title: Clinical Outcomes and Prognostic Factors for Salivary Duct Carcinoma: A Multi-Institutional Analysis of 141 Patients.
abstract: Among salivary gland malignancies, the prognosis of salivary duct carcinoma (SDC) is assumed to be the poorest. However, because of its low incidence, reliable survival estimates and prognostic factors based on a large number of patients remain to be elucidated, thereby making it impossible to standardize the optimal treatment for SDC.
  
  
  
  We performed this multi-institutional, retrospective analysis by collecting the clinical information of 141 patients with SDC without distant metastasis who underwent curative surgery as the initial treatment to elucidate overall survival (OS) and disease-free survival (DFS) along with their prognostic factors.
  
  
  
  The 3-year OS and DFS rates were 70.5 and 38.2 %, respectively. Multivariate analysis revealed that age ≥65 years (p < 0.001) and N1 and N2 (p = 0.047 and <0.001, respectively) were independent prognostic factors for OS, whereas the primary site of the minor salivary and sublingual gland (p < 0.001) and N2 (p < 0.001) were those for DFS. The most common treatment failure was distant metastasis (55 patients, 39.0 %). For early parotid SDC, neither total parotidectomy in the patients with early T stage nor nerve resection in the patients without facial nerve palsy showed survival benefits.
  
  
  
  Advanced N stage independently affects both OS and DFS. Partial parotidectomy with facial nerve preservation could be a less invasive standard surgical procedure for parotid gland SDC in the early T stage without facial nerve palsy. Effective systemic therapy is imperative to improve DFS of SDC.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan.|Department of Otorhinolaryngology, Saiseikai Yokohama Tobu Hospital, Yokohama, Japan.
authors.forename: Kuninori
authors.initials: K
authors.lastname: Otsuka
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan. yorihisa@ja2.so-net.ne.jp.
authors.forename: Yorihisa
authors.initials: Y
authors.lastname: Imanishi
authors.affiliation: Department of Head and Neck Oncology and Surgery, International University of Health and Welfare Mita Hospital, Tokyo, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tada
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawakita
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kano
authors.affiliation: Department of Otolaryngology, Tokyo Medical University School of Medicine, Tokyo, Japan.
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Tsukahara
authors.affiliation: Department of Otolaryngology, Tokyo Medical University School of Medicine, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ozawa
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Okami
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sakai
authors.affiliation: Department of Head and Neck Surgery, Niigata Cancer Center Hospital, Niigata, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Head and Neck Surgery, Niigata Cancer Center Hospital, Niigata, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ueki
authors.affiliation: Department of Pathology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Toyoyuki
authors.initials: T
authors.lastname: Hanazawa
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Chazono
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Department of Anatomic Pathology, Tokyo Medical University School of Medicine, Tokyo, Japan.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nagao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044584:Carcinoma, Ductal / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate