title: Clinical significances of preoperative serum interleukin-6 and C-reactive protein level in operable gastric cancer.
abstract: BACKGROUND
  The interleukin-6 (IL-6) pathway is one of the mechanisms that link inflammation and angiogenesis to malignancy. Because the C-reactive protein (CRP) is a representative marker for inflammation, CRP has recently been associated with the progression of disease in many cancer types. The principal objective of this study was to determine the preoperative serum levels of IL-6 and CRP in gastric carcinoma, and to correlate them with disease status and prognosis.
  
  
  METHODS
  A total of 115 patients who underwent gastrectomy were enrolled in this study. Serum levels of IL-6 were assessed via Enzyme-Linked Immuno-Sorbent Assay (ELISA), and CRP was measured via immunoturbidimetry. Histological findings included tumor size, depth of tumor invasion, lymph node (LN) metastasis, and TNM stage (6th AJCC Stage Groupings: The staging systems; Primary tumor, regional LN, metastasis).
  
  
  RESULTS
  Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 and CRP levels were correlated with invasion depth (P < 0.001, P = 0.001), LN metastasis (P < 0.001, P = 0.024) and TNM stage (P < 0.001, P < 0.001). The presence of peritoneal seeding metastasis is associated with IL-6 levels (P = 0.012). When we established the cutoff value for IL-6 level (6.77 pg/dL) by ROC curve, we noted significant differences in time to progression (TTP; P < 0.001) and overall survival (OS; P = 0.010). However, CRP evidenced no significance with regard to patients' TTP and OS levels. Serum IL-6 levels were correlated positively with CRP levels (r2 = 0.049, P = 0.018).
  
  
  CONCLUSIONS
  Preoperative serum IL-6 and CRP levels might be markers of tumor invasion, LN metastasis, and TNM stage. Preoperative high IL-6 levels were proposed as a poor prognostic factor for disease recurrence and overall survival in patients with gastric cancers.
authors.affiliation: Department of Internal Medicine, Dong-A university College of Medicine, Busan, Korea. dinkum1211@naver.com
authors.forename: Do-Kyong
authors.initials: DK
authors.lastname: Kim
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Oh
authors.forename: Hyuk-Chan
authors.initials: HC
authors.lastname: Kwon
authors.forename: Suee
authors.initials: S
authors.lastname: Lee
authors.forename: Kyung A
authors.initials: KA
authors.lastname: Kwon
authors.forename: Byung Geun
authors.initials: BG
authors.lastname: Kim
authors.forename: Seong-Geun
authors.initials: SG
authors.lastname: Kim
authors.forename: Sung-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Jang
authors.forename: Min Chan
authors.initials: MC
authors.lastname: Kim
authors.forename: Kyeong Hee
authors.initials: KH
authors.lastname: Kim
authors.forename: Jin-Yeong
authors.initials: JY
authors.lastname: Han
authors.forename: Hyo-Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism*; D002277:Carcinoma / Q000097:blood / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009385:Neoplastic Processes; D011300:Preoperative Care; D011379:Prognosis; D013274:Stomach Neoplasms / Q000097:blood / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology
chemical_list: D015850:Interleukin-6; D002097:C-Reactive Protein