title: Hypercalcemia: a dose-limiting toxicity associated with 13-cis-retinoic acid.
abstract: OBJECTIVE
  13-cis-Retinoic acid (cis-RA) has efficacy in the treatment and prevention of certain malignancies. In vitro effects against neuroblastoma include induction of differentiation, inhibition of proliferation, and decreased N-myc expression. We hypothesized that cis-RA may be effective against minimal residual disease in neuroblastoma patients. A phase I trial to determine the maximal tolerated dosage and toxicity of cis-RA in pediatric patients with neuroblastoma after bone marrow transplantation was initiated.
  
  
  METHODS
  Forty-nine pediatric patients (status post-bone marrow transplant for neuroblastoma) were treated for 14 days with oral cis-RA in escalating doses from 100 to 200 mg/m2/day followed by a 14-day rest period for up to 12 months.
  
  
  RESULTS
  In three of 39 patients (7.7%) evaluable for calcium levels, hypercalcemia (12.6-18.7 mg/dl) was the dose-limiting toxicity. Grade 1-3 hypercalcemia occurred in nine of 39 patients (23%). The overall incidence of hypercalcemia was 31% (12 of 39). Only one patient was symptomatic due to the hypercalcemia, with arthralgias and myalgias. The hypercalcemia resolved with temporary discontinuation of the drug and a 25% dose reduction for subsequent courses.
  
  
  CONCLUSIONS
  Hypercalcemia is a novel dose-limiting toxicity for cis-RA. Patients receiving high doses of cis-RA should have monitoring of serum calcium levels.
authors.affiliation: Department of Pediatrics, Childrens Hospital Los Angeles, CA 90027-6016.
authors.forename: J G
authors.initials: JG
authors.lastname: Villablanca
authors.forename: A A
authors.initials: AA
authors.lastname: Khan
authors.forename: V I
authors.initials: VI
authors.lastname: Avramis
authors.forename: C P
authors.initials: CP
authors.lastname: Reynolds
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects / Q000097:blood / Q000633:toxicity*; D016026:Bone Marrow Transplantation; D002118:Calcium / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000139:chemically induced*; D015474:Isotretinoin / Q000009:adverse effects / Q000097:blood / Q000633:toxicity*; D009447:Neuroblastoma / Q000188:drug therapy* / Q000517:prevention & control / Q000601:surgery
chemical_list: D000970:Antineoplastic Agents; D015474:Isotretinoin; D002118:Calcium