Clinical value of combined determination of plasma L-DOPA/tyrosine ratio, S100B, MIA and LDH in melanoma.
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.
Garnier
Jean-Pierre
JP
Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris V, France.
Letellier
Sabine
S
Cassinat
Bruno
B
Lebbé
Celeste
C
Kerob
Delphine
D
Baccard
Michel
M
Morel
Patrice
P
Basset-Seguin
Nicole
N
Dubertret
Louis
L
Bousquet
Bernard
B
Stoitchkov
Konstantin
K
Le Bricon
Thierry
T
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
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C074879:MIA antigen, human; D009418:S100 Proteins; D014443:Tyrosine; D007980:Levodopa