title: Serum amyloid a as a predictive marker for radiation pneumonitis in lung cancer patients.
abstract: OBJECTIVE
  To investigate serum markers associated with radiation pneumonitis (RP) grade ≥3 in patients with lung cancer who were treated with radiation therapy.
  
  
  METHODS
  Pretreatment serum samples from patients with stage Ib-IV lung cancer who developed RP within 1 year after radiation therapy were analyzed to identify a proteome marker able to stratify patients prone to develop severe RP by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Dosimetric parameters and 3 biological factors were compared.
  
  
  RESULTS
  Serum samples from 16 patients (28%) with severe RP (grade 3-4) and 42 patients (72%) with no or mild RP (grade 0-2) were collected for analysis. All patients received a median of 54 Gy (range, 42-70 Gy) of three-dimensional conformal radiation therapy with a mean lung dose (MLD) of 1502 cGy (range, 700-2794 cGy). An m/z peak of 11,480 Da was identified by SELDI-TOF-MS, and serum amyloid A (SAA) was the primary splitter serum marker. The receiver operating characteristic area under the curve of SAA (0.94; 95% confidence interval [CI], 0.87-1.00) was higher than those of C-reactive protein (0.83; 95% CI, 0.72-0.94), interleukin-6 (0.79; 95% CI, 0.65-0.94), and MLD (0.57; 95% CI, 0.37-0.77). The best sensitivity and specificity of combined SAA and MLD for predicting RP were 88.9% and 96.0%, respectively.
  
  
  CONCLUSIONS
  Baseline SAA could be used as an auxiliary marker for predicting severe RP. Extreme care should be taken to limit the lung irradiation dose in patients with high SAA.
authors: Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors: Yu-Shan
authors: YS
authors: Wang
authors: Heng-Jui
authors: HJ
authors: Chang
authors: Yue-Cune
authors: YC
authors: Chang
authors: Su-Chen
authors: SC
authors: Huang
authors: Hui-Ling
authors: HL
authors: Ko
authors: Chih-Chia
authors: CC
authors: Chang
authors: Yu-Wung
authors: YW
authors: Yeh
authors: Jiunn-Song
authors: JS
authors: Jiang
authors: Cheng-Yen
authors: CY
authors: Lee
authors: Mau-Shin
authors: MS
authors: Chi
authors: Kwan-Hwa
authors: KH
authors: Chi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D017564:Radiation Pneumonitis / Q000175:diagnosis*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods; D000685:Serum Amyloid A Protein / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D015415:Biomarkers; D000685:Serum Amyloid A Protein