Extracranial germ cell tumours in children and adolescents: Results from the French TGM13 protocol

Abstract

Background: Chemotherapy for non-seminomatous germ cell tumours (NSGCT) exposes to dose-dependent toxicities. The TGM13-NS protocol (EudraCT 2013-004039-60) aimed to decrease the chemotherapy burden compared to the previous TGM95 protocol while maintaining the 5-year event-free survival (EFS) at 80% or more.

Procedure: Patients less than 19 years of age with disseminated NSGCT were enrolled (May 2014 to May 2019) and stratified into four groups: two intermediate-risk (IR: localised tumour with low tumour markers [TM]) groups treated with VBP (vinblastine-bleomycin-cisplatin): three courses for IR1 (ovarian tumour any age/testis tumour less than or equal to 10 years) and four courses for IR2 (extragonadal tumour 10 years or less) groups, and two high-risk (HR: metastatic and/or high TM) groups treated with etoposide-cisplatin and either ifosfamide (VIP) or bleomycin (BEP): three courses for HR1 (ovarian tumour any age/testis tumour less than or equal to 10 years and low TM/testis tumour more than 10 years and very low TM) groups and four courses for HR2 (remainder) groups.

Results: One hundred fifteen patients were included: median age of 12.8 years (0.4-18.9); tumour sites: 44 ovaries, 37 testes and 34 extragonadal. The 5-year EFS and overall survival (OS) were 87% (95% CI: 80-92) and 95% (89-98), respectively (median follow-up: 3.5 years, range: 0.2-5.9), similar to those of the TGM95 protocol (5-year EFS 89% (84-93), 5-year OS 93% (89-95), p = .561). The 5-year EFS were 93% (95% CI: 80-98), 88% (71-95) and 79% (62-90) for ovarian, testicular and extragonadal tumours, respectively. The 5-year EFS varied (p = .02) according to the risk groups: 90% (66-97), 64% (30-85), 95% (72-99) and 87% (74-94) for IR1, IR2, HR1 and HR2, respectively. TM decline adjusted to tumour site, and alpha-fetoprotein (AFP) level revealed a prognostic impact of time to normalisation on EFS: HR = 1.03 (1.003-1.007).

Conclusion: Risk-adapted and globally decreased chemotherapy burden maintains excellent outcomes, exclusive of the IR2 group, which warrants more intensive chemotherapy.

Keywords: chemotherapy; children; germ cell tumours; tumour marker decline.