Hodgkin Lymphoma in Adolescents Treated with Adult Protocols: An Analysis From the German Hodgkin Study Group (GHSG).

The standard of care for adolescent Hodgkin lymphoma (HL) patients is undefined, particularly the choice between adult and pediatric protocols. We thus analyzed and compared risk factors, outcome and incidence of secondary malignancies in adolescents and young adults treated within study protocols of the German Hodgkin Study Group (GHSG) to evaluate whether adolescents represent a distinct patient group.

3785 patients of all stages treated within the second (HD4-HD6, 1988-1993) and third (HD7-HD9, 1993-1998) trial generation of the GHSG were retrospectively analyzed. 557 patients were adolescents aged 15 to 20 and 3228 patients were young adults aged 21 to 45. Treatment consisted of chemo- and/or radiotherapy.

The risk factors large mediastinal mass (more than 1/3 of the maximum intrathoracic diameter) and involvement of three or more lymph node areas were more common in adolescents (30.2% vs. 20.9% and 67.7% vs. 58.7%, respectively, p<.001). The incidence of other risk factors did not differ significantly between age groups. With a median follow-up of 81 months for freedom from treatment failure (FFTF) and 85 months for overall survival (OS), FFTF rates in both groups were comparable (p=.305) while adolescents had a superior OS (p=.008). 6-year FFTF estimates were 80.2% and 79.7%, 6-year OS estimates were 93.6% and 90.9% in adolescents and young adults, respectively. Young adults had a higher risk to develop secondary malignancies. Secondary malignancy rates were 1.6% (9 of 557) in adolescents and 3.1% (101 of 3228) in young adults with secondary hematological malignancies (AML/MDS, NHL) representing the majority of cases in both groups (6/9 in adolescents and 55/101 in young adults). Since adolescents differ from young adults in terms of cancer risk in the general population, standardized incidence ratio (SIR) and absolute excess risk (AER) per 100.000 person-years were calculated. The SIR was higher in adolescents (5.56 vs. 4.58) while the AER was higher in young adults (394 vs. 194). However, differences between age groups were not significant for both.

There are only slight differences between adolescents and young adults regarding risk factors, outcome and incidence of secondary malignancies. Therefore, treatment with adult protocols can be considered effective and safe in adolescent HL patients.

No relevant conflicts of interest to declare.