title: Clinical significance of preoperative serum interleukin-6 and C-reactive protein level in breast cancer patients.
abstract: BACKGROUND
  Breast cancer is a disease that continues to plague females during their entire lifetime. IL-6 and CRP are found to be elevated in various inflammatory and malignant diseases and their levels are found to correlate with the extent of the disease. The primary objective of this study was to determine the preoperative serum levels of IL-6 and CRP in breast carcinoma, and to correlate them with the staging of the disease and the prognosis.
  
  
  METHODS
  59 female patients admitted for breast cancer were identified for the study and were subjected to thorough evaluation. Serum levels of IL-6 were assessed via Enzyme-Linked Immuno-Sorbent Assay (ELISA), and CRP was measured via immunoturbidimetry. Histological findings included tumour size, lymph node (LN) metastasis, and tumour staging. Relevant investigations were made to find out the presence of distant metastasis. Statistical analysis of the data was then processed.
  
  
  RESULTS
  Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 and CRP levels correlated with LN metastasis (P < 0.001, P < 0.001) and TNM stage (P < 0.001, P < 0.001). Tumour invasion and the presence of distant metastasis is associated with higher IL-6 levels (P = 0.001, P = 0.009). When we established the cutoff value for IL-6 level (20.55 pg/dl) by ROC curve, we noted a significant difference in overall survival (OS; P = 0.008). However, CRP evidenced no significance with regard to patient's OS levels. Serum IL-6 levels were correlated positively with CRP levels (r² = 0.579, P < 0.01)
  
  
  CONCLUSIONS
  Serum levels of IL-6 correlates well with the extent of tumor invasion, LN metastasis, distant metastasis and TNM staging thus enveloping all aspects of breast cancer.
authors.affiliation: Department of General Surgery, Coimbatore Medical College Hospital, Coimbatore, Tamil Nadu, India. pravashu2624@gmail.com
authors.forename: Praveen
authors.initials: P
authors.lastname: Ravishankaran
authors.forename: R
authors.initials: R
authors.lastname: Karunanithi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D002097:C-Reactive Protein / Q000378:metabolism*; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D012372:ROC Curve; D015996:Survival Rate
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D002097:C-Reactive Protein