Phase II trial of cyclophosphamide, leucovorin, 5-fluorouracil 24-hour infusion and tamoxifen in pancreatic cancer.

Leucovorin modulates the cytotoxic effects of 5-fluorouracil (5-FU) in the treatment of cancer. 24-hour infusion of 5-FU has been shown to enhance antitumor activity in colorectal cancer compared to bolus infusion. According to experimental data cyclophosphamide and tamoxifen may enhance the effectiveness of leucovorin and 5-FU. A phase II trial was initiated to evaluate the effect of a combination of low-dose cyclophosphamide (C), leucovorin (L), 5-FU (F) and tamoxifen (T) (CLFT) in advanced pancreatic cancer. Fifty patients were treated monthly with 300 mg/m2 cyclophosphamide and weekly with 500 mg/m2 leucovorin followed by a 24-hour infusion of 2000 mg/m2 5-FU and tamoxifen 20 mg bid. Three patients had a partial response (6%), two a minor response (4%) and 32 (64%) no change of disease. The median survival time was 8.5 months for all patients, the median time to progression of disease was 4.6 months and the 1-year survival rate was 28%. CLFT was fairly well tolerated. These data suggest that biochemical modulation of 24-hour infusional 5-FU with leucovorin together with cyclophosphamide and tamoxifen has some positive effects in the treatment of pancreatic cancer.