ABSTRACT

Damage to the mitochondria may lead to serious conditions that are difficult to treat. Doxorubicin is one of the most widely used chemotherapeutic drugs for the treatment of malignancies in children and adults, and reportedly causes damage to the mitochondria. Unfortunately, the dangerous cardiac side effects of doxorubicin appear when the patient is in the midst of a vigorous fight against the disease, either by taking doxorubicin alone or in combination with other drugs. This study aimed to determine whether exogenous healthy and functional mitochondria are internalized by cells, can it help the survival of these cells, and can reduce cardiotoxicity. For this purpose, isolated, pure, and functional exogenous mitochondria were injected into the tail vein of a rat model of doxorubicin-induced cardiotoxicity. After that, the heart function of the rats and their antioxidant status, inflammatory markers, and histopathological examination were investigated. Our findings show that intravenous mitochondrial transplantation provided efficient mitochondrial uptake and reduced cardiotoxicity by reducing ROS production, lipid peroxidation, and inflammation. In addition, the levels of ATP and antioxidant enzymes increased after mitochondrial transplantation; therefore all of these complex processes resulted in the reduction of apoptosis and necrosis in rat heart tissue. These promising results open the way to more effective cancer treatment without the side effects of related drugs. Transplanting exogenous mitochondria probably enhances the cell's mitochondrial network, potentially treating mitochondria-related disorders such as cardiovascular and neurodegenerative diseases, although the exact relationship between mitochondrial damage and these conditions remains unclear.

PMID:37812888 | DOI:10.1016/j.biopha.2023.115651

20:10

PubMed articles on: Cardio-Oncology

Cardiac Safety of Pegylated Liposomal Doxorubicin After Conventional Doxorubicin Exposure in Patients With Sarcoma and Breast Cancer

Cureus. 2023 Sep 7;15(9):e44837. doi: 10.7759/cureus.44837. eCollection 2023 Sep.

ABSTRACT

BACKGROUND: Lifetime cumulative doses of conventional doxorubicin (>450 mg/m2) are associated with dose-dependent cardiotoxicity. In sarcoma and breast cancer, conventional doxorubicin is often utilized in the adjuvant setting, whereas pegylated liposomal doxorubicin (PLD) is typically reserved for recurrent and metastatic disease. PLD is believed to be associated with reduced cardiotoxicity compared to conventional doxorubicin. Limited data exists evaluating the cardiotoxicity associated with PLD treatment after conventional doxorubicin, especially when doxorubicin lifetime doses approach the established cumulative total lifetime dose of 450-550 mg/m2. This study aims to further qualify the cardiac safety of PLD use in patients who have had prior exposure to conventional doxorubicin.

METHODS: This was a single-center, observational, retrospective cohort study conducted in patients ≥18 years with sarcoma or breast cancer who were exposed to conventional doxorubicin from an earlier line of treatment before PLD between January 2010 to May 2022. Patients were evaluated for the presence of cardiac toxicity at any point in their treatment course. Cardiac toxicity was defined as ≥ 10% decrease in left ventricle ejection fraction (LVEF) or a new diagnosis of heart failure within six months after PLD cessation. The time interval between the last conventional doxorubicin exposure and PLD initiation and the time interval between PLD initiation and LVEF monitoring were also analyzed.

RESULTS: 494 patients were screened, and 50 met inclusion criteria: eight with sarcoma and 42 with breast cancer. The median lifetime cumulative conventional doxorubicin dose in patients with sarcoma was 450 mg/m2 with a maximum dose of 825 mg/m2 and 240 mg/m2 with a maximum dose of 300 mg/m2 in breast cancer patients. The median lifetime cumulative PLD dose was 105 mg/m2 (range: 35-150 mg/m2) in the sarcoma group and 105 mg/m2 (range: 35-510 mg/m2) in the breast cancer group. A decrease of ≥ 10% in LVEF was not observed in the sarcoma group. Patients with breast cancer had available LVEF data on PLD, and three of these patients experienced ≥ 10% in LVEF drop, with one of these patients diagnosed with heart failure. The average cumulative dose of PLD administered in patients with > 10% decrease in LVEF was 177 mg/m2 and had an average of 3.5 cycles. Five sarcoma patients initiated PLD treatment within two years after conventional doxorubicin exposure, while most breast patients initiated PLD treatment at least 10 years following conventional doxorubicin exposure. The average time from PLD initiation to first and second available LVEF monitoring was one and five months in the sarcoma group and three and eight months in the breast cancer group, respectively.

CONCLUSION: PLD administration in patients with prior exposure to conventional doxorubicin appears to be safe, with limited cardiotoxicity in patients with sarcoma and breast cancer. Future research is needed to determine if and how often routine cardiac monitoring is needed for patients on PLD without existing cardiac risk.

PMID:37809186 | PMC:PMC10559758 | DOI:10.7759/cureus.44837

20:10

PubMed articles on: Cardio-Oncology

Papillary Adenocarcinoma: A Rare Subtype of Lung Adenocarcinoma

Cureus. 2023 Sep 7;15(9):e44838. doi: 10.7759/cureus.44838. eCollection 2023 Sep.