title: Difficulty of predicting the presence of lymph node metastases in patients with clinical early stage gastric cancer: a case control study.
abstract: BACKGROUND
  The relationship between pathological factors and lymph node metastasis of pathological stage early gastric cancer has been extensively investigated. By contrast, the relationship between preoperative factors and lymph node metastasis of clinical stage early gastric cancer has not been investigated. The present study was to investigate discrepancies between preoperative and postoperative values.
  
  
  METHODS
  From January 2011 to December 2013, 1042 patients with clinical stage early gastric cancer who underwent gastrectomy with lymphadenectomy were enrolled. Preoperative and postoperative values were collected for subsequent analysis. Receiver operating characteristics curves were computed using independent predictive factors.
  
  
  RESULTS
  Several discrepancies were observed between preoperative and postoperative values, including existence of ulcer, gross type, and histology (all McNemar p-values were <0.001). Multivariate analyses identified the following independent predictive factors for lymph node metastasis: postoperative values including age (p = 0.002), tumor size (p < 0.001), and tumor depth (p < 0.001); preoperative values including age (p = 0.017), existence of ulcer (p = 0.037), tumor size (p = 0.009), and prediction of the presence of lymph node metastasis in computed tomography scans (p = 0.002). These postoperative and preoperative independent predictive factors produced areas under the receiver operating characteristics curves of 0.824 and 0.660, respectively.
  
  
  CONCLUSIONS
  Surgeons need to be aware of limitations in preoperative predictions of the presence of lymph node metastasis for clinical stage early gastric cancer.
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. mnaksrg2@yahoo.co.jp.|Department of Gastric Surgery, Tokyo Medical and Dental University, Tokyo, Japan. mnaksrg2@yahoo.co.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakagawa
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. Laki98@yuhs.ac.
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Choi
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. jar319@yuhs.ac.|Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea. jar319@yuhs.ac.
authors.forename: Ji Yeong
authors.initials: JY
authors.lastname: An
authors.affiliation: Department of Internal Medicine, Institute of Gastroenterology, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea. hchung@yuhs.ac.
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Chung
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. sshgs@yuhs.ac.|Department of Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, South Korea. sshgs@yuhs.ac.
authors.forename: Sang Hyuk
authors.initials: SH
authors.lastname: Seo
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. no1kal@yuhs.ac.
authors.forename: Hyun Beak
authors.initials: HB
authors.lastname: Shin
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. SGGUMA@yuhs.ac.
authors.forename: Hui-Jae
authors.initials: HJ
authors.lastname: Bang
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. Lishuangxi@outlook.com.|Department of Gastrointestinal Surgery, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, China. Lishuangxi@outlook.com.
authors.forename: Shuangxi
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. CAIRUS@yuhs.ac.
authors.forename: Hyung-Il
authors.initials: HI
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. jhcheong@yuhs.ac.
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Cheong
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. wjhyung@yuhs.ac.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Hyung
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, 50 Yonsei-Ro, Seodaemun-gu, 120-752, Seoul, South Korea. sunghoonn@yuhs.ac.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea. sunghoonn@yuhs.ac.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D057234:Preoperative Period; D011379:Prognosis; D012372:ROC Curve; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery