Director of Hematology, West China Hospital, Sichuan University
From June 8th to 11th, 2023, the 28th European Hematology Association (EHA) annual conference was held grandly in Frankfurt, Germany. The EHA conferences have always been spectacular, with research on lymphoma consistently attracting significant attention. A study on gray zone lymphoma by Dr Ting Niu’s team from West China Hospital of Sichuan University ( Abstract No.: P1198) was selected for this EHA. The research aimed to summarize the clinical characteristics and factors influencing the prognosis of gray zone lymphoma by reviewing the relevant data in the SEER database. To gain a deeper understanding of the research, Oncology Frontier invited Dr Niu to provide aninterpretation as below.
Gray zone lymphoma (GZL) is a rare disease, with pathological features between diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma (HL). Currently, there’s limited clinical data on GZL, restricting our understanding of its clinical characteristics and prognosis. This study aims to analyze the clinical features, results, and prognostic factors of GZL patients.
We searched the Surveillance, Epidemiology, and End Results (SEER) registry database, collecting all data from patients diagnosed with GZL and undergoing chemotherapy between 2000 and 2018. We used the Cox and Fine-Gray regression models to evaluate overall survival (OS) and GZL-specific survival.
Research Results
– Characteristics differ based on the primary site of the disease.
– Among 211 patients included, most were aged ≥55 years (51.7%). Lymph nodes were the most common primary sites (85.3%). Patients with primary lymph node sites showed more frequent B symptoms (P=0.041) and advanced-stage disease (P<0.001).
– Factors affecting GZL prognosis
– The 5-year OS rate and lymphoma-specific mortality rate for treated GZL patients were 75.1% (95%CI: 69.0%-81.2%) and 20.8% (95%CI: 15.1%-26.5%), respectively. Combined radiotherapy improved the OS (P=0.011) and lymphoma-specific survival (LSS, P=0.031). Other independent prognostic factors included age, race, and ethnicity. Combined radiotherapy, absence of B symptoms, Hispanic ethnicity, and age <55 typically had a higher 3-year conditional survival.
Researcher’s Remarks
GZL is a unique disease, with clinical manifestations, cytology, and phenotypic features between DLBCL and classical HL. Due to its rarity, clinical data on GZL is relatively scarce, and many existing studies have small sample sizes or significant heterogeneity in results, limiting our understanding of GZL’s clinical characteristics and outcomes. This study is the first and largest-scale population study on chemotherapy-treated GZL patients, significantly enhancing the generalizability of results. The age limit of 55 set in the study provides an excellent predictor for prognosis. Besides, focusing on several key clinical features helps understand the characteristics of GZL patients. Apart from standard survival analysis, dynamic survival indicators are also used, offering a comprehensive clinical evaluation.
Overall, the study results clearly indicate that chemotherapy-treated GZL patients have the potential for long-term survival, and those who undergo combined radiotherapy show improved OS and LSS. Other vital survival prognostic factors include race, B symptoms, and Ann Arbor staging. Understanding these unique clinical features and survival prediction factors of GZL will assist doctors in clinical decision-making.
