Reversibility of trastuzumab-related cardiotoxicity: new insights based on clinical course and response to medical treatment.
OBJECTIVE
Trastuzumab is an important biologic agent with significant activity in breast cancers that overexpress the HER2/neu marker. However, trastuzumab is associated with cardiotoxicity that has not yet been fully explored. We present our experience with patients who developed trastuzumab-related cardiotoxicity.


METHODS
Over a 4-year period, 38 patients with HER2/neu-positive breast cancer were referred for suspected trastuzumab-related cardiotoxicity. All patients had previously received anthracycline-based chemotherapy. Results After doxorubicin but before trastuzumab, the mean (+/- standard deviation) left ventricular ejection fraction (LVEF) was 0.61 +/- 0.13, and the LVEF decreased to 0.43 +/- 0.16 after trastuzumab (P < .0001). After withdrawal of trastuzumab, the LVEF increased to 0.56 +/- 0.11. Mean time to recovery of LVEF was 1.5 months and was temporally associated with medical treatment in 32 (84%) of the 38 patients but occurred without treatment in six patients (16%). Increases in LVEF were noted in 37 of the 38 patients. Twenty-five of these patients were re-treated with trastuzumab; three patients had recurrent left ventricular dysfunction, but 22 patients (88%) did not. All re-treatment patients continued on their therapeutic regimen for heart failure when rechallenged with trastuzumab. Nine patients underwent endomyocardial biopsy. Ultrastructural changes were not seen.


CONCLUSIONS
Patients who develop cardiotoxicity while receiving trastuzumab therapy generally improve on removal of the agent. The mechanism of trastuzumab-related cardiac dysfunction is different from that of anthracycline cardiotoxicity, in part, demonstrated by the absence of anthracycline-like ultrastructural changes. Reintroducing trastuzumab may be appropriate for some individuals who previously have experienced trastuzumab-related cardiac dysfunction.
Ewer
Michael S
MS
Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, 77030, USA. mewer@mdanderson.org
Vooletich
Mary T
MT
Durand
Jean-Bernard
JB
Woods
Myrshia L
ML
Davis
Joseph R
JR
Valero
Vicente
V
Lenihan
Daniel J
DJ
D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000008:administration & dosage; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects*; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy*; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006321:Heart / Q000187:drug effects*; D006333:Heart Failure / Q000139:chemically induced* / Q000188:drug therapy; D006801:Humans; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D000068878:Trastuzumab; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced* / Q000188:drug therapy
D018943:Anthracyclines; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D004317:Doxorubicin; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab