Forest plot showing multivariable Cox regression analysis of factors determining the OS from the day of first progression or relapse in patients participating in the PETAL trial. The analysis was restricted to 199 progressing or relapsing patients with a well-defined diagnosis (DLBCL, 146; PMBCL, 4; FL grade 3, 15; ALK⁺ ALCL, 4; ALK⁻ PTCL, 30) fulfilling the study inclusion criteria and receiving antineoplastic treatment for relapse or progression (chemotherapy, immunotherapy, and/or radiotherapy without transplantation, 109; auto-SCT without allogeneic transplantation, 65; and allogeneic transplantation, 25). Overall, 112 patients relapsed within the first year after iPET evaluation, and 87 relapsed later. At the time of first relapse, 21 patients had stage I relapse, 178 had stage II to IV (including 41 patients with unknown stage whose disease course was indistinguishable from that of patients with stage IV disease [Figure 4]), 91 were aged ≤60 years, and 108 were older. Age also failed to reach statistical significance when it was included as a continuous variable into the model (HR, 1.016 per year; 95% CI, 0.999-1.034; P = .068). There were 135 events (deaths) among 199 patients.