title: Development and external validation of a nomogram for overall survival after curative resection in serosa-negative, locally advanced gastric cancer.
abstract: BACKGROUND
  Few nomograms can predict overall survival (OS) after curative resection of advanced gastric cancer (AGC), and these nomograms were developed using data from only a few large centers over a long time period. The aim of this study was to develop and externally validate an elaborative nomogram that predicts 5-year OS after curative resection for serosa-negative, locally AGC using a large amount of data from multiple centers in Japan over a short time period (2001-2003).
  
  
  METHODS
  Of 39 859 patients who underwent surgery for gastric cancer between 2001 and 2003 at multiple centers in Japan, we retrospectively analyzed 5196 patients with serosa-negative AGC who underwent Resection A according to the 13th Japanese Classification of Gastric Carcinoma. The data of 3085 patients who underwent surgery from 2001 to 2002 were used as a training set for the construction of a nomogram and Web software. The data of 2111 patients who underwent surgery in 2003 were used as an external validation set.
  
  
  RESULTS
  Age at operation, gender, tumor size and location, macroscopic type, histological type, depth of invasion, number of positive and examined lymph nodes, and lymphovascular invasion, but not the extent of lymphadenectomy, were associated with OS. Discrimination of the developed nomogram was superior to that of the TNM classification (concordance indices of 0.68 versus 0.61; P < 0.001). Moreover, calibration was accurate.
  
  
  CONCLUSIONS
  We have developed and externally validated an elaborative nomogram that predicts the 5-year OS of postoperative serosa-negative AGC. This nomogram would be helpful in the assessment of individual risks and in the consideration of additional therapy in clinical practice, and we have created freely available Web software to more easily and quickly predict OS and to draw a survival curve for these purposes.
authors.affiliation: Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata.
authors.forename: S
authors.initials: S
authors.lastname: Hirabayashi
authors.affiliation: Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata sugishin@med.niigata-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Kosugi
authors.affiliation: Department of Surgery, National Hospital Organization Tokyo Medical Center, Tokyo.
authors.forename: Y
authors.initials: Y
authors.lastname: Isobe
authors.affiliation: Department of Surgery, Niigata Cancer Center Hospital, Niigata.
authors.forename: A
authors.initials: A
authors.lastname: Nashimoto
authors.affiliation: Endoscopy Division, National Cancer Center Hospital, Tokyo.
authors.forename: I
authors.initials: I
authors.lastname: Oda
authors.affiliation: Department of Surgery, Yamagata Prefectural Kahoku Hospital, Yamagata.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
authors.forename: I
authors.initials: I
authors.lastname: Miyashiro
authors.affiliation: Center for Clinical and Translational Research, National Center for Global Health and Medicine, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Tsujitani
authors.affiliation: Department of Surgery II, Nagoya University School of Medicine, Nagoya.
authors.forename: Y
authors.initials: Y
authors.lastname: Kodera
authors.affiliation: Department of Gastrointestinal Surgery, Graduate School of Medicine, University of Tokyo, Tokyo.
authors.forename: Y
authors.initials: Y
authors.lastname: Seto
authors.affiliation: Department of Surgery, Kinki University Faculty of Medicine, Osaka.
authors.forename: H
authors.initials: H
authors.lastname: Furukawa
authors.affiliation: Endoscopy Division, Shizuoka Cancer Center Hospital, Shizuoka.
authors.forename: H
authors.initials: H
authors.lastname: Ono
authors.affiliation: Department of Gastroenterology, Kitasato University East Hospital, Sagamihara.
authors.forename: S
authors.initials: S
authors.lastname: Tanabe
authors.affiliation: Department of Surgery, Showa General Hospital, Tokyo.
authors.forename: M
authors.initials: M
authors.lastname: Kaminishi
authors.affiliation: Department of Gastroenterological Surgery, Cancer Institute Ariake Hospital, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Nunobe
authors.affiliation: Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fukagawa
authors.affiliation: Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata.
authors.forename: R
authors.initials: R
authors.lastname: Matsuo
authors.affiliation: Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata.
authors.forename: T
authors.initials: T
authors.lastname: Nagai
authors.affiliation: Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Katai
authors.affiliation: Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata.
authors.forename: T
authors.initials: T
authors.lastname: Wakai
authors.affiliation: Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata.
authors.forename: K
authors.initials: K
authors.lastname: Akazawa
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005743:Gastrectomy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D055815:Young Adult
keywords: advanced gastric cancer; external validation; multivariable analysis; nomogram; prognosis; survival analysis