MONITORING FOR ANTHRACYCLINE CARDIOTOXICITY

Objective. To review the basis for recommendations of the Cardiology C ommittee of the Children's Cancer Study Group, published in Pediatrics , for serial cardiac monitoring of cancer patients during anthracyclin e therapy and reduction of therapy should cardiac studies show abnorma lities. Design. Because the effects of overall morbidity and mortality should be considered when a recommendation is made to withhold potent ially lifesaving chemotherapy based on abnormal cardiac findings of pa tients without clinical evidence of cardiac dysfunction, supporting st udies referenced in the published recommendations were reviewed. Speci fically, studies were evaluated to determine whether a reduction in an thracycline dose, as a result of abnormal cardiac findings by monitori ng, reduced cardiac morbidity and related mortality compared with a pr ospectively followed control population without dose modification. In addition, the effects of cardiac monitoring and subsequent anthracycli ne dose modification on oncologic morbidity and mortality were reviewe d in these studies. Finally, the contributions of the cardiac and onco logic effects of dose modification were examined to determine the effe ct of this change in therapy on overall morbidity and mortality. Resul ts. None of the studies cited in developing these recommendations pros pectively determined, with controls, the effects of cardiac monitoring and anthracycline dose modification on cardiac, oncologic, or overall morbidity and mortality. Therefore, none of the studies cited in supp ort of cardiac monitoring and subsequent dose reduction demonstrated t he efficacy of such an approach. In the absence of such data, concerns are raised as to whether such a monitoring program with subsequent do se modification might do more harm than good. In addition, none of the methods of screening for anthracycline cardiotoxicity has been shown to be adequately predictive of early or late cardiac outcomes. Finally , adoption of these recommendations would inhibit the investigation of the efficacy of the proposed plan. Conclusion. Given the absence of s upportive data and the potential to do harm, no recommendation for dos e modification based on abnormal cardiac findings in patients without clinical evidence of cardiotoxicity can be endorsed, including those o f the Cardiology Committee of the Children's Cancer Study Group. When clinical evidence of cardiotoxicity is present, anthracycline dose mod ification is recommended. A prospective controlled study to determine the effects of dose modification based on cardiac test results is indi cated.