HYPOCALCEMIA ASSOCIATED WITH 5-FLUOROURACIL AND LOW-DOSE LEUCOVORIN IN PATIENTS WITH ADVANCED COLORECTAL OR GASTRIC CARCINOMAS

BACKGROUND. The biochemical modulation of 5-fluorouracil (5-FU) by leu covorin (LV) has demonstrated significantly increased response rates i n comparison with the use of 5-FU alone in patients with advanced colo rectal carcinoma. However, the higher response rate of LV/5-FU may occ ur at the expense of increased toxicity and side effects such as diarr hea, myelosuppression, and mucositis. During chemotherapy, a high inci dence of hypocalcemia associated with this chemotherapy regimen was no ted. This study was therefore aimed at assessing the side effects of c hemotherapy using low dose LV/5-FU on calcium metabolism. METHODS. Twe nty-five patients with advanced gastric or colorectal carcinoma were t reated with chemotherapy comprised of low dose LV administered at 20 m g/m(2)/day by intravenous bolus, followed by 1-hour intravenous infusi on of 5-FU at 425-600 mg/m(2)/day for 5 consecutive days every 28 days . RESULTS. The toxic effects were generally mild, and included diarrhe a, mucositis, leukopenia, and nausea/vomiting. Fifteen patients (65%) experienced hypocalcemia. The plasma 1,25-(OH)(2)D-3 levels were signi ficantly reduced on Day 5 due to the chemotherapy. CONCLUSIONS. The to xic effects of the regimen were generally mild. However, a high percen tage of hypocalcemia occurred with the combination of LV/5-FU. It is t herefore necessary to examine carefully the serum calcium levels of pa tients when using this chemotherapeutic modality. (C) 1996 American Ca ncer Society.