas

Peripheral T-Cell Lymphomas (PTCLs) are a diverse group of aggressive malignancies arising from mature (post-thymic) T-cells or Natural Killer (NK) cells. They represent approximately 10–15% of all non-Hodgkin lymphomas and carry a generally poorer prognosis than their B-cell counterparts, largely because targeted agents comparable to rituximab/CD20 have been slower to emerge.

Major Subtypes

PTCL-NOSPeripheral T-Cell Lymphoma, Not Otherwise Specified~25% of PTCLs

A heterogeneous category for T-cell lymphomas that do not fit a defined subtype. Most carry poor prognosis; median OS ~5–7 years in recent series with aggressive therapy.

AITLAngioimmunoblastic T-Cell Lymphoma~18–20% of PTCLs

Arises from follicular helper T-cells (TFH). Often presents with widespread disease, B symptoms, polyclonal hypergammaglobulinemia, and autoimmune features. Frequently harbor IDH2, TET2, DNMT3A, and RHOA mutations.

ALCL (ALK+)Anaplastic Large Cell Lymphoma, ALK-Positive~7% of PTCLs

Driven by the ALK fusion oncogene (most commonly NPM1-ALK from t(2;5)). Predominantly affects young patients. Excellent prognosis — ~80–90% 5-year OS with CHOP. CD30-positive.

ALCL (ALK−)Anaplastic Large Cell Lymphoma, ALK-Negative~5-6% of PTCLs

Similar morphology to ALK+ ALCL but lacks the ALK fusion; intermediate prognosis (OS 30–49% at 5 years). CD30-positive. Brentuximab vedotin is incorporated upfront in BV-CHP.

ENKTLExtranodal NK/T-Cell Lymphoma, Nasal Type~5% of PTCLs globally

Strongly associated with EBV. Most common in Asia and Latin America; rare in Western countries. L-asparaginase-containing regimens (SMILE, AspaMetDex) are the backbone; radiation for localized disease.

💊 Treatment Approaches

CHOP / CHOEP

Standard first-line backbone for most PTCL subtypes

CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) is the standard starting point. Adding etoposide (CHOEP) improves outcomes in younger patients with ALK+ ALCL. For most other PTCL subtypes, CHOP provides modest results — the backbone of the field awaiting better options.

BV-CHP (Brentuximab Vedotin + CHP)

CD30-positive PTCLs: ALK+ ALCL, ALK- ALCL, AITL (if CD30+)

ECHELON-2 trial: BV-CHP significantly improved PFS and OS vs CHOP in CD30+ PTCLs (primarily ALCL). Brentuximab vedotin targets CD30 with an MMAE payload. BV-CHP is now the standard first-line regimen for CD30+ peripheral T-cell lymphomas.

Autologous SCT in First Remission

Recommended consolidation for eligible patients (most PTCL subtypes)

For patients who achieve CR with induction and can tolerate transplant, upfront auto-SCT is recommended consolidation for most PTCL subtypes (except ALK+ ALCL, where it is usually reserved for relapse). Prolongs remission duration, though many patients still relapse.

Romidepsin / Belinostat (HDAC Inhibitors)

Relapsed / refractory PTCL (single-agent)

Romidepsin and belinostat are FDA-approved HDAC inhibitors for relapsed/refractory PTCL with ORRs of 25–38%. Generally used as single agents or in combination in heavily pre-treated patients.

Pralatrexate (Folotyn)

Relapsed / refractory PTCL

First drug approved specifically for PTCL (2009). An antifolate with strong affinity for RFC-1 transporter. ORR ~29% in heavily pre-treated patients. Mucositis is a dose-limiting toxicity; folic acid and B12 supplementation required.