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Serum cardiac troponin T levels during treatment of early-stage breast cancer.

PURPOSE
To measure serum troponin T concentrations in patients with early-stage left breast cancer during breast-conserving radiation therapy. Troponin T has been introduced recently as a sensitive and specific marker for acute myocardial injury.


PATIENTS AND METHODS
We compared pretreatment and posttreatment serum troponin T values in 50 patients undergoing radiation therapy to the entire left breast following conservative surgery for stage I and II breast cancer.


RESULTS
No changes in troponin T concentrations were found after 45 to 46 Gy whole-breast irradiation. All women had undetectable or normal troponin T on the first and last day of treatment. There was no evidence of an upward trend during treatment.


CONCLUSION
Radiation therapy to the left breast does not affect serum cardiac troponin T levels, despite the fact that a portion of the myocardium lies within the high-dose region. This suggests that the acute effects of radiation on the myocardium are minor. Long-term evaluation of these patients is necessary to rule out the possibility of late cardiac morbidity due to accelerated atherosclerosis. This study also suggests that an elevated troponin T level during or shortly after left breast irradiation should not be attributed to treatment.