Intermediate prognosis in metastatic germ cell tumours-outcome and prognostic factors

BACKGROUND: For metastatic germ cell tumour patients with intermediate prognosis (IPGCT) according to the IGCCCG classification 5-year overall survival (OS) rates of 79% were described, but recent data suggest significant changes.

PATIENTS AND METHODS: To compare the outcome of current IPGCT with former patients and to find new prognosticators a retrospective observational study was performed. Eligibility criteria were: age ≥16 years, diagnosed between 1979 and 2014. Primary end-point was the 5-year OS rate.

RESULTS: This database includes 707 IPGCT: group 1 was diagnosed 1979-1996 (n = 237), and group 2 1997-2014 (n = 470). Median follow-up was 8.6 years (IQR: 14.4). Group 1 and 2 received first-line treatment with BEP (median 4 cycles; range 1-6) in 99% (group 1) and 95% (group 2), respectively. The proportion of first-line chemotherapy responders (CR and marker negative PR) was similar: 94% (group 1) and 96% (group 2), respectively (P = 0.290), but OS was superior in group 2 with a 5-year OS rate of 89% compared with 83% in group 1 (P = 0.035). In refractory disease, high-dose chemotherapy and treatment beyond second line was performed more often in group 2. A lactate dehydrogenase (LDH) cut-off value of 2 ULN (P = 0.002; HR 2.121) and alpha-fetoprotein (AFP) levels of 6200 IU/ml (P = 0.032; HR 2.155) pre-chemotherapy were independent prognosticators for OS in a multivariate analysis.

CONCLUSION: Outcome of IPGCT has improved and is now closer to the good prognosis category. LDH and AFP levels represent potential markers to stratify IPGCT before treatment initiation.