Study of CoQ10 During One Cycle of Doxorubicin Treatment for Breast Cancer

Inclusion Criteria: * Diagnosis of early stage breast cancer (stage I, II, or III); * Scheduled to receive at least four rounds of dose dense doxorubicin therapy in the neoadjuvant or adjuvant setting; * No other history of prior chemotherapy, radiation, or hormonal therapy in the previous 5 years; * For women receiving adjuvant therapy, single lumen implanted venous access device (i.e. single port) for unilateral cancer and double lumen implanted venous access device (i.e. double port) for bilateral breast cancer * Age 21 years or older; * ECOG performance status ≤ 2 (Karnofsky \> 60%); * Normal organ and marrow function defined as: Leukocytes ≥ 3,000/uL, Absolute neutrophils count (ANC) ≥ 1,500/uL at baseline, Platelets ≥ 100,000/uL, Total bilirubin ≤ 1.5 X normal institutional limits, AST (SGOT)/ALT (SGPT) ≤ 2.5 X institutional ULN, Serum creatinine within normal institutional limits; * Left ventricular ejection fraction \> 55%; * No history of CoQ10 supplement use within 30 days of initiating study drug; * No uncontrolled or significant co-morbid illness; * Not pregnant, not breastfeeding, and not planning on becoming pregnant during the course of the study; * Willingness to comply with all study intervention and follow-up procedures; * Ability to speak English or Spanish; and * Ability to provide informed consent. Exclusion Criteria: * Inability to understand or an unwillingness to sign a written informed consent document; * Any significant toxic side effects related to first or second dose of doxorubicin/cyclophosphamide chemotherapy or biologic therapy that did not resolve to less than a CTCAE 3.0 grade 3 non-hematological toxicity; * Currently using any investigational agent; * Unstable or severe intercurrent medical condition that, in the opinion of the investigator, might interfere with the participant's ability to follow the protocol or achieve study objectives; * Psychological or sociological conditions, addictive disorders, or family problems that would preclude adherence with study drug or compliance with the protocol * Women who report pregnancy, are breast feeding, or have a positive pregnancy test; * Use of CoQ10 supplement use within 30 days of initiating study drug; * Use of over-the-counter nutritional vitamin greater than 5x RDA; * Fish allergy (due to fish-based softgel shell); * Currently taking FDA cardioprotective drugs, such as Zinecard (dexrazoxane); * History of chronic hepatitis B, hepatitis C, and HIV infection; * Problems swallowing oral medications due to prolonged emesis, mucositis, esophageal dysfunction, etc.; and, * Currently taking any form of antioxidant supplements while on study. * Use of warfarin. * Kosher (due to fish-based softgel shell) * Dietary restriction of tilapia (due to tilapia fish-based softgel shell) * Titanium Dioxide allergy (due to the opaque coloring used in the softgel).