Non-Hodgkin Lymphoma in Adolescents: Experiences in 378 Adolescent NHL Patients Treated According to Pediatric NHL-BFM Protocols.

Abstract 102

There are considerable differences with respect to incidence, biology, treatment and outcome of Non-Hodgkin Lymphoma (NHL) between children and adults. Patients of adolescent age are forming a separate group that falls between those categories. Even though recent reports pay increasing attention to these patients, the impact of adolescent age on the characteristics and outcome of NHL remains yet to be determined.

Therefore, the current analyses aimed to analyze the outcome of adolescents treated according to BFM protocols for childhood NHL.

Patients were treated according to the subsequent protocols NHL-BFM 86, 90, 95, 04, ALCL 99, and EURO-LB 02. Treatment subgroups were: 1) lymphoblastic lymphoma (LBL), 2) mature B-cell NHL including Burkitt lymphoma/leukemia (BL/B-AL), diffuse large B-cell lymphoma of centroblastic subtype (DLBCL-CB) and primary mediastinal B-cell lymphoma (PMLBL), and 3) anaplastic large cell lymphoma (ALCL).

From October 1986 to December 2007, a total of 2915 protocol patients (pts) were registered in the NHL-BFM study center. Of these, 378 pts (13%) were of adolescent (15-18 years (y)) at diagnosis. Within the adolescent age group BL/B-AL were the largest subgroup (101 pts), followed by ALCL (74 pts), DLBCL-CB (55 pts), T-LBL (45 pts), PMLBL (24 pts), pB-LBL (13 pts) and other rare or not further specified NHL subtypes (66 pts). The 5-year event free survival (pEFS) was 79±2% for adolescents compared to 85±1% in pts aged <15y (p 0.014).

Regarding histological subtypes, pEFS was inferior in adolescents compared to children in BL/B-AL pts (82±4% vs 88±1%, p 0.06) and in DLBCL-CB (pEFS 85±5% vs 96±2%, p 0.002). There was no difference in outcome for adolescents compared with children in T-LBL (pEFS (5y) 87±6% vs 82±2%, p 0.24), ALCL (70±6% vs 70±3%) and PMLBL (57±10% vs 68±8%, p 0.55).

Further analyses in adolescents revealed a higher frequency of advanced stages of disease (> stage II) in females (94/119) vs males (177/259, p 0.04), but less frequent CNS disease in females (3/119 vs 23/259; p 0.03). pEFS (5y) was inferior for adolescent females (70±5% vs 84±2% in males, p 0.004). This was mainly due to the unfavorable pEFS for adolescent female pts with T-LBL (pEFS 57±17% vs 97±3%, p 0.001) and DLBCL-CB (pEFS 71±9% vs 97±3%, p 0.007). For the other histological NHL-subtypes there were no statistically significant differences in outcome according to gender.

Adolescents with NHL treated according to pediatric NHL-BFM protocols have an acceptable outcome that is marginally inferior to that in children. Within the adolescent age group, female pts are diagnosed more frequently with advanced stages of disease. In adolescent pts with T-LBL and DLBCL-CB, female gender is associated with a worse prognosis.