Conclusions: This GP regimen demonstrated an impressive anti-tumoral activity in locally advanced NPC, with a favorable toxicity profile. The current approach may improve the outcome of patients with locally advanced NPC and merits further

Materials/Methods:80patientswhounderwentdefinitivechemoradiationfor StageIII‐IVsquamous cell cancerof thehypopharynx, oropharynx and larynx were identified. All patients had a minimum 18-month follow-up. Data were collected on T-Stage, N-Stage, gross tumor volume, and involved node volume based on treatment planning CT scans; these were correlated to survival and tumor control data obtained from retrospective analysis. Results:Bivariateregressionfoundprimarytumorvolumetobeasignificantpredictorforlengthofsurvival(p=0.022)andtimeto recurrence ( p= 0.007), with smaller volumes leading to better outcomes. A similar analysis for involved lymph node volume did not show a significant correlation between nodal volume and risk of tumor recurrence or death. Tumor volume was a continuous predictor of tumor control and survival, with 35cc appearing to be the point at which there was the most significant difference in outcomes. Patients with volumes\35cc had a significantly better prognosis, in terms of 5-year overall survival (84% vs. 43%,p = \0.001), progression-free survival (61% vs. 33%, p = 0.004), and time to progression (71% vs. 41%, p = 0.004). The tumor volume data was also analyzed against age, gender, T-Stage, N-Stage, and site of disease in a proportional hazards model to determine factorswithpredictivevalueforriskoffailure.Tumorvolume .35ccwasthebestpredictorofrecurrence(HR=4.7,CI=1.9,11.6; p = 0.001), followed by site (HR = 2.1, CI = 1.3, 3.5; p = 0.004). Similarly, tumor volume (HR = 10.0, CI = 2.9, 35.1; p =\0.001) and site (HR = 2.3, CI = 1.2, 4.4; p = 0.014) were also strong predictors for overall survival. The other factors did not show a statistically significanteffect on the risk of failure. Additionally, gross tumor volume was a predictor for the site of failure. Analysis of variance found tumors that failed locoregionally to be on average 21.6cc larger than tumors that did not fail (p = 0.028).