Tumor-tissue and plasma concentrations of platinum during chemotherapy of non-small-cell lung cancer patients.

Tumor-tissue and plasma concentrations of platinum were studied prospectively in two groups of eight patients who were suffering from advanced non-small-cell lung cancer. Treatments including two different schedules of cisplatin administration (25 vs 100 mg/m2 on day 1) were compared. At 30 min after the beginning of the cisplatin infusion, blood samples and bronchoscopically obtained biopsy specimens were taken for determinations of platinum concentrations by means of flameless atomic absorption spectrophotometry. The procedure did not induce any complication. Total plasma platinum concentrations at 30 min were significantly lower (P less than 0.01) in patients receiving 25 mg/m2 (0.49 +/- 0.23 microgram Pt/ml) than in those receiving 100 mg/m2 (1.44 +/- 0.62 micrograms Pt/ml), whereas no significant difference was observed in tumor-tissue platinum concentrations (22.49 +/- 53.89 ng Pt/mg in patients receiving 25 mg/m2 vs 51.13 +/- 65.52 ng Pt/mg in those receiving 100 mg/m2). There was a weak correlation between simultaneous plasma and tumor-tissue platinum concentrations at 30 min. Tumor-tissue platinum concentrations seem to be poorly influenced by the cisplatin dose. This finding suggests a great interindividual variability of platinum tumor-diffusion properties in non-small-cell lung cancer.