title: Prognostic Value of p16 Status on the Development of a Complete Response in Involved Oropharynx Cancer Neck Nodes After Cisplatin-Based Chemoradiation: A Secondary Analysis of NRG Oncology RTOG 0129.
abstract: To determine the relationship between p16 status and the regional response of patients with node-positive oropharynx cancer treated on NRG Oncology RTOG 0129.
  
  
  
  Patients with N1-N3 oropharynx cancer and known p16 status who underwent treatment on RTOG 0129 were analyzed. Pathologic complete response (pCR) rates in patients treated with a postchemoradiation neck dissection (with p16-positive or p16-negative cancer) were compared by Fisher exact test. Patients managed expectantly were compared with those treated with a neck dissection.
  
  
  
  Ninety-nine (34%) of 292 patients with node-positive oropharynx cancer and known p16 status underwent a posttreatment neck dissection (p16-positive: n=69; p16-negative: n=30). The remaining 193 patients with malignant lymphadenopathy at diagnosis were observed. Neck dissection was performed a median of 70 (range, 17-169) days after completion of chemoradiation. Neither the pretreatment nodal stage (P=.71) nor the postradiation, pre-neck dissection clinical/radiographic neck assessment (P=.42) differed by p16 status. A pCR was more common among p16-positive patients (78%) than p16-negative patients (53%, P=.02) and was associated with a reduced incidence of local-regional failure (hazard ratio 0.33, P=.003). On multivariate analysis of local-regional failure, a test for interaction between pCR and p16 status was not significant (P=.37). One-hundred ninety-three (66%) of 292 of initially node-positive patients were managed without a posttreatment neck dissection. Development of a clinical (cCR) was not significantly influenced by p16-status (P=.42). Observed patients with a clinical nodal CR had disease control outcomes similar to those in patients with a pCR neck dissection.
  
  
  
  Patients with p16-positive tumors had significantly higher pCR and locoregional control rates than those with p16-negative tumors.
authors.affiliation: Fox Chase Cancer Center, Philadelphia, Pennsylvania. Electronic address: thomas.galloway@fccc.edu.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Galloway
authors.affiliation: NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania.
authors.forename: Qiang Ed
authors.initials: QE
authors.lastname: Zhang
authors.affiliation: Centre Hospitalier de l'Universite de Montreal-Notre Dame, Montréal, Québec, Canada.
authors.forename: Phuc Felix
authors.initials: PF
authors.lastname: Nguyen-Tan
authors.affiliation: University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: David I
authors.initials: DI
authors.lastname: Rosenthal
authors.affiliation: Centre Hospitalier de l'Universite de Montreal-Notre Dame, Montréal, Québec, Canada.
authors.forename: Denis
authors.initials: D
authors.lastname: Soulieres
authors.affiliation: L Hotel-Dieu de Quebec, Québec City, Québec, Canada.
authors.forename: André
authors.initials: A
authors.lastname: Fortin
authors.affiliation: The James Brown Cancer Center-University of Louisville, Louisville, Kentucky.
authors.forename: Craig L
authors.initials: CL
authors.lastname: Silverman
authors.affiliation: University of California Davis Medical Center, Sacramento, California.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Daly
authors.affiliation: Fox Chase Cancer Center, Philadelphia, Pennsylvania.
authors.forename: John A
authors.initials: JA
authors.lastname: Ridge
authors.affiliation: London Regional Cancer Program, London, Ontario, Canada.
authors.forename: J Alexander
authors.initials: JA
authors.lastname: Hammond
authors.affiliation: Stanford University Medical Center, Stanford, California.
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D059248:Chemoradiotherapy / Q000401:mortality / Q000706:statistics & numerical data; D002945:Cisplatin / Q000627:therapeutic use*; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality / Q000706:statistics & numerical data; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D005260:Female; D006801:Humans; D038622:Internationality; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008297:Male; D009333:Neck; D037981:Neck Dissection / Q000401:mortality* / Q000706:statistics & numerical data; D009959:Oropharyngeal Neoplasms / Q000378:metabolism* / Q000401:mortality* / Q000628:therapy*; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D002945:Cisplatin