Interim PET-CT may predict PFS and OS in T-ALL/LBL adult patients

// Liang Wang 1, 2, * , Jing-Hua Wang 1, 2, * , Xi-Wen Bi 2, 3, * , Xiao-Qin Chen 1, 2 , Yue Lu 1, 2 and Zhong-Jun Xia 1, 2 1 Department of Hematologic Oncology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China 2 State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China 3 Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China * These authors contributed equally to this work Correspondence to: Zhong-Jun Xia, email: xiazhj@sysucc.org.cn Keywords: T lymphoblastic leukemia/lymphoma, PET-CT, international harmonization project criteria, prognosis Received: August 31, 2016      Accepted: March 29, 2017      Published: July 26, 2017 ABSTRACT T lymphoblastic leukemia/lymphoma (T-ALL/LBL) is highly aggressive. Although intensive chemotherapies such as ALL-type regimens are commonly used, about half adult patients eventually relapse and die of T-ALL/LBL. Overwhelming evidences have confirmed that interim PET can predict survival outcomes and guide subsequent treatments in Hodgkin lymphoma. However, whether interim PET-CT can predict survival outcomes or not in T-ALL/LBL patients remains unclear. 47 adult patients of T-ALL/LBL were retrospectively reviewed. Interim PET-CT was done after induction therapy and evaluated according to the International Harmonization Project criteria. After induction therapy, interim PET-CT was positive in 19 patients (40.4%). After a median follow up time of 34 months, the 2-year and 3-year progression free survival (PFS) rate were 39% and 30%, respectively, and the 2-year and 3-year overall survival (OS) rate were 54% and 45%, respectively. Using Kaplan-Meier survival analysis, it was found that interim PET-CT positivity correlated with significantly inferior PFS and OS (2-year PFS rate for patients with positive or negative interim PET were 21.1% or 56.0%, respectively, p = 0.002; 2-year OS rate for patients with positive or negative interim PET were 31.6% or 63.7%, respectively, p = 0.010). However, there was no significant relationship between PFS, OS and bone marrow infiltration, lactate dehydrogenase level, and stages ( p > 0.05). Interim PET-CT may predict PFS and OS in adult patients of T-ALL/LBL, which needs to be validated in prospective clinical trials. The optimal criteria for interim PET-CT evaluation and risk-adapted treatment strategy determined by interim PET-CT should be investigated in future clinical practice.