title: Performance of a nomogram predicting disease-specific survival after an R0 resection for gastric cancer in patients receiving postoperative chemoradiation therapy.
abstract: OBJECTIVE
  The internationally validated Memorial Sloan-Kettering Cancer Center (MSKCC) gastric carcinoma nomogram was based on patients who underwent curative (R0) gastrectomy, without any other therapy. The purpose of the current study was to assess the performance of this gastric cancer nomogram in patients who received chemoradiation therapy after an R0 resection for gastric cancer.
  
  
  METHODS
  In a combined dataset of 76 patients from the Netherlands Cancer Institute (NKI), and 63 patients from MSKCC, who received postoperative chemoradiation therapy (CRT) after an R0 gastrectomy, the nomogram was validated by means of the concordance index (CI) and a calibration plot.
  
  
  RESULTS
  The concordance index for the nomogram was 0.64, which was lower than the CI of the nomogram for patients who received no adjuvant therapy (0.80). In the calibration plot, observed survival was approximately 20% higher than the nomogram-predicted survival for patients receiving postoperative CRT.
  
  
  CONCLUSIONS
  The MSKCC gastric carcinoma nomogram significantly underpredicted survival for patients in the current study, suggesting an impact of postoperative CRT on survival in patients who underwent an R0 resection for gastric cancer, which has been demonstrated by randomized controlled trials. This analysis stresses the need for updating nomograms with the incorporation of multimodal strategies.
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Johan L
authors.initials: JL
authors.lastname: Dikken
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Coit
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Baser
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Mithat
authors.initials: M
authors.lastname: Gönen
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Murray F
authors.initials: MF
authors.lastname: Brennan
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Edwin P M
authors.initials: EP
authors.lastname: Jansen
authors.affiliation: Department of Gastroenterology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Boot
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.affiliation: Department of Gastroenterology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Annemieke
authors.initials: A
authors.lastname: Cats
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands. Electronic address: m.verheij@nki.nl.
authors.forename: Marcel
authors.initials: M
authors.lastname: Verheij
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002173:Cancer Care Facilities; D059248:Chemoradiotherapy / Q000401:mortality*; D005260:Female; D005743:Gastrectomy / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009519:New York City; D049451:Nomograms; D011184:Postoperative Period; D011336:Probability; D011379:Prognosis; D011879:Radiotherapy Dosage; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D016019:Survival Analysis