Utilization of cardiac monitoring tests in women with non-metastatic breast cancer treated with trastuzumab.

Aims: Trastuzumab, one of the best known examples of personalized medicine, requires regular cardiac monitoring because it can cause heart failure. We aimed to assess the utilization of cardiac monitoring in women with nonmetastatic breast cancer receiving trastuzumab-based chemotherapy in routine clinical practice.

Patients & methods: The medical records of women continuously enrolled in a large national health insurance plan who were diagnosed with nonmetastatic breast cancer and treated with trastuzumab from 2006 to 2008 were reviewed (n = 109). The primary outcome variables were the use and type of cardiac monitoring testing before and during trastuzumab therapy. An exploratory multivariable logistic regression analysis was performed to identify predictors for receiving cardiac monitoring both at baseline and during trastuzumab treatment.

Results: Monitoring both before and during therapy was less common (62%), although 74% had cardiac monitoring before therapy and 80% had at least one test during therapy. Radionuclide ventriculogram was utilized more often than echocardiography (48 vs 42%). Only the use of anthracycline (odds ratio: 2.39; 95% CI: 1.01-5.71) was significantly associated with use of a cardiac monitoring both at baseline and during trastuzumab treatment.

Conclusion: The use of cardiac monitoring testing was variable and opportunities to improve quality and reduce cost are evident. These results have clinical implications for other personalized medicine interventions requiring regular laboratory monitoring.