title: Identification of prognostic subgroups among patients with metastatic 'IGCCCG poor-prognosis' germ-cell cancer: an explorative analysis using cart modeling.
abstract: OBJECTIVE
  The IGCCCG classification has identified three prognostic groups of patients with metastatic germ-cell tumors. 'Poor prognosis' is based on primary tumor localization, the presence of visceral metastases, and/or high tumor-marker levels. The overall survival rate of these patients is about 45%-55%. The present analysis attempts to identify subsets of patients with a more or less favorable outcome among the 'poor-prognosis' group.
  
  
  METHODS
  We retrospectively explored prognostic subgroups in 332 patients with 'IGCCCG' poor-risk GCT using the classification-and-regression-tree model (CART). The following variables were included: primary tumor localization, presence of visceral or lung metastases, presence of an abdominal tumor, number of metastatic sites, serum levels of beta-HCG, AFP and LDH. All patients had been treated with cisplatin-etoposide-based chemotherapy within controlled clinical trials between 1984 and 1997.
  
  
  RESULTS
  
  
  
  METHODS
  gonadal/retroperitoneal (G/R) primary tumor 260 patients (78%), mediastinal primary tumor 72 patients (22%), visceral metastases 205 patients (62%) including 33 patients with CNS metastases, lung metastases 247 patients (74%), abdominal tumor 241 patients (72%), elevated AFP, beta-HCG or LDH levels 235 (71%), 253 (76%) and 275 (83%) of patients, respectively. Patients with primary mediastinal disease plus lung metastases exhibited the worst two-year PFS (28%), whereas patients with a primary G/R tumor and without visceral metastases showed the highest chance of two-year PFS (75%). The latter group of patients without visceral metastases and with a primary G/R tumor also had the most favourable two-year OS (84%). In contrast, patients with a primary mediastinal tumor and visceral metastases displayed the worst two-year OS (49%).
  
  
  CONCLUSIONS
  Different prognostic subsets of patients can be identified among the group of 'poor-prognosis' GCT patients. The CART analysis model results in a hierarchy of prognostic factors which may allow to more precisely estimate the individual patient's prognosis. Identifying subgroups of 'very poor-prognosis' among 'poor-prognosis' patients may allow to test for new treatment strategies in selected subgroups.
authors.affiliation: Department of Hematology/Oncology, University of Tübingen Medical Center, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kollmannsberger
authors.forename: C
authors.initials: C
authors.lastname: Nichols
authors.forename: C
authors.initials: C
authors.lastname: Meisner
authors.forename: F
authors.initials: F
authors.lastname: Mayer
authors.forename: L
authors.initials: L
authors.lastname: Kanz
authors.forename: C
authors.initials: C
authors.lastname: Bokemeyer
mesh_terms: D000293:Adolescent; D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D018572:Disease-Free Survival; D005260:Female; D018237:Germinoma / Q000097:blood / Q000401:mortality / Q000556:secondary*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008175:Lung Neoplasms / Q000097:blood / Q000401:mortality / Q000556:secondary*; D008297:Male; D008479:Mediastinal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013736:Testicular Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D007770:L-Lactate Dehydrogenase