title: Identification of a novel marker associated with risk for delayed chemotherapy-induced vomiting.
abstract: OBJECTIVE
  Besides chemotherapy drugs, a number of patient-related factors (i.e., gender, age, history of alcohol consumption, and/or motion sickness) may be used to calculate the risk for chemotherapy-induced vomiting. We evaluated data with the intent of identifying a unique variable associated with delayed vomiting in patients receiving moderately emetogenic chemotherapy (MEC).
  
  
  METHODS
  From an ongoing research study, the serotonin metabolite, 5-hydroxyindole acetic acid (5-HIAA), creatinine, and substance P were measured over a 72-h period in 25 patients receiving MEC. All patients were treated with a 5-hydroxytryptamine-3 receptor antagonist plus dexamethasone according to published guidelines; none received aprepitant prophylactically. Urine 5-HIAA/creatinine and serum substance P values were grouped according to the development (+) or absence (-) of delayed emesis. Baseline mean values associated with the two neurotransmitters were analyzed by analysis of variance.
  
  
  RESULTS
  Eleven patients developed moderate to severe delayed vomiting; the other 14 were symptom-free. The pretreatment log (mean 5-HIAA/creatinine) was 1.22 and 1.81 in the (+) and (-) emesis groups, respectively, p = 0.0049; the pretreatment log (mean substance P) for the same respective groups was 5.33 and 4.09 pg/mL, p > 0.05. The log (mean ratio of substance P to 5-HIAA/creatinine) between-group difference in those with and without emesis was 4.53 and 2.52, respectively, p = 0.0002. The 5-HIAA/creatinine and ratio of substance P to 5-HIAA/creatinine data were also used to determine cutoff points which resulted in the optimal predictive accuracy.
  
  
  CONCLUSIONS
  These preliminary findings suggest that an elevated pretreatment ratio of substance P to 5-HIAA/creatinine >70 is associated with the development of delayed vomiting induced by MEC.
authors.affiliation: Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV, USA. ghiga@hsc.wvu.edu
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Higa
authors.forename: Miklos L
authors.initials: ML
authors.lastname: Auber
authors.forename: Gerry
authors.initials: G
authors.lastname: Hobbs
mesh_terms: D000328:Adult; D000368:Aged; D000932:Antiemetics / Q000008:administration & dosage / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016022:Case-Control Studies; D003404:Creatinine / Q000652:urine*; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy; D011237:Predictive Value of Tests; D058831:Serotonin 5-HT3 Receptor Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D012720:Severity of Illness Index; D013373:Substance P / Q000097:blood*; D013997:Time Factors; D014839:Vomiting / Q000139:chemically induced* / Q000188:drug therapy
chemical_list: D000932:Antiemetics; D000970:Antineoplastic Agents; D015415:Biomarkers; D058831:Serotonin 5-HT3 Receptor Antagonists; D013373:Substance P; D006897:Hydroxyindoleacetic Acid; D003907:Dexamethasone; D003404:Creatinine