Risk factors predicting outcomes for primary refractory hodgkin lymphoma patients treated with salvage chemotherapy and autologous stem cell transplantation.

We aimed to identify risk factors that predict functional imaging (FI) response to salvage chemotherapy and evaluate outcomes following autologous stem cell transplant (ASCT) in primary refractory Hodgkin Lymphoma (HL). From 1 October 1994 to 10 July 2015, 192 primary refractory HL patients were treated on sequential second line protocols. Event-free survival (EFS) and overall survival (OS) were calculated from the date of histological confirmation of refractory disease. Covariates were analysed for relationship with FI response and EFS. By intent-to-treat, the median EFS was 8·9 years and OS 10·4 years with 41% having positive post-salvage FI. On multivariate analysis, the presence of B symptoms and bulk ≥5 cm predicted for positive FI, with odds ratios of 2·15 and 2·03, respectively. For the 167 (87%) transplanted patients, 60% had a negative pre-ASCT FI. Median EFS and OS were not reached with at a median follow-up of 3·6 years in surviving patients. Both stage IV refractory disease and persistent FI abnormality pre- ASCT were associated with worse outcomes: 3-year EFS was 84%, 54% and 28% for zero, 1 and 2 risk factors, respectively (P < 0·001). Further studies are needed to validate our prognostic model and to determine optimal therapy for patients with multiple risk factors.