SERUM TROPONIN-T LEVELS DURING TREATMENT OF EARLY-STAGE BREAST-CANCER

Purpose: To measure serum troponin T concentrations in patients with e arly-stage left breast cancer during breast-conserving radiation thera py. Troponin T has been introduced recently as a sensitive and specifi c marker for acute myocardial injury. Patients and Methods: We compare d pretreatment and posttreatment serum troponin T values in 50 patient s undergoing radiation therapy to the entire left breast following con servative surgery for stage I and II breast cancer. Results: No change s in troponin T concentrations were found after 45 to 46 Gy whole-brea st irradiation. All women had undetectable or normal troponin T on the first and last day of treatment. There was no evidence of an upward t rend during treatment. Conclusion: Radiation therapy to the left breas t does nor affect serum cardiac troponin T levels, despite the fact th at a portion of the myocardium lies within the high-dose region. This suggests that the acute effects of radiation on the myocardium are min or. Long-term evaluation of these patients is necessary to rule out th e possibility of late cardiac morbidity due to accelerated atheroscler osis, This study also suggests that an elevated troponin T level durin g or shortly after left breast irradiation should not be attributed to treatment. (C) 1995 by American Society of Clinical Oncology.