Latin American Consensus for the Diagnosis, Staging, and Treatment of Peripheral T-Cell Lymphoma Not Otherwise Specified.

Abstract

Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) is an aggressive, heterogeneous subtype of non-Hodgkin lymphoma with poor prognosis and limited therapeutic options. In Latin America (LATAM), management is challenged by restricted access to advanced diagnostics, higher prevalence of oncogenic viruses (Epstein-Barr virus, HTLV-1), and variable health care resources. This international consensus provides evidence-based, regionally adapted recommendations for diagnosis, staging, risk stratification, treatment, and follow-up of adult patients with PTCL-NOS. A multidisciplinary panel of hematologists and oncologists from multiple LATAM countries, who are members of the <i>Grupo de Estudio Latinoamericano de Linfoproliferativos</i>, used a modified Delphi process (February-July 2025). An initial questionnaire of 11 items addressed diagnostic evaluation, staging, risk stratification, first-line therapy, response assessment, consolidation with stem-cell transplantation, salvage therapy, and supportive care. Consensus was defined as ≥80% agreement on a five-point Likert scale using the RAND/UCLA appropriateness method. Two rounds of anonymous voting and discussion incorporated cost-effectiveness and local resource constraints. Key recommendations include (1) positron emission tomography (PET)/computed tomography (CT) as preferred staging modality (with total metabolic tumor volume for prognostication) plus mandatory bone-marrow biopsy; (2) Prognostic Index for PTCL-U as primary risk-stratification tool; (3) cyclophosphamide, doxorubicin, vincristine, etoposide, prednisone for fit patients ≤60 years with planned autologous stem-cell transplantation (ASCT), versus cyclophosphamide, doxorubicin, vincristine, and prednisone-21 otherwise; (4) brentuximab vedotin + cyclophosphamide, doxorubicin, prednisone for CD30⁺ cases (≥10% expression); (5) interim and end-of-treatment PET/CT for response assessment; (6) ASCT in first complete remission; (7) early allogeneic transplantation referral for relapsed/refractory disease; and (8) standardized immunohistochemistry/flow cytometry panels. Resource-limited adaptations prioritize accessible strategies and encourage clinical trial participation. This LATAM-specific consensus integrates global evidence with regional realities to optimize outcomes for PTCL-NOS. Implementation should standardize care, reduce diagnostic delays, and improve equitable access to effective therapies across LATAM.