Effect of fluoropyrimidines on delayed cutaneous hypersensitivity.

although recently paradoxical potentiation of antibody titers has been reported (11, 14). Cancer chemotherapists have been concerned for many years that the drugs used in treating cancer might suppress any host immunity to the tumor and actually hasten rather than retard its spread. It was for this reason that the present study was under taken. Briefly, the experimental design consisted of assessing delayed cutaneous hypersensitivity to various antigens in a series of cancer patients. These patients all had metastatic cancer and were given chemotherapy after the skin tests were read. At the termination of the course of drug therapy the tests were repeated. MATERIALS AND METHODS In every instance the patient was receiving his 1st course of the drug under study. All patients were in good general condition, without fever or acute illness, and none had been receiving corticosteroids. Radiotherapy had not been given nor surgery performed in the preceding month. Prior to initiation of chemotherapy, the subjects were skin tested with intermediate purified protein derivative (PPD) (0.001 mg), histoplasmin, and 1 : 100 dilution extracts of Candida albicans@ and trichophytin.4 At the end of therapy the patients were retested with antigens of the same lot, concentration, and volume, but at sites removed from the 1st series. In all instances skin tests were read at 48 hr. A reading of â€oepositive†• required induration of greater than 5 mm in diameter, with asso ciated erythema. Since patients with disseminated neoplasia have been shown to be relatively anergic (16), these 4 antigens were chosen with the expectation that most of the patients would react positively to at least 1. Anti-tumor drug therapy was initiated within 3 days after the reading of the 1st skin tests. Drug dosage was as follows : 5-fluoro-2'-deoxyuridine (FUDR) was given by rapid i.v. injection at a dosage of 30 mg/kg/day for 5 days, followed by doses of 15 mg/kg every other day until toxicity appeared. 5-Fluorouracil (5-FU) was administered in the same manner and schedule as FUDR, but at 12 and 6 mg/kg. When given by con tinuous intra-arterial infusion, the dosage of 15 mg/kg/day was used from 4 to 10 days. Cyclophosphamide was given in a schedule of 400 mg/day (rapid i.v. injection) for 6†" 8 days. Pactamycin,5 azotomycin, tubercidin, and hexamethylmelamine, all of which are currently under collaborative investigation, were given in dosages and schedules designed to produce mild cytotoxic manifesta tions. In …