en Health Services, Quality of Life and Outcomes Original/Research Article <div style="text-align: justify;"><strong>Introduction: </strong>Anthracyclines are one of the classes of chemotherapy drugs that &nbsp;are widely used to treat many types of cancers including breast cancer. Taking this class of medications has a significant relationship with cardiac dysfunction. N-acetylcysteine has antioxidant properties and may be effective in preventing cardiac dysfunctions. In this study, we investigated the effect of N-acetylcysteine in preventing cardiotoxicity in breast cancer patients receiving anthracycline.<br> <strong>Methods: &nbsp;</strong>A &nbsp;total &nbsp;of &nbsp;60 &nbsp;breast &nbsp;cancer &nbsp;patients &nbsp;who &nbsp;underwent &nbsp;chemotherapy &nbsp;with anthracyclines were enrolled in the present case-control study and divided into two groups. The case group received 600 mg of N-acetylcysteine per day adjacent to chemotherapy; while &nbsp;the &nbsp;control &nbsp;group &nbsp;did &nbsp;not &nbsp;receive &nbsp;this &nbsp;medication. &nbsp;One &nbsp;month &nbsp;after &nbsp;the &nbsp;last chemotherapy session, troponin I was measured as a predictor of cardiotoxicity.<br> <strong>Results: </strong>Troponin I was positive in one patient in the case group compared with 3 patients in the control group without any significant difference among groups (P> 0.05) However, the respective mean&plusmn;SD level of troponin I was 0.120&plusmn;0.039 and 0.192&plusmn;0.063 in the case and control groups with a statistically significant difference among groups (P <0.001).<br> <strong>Conclusions: </strong>Administration of 600 mg N-acetylcysteine per day during the anthracycline- based chemotherapy protocol in breast cancer patients may reduce the mean troponin I levels which can be a prediction of reduced anthracyclines cardiotoxicity.</div> Anthracyclines, N-Acetylcysteine, Cardiotoxicity, Breast Cancer 16 19 http://mcijournal.com/browse.php?a_code=A-10-287-1&slc_lang=en&sid=1 Hamid Khazdooz Khazdooz@gmail.com 10031947532846002198 10031947532846002198 No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran Mahyar Nourian mahyarnourian1369@gmail.com 10031947532846002199 10031947532846002199 No Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Hasan Jalaeikhoo jalaeikhoo@gmail.com 10031947532846002200 10031947532846002200 No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran. Mohsen Rajaeinejad mrajaei@gmail.com 10031947532846002201 10031947532846002201 No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran. Adel Johari Moghadam 10031947532846002202 10031947532846002202 No 1 AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran Mostafa Iranpour m.iranpour@sbmu.ac.ir 10031947532846002203 10031947532846002203 No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran. Hamed Naghoosi naghoosi@ut.ac.ir 10031947532846002204 10031947532846002204 No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran. Shahnaz Tofangchiha stofangchiha@yahoo.com 10031947532846002205 10031947532846002205 Yes AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran.