Pre-orchiectomy tumor marker levels should not be used for International Germ Cell Consensus Classification (IGCCCG) risk group assignment

Purpose: To investigate whether the use of pre-orchiectomy instead of pre-chemotherapy tumor marker (TM) levels has an impact on the International Germ Cell Consensus Classification (IGCCCG) risk group assignment in patients with metastatic germ cell tumors (GCT).

Methods: Demographic and clinical information of all patients treated for primary metastatic testicular non-seminomatous GCT in our tertiary care academic center were extracted from medical charts. IGCCCG risk group assignment was correctly performed with pre-chemotherapy marker levels and additionally with pre-orchiectomy marker levels. Agreement between pre-chemotherapy and pre-orchiectomy risk group assignments was assessed using Cohen's kappa.

Results: Our cohort consisted of 83 patients. The use of pre-orchiectomy TMs resulted in an IGCCCG risk group upstaging in 12 patients (16%, 8 patients from good to intermediate risk and 4 patients from intermediate to poor risk) and a downstaging in 1 patient (1.2%, from intermediate- to good-risk). The agreement between pre-orchiectomy and pre-chemotherapy IGCCCG risk groups resulted in a Cohen's kappa of 0.888 (p < 0.001).

Conclusions: Using pre-orchiectomy TMs can result in incorrect IGCCCG risk group assignment, which in turn can impact on the clinical management and follow-up of patients with metastatic GCT. Thus, adherence to the IGCCCG standard using pre-chemotherapy TMs levels is recommended.