Methotrexate (MTX) is a folate analog competitive with reduced folates for cellular transport and metabolism. Since the normal plasma folate concentration is only 10-8M, we tested the possibility that there may be a saturable uptake of MTX by proliferating tumor tissue at plasma MTX concentrations of only 10-7 to 10-6M. Patients with advanced malignancies, refractory to accepted therapy, were given low-dose oral MTX (30-60 mg/m2 total dose in four to eight divided doses). Tumor tissue was biopsied 18-24 h after the last oral dose of MTX. The concentrations of MTX and its polyglutamated derivatives were measured in these samples. Forty-eight percent of the drug in the tumor samples was present as a polyglutamated derivative.
|Original language||English (US)|
|Number of pages||3|
|Journal||Cancer Chemotherapy and Pharmacology|
|State||Published - Aug 1 1987|
ASJC Scopus subject areas
- Cancer Research
- Pharmacology (medical)