High-risk interim PET negative patients in Hodgkin's lymphoma

Abstract

Interim FDG-PET/CT done as early as after the first or second cycle of first line chemotherapy is now recognised as a good predictor of outcome in classic Hodgkin's lymphoma. This scan has been successfully used as a guide to escalate or de-escalate therapy in several important trials. 1 Radford J Illidge T Barrington S PET-directed therapy for Hodgkin's lymphoma. N Engl J Med. 2015; 373: 392 Crossref PubMed Scopus (4) Google Scholar Interim PET negative scans have a high negative predictive value, the abrupt decrease of the fluorodeoxyglucose signal expression during therapy is explained by the switch-off of activity of the microenvironmental cells recruited by chemokines that are produced by the Hodgkin Reed-Sternberg cells. 2 Gallamini A Positron emission tomography scanning: a new paradigm for the management of Hodgkin's lymphoma. Haematologica. 2010; 95: 1046-1068 Crossref PubMed Scopus (31) Google Scholar Indeed, the intense fluorodeoxyglucose uptake observed in Hodgkin's lymphoma at staging of the disease is explained mainly by the activity of the GLUT3 receptors on the microenvironmental cells, which account for 99% of cells in the Hodgkin's lymphoma tumour. However, 10–15% of patients with a negative interim PET scan still had disease progression or relapsed. 3 Johnson P Federico M Kirkwood A et al. Adapted treatment guided by interim PET-CT Scan in advanced Hodgkin's lymphoma. N Engl J Med. 2016; 374: 2419-2429 Crossref PubMed Scopus (488) Google Scholar In a prospective study, 3 Johnson P Federico M Kirkwood A et al. Adapted treatment guided by interim PET-CT Scan in advanced Hodgkin's lymphoma. N Engl J Med. 2016; 374: 2419-2429 Crossref PubMed Scopus (488) Google Scholar the 3 year progression-free survival rate of patients who were PET negative after two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) was 86% (95% CI 82·1–88·6). No diagnostic tool has been proposed yet for better identification of PET negative patients who relapse these patients. The combined role of biomarkers and interim PET scan in prediction of treatment outcome in classical Hodgkin's lymphoma: a retrospective, European, multicentre cohort studyThe CART algorithm correctly predicted the response to treatment in more than a half of patients who had a relapse or disease progression despite a negative PET-2 scan, thus increasing the negative predictive value of PET-2. In keeping with preliminary results from interim PET response adapted clinical trials of patients with advanced Hodgkin's lymphoma, there might be a non-negligible proportion of treatment failures in the interim PET negative group treated with standard ABVD. Full-Text PDF