Jais, Jean‐Philippe

Purpose Selection bias in clinical trials has consequences for scientific validity and applicability of study results to the general population. There is concern that patients with clinically aggressive disease may not have enrolled in recent diffuse large B-cell lymphoma (DLBCL) trials due to the consent process and the inability to delay therapy for eligibility evaluation. We have examined the diagnosis-to-treatment interval (DTI) and its association with clinical factors and outcome in a clinic-based observational cohort of patients with DLBCL from the United States. Validation of results was performed in an independent, clinical trial-based cohort from Europe. Patients and Methods Patients were prospectively enrolled in the University of Iowa and Mayo Clinic Specialized Programs of Research Excellence Molecular Epidemiology Resource (MER; N = 986) or the Lymphoma Study Association (LYSA) LNH-2003 clinical trials program (N = 1,444). All patients received anthracycline-based immunochemotherapy at initial diagnosis. Associations of DTI with clinical factors and outcome were examined. Outcome was assessed using event-free survival at 24 months from diagnosis (EFS24). Results Median (range) DTI was 15 days (0 to 155 days in the MER and 23 days (0 to 215 days) in LYSA. Shorter DTI was strongly associated with adverse clinical factors, including elevated lactate dehydrogenase levels, poor performance status, B symptoms, and higher International Prognostic Index in both cohorts (all P < .001). Longer DTI was associated with improved EFS24 in both the MER (per-week odds ratio, 0.80; 95% CI, 0.74 to .0.87) and LYSA (per-week odds ratio, 0.90; 95% CI, 0.86 to 0.94); association with EFS24 remained significant after adjustment for International Prognostic Index. Conclusion DTI is strongly associated with prognostic clinical factors and outcome in newly diagnosed DLBCL. DTI should be reported in all clinical trials of newly diagnosed DLBCL and future trials should take steps to avoid selection bias due to treatment delay.

Purpose Studies of diffuse large B-cell lymphoma (DLBCL) are typically evaluated by using a time-to-event approach with relapse, re-treatment, and death commonly used as the events. We evaluated the timing and type of events in newly diagnosed DLBCL and compared patient outcome with reference population data. Patients and Methods Patients with newly diagnosed DLBCL treated with immunochemotherapy were prospectively enrolled onto the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource (MER) and the North Central Cancer Treatment Group NCCTG-N0489 clinical trial from 2002 to 2009. Patient outcomes were evaluated at diagnosis and in the subsets of patients achieving event-free status at 12 months (EFS12) and 24 months (EFS24) from diagnosis. Overall survival was compared with age- and sex-matched population data. Results were replicated in an external validation cohort from the Groupe d'Etude des Lymphomes de l'Adulte (GELA) Lymphome Non Hodgkinien 2003 (LNH2003) program and a registry based in Lyon, France. Results In all, 767 patients with newly diagnosed DLBCL who had a median age of 63 years were enrolled onto the MER and NCCTG studies. At a median follow-up of 60 months (range, 8 to 116 months), 299 patients had an event and 210 patients had died. Patients achieving EFS24 had an overall survival equivalent to that of the age- and sex-matched general population (standardized mortality ratio [SMR], 1.18; P = .25). This result was confirmed in 820 patients from the GELA study and registry in Lyon (SMR, 1.09; P = .71). Simulation studies showed that EFS24 has comparable power to continuous EFS when evaluating clinical trials in DLBCL. Conclusion Patients with DLBCL who achieve EFS24 have a subsequent overall survival equivalent to that of the age- and sex-matched general population. EFS24 will be useful in patient counseling and should be considered as an end point for future studies of newly diagnosed DLBCL.