Randomized double-blind prospective trial to evaluate the effects of sargramostim versus placebo in a moderate-dose fluorouracil, doxorubicin, and cyclophosphamide adjuvant chemotherapy program for stage II and III breast cancer.

PURPOSE: To determine the effects of sargramostim (recombinant human granulocyte-macrophage colony-stimulating factor [rhu GM-CSF]) on the incidence, duration, and complications of myelosuppression after moderate-dose fluorouracil, doxorubicin, cyclophosphamide (FAC) adjuvant chemotherapy in patients with node-positive breast cancer. PATIENTS AND METHODS: In this randomized, double-blind, placebo-controlled study, 142 women with stage II and III breast cancer were to receive four 21-day cycles of chemotherapy that consisted of fluorouracil 600 mg/ m2 intravenously (IV), doxorubicin 60 mg/m2 IV, and cyclophosphamide 750 mg/m2 IV on day 1, followed by placebo or GM-CSF 250 micrograms/m2/d daily subcutaneously (SC) on days 3 through 15. All patients received prophylactic ciprofloxacin by mouth when the absolute neutrophil count (ANC) was less than 1,000/microL. RESULTS: Eighty-six percent of GM-CSF patients (n = 62) and 96% of placebo patients (n = 69) completed four assessable cycles of treatment on study. Overall, the median duration of severe neutropenia (ANC < 500/microL) was 2.8 days with GM-CSF and 6.8 days with placebo (P < .001); the duration of ANC less than 1,000/microL was 6.0 versus 9.1 days, respectively (P < .001). Hospitalizations for febrile neutropenia were uncommon in either group: GM-CSF, six; placebo, eight. The only other difference in hematologic toxicity was grade 3/4 thrombocytopenia observed with greater frequency in GM-CSF patients than placebo patients in cycles 3 and 4. GM-CSF increased mean the FAC dose-intensity among patients who completed two or more cycles (P < .001). GM-CSF was generally well tolerated and associated with more injection-site reactions, but less mucositis than placebo. There were no deaths on study. CONCLUSION: GM-CSF significantly enhanced ANC recovery after FAC chemotherapy; it decreased the incidence and duration of associated neutropenia and moderately increased the dose-intensity of adjuvant chemotherapy. Whether these effects will ultimately translate into improved long-term outcome remains to be determined.

Transcriptional regulation of transferrin receptor expression by cultured lymphoblastoid T cells treated with phorbol diesters.

Expression of transferrin receptors (TFR) is required for lymphocyte proliferation. Treatment of lymphoblastic leukemia cell lines with phorbol diester tumor promoters decreases proliferation and induces differentiation. Among changes induced by phorbol diesters is decreased cell surface expression of TFR. To elucidate effects of phorbols on lymphocyte growth and differentiation, we examined TFR expression by measuring 125I-transferrin binding, levels of TFR mRNA by Northern analysis and dot-blot hybridization, and rates of TFR gene transcription by nuclear run-on experiments in CCRF-CEM lymphoblastoid T cells treated with PMA or phorbol dibutyrate. Cell surface expression of TFR was decreased 60 to 85% within 2 min of exposing cells to phorbols and remained decreased for 96 h. Steady state levels of TFR mRNA decreased to less than 30% of control after 48 h. After treating cells with actinomycin D, estimated TFR mRNA t 1/2 was 2.7 h and was unaltered in phorbol-treated cells. Levels of TFR mRNA were not affected by treatment of cells with cycloheximide in either control or phorbol-treated cells. Therefore, post transcriptional mRNA processing by protein factors did not account for decreased TFR mRNA in phorbol-treated cells. Compared to baseline levels, rates of TFR gene transcription in PMA-treated cells increased up to two-fold during the initial 6 h of culture, then decreased over the ensuing 12 h to less than 10% of baseline values. This pattern was not seen in control cultures. Therefore, regulation of TFR gene transcription is a consequence of treating CEM cells with phorbol diesters. Cell surface expression of TFR in phorbol-treated lymphoblastoid T cells may be mediated in part at the level of gene transcription.

A phase I trial of trimetrexate (NSC352122) on a daily x 5 schedule in patients with refractory adult leukemia.

Seven adult patients with refractory acute leukemia were administered trimetrexate (TMTX), a non-classical folate antagonist, in a phase I trial. TMTX was administered as an intravenous bolus for five consecutive days at doses of 9-12 mg/m2 based on marrow response. The maximum tolerated dose was 12 mg/m2. Hepatotoxicity was the dose-limiting toxicity. Initial dosage reductions in patients with liver disease and/or low protein concentrations may be necessary since TMTX is significantly protein bound and cleared primarily by hepatic metabolism. The recommended phase II dose on this dosing schedule is 9 mg/m2.