title: Association between salivary α-amylase activity and pain relief scale scores in cancer patients with bone metastases treated with radiotherapy.
abstract: BACKGROUND
  Subjective assessment tools such as visual analog scales (VAS) or pain scores are commonly used to evaluate the intensity of chronic cancer-induced pain. However, their value is limited in some cases. We measured changes in VAS pain scores and salivary α-amylase (sAA) concentrations in cancer patients receiving radiotherapy for bone metastases to ascertain the correlation between these measures.
  
  
  METHODS
  We enrolled 30 patients with bone metastases attending a single institution from June 2010 to March 2011. All patients with cancer-induced bone pain received radiation therapy (RT) at the same dose (30 Gy) and fractionation (3 Gy/fraction, 5 days/week) for palliative pain relief. We assessed heart rate (HR), systolic and diastolic blood pressures (DBP/SBP) and VAS pain scores before (d0) and after five (d5) and ten fractions (d10) of irradiation. sAA and salivary cortisol (SC) concentrations were measured using a portable analyzer and automated chemiluminescence analyzer, respectively.
  
  
  RESULTS
  Radiotherapy markedly decreased VAS scores from (82.93 ± 9.29) to (31.43 ± 16.73) mm (P < 0.001) and sAA concentrations from (109.40 ± 26.38) to (36.03 ± 19.40) U/ml (P <0.001). Moreover, there was a significant correlation between these two indices (P <0.01, r = 0.541). HR decreased by 6.5% after radiotherapy, but did not correlate with VAS scores (P >0.05). SC concentrations and BP did not change significantly during the study (P >0.05).
  
  
  CONCLUSIONS
  The significant correlation between sAA concentrations and VAS pain scores identified in these preliminary results suggests that this biomarker may be a valuable, noninvasive and sensitive index for the objective assessment of pain intensity in patients with cancer-induced bone pain.
authors.affiliation: Cancer Research Center, Qilu Hospital, Shandong University, Medical School of Shandong University, Jinan, Shandong 250012, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Wen-yan
authors.initials: WY
authors.lastname: Dong
authors.forename: Jian-bo
authors.initials: JB
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.forename: Shu-fang
authors.initials: SF
authors.lastname: Wei
authors.forename: Lin
authors.initials: L
authors.lastname: Ye
authors.forename: Qing-wei
authors.initials: QW
authors.lastname: Wang
mesh_terms: D000368:Aged; D001859:Bone Neoplasms / Q000201:enzymology* / Q000532:radiotherapy* / Q000556:secondary; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000201:enzymology / Q000532:radiotherapy*; D059408:Pain Management; D010147:Pain Measurement; D055291:Salivary alpha-Amylases / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D055291:Salivary alpha-Amylases