Outcome in Irradiated Oral Cavity Carcinoma: An Update

Background: In contrast to pharyngo-laryngeal cancer, definitive radiation-chemotherapy of advanced oral cavity cancer (OCC) results in inferior disease control rates. Surgery in combination with radiation +/concomitant chemotherapy is therefore the treatment of choice for squamous cell OCC stages >/=pT1-2pN0-1. Modern intensity modulated radiation techniques (IMRT) allow more conformal dose distribution to the tumor area with consecutively less dose to surrounding normal tissues. Aim was to give a recent overview about outcome data in OCC treated in the modern IMRT era (i.e. time period since ~2000) including presentation of the own single institution results. Methods: our OCC IMRT cohort was evaluated with respect to disease control and radioosteonecrosis (RON) as most serious late term effect following radiation. Results: 202 OCC patients treated between 10/2002-10/2013 with a follow up of mean 30months (3-124) were assessed. 5-year overall and distant metastasis free survival, local and nodal control rates for postoperatively (n=147 (73%), 60-66Gy tumor dose) vs definitively (n=55 (27%), 70Gy) irradiated patients was 70 vs 36% (p<0.0001) and 84%vs84% (p=0.2), 70% vs 40% (p<0.0001) and 83% vs 70% (p=0.006), respectively. The incidence of RONgrade 1-2 was 3% (:12/147 (9%) in postoperative, 1/55 (2%) in definitive IMRT); 1grade 3 RON was observed after post IMRT dental implants. In all grade 1-2 RON, restitutio ad integrum was achieved after conservative treatment or limited surgery (debridment/ decortication/sequestrectomy). Conclusion: Disease control and survival following combined postoperative MRT are significantly higher than after definitive IMRT(-chemotherapy). The RON incidence revealed being higher in the operated subgroup.