A clinical study of 5-fluorouracil.

The impor tance of several pyr imidines in nucleic acid metabo l i sm has made the invest igat ion of their chemical analogs of interest to cancer chemotherapy. Recent ly , Heidelberger and coworkers (3) synthesized a group of f luorinated pyr imidines and pyr imid ine precursors which have been shown to have an t i tumor ac t iv i ty in several an imal tumor systems. M c I v e r (6) et al. studied 5-fluorouracil (FU) clinically and observed severe leukopenia, th rombocytopen ia , and gastrointest ina l side effects in several patients. Curreri and his associates (2) also reported a few pat ients whose tumors decreased in size following the admin is t ra t ion of FU. Because of the interest in th i s class of compounds, a pharmacologic s tudy of F U in m a n was under t aken in pat ients wi th advanced neoplasia in an a t t empt to find a sui table dosage schedule by which one migh t inh ib i t tumor growth in m a n with m i n i m a l toxicity. The results in regard to toxic mani fes ta t ions and an t i tumor ac t iv i ty are reported here.