Preventing organ-specific chemotherapy toxicity

Indian propolis ameliorates the mitomycin C-induced testicular toxicity by reducing DNA damage and elevating the antioxidant activity

Development of excellent curative therapy for most of the malignancies has resulted in a growing population of cancer survivors who are at increased risk for a variety of health problems including infertility. Therefore, fertility preservation has become an important issue during cancer treatment in recent years. Combination therapy with natural agents such as vitamins, antioxidants, dietary supplements, and plant products are considered as an attractive option to mitigate normal tissue toxicity imparted by chemotherapy. The aim of the present study was to explore the beneficial effect of hydroethanolic extract of Indian propolis (HEIP) on mitigating mitomycin C (MMC)-induced testicular damage and its mechanism of action. Healthy adult male mice were injected intraperitoneally with saline, MMC, HEIP and HEIP followed by MMC after 1h. The animals were dissected at 35days after various treatments to analyze testicular function. MMC administration resulted in significant reduction in testicular function in a dose-dependent manner at 35days after treatment which significantly improved by HEIP pre-treatment. At 24h after treatment, MMC induced significant increase in oxidative stress, γ-H2AX foci and expression of RAD51 and KU80 in testicular cells. Prior treatment with HEIP decreased the oxidative stress, reduced DNA damage and restored the testicular testosterone and inhibin B level. In conclusion, co-administration of Indian propolis extract may play a promising beneficial role in fertility preservation of males undergoing chemotherapy.

Treatment-related cardiotoxicity in survivors of childhood cancer

Treatment advances and higher participation rates in clinical trials have rapidly increased the number of survivors of childhood cancer. However, chemotherapy and radiation treatments are cardiotoxic and can cause cardiomyopathy, conduction defects, myocardial infarction, hypertension, stroke, pulmonary oedema, dyspnoea and exercise intolerance later in life. These cardiotoxic effects are often progressive and irreversible, emphasizing a need for effective prevention and treatment to reduce or avoid cardiotoxicity. Medical interventions, such as angiotensin-converting enzyme inhibitors, β-blockers, and growth hormone therapy, might be used to treat cardiotoxicity in childhood cancer survivors. Preventative strategies should include the use of dexrazoxane, which provides cardioprotection without reducing the oncological efficacy of doxorubicin chemotherapy; less-toxic anthracycline derivatives and the use of antioxidant nutritional supplements might also be beneficial. Continuous-infusion doxorubicin provides no benefit over bolus infusion in children. Identifying patient-related (for example, obesity and hypertension) and drug-related (for example, cumulative dose) risk factors for cardiotoxicity could help tailor treatments to individual patients. However, all survivors of childhood cancer are at increased risk of cardiotoxicity, suggesting that survivor screening recommendations for assessment of global risk of premature cardiovascular disease should apply to all survivors. Optimal, evidence-based monitoring strategies and multiagent preventative treatments still need to be identified.

[Procedures for fertility preservation in female cancer patients]

Improving survival rates and quality of life following modern combined cancer treatments have resulted a growing number of patients requesting maintenance of reproductive functions. Several methods are currently available to maintain fertility during oncotherapy. Even though most of them are still experimental and their efficacy and safety have not been determined, the future for fertility preservation in women with cancer is promising. In vitro fertilization with embryo cryopreservation offers an established method, but time to delay cancer treatment could be risky regarding the progression of several cancer types. Moreover, exposure to a high oestrogen milieu during ovarian stimulation is undesirable when patients have estrogen-sensitive malignant tumours. Cryopreservation of mature oocytes following in vitro fertilization and intracytoplasmatic sperm injection offers advantages, but it is still limited due to its low success rate. Emerging techniques of ovarian tissue cryopreservation followed by autotransplantation have been clinically explored. Novel technologies of tissue freezing and thawing promise improving results. However, only one live birth following autotransplanted frozen-thawed ovarian tissue has been established. This procedure can be offered in the future for prepubertal girls before cancer treatment to maintain future fertility. Gonadal tissue cryopreservation and transplantation should be considered experimental in humans for the present time until greater evidence regarding efficacy and safety is accrued.