title: Prediction of distant metastasis in head neck cancer patients: implications for induction chemotherapy and pre-treatment staging?
abstract: OBJECTIVE
  Intensity modulated radiation therapy (IMRT) combined treatment approaches, surgical and radiodiagnostic advances, respectively, lead to improved local-regional control in head neck cancer (HNC). With increasing local-regional control, distant metastases (DM) become more meaningful. In some trials without concomitant chemotherapy, induction chemotherapy (IC) resulted in an absolute reduction of DM by ~10-15%. In order to define a more efficient selection of patients at risk for DM with respect to IC and M-staging, we analysed our patients treated by contemporary standards.
  
  
  METHODS
  Between 1/2002 to 12/2007, 409 HNC patients were treated with IMRT; 303/409 (74%) underwent definitive, 106 (26%) postoperative IMRT. The mean/median follow-up was 23/20 months (3-72). 70% tolerated 4-7, 9% 1-3 cycles of simultaneous cisplatin. Treatment followed a prospectively designed protocol. In a previous study with 172 HNC IMRT patients, gross tumor volume (GTV) was found the strongest predictor for local-regional control. In the current study, this criterion has been prospectively tested for DM. Numbers needed to treat were calculated for IC.
  
  
  RESULTS
  DM developed in 28/399 (7%) patients; 10 presented initially with DM (total 38/409). In 13/28 (46%), DM remained the only manifestation of disease. GTV was the strongest predictor for DM (p < 0.0001) of all tested. Only 4% of patients with GTV < 70 cc developed DM, vs. 25% (18/73) with > 70 cc; only 6 of them (6/73, 8%) developed isolated DM.
  
  
  CONCLUSIONS
  GTV was the most significant predictor for DM, that could guide selective pre-treatment M-staging. The subgroup with isolated DM in the high risk group, that could benefit from IC, is small.
authors.affiliation: Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland. gabriela.studer@usz.ch
authors.forename: Gabriela
authors.initials: G
authors.lastname: Studer
authors.forename: Burkhardt
authors.initials: B
authors.lastname: Seifert
authors.forename: Christoph
authors.initials: C
authors.lastname: Glanzmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002945:Cisplatin / Q000627:therapeutic use*; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000556:secondary; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000188:drug therapy / Q000473:pathology* / Q000517:prevention & control; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin