Simple Summary: Multimodal treatment of nasopharyngeal carcinoma (NPC) in children and
young adults with induction chemotherapy, followed by radiochemotherapy and interferon-β (IFN-
β) maintenance, has been successfully applied in studies NPC-91 and NPC-2003 of the German Society
of Pediatric Oncology and Hematology (GPOH). We, here, present updated survival rates of
the NPC-2003 study cohort after longer follow-up and include 21 additional patients recruited after
closure of the study and treated as per the NPC-2003 study protocol (interim cohort) in our survival
analysis. Survival rates remain high after extended follow-up and in the larger cohort with EFS and
OS of 94% and 97%, respectively, reinforcing the high antitumor efficacy of this multimodal treatment
concept. Seven patients with CR after induction therapy received a reduced radiation dose of
54 Gy, and none of them relapsed. Thus, the reduction of radiation dose seems feasible and has the
potential to reduce treatment-related late effects in this vulnerable population.
Abstract: Nasopharyngeal carcinoma (NPC) in children and young adults has been treated within
two consecutive prospective trials in Germany, the NPC-91 and the NPC-2003 study of the German
Society of Pediatric Oncology and Hematology (GPOH). In these studies, multimodal treatment
with induction chemotherapy, followed by radio (chemo)therapy and interferon-beta maintenance,
yielded promising survival rates even after adapting total radiation doses to tumor response. The
outcome of 45 patients in the NPC-2003 study was reassessed after a median follow-up of 85 months.
In addition, we analyzed 21 further patients after closure of the NPC-2003 study, recruited between
2011 and 2017, and treated as per the NPC-2003 study protocol. The EFS and OS of 66 patients with
locoregionally advanced NPC were 93.6% and 96.7%, respectively, after a median follow-up of 73
months. Seven patients with CR after induction therapy received a reduced radiation dose of 54 Gy;
none relapsed. In young patients with advanced locoregional NPC, excellent long-term survival
rates can be achieved by multimodal treatment, including interferon-beta. Radiation doses may be
reduced in patients with complete remission after induction chemotherapy and may limit radiogenic
late effects.