A B S T R A C T PurposeCumulative sensory neurotoxicity (sNT) is the dose-limiting toxicity of oxaliplatin, which commonly leads to early discontinuation of oxaliplatin-based therapy in the palliative and adjuvant settings. In a nonrandomized, retrospective study, intravenous (IV) calcium/magnesium (Ca/Mg) was associated with reduced oxaliplatin-induced sNT. MethodsPatients with colon cancer undergoing adjuvant therapy with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) were randomly assigned to Ca/Mg (1g calcium gluconate plus 1g magnesium sulfate pre-and post-oxaliplatin) or placebo, in a double-blinded manner. The primary end point was the percentage of patients with grade 2 or greater sNT at any time during or after oxaliplatin-based therapy by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE; version 3) criteria. An oxaliplatin-specific sNT scale and patient questionnaires were also used to assess sNT. After 104 of 300 planned patients were enrolled, the study was closed. This was due to preliminary reports from another trial that suggested that Ca/Mg decreased treatment efficacy; these data were subsequently found to be incorrect. ResultsOverall, 102 patients were available for analysis. Ca/Mg decreased the incidence of chronic, cumulative, grade 2 or greater sNT, as measured by NCI CTCAE (P ϭ .038) and also by the oxaliplatin-specific sNT scale (P ϭ .018). In addition, acute muscle spasms associated with oxaliplatin were significantly reduced (P ϭ .01) No effect on acute, cold-induced sNT was found. No substantial differences in adverse effects were noted between Ca/Mg and placebo. ConclusionDespite early termination and decreased statistical power, this study supports IV Ca/Mg as an effective neuroprotectant against oxaliplatin-induced cumulative sNT in adjuvant colon cancer.

Postmenopausal women with breast cancer (BC) are at increased risk for bone loss. Bisphosphonates improve bone mineral density (BMD) in normal postmenopausal women. The purpose of this study was to determine if immediate treatment with zoledronic acid preserves BMD in postmenopausal women with BC starting letrozole after tamoxifen. Postmenopausal women with BC completing tamoxifen were treated with daily letrozole 2.5 mg/vitamin D 400 I.U., calcium 500 mg twice daily and were randomized to upfront or delayed zoledronic acid 4 mg every 6 months. Patients in the delayed arm were only given zoledronic acid if they developed a post-baseline BMD T score <−2.0 or had a fracture. The primary endpoint was the mean percent change in lumbar spine (LS) BMD at 1 year. About 558 women enrolled; 395 provided 1 year BMD data. The upfront arm experienced a mean change of +3.66% in LS BMD versus -1.66% for the delayed group (P < 0.001). Changes at the femoral neck/total hip were also greater for the upfront versus delayed arms (P < 0.001; P < 0.001) with differences persisting at 2 years. Patients in the delayed arm were more likely to experience a clinically meaningful 5% loss of BMD at all sites versus the upfront zoledronate group. Patients in the upfront arm were slightly more likely to report limb edema, fatigue, fever, nausea and jaw osteonecrosis(1%). Upfront zoledronic acid prevents bone loss in postmenopausal women with BC starting letrozole after tamoxifen.