title: HPV-negative squamous cell carcinoma of the anal canal is unresponsive to standard treatment and frequently carries disruptive mutations in TP53.
abstract: BACKGROUND
  Human papillomavirus (HPV), p16 expression, and TP53 mutations are known prognostic factors in head and neck squamous cell carcinoma, but their role in squamous cell carcinoma of the anal canal (SCCAC) is less well established. The objective of this study was to determine the prognostic significance of tumour HPV status, p16 and p53 expression, and mutations in TP53 in patients with SCCAC receiving (chemo)radiotherapy.
  
  
  METHODS
  Human papillomavirus DNA was determined using an INNO-LiPA-based assay in tumour tissue of 107 patients with locally advanced SCCAC. Patients were treated with radiotherapy, with or without concurrent chemotherapy consisting of a fluoropyrimidine and mitomycin C. Expression of p16 and p53 was determined using immunohistochemistry. Exons 2-11 of TP53 in tumour tissue were sequenced.
  
  
  RESULTS
  DNA of high-risk HPV types was detected in 93 out of 107 tumours (87%), all of which overexpressed p16 (HPV+/p16+). Of 14 HPV-negative (HPV-) tumours (13%), 10 (9%) were p16-negative (HPV-/p16-) and 4 (4%) overexpressed p16 (HPV-/p16+). Patients with HPV-/p16- disease had inferior 3-year locoregional control (LRC) (15%) compared with patients with HPV+/p16+ tumours (82%, P<0.001) and HPV-/p16+ tumours (75%, P=0.078). Similarly, 3-year overall survival (OS) was 35% (HPV-/p16-) vs 87% (HPV+/p16+, P<0.001) and 75% (HPV-/p16+, P=0.219). Disruptive mutations in TP53 were found in 80% of HPV-/p16- tumours vs 6% of HPV+/p16+ tumours (P<0.001). In multivariate analysis, HPV-/p16- status was an independent predictor of inferior LRC and OS.
  
  
  CONCLUSIONS
  HPV- tumours are frequently TP53 mutated. HPV-/p16- status is a strong predictor for reduced LRC and OS, and alternative treatment strategies for patients with HPV-/p16- disease need to be explored.
authors: 1] Division of Clinical Pharmacology, Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [2] Department of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [3] Division of Gastroenterology and Hepatology, Department of Medical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors: D
authors: D
authors: Meulendijks
authors: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors: N B
authors: NB
authors: Tomasoa
authors: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors: L
authors: L
authors: Dewit
authors: Department of Molecular Biology, Slotervaart Hospital, Amsterdam, The Netherlands.
authors: P H M
authors: PH
authors: Smits
authors: Department of Molecular Biology, Slotervaart Hospital, Amsterdam, The Netherlands.
authors: R
authors: R
authors: Bakker
authors: Department of Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors: M-L F
authors: ML
authors: van Velthuysen
authors: Department of Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors: E H
authors: EH
authors: Rosenberg
authors: 1] Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [2] Faculty of Science, Division of Pharmacoepidemiology and Clinical Pharmacology, Department of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
authors: J H
authors: JH
authors: Beijnen
authors: 1] Division of Clinical Pharmacology, Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [2] Department of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [3] Faculty of Science, Division of Pharmacoepidemiology and Clinical Pharmacology, Department of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
authors: J H M
authors: JH
authors: Schellens
authors: Division of Gastroenterology and Hepatology, Department of Medical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands.
authors: A
authors: A
authors: Cats
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D052685:Alphapapillomavirus / Q000145:classification / Q000302:isolation & purification*; D001005:Anus Neoplasms / Q000235:genetics / Q000628:therapy* / Q000821:virology; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000628:therapy* / Q000821:virology; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D004358:Drug Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D030361:Papillomavirus Infections / Q000235:genetics / Q000821:virology; D011878:Radiotherapy; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53