Predictive value of modeled AUC(AFP-hCG), a dynamic kinetic parameter characterizing serum tumor marker decline in patients with nonseminomatous germ cell tumor.

OBJECTIVE: The early decline profile of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) in patients with nonseminomatous germ cell tumors (NSGCT) treated with chemotherapy may be related to the risk of relapse. We assessed the predictive values of areas under the curve of hCG (AUC(hCG)) and AFP (AUC(AFP)) of modeled concentration-time equations on progression-free survival (PFS). METHODS: Single-center retrospective analysis of hCG and AFP time-points from 65 patients with IGCCCG intermediate-poor risk NSGCT treated with 4 cycles of bleomycin-etoposide-cisplatin (BEP). To determine AUC(hCG) and AUC(AFP) for D0-D42, AUCs for D0-D7 were calculated using the trapezoid rule and AUCs for D7-D42 were calculated using the mathematic integrals of equations modeled with NONMEM. Combining AUC(AFP) and AUC(hCG) enabled us to define 2 predictive groups: namely, patients with favorable and unfavorable AUC(AFP-hCG). Survival analyses and ROC curves assessed the predictive values of AUC(AFP-hCG) groups regarding progression-free survival (PFS) and compared them with those of half-life (HL) and time-to-normalization (TTN). RESULTS: Mono-exponential models best fit the patterns of marker decreases. Patients with a favorable AUC(AFP-hCG) had a significantly better PFS (100% vs 71.5%, P = .014). ROC curves confirmed the encouraging predictive accuracy of AUC(AFP-hCG) against HL or TTN regarding progression risk (ROC AUCs = 79.6 vs 71.9 and 70.2 respectively). Because of the large number of patients with missing data, multivariate analysis could not be performed. CONCLUSION: AUC(AFP-hCG) is a dynamic parameter characterizing tumor marker decline in patients with NSGCT during BEP treatment. Its value as a promising predictive factor should be validated.

Determination of cardiac troponin I forms in the blood of patients with unstable angina pectoris.

OBJECTIVE: To determine the predominant form in which cardiac troponin I circulates in the bloodstream of unstable angina patients. DESIGN AND METHODS: The cardiac troponin I forms released in the bloodstream of 25 patients suffering from unstable angina were examined by using three immunoenzymatic assays: the total cTnI assay for detection of free and complexed cTnI, the IC-TIC assay for detection of the IC and TIC troponin complexes, and the IT-TIC assay for detection of the IT and TIC troponin complexes. RESULTS: Approximately 60% of patients with unstable angina had at least one positive value in the total cTnI assay or in the IC-TIC assay. Our results demonstrated that the predominant cardiac troponin I form circulating in the bloodstream of patients with unstable angina was the IC complex. Free cTnI, IT, and/or TIC forms were seldom found, the frequency of IT and/or TIC complexes being higher than that observed previously in patients with acute myocardial infarction. CONCLUSIONS: The release pattern of cTnI in patients suffering from unstable angina is similar to that previously observed in patients with acute myocardial infarction, i.e., a predominance of the IC complex.