Outcome of intravenous calcium and magnesium (Ca/Mg) in oxaliplatin-containing regimens compared with no Ca/Mg.

Abstract

e19681 Background: Peripheral neuropathy (PN) is a cumulative toxicity of oxaliplatin (OX). Retrospective studies have reported that Ca/Mg infusions may reduce the incidence of PN and may allow patients to be treated without dose reductions for a longer duration. The objectives of this study were to retrospectively evaluate the effect of Ca/Mg on the number of treatment cycles, duration of OX therapy, cumulative OX dose, and progression free survival (PFS) in a large university-based practice. Methods: 149 patients treated with OX-containing regimens were retrospectively reviewed for co-administration of Ca/Mg infusions. Ca/Mg was given as 1 gm CaCl2 and 1 gm MgSO4 in 100 ml of IV solution over 30 min pre and post OX. Treatment assignment was at physician discretion. Patients were divided into groups based on histology, stage, and whether Ca/Mg was given. Patients in the “no Ca/Mg” group never received this treatment. All data were retrieved from the YCC EMR and reviewed by the authors. Patients were treated between 5/12/03 and 9/25/09. Results: 149 records were reviewed including 106 with Ca/Mg and 43 without. In patients with stage IV CRC, the Ca/Mg group (n=22) was associated with a statistically significant increased PFS (8.5 vs 4.6 months p=0.0394) compared to those not given Ca/Mg (n=13). There was a trend towards improved treatment duration (5.8 vs 3.8 months p=0.1065), cycles given (10.9 vs 7.8 cycles p=0.173), and total OX dose (677.5 vs 306.2 mg/m2 p=0.1366). In the adjuvant CRC setting, the Ca/Mg group (n=27) also showed a statistically significant improvement in PFS (36.3 vs. 22.8 months p=0.0445) compared to those not given Ca/Mg (n=10). Comparison of these adjuvant groups showed no statistical differences in total OX dose, duration of tx, or total tx cycles. Conclusions: In this retrospective chart review of patients treated with oxaliplatin-based chemotherapy, use of IV Ca/Mg showed a statistically significant increase in PFS in patients with CRC in both the adjuvant and metastatic settings. Despite the limited sample size and statistical power, significance and trends support the use of Ca/Mg to reduce the impact of PN, without signs of interfering with oxaliplatin anti-tumor activity.