title: Primary Tumor Resection in Patients With Metastatic Colorectal Cancer Is Associated With Reversal of Systemic Inflammation and Improved Survival.
abstract: BACKGROUND
  The true survival benefit of noncurative primary tumor resection in patients with de novo metastatic colorectal cancer (mCRC) remains uncertain. The present study examined the effect of primary tumor resection on systemic inflammation and survival in patients with mCRC.
  
  
  METHODS
  Consecutive patients with de novo mCRC who had undergone primary tumor resection were identified from a prospective database. Patients were excluded if they had undergone resection of metastases, had undergone delayed primary resection, or if blood samples were unavailable. The neutrophil/lymphocyte ratio (NLR) was used as a biomarker of systemic inflammation. Overall survival (OS) was compared between patient groups according to the pre- and postprimary resection NLR. The associations between the reversal of an elevated NLR and primary tumor bulk or performance status were explored.
  
  
  RESULTS
  A total of 145 eligible patients were identified from the database, with a median age of 70 years. The baseline NLR was elevated (> 5) in 65 patients, 36 (55%) of whom had a low NLR after surgery. The reversal of an elevated NLR was associated with significantly improved OS (hazard ratio, 0.53; P = .017). A similar benefit was seen after excluding patients undergoing emergency primary resection. NLR reversal was more frequent in patients with larger primary tumors or good performance status.
  
  
  CONCLUSIONS
  The present study is the first to demonstrate a relationship between the reversal of a systemic inflammatory response and the improved survival after primary resection in those with mCRC. A greater effect was seen in patients with large primary tumors. If validated, these observations could guide clinical decision-making in patients with mCRC at presentation.
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia; University of Melbourne, Melbourne, Australia.
authors.forename: Natalie
authors.initials: N
authors.lastname: Turner
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia; University of Melbourne, Melbourne, Australia; Department of Oncology, Western Health, Footscray, Australia. Electronic address: ben.tran@mh.org.au.
authors.forename: Ben
authors.initials: B
authors.lastname: Tran
authors.affiliation: Department of Radiology, Western Health, Footscray, Australia.
authors.forename: Phillip V
authors.initials: PV
authors.lastname: Tran
authors.affiliation: Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia.
authors.forename: Mathuranthakan
authors.initials: M
authors.lastname: Sinnathamby
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; University of Melbourne, Melbourne, Australia.
authors.forename: Hui-Li
authors.initials: HL
authors.lastname: Wong
authors.affiliation: Department of Colorectal Surgery, The Royal Melbourne Hospital, Parkville, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Jones
authors.affiliation: Department of Colorectal Surgery, Western Health, Footscray, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Croxford
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia; University of Melbourne, Melbourne, Australia.
authors.forename: Jayesh
authors.initials: J
authors.lastname: Desai
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia; University of Melbourne, Melbourne, Australia; Department of Oncology, Western Health, Footscray, Australia.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Tie
authors.affiliation: Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia.
authors.forename: Kathryn Maree
authors.initials: KM
authors.lastname: Field
authors.affiliation: Department of Oncology, Western Health, Footscray, Australia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Kosmider
authors.affiliation: BioGrid Australia, Melbourne, Australia.
authors.forename: Susie
authors.initials: S
authors.lastname: Bae
authors.affiliation: Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Department of Medical Oncology, The Royal Melbourne Hospital, Parkville, Australia; University of Melbourne, Melbourne, Australia; Department of Oncology, Western Health, Footscray, Australia; BioGrid Australia, Melbourne, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Gibbs
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009504:Neutrophils / Q000378:metabolism*; D018579:Patient Selection; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Colorectal Cancer; Immune response; Neutrophil/lymphocyte ratio; Noncurative resection; Primary resection