title: Mortality in tongue cancer patients treated by curative surgery: a retrospective cohort study from CGRD.
abstract: BACKGROUND
  Our study aimed to compare the outcomes of surgical treatment of tongue cancer patients in three different age groups.
  
  
  METHODS
  From 2004 to 2013, we retrospectively analyzed the clinical data of 1,712 patients who were treated in the four institutions constituting the Chang Gung Memorial Hospitals (CGMH). We divided and studied the patients in three age groups: Group 1, younger (<65 years); Group 2, young old (65 to <75); and Group 3, older old patients (≥75 years).
  
  
  RESULTS
  Multivariate analyses determined the unfavorable, independent prognostic factors of overall survival to be male sex, older age, advanced stage, advanced T, N classifications, and surgery plus chemotherapy. No significant differences were found in adjusted hazard ratios (HR) of death in early-stage disease (stage I-II) among Group 1 (HR 1.0), Group 2 (HR 1.43, 95% confidence interval (CI) [0.87-2.34],p= 0.158), and Group 3 (HR 1.22, 95% CI [0.49-3.03],p= 0.664) patients. However, amongst advanced-stage patients (stage (III-IV)), Group 3 (HR 2.53, 95% CI [1.46-4.38],p= 0.001) showed significantly worse survival than the other two groups after other variables were adjusted for. Fourteen out of 21 older old, advanced-staged patients finally died, and most of the mortalities were non-cancerogenic (9/14, 64.3%), and mostly occurred within one year (12/14, 85%) after cancer diagnosis. These non-cancer cause of death included underlying diseases in combination with infection, pneumonia, poor nutrition status, and trauma.
  
  
  CONCLUSIONS
  Our study showed that advanced T classification (T3-4), positive nodal metastasis (N1-3) and poorly differentiated tumor predicted poor survival for all patients. Outcome of early-stage patients (stage I-II) among three age groups were not significantly different. However, for advanced-stage patients (stage III-IV), the older old patients (≥75) had significantly worse survival than the other two patient groups. Therefore, for early-stage patients, age should not deny them to receive optimal treatments. However, older old patients (≥75) with advanced cancer should be comprehensively assessed by geriatric tools before surgical treatment and combined with intensive postoperative care to improve outcome, especially the unfavorable non-cancerogenic mortalities within one year after cancer diagnosis.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; Center of Excellence for Chang Gung Research Datalink, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Ming-Shao
authors.initials: MS
authors.lastname: Tsai
authors.affiliation: Department of Radiation Oncology, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Chia-Hsuan
authors.initials: CH
authors.lastname: Lai
authors.affiliation: Center of Excellence for Chang Gung Research Datalink, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Chuan-Pin
authors.initials: CP
authors.lastname: Lee
authors.affiliation: Center of Excellence for Chang Gung Research Datalink, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; Department of Traditional Chinese Medicine, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; School of Traditional Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yao-Hsu
authors.initials: YH
authors.lastname: Yang
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; Department of Environmental and Occupational Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Pau-Chung
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Department of Otolaryngology -Head and Neck Surgery, Linkou Chang Gung Memorial Hospital , Taoyuan , Taiwan.
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Geng-He
authors.initials: GH
authors.lastname: Chang
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Yao-Te
authors.initials: YT
authors.lastname: Tsai
authors.affiliation: Department of Medical Oncology, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Chang-Hsien
authors.initials: CH
authors.lastname: Lu
authors.affiliation: Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital , Kaohsiung , Taiwan.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Chien
authors.affiliation: Department of Otolaryngology -Head and Neck Surgery, Keelung Chang Gung Memorial Hospital , Keelung , Taiwan.
authors.forename: Chi-Kuang
authors.initials: CK
authors.lastname: Young
authors.affiliation: Department of Otolaryngology -Head and Neck Surgery, Linkou Chang Gung Memorial Hospital , Taoyuan , Taiwan.
authors.forename: Ku-Hao
authors.initials: KH
authors.lastname: Fang
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Chin-Jui
authors.initials: CJ
authors.lastname: Liu
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital , Chiayi , Taiwan.
authors.forename: Re-Ming A
authors.initials: RA
authors.lastname: Yeh
authors.affiliation: Center of Excellence for Chang Gung Research Datalink, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; Department of Radiation Oncology, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Chen
keywords: Age; CGRD (Chang Gung Research Database); Old; Oral cancer; Oral cavity; Prognosis; Risk factors; Survival