title: Predictors of Distant Metastasis after Radical Surgery Followed by Postoperative Radiotherapy with or without Chemotherapy for Oropharyngeal Cancer.
abstract: OBJECTIVE
  We investigated the prognostic factors for distant metastasis (DM) in patients with locally advanced oropharyngeal cancer (OPC) treated with surgery and adjuvant radiotherapy with or without concurrent chemotherapy.
  
  
  METHODS
  Eighty-five patients treated between January 1995 and August 2014 were evaluated retrospectively. Data regarding the pathological tumour and nodal status, human papillomavirus (HPV) status, treatment characteristics, and pretreatment maximum standardized uptake value (SUVmax) of 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography scan (18F-FDG PET-CT) were evaluated, and their influence on DM and survival outcomes were analyzed.
  
  
  RESULTS
  Median follow-up period was 48.0 months. Recurrence was observed in 20 patients, including locoregional recurrence and DM. DM was observed in 13 patients. A multivariate analysis confirmed that the presence of lymphovascular invasion (p=0.031), lower neck lymph node (LN) involvement (p=0.006), SUVmax ≥ 9.7 (p=0.014), and tumour size ≥ 3 cm (p=0.037) significantly affected DM. HPV status was not associated with DM. Perineural invasion (p=0.048), lower neck LNinvolvement (p=0.008), SUVmax ≥ 9.7 (p=0.019), and tumour size ≥ 3 cm (p=0.033) were also significant factors for the DM-free survival rate.
  
  
  CONCLUSIONS
  Lower neck LN involvement, high SUVmax in pretreatment18F-FDG PET-CT, and large tumour size were predictive factors for DM in patients of OPC.
authors.affiliation: Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Mi Joo
authors.initials: MJ
authors.lastname: Chung
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yeon Sil
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji Yoon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yun Hee
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Jang
authors.affiliation: Department of Medical Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jin Hyoung
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Nuclear Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ie Ryung
authors.initials: IR
authors.lastname: Yoo
authors.affiliation: Department of Hospital Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D027383:Papillomaviridae / Q000472:pathogenicity; D049268:Positron-Emission Tomography; D011379:Prognosis
keywords: Distant metastasis; Lower neck involvement; Oropharyngeal neoplasms; Pretreatment 18F-FDG PET-CT scan; Radiotherapy; SUVmax