title: Tumor interstitial fluid and postoperative recurrence of tumors: An experimental study for verifying hypothesis of "tumor-phlegm microenvironment".
abstract: OBJECTIVE
  To explore a method of extracting tumor interstitial fluid (TIF) which is similar to muddy phlegm in Chinese medicine (CM), interleukin-8 (IL-8) in concentration was taken as the representative of the content of TIF, analyzed in the extracted TIF and the original tumor tissue, and examined to see whether TIF has an interfering effect on tumor recurrence.
  
  
  METHODS
  Tumor tissue was ground, centrifuged, and filtered for intercellular substances. Tumor-bearing Kunming S180 mice were raised for 21 days and then the tumors were removed to observe the influence of intervention with TIF, normal saline (NS) and a blank control on tumor recurrence.
  
  
  RESULTS
  The content of IL-8 in the filtered and unfiltered tumor tissue was not significantly different (P>0.05). Postoperative tumor recurrence in TIF intervention group was significantly higher than that in the NS intervention and control groups (60%, 12/20 vs. 20%, 4/20. vs. 15%, 3/20, χ(2) =11.058, P<0.01). Tumor cells grew vigorously and infiltrated to muscular tissue in TIF intervention group. Large numbers of tumor cells were seen necrotic in the NS intervention group, and small numbers of tumor cells were seen necrotic in the blank control group.
  
  
  CONCLUSIONS
  TIF can be effectively extracted by the means described. It does not contain tumor cells, but its contents such as IL-8 may stimulate tumor cell growth and promote postoperative tumor recurrence, which provided preliminary experimental basis for hypothesis of "tumor-phlegm microenvironment".
authors.affiliation: Department of Traditional Chinese Medicine, Shanghai Changzheng Hospital, the Second Military Medical University, China.
authors.forename: Da-zhi
authors.initials: DZ
authors.lastname: Sun
authors.forename: Da-wei
authors.initials: DW
authors.lastname: Ju
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.forename: Ye
authors.initials: Y
authors.lastname: Lu
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Chang
authors.initials: C
authors.lastname: Li
authors.forename: Pin-kang
authors.initials: PK
authors.lastname: Wei
mesh_terms: D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D045604:Extracellular Fluid; D016209:Interleukin-8 / Q000032:analysis; D051379:Mice; D009374:Neoplasms, Experimental / Q000473:pathology*; D011184:Postoperative Period; D012008:Recurrence
chemical_list: D016209:Interleukin-8