title: Human papillomavirus confers radiosensitivity in cancer cervix: a hypothesis toward a possible restoration of apoptotic pathways based on clinical outcomes.
abstract: OBJECTIVE
  To evaluate if high baseline local human papillomavirus (HPV) titer confers radiosensitivity in cancer cervix. A hypothesis is proposed to explain the clinical outcomes.
  
  
  METHODS
  121 serial HPV titers from cervical smears of 21 patients were estimated during radiotherapy (RT) and correlated with RT dose-response curves, local response and local disease-free survival (LDFS).
  
  
  RESULTS
  Local response (p = 0.04) and LDFS (p = 0.06) were better in high HPV than low HPV baseline group. On multivariate analysis, RT doses for 50% tumor regression and baseline HPV titer were the only predictors for LDFS.
  
  
  CONCLUSIONS
  Serial reductions of HPV titers following RT could restore the HPV induced temporarily downregulated p53 and pRb apoptotic pathways resulting in radiosensitivity of these tumors.
authors.affiliation: Department of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Niloy Ranjan
authors.initials: NR
authors.lastname: Datta
authors.forename: Shalini
authors.initials: S
authors.lastname: Singh
authors.forename: Piyush
authors.initials: P
authors.lastname: Kumar
authors.forename: Dinesh
authors.initials: D
authors.lastname: Gupta
mesh_terms: D000328:Adult; D017209:Apoptosis; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000150:complications* / Q000821:virology*; D011379:Prognosis; D011836:Radiation Tolerance; D015398:Signal Transduction; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000209:etiology* / Q000378:metabolism / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D019562:Viral Load
keywords: HPV; apoptosis; cervical cancer; p53; pRb; radiation dose–response; radiation therapy; radiosensitivity