Phase I study of prolonged-infusion gemcitabine combined with cyclophosphamide in patients with metastatic carcinoma of the breast: tolerability of an optimal dose schedule.

BACKGROUND: A phase I study was initiated to determine the maximum tolerated dose (MTD) of prolonged-infusion gemcitabine combined with cyclophosphamide in patients with metastatic breast carcinoma (MBC). METHODS: Patients with MBC were treated with gemcitabine infusion at 10 mg/m2/min and cyclophosphamide by intravenous piggyback injection, 4 h after initiation of the infusion. We treated 3-6 patients at a particular dose level until the MTD was determined. RESULTS: Overall, 44 patients received a total of 197 courses of therapy. Both drugs were given on days 1, 8 and 15 to 14 patients (68 courses). Delayed white blood cell recovery necessitated first protocol amendment to drop cyclophosphamide on days 8 and 15 in 9 patients (43 cycles). A second amendment was needed to drop gemcitabine on day 15 because of thrombocytopenia in 21 patients (86 courses). The dose-limiting toxicity was thrombocytopenia. The MTD of an optimal dose schedule was 800 mg/m2 gemcitabine infused at a rate of 10 mg/m2/min on days 1 and 8, and 400 mg/m2 cyclophosphamide, by intravenous piggyback injection, on day 1, 4 h after initiation of the gemcitabine infusion. CONCLUSIONS: The MTD can be given safely every 4 weeks to patients with MBC. Phase II studies are warranted to evaluate the clinical activity of this therapy.

Immunoproliferative small intestinal disease: current concepts.

Immunoproliferative small intestinal disease is a distinctive lymphoproliferative disorder. Among these disorders, it is the only disease associated with a specific and characteristic abnormal protein, and also an identifiable, at least in some patients, early phase with a benign-looking histo-pathologic expression. Whether the disease at this stage is malignant or not is not known. Treatment of this early phase with antibiotics may cause remission in some patients. This observation is significant and raises the question of chemoprevention in lymphomas. In contrast to primary nonimmunoproliferative small intestinal lymphomas, in which the pathology in the intestine is usually focal and involving specific segments of the intestine and leaving the segments between the involved areas free of disease, the pathology in immunoproliferative small intestinal disease is diffuse, with a mucosal cellular infiltrate involving large segments of the intestine and sometimes the entire length of the intestine, thus producing malabsorption. Preliminary recent epidemiological data have shown a decrease in the incidence of this disease in endemic areas, and therefore environmental factors are suspected to play a major role in its pathogenesis. Additional research is indicated not only to understand this specific lymphoproliferative disorder but also to understand lymphomas in general.