Adolescents and young adults versus adults’ patients with large B-cell lymphoma: A matched-control analysis on 55 patients.

e18526 Background: Among non-Hodgkin’s lymphomas, large B-cell lymphoma (LBCL) accounts for 60% in adolescents and young adults (AYA). There are no so many reports in the literature on LBCL in AYA patients. Moreover, there are no data available to suggest whether AYA patients with LBCL would benefit more from pediatric-chemotherapy regimen or from adult rituximab-chemotherapy treatment. In order to clarify this point, we conducted a matched-control analysis comparing AYA patients and adult’s patients with LBCL. Methods: We performed a clinical and pathological review of LBCL cases referred to our institution over a 15-year period from 1996 to 2010. Fifty-five AYA (16-30 years) were fully matched to 165 adult’s patients aged between 31 years and 65 years (ratio 1/3) for each of the following factors: international prognostic index (IPI), chemotherapy regimen, and rituximab delivery. Results: When compared to LBCL adults’ patients, pathological features in AYA showed a high incidence of primary mediastinal thymic LBCL subtype (33% vs. 5%, P= 0, 0001), while histological transformation was rare (2% vs. 14%, P= 0, 01). LBCL in AYA also presented with a bulky mediastinal mass (51% vs. 21%, P= 0, 0001), gastrointestinal tract involvement was less frequent (2% vs. 13%, P=0, 03), and LDH value was significantly higher (73% vs. 54%, P= 0, 01). The complete response rate to chemotherapy combination regimen was at 82% in AYA, with no difference with that observed in adult patients (82%, P=0, 8). With a median follow-up of 80 months, the 5-year overall survival (OS) and event-free survival (EFS) of AYA patients were at 73% ± 12% and 68% ± 12%, respectively. The matched-control analysis showed no difference either for OS (P = 0.8) or EFS (P = 0.9). Conclusions: LBCL in AYA should be considered as a true clinical and pathological entity. However, age does not confer a prognostic value different from that observed in LBCL in patients older than 30 years.