title: Clinical value of combined determination of plasma L-DOPA/tyrosine ratio, S100B, MIA and LDH in melanoma.
abstract: OBJECTIVE
  L-DOPA/tyrosine ratio (an index of tyrosinase activity), melanoma antigens S100B and MIA, lactate deshydrogenase (LDH) and their combinations were evaluated for clinical value as tumour markers in melanoma.
  
  
  METHODS
  Blood samples were obtained in 170 melanoma patients (stage I-II: n=57, III: n=54, IV: n=59) at inclusion and in a sub-group of 82 subjects during follow-up for up to 4 years. Laboratory analyses were performed by HPLC (L-DOPA, L-tyrosine), immunoassays (S100B, MIA) and colourimetry (LDH).
  
  
  RESULTS
  All markers, except LDH, were elevated in stage IV versus other stages. S100B and MIA highly correlated, especially in stage IV (r(s): 0.849, p<0.001). The combination of L-DOPA/tyrosine ratio with S100B displayed the highest sensitivity/specificity (73/70%) to confirm stage III-IV or stage IV alone (69/75%) (ROC optimised cut-off). Only the L-DOPA/tyrosine ratio significantly increased (+36% over 5 months, p=0.001) during progression from stage I-III to higher stages. S100B, MIA and LDH, but not the L-DOPA/tyrosine ratio, responded to progression towards death in stage IV. All markers exhibited a prognostic value in deceased patients (n=44); S100B and MIA were the best predictors of survival time by Cox proportional-hazards regression.
  
  
  CONCLUSIONS
  The combination of plasma L-DOPA/tyrosine ratio and S100B appears an attractive approach for the biological follow-up of melanoma patients.
authors.affiliation: Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris V, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Garnier
authors.forename: Sabine
authors.initials: S
authors.lastname: Letellier
authors.forename: Bruno
authors.initials: B
authors.lastname: Cassinat
authors.forename: Celeste
authors.initials: C
authors.lastname: Lebbé
authors.forename: Delphine
authors.initials: D
authors.lastname: Kerob
authors.forename: Michel
authors.initials: M
authors.lastname: Baccard
authors.forename: Patrice
authors.initials: P
authors.lastname: Morel
authors.forename: Nicole
authors.initials: N
authors.lastname: Basset-Seguin
authors.forename: Louis
authors.initials: L
authors.lastname: Dubertret
authors.forename: Bernard
authors.initials: B
authors.lastname: Bousquet
authors.forename: Konstantin
authors.initials: K
authors.lastname: Stoitchkov
authors.forename: Thierry
authors.initials: T
authors.lastname: Le Bricon
mesh_terms: D000368:Aged; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000378:metabolism; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000401:mortality; D008875:Middle Aged; D011446:Prospective Studies; D009418:S100 Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000401:mortality; D016019:Survival Analysis; D014443:Tyrosine / Q000378:metabolism
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C074879:MIA antigen, human; D009418:S100 Proteins; D014443:Tyrosine; D007980:Levodopa