A Nationwide Prospective Multicenter Study of Clinical Features and Outcomes of Non-Hodgkin Lymphoma in Thailand: An Analysis of 939 Cases

Non-Hodgkin lymphoma (NHL) is the most common hematologic malignancy in Thailand. The objective of the study was to evaluate clinical features, histopathology, treatment outcomes and prognostic factors in Thai adult patients with NHL.

Using web-based registry system, we prospectively collected clinical information of newly diagnosed NHL patients from eleven major medical centers situated in various geographic regions of Thailand. All histopathological diagnoses were reviewed by consensus meeting of panels of 6 expert hematopathologists and classified according to the 2008 WHO classification of the lymphoid neoplasms. Clinical features and treatment outcomes were analyzed using STATA program.

Between January 2007 and May 2009, there were a total of 939 NHL patients whose clinical information including follow-up data and tissue samples were readily available for analysis. The median age was 58 years (range, 15–99). Forty six percent of the patients were ≥60 years of age. Male:female was 1.18:1. The six leading subtypes were diffuse large B-cell lymphoma (67%), extranodal marginal zone lymphoma of MALT type (7%), follicular lymphoma (6%), mantle cell lymphoma (4%), peripheral T-cell lymphoma, not otherwise specified (NOS) (3%) and extranodal NK/T-cell lymphoma, nasal type (3%). T-cell lymphoma constituted 10% of all NHL. The three most common subtypes in T-cell lymphomas were peripheral T-cell lymphoma, NOS (26%), extranodal NK/T-cell lymphoma, nasal type (25%) and angioimmunoblastic T-cell lymphoma (15%). Fifty-eight percent of all patients had advanced disease (stage III, IV), 42% had B symptoms and 54% had elevated serum LDH. The IPI risk groups were 23% low, 30% low-intermediate, 30% high-intermediate and 17% high-risk. HIV-associated NHL was seen in 4.4% of the patients. Of the 801 patients who received chemotherapy, 90% were treated with anthracycline-containing regimen. Twenty-five percent of the patients received rituximab. Of the 663 evaluable patients, the rate of objective tumor response was 75% (CR+CR_u, 59%). At a median follow-up time of 13 months, the 4-year projected overall survival (OS) was 73% (95% CI 69–77%). The OS of patients with T-cell lymphoma was inferior to B-cell lymphoma (58% vs. 74%, p = 0.04). With multivariate analysis, the independent adverse prognostic factors for OS in B-cell lymphoma were poor performance status (HR 2.4, 95% CI 1.7–3.5), elevated serum LDH (HR 2.1, 95% CI 1.4–3.1), stage III/IV (HR 1.6, 95% CI 1.1–2.3), WHO subtype (HR 1.1, 95% CI 1.0–1.2), no chemotherapy (HR 3.1, 95% CI 1.9–5.1) and no rituximab treatment (HR 1.7, 95% CI 1.1–2.6). The independent adverse factors for OS in T-cell lymphoma were elevated serum LDH (HR 3.7, 95% CI 1.2–11.1) and male sex (HR 3.4, 95% CI 1.3–8.8).

This study confirmed the characteristic features of NHL among Thai population, i.e., a preponderance of diffuse large B-cell lymphoma and a low incidence of follicular lymphoma within B-cell lymphoma; a relatively high incidence of nasal NK/T-cell lymphoma within T-cell lymphoma. The IPI risk-groups and survival outcomes were comparable to most previously published reports.

Bunworasate:Novartis Pharmaceutical: Research Funding. Off Label Use: Nilotinib is a safe and effective treatment for patients with CML. Chuncharunee:Novartis: Research Funding.