Use of dexrazoxane as a cardioprotectant in patients receiving doxorubicin or epirubicin chemotherapy for the treatment of cancer. The Provincial Systemic Treatment Disease Site Group.

GUIDELINE QUESTIONS

1. Should dexrazoxane be used routinely in patients with advanced or metastatic cancer who are at risk of developing cardio toxicity when receiving chemotherapy containing doxorubicin or epirubicin? 2) Do the available data support the use of dexrazoxane when anthracyclines are being used in the adjuvant setting for patients at risk of developing cardiotoxicity?

OBJECTIVE

To make recommendations regarding the use of dexrazoxane to prevent cardiotoxicity in patients with nonhematological malignancies who are receiving anthracycline- containing chemotherapy.

OUTCOMES

Clinical and subclinical cardiotoxicity, noncardiac toxicity and impact on efficacy outcomes such as response and overall survival are considered.

PERSPECTIVE (VALUES): Evidence was selected, reviewed and synthesized by 2 members of Cancer Care Ontario's Systemic Treatment Disease Site Group (STDSG), formerly the Systemic Treatment Program Committee. Drafts of this document have been circulated and reviewed by members of the STDSG. The STDSG comprises medical oncologists, pharmacists, supportive care personnel and administrators. Community representatives did not participate in the development of this guideline, but they will be included in future guidelines.

QUALITY OF EVIDENCE

Seven randomized controlled trials (RCTs), 2 with placebo control, were available for analysis.

BENEFITS

Data for clinical cardiotoxicity from 6 trials were pooled (n = 1070). The meta-analysis indicated that the risk of experiencing clinical cardiotoxicity was significantly reduced by dexrazoxane (risk ratio 0.24; 95% confidence interval [CI] 0.11 to 0.52; p = 0.00031). There was no significant benefit shown in individual trials for objective response or survival.

HARMS

One of the RCTs revealed a significantly lower objective response rate in the dexrazoxane arm. However, a meta-analysis of objective response across 5 trials of breast cancer patients (n = 818) did not confirm this effect (odds ratio 0.85; 95% CI 0.61 to 1.18; p = 0.33). The use of dexrazoxane increased the incidence of myelosuppression and other noncardiac toxicities, but these were generally mild.

PRACTICE GUIDELINE

The evidence supports the use of dexrazoxane to provide protection against the cardiotoxicity associated with conventional-dose doxorubicin in patients with advanced but anthracycline-sensitive cancer, in whom the continued use of anthracycline-containing chemotherapy is indicated in the opinion of the treating physician and who have received 300 mg/m2 or more of doxorubicin. The evidence supports the use dexrazoxane to provide protection against the cardiotoxicity associated with conventional-dose epirubicin in patients with advanced but anthracycline-sensitive cancer, in whom the continued use of anthracycline-containing chemotherapy is indicated in the opinion of the treating physicians. There are no data indicating the optimal cumulative dose of epirubicin at which dexrazoxane should be instituted. For doxorubicin, use of dexrazoxane is recommended after the cumulative dose reaches 300 mg/m2 (i.e., 55% of the recommended maximum). A similar formula could be used for epirubicin, that is, institution of dexrazoxane when the cumulative dose of epirubicin reaches 550 mg/m2, as the recommended maximum cumulative dose in Canada is 1000 mg/m2. Preclinical studies did not show any cardioprotectant effect for dexrazoxane when used with mitoxantrone, and no clinical studies have been done. Therefore, dexrazoxane is not recommended for use with mitoxantrone. There is no evidence for or against the use of dexrazoxane in the adjuvant setting for any tumour type. Because of concerns that dexrazoxane may reduce the efficacy of anthracyclines, and because data are not yet available on long-term toxicities, further studies should be performed before the drug is used in this setting.