title: CXCR2 expression and postoperative complications affect long-term survival in patients with esophageal cancer.
abstract: BACKGROUND
  Esophagectomy is one of the most invasive surgical treatments for digestive tract cancer, and the blood levels of inflammatory cytokines such as interleukin-1, interleukin-6, and interleukin-8 are increased for several hours after surgery or in patients experiencing postoperative complications. CXCR2, an interleukin-8 receptor, is reportedly expressed in several carcinomas, and interleukin-8 signaling promotes cancer cell proliferation. The impact of postoperative complications following esophagectomy on long-term survival is controversial. In this study, we demonstrate the significance of CXCR2 expression and validate the effects of CXCR2 expression and postoperative complications on long-term prognosis of esophageal squamous cell carcinoma using resected specimens.
  
  
  METHODS
  Eighty-two specimens were sectioned from archived, paraffin-embedded tumor tissues obtained from patients with esophageal squamous cell carcinoma who underwent esophagectomy and extended lymphadenectomy for complete resection of cancer in our institute between 1997 and 2002. Immunohistochemistry was performed using a polyclonal antibody to CXCR2, and the correlation of stainability with clinicopathological factors and long-term survival was examined.
  
  
  RESULTS
  CXCR2 was expressed in 33 of 82 (40.2 %) specimens. In the CXCR2-positive group, the recurrence-free survival and overall survival rates of patients who developed postoperative complications were both significantly lower than those for patients who did not develop any complications. In contrast, in the CXCR2-negative group, there was no significant difference in long-term prognosis between patients with and without complications. CXCR2 positivity combined with postoperative complications was an independent risk factor for subsequent tumor recurrence, showing the highest hazard ratio.
  
  
  CONCLUSIONS
  Our results suggest that the patients with CXCR2-positive esophageal cancer who develop postoperative complications have a poor prognosis and should be carefully followed.
  
  
  BACKGROUND
  This study was approved by Keio University School of Medicine Ethics Committee with a trial registration number of 2011-241.
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. tmsha@infoseek.jp.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nishi
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. htakeuchi@a6.keio.jp.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. matsuda-sa@umin.ac.jp.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Matsuda
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. oguogu76@yahoo.co.jp.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ogura
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. hkawakubo@z3.keio.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kawakubo
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. fukudak@z6.keio.jp.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Fukuda
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. rieko-na@cam.hi-ho.ne.jp.
authors.forename: Rieko
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. surgeontsune@yahoo.co.jp.
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. nori-kkr@umin.ac.jp.
authors.forename: Norihito
authors.initials: N
authors.lastname: Wada
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. saiky@z8.keio.jp.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Saikawa
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. t-omori@jcom.home.ne.jp.
authors.forename: Tai
authors.initials: T
authors.lastname: Omori
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. kitagawa@a3.keio.jp.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D004938:Esophageal Neoplasms / Q000378:metabolism / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D016629:Esophagectomy / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011379:Prognosis; D023063:Receptors, Interleukin-8B / Q000378:metabolism*; D012189:Retrospective Studies; D015996:Survival Rate; D013908:Thoracotomy
chemical_list: D014408:Biomarkers, Tumor; D023063:Receptors, Interleukin-8B