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Pharmacological Reports : PR Dec 2021Breast cancer is the most common female malignancy and the second leading cause of cancer related deaths. It is estimated that about 40% of all cancer in women is... (Review)
Review
Breast cancer is the most common female malignancy and the second leading cause of cancer related deaths. It is estimated that about 40% of all cancer in women is hormonally mediated. Both estrogens and androgens play critical roles in the initiation and development of breast cancer. Estrogens influence normal physiological growth, proliferation, and differentiation of breast tissues, as well as the development and progression of breast malignancy. Breast cancer is caused by numerous endo- and exogenous risk factors. The paper presents estrogen metabolism, in particular 17β-estradiol and related hormones. The mechanisms of estrogen carcinogenesis include the participation of estrogen receptors, the genotoxic effect of the estrogen metabolites, and epigenetic processes that are also presented. The role of reactive oxygen species in breast cancer has been described. It called attention to a role of numerous signaling pathways in neoplastic transformation. Chemoprotective agents, besides other phytoestrogens, classical antioxidants, synthetic compounds, and their mechanisms of action have been shown.
Topics: Animals; Anticarcinogenic Agents; Breast Neoplasms; Chemoprevention; Epigenesis, Genetic; Estrogens; Female; Humans; Reactive Oxygen Species; Receptors, Estrogen; Risk Factors; Signal Transduction
PubMed: 34462889
DOI: 10.1007/s43440-021-00317-0 -
Journal of Hepatology Nov 2021In many countries worldwide, the burden of hepatocellular carcinoma (HCC) associated with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis... (Review)
Review
In many countries worldwide, the burden of hepatocellular carcinoma (HCC) associated with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing. Preventive strategies are needed to counteract this trend. In this review, we provide an overview of the evidence on preventive strategies in NAFLD-associated HCC. We consider the impact of lifestyle factors such as weight loss, physical activity, smoking, dietary patterns and food items, including coffee and alcohol, on both HCC and NAFLD/NASH. Furthermore, evidence on chemopreventive treatments, including aspirin, antidiabetic treatments and statins is summarised. The role of adjuvant therapies for tertiary prevention of HCC is briefly reviewed.
Topics: Carcinoma, Hepatocellular; Chemoprevention; Diabetes Complications; Diabetes Mellitus; Humans; Life Style; Liver Neoplasms; Non-alcoholic Fatty Liver Disease; Obesity; Risk Factors
PubMed: 34339764
DOI: 10.1016/j.jhep.2021.07.025 -
International Journal of Molecular... Oct 2019The use of synthetic, natural, or biological agents to minimize the occurrence of cancer in healthy individuals is defined as cancer chemoprevention. Chemopreventive... (Review)
Review
The use of synthetic, natural, or biological agents to minimize the occurrence of cancer in healthy individuals is defined as cancer chemoprevention. Chemopreventive agents inhibit the development of cancer either by impeding DNA damage, which leads to malignancy or by reversing or blocking the division of premalignant cells with DNA damage. The benefit of this approach has been demonstrated in clinical trials of breast, prostate, and colon cancer. The continuous increase in cancer cases, failure of conventional chemotherapies to control cancer, and excessive toxicity of chemotherapies clearly demand an alternative approach. The first trial to show benefit of chemoprevention was undertaken in breast cancer patients with the use of tamoxifen, which demonstrated a significant decrease in invasive breast cancer. The success of using chemopreventive agents for protecting the high risk populations from cancer indicates that the strategy is rational and promising. Dietary components such as capsaicin, cucurbitacin B, isoflavones, catechins, lycopenes, benzyl isothiocyanate, phenethyl isothiocyanate, and piperlongumine have demonstrated inhibitory effects on cancer cells indicating that they may serve as chemopreventive agents. In this review, we have addressed the mechanism of chemopreventive and anticancer effects of several natural agents.
Topics: Animals; Anticarcinogenic Agents; Chemoprevention; Humans; Neoplasms; Phytochemicals; Structure-Activity Relationship
PubMed: 31600949
DOI: 10.3390/ijms20204981 -
Seminars in Oncology Feb 2016
Topics: Anticarcinogenic Agents; Chemoprevention; Humans; Neoplasms; Primary Prevention
PubMed: 26970121
DOI: 10.1053/j.seminoncol.2015.11.002 -
AIDS (London, England) Jul 2016Preexposure prophylaxis (PrEP) offers a promising new approach to HIV prevention. This systematic review and meta-analysis evaluated the evidence for use of oral PrEP... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Preexposure prophylaxis (PrEP) offers a promising new approach to HIV prevention. This systematic review and meta-analysis evaluated the evidence for use of oral PrEP containing tenofovir disoproxil fumarate as an additional HIV prevention strategy in populations at substantial risk for HIV based on HIV acquisition, adverse events, drug resistance, sexual behavior, and reproductive health outcomes.
DESIGN
Rigorous systematic review and meta-analysis.
METHODS
A comprehensive search strategy reviewed three electronic databases and conference abstracts through April 2015. Pooled effect estimates were calculated using random-effects meta-analysis.
RESULTS
Eighteen studies were included, comprising data from 39 articles and six conference abstracts. Across populations and PrEP regimens, PrEP significantly reduced the risk of HIV acquisition compared with placebo. Trials with PrEP use more than 70% demonstrated the highest PrEP effectiveness (risk ratio = 0.30, 95% confidence interval: 0.21-0.45, P < 0.001) compared with placebo. Trials with low PrEP use did not show a significantly protective effect. Adverse events were similar between PrEP and placebo groups. More cases of drug-resistant HIV infection were found among PrEP users who initiated PrEP while acutely HIV-infected, but incidence of acquiring drug-resistant HIV during PrEP use was low. Studies consistently found no association between PrEP use and changes in sexual risk behavior. PrEP was not associated with increased pregnancy-related adverse events or hormonal contraception effectiveness.
CONCLUSION
PrEP is protective against HIV infection across populations, presents few significant safety risks, and there is no evidence of behavioral risk compensation. The effective and cost-effective use of PrEP will require development of best practices for fostering uptake and adherence among people at substantial HIV risk.
Topics: Administration, Oral; Adult; Anti-HIV Agents; Chemoprevention; Female; HIV Infections; Humans; Male; Placebos; Pre-Exposure Prophylaxis; Tenofovir; Young Adult
PubMed: 27149090
DOI: 10.1097/QAD.0000000000001145 -
Malaria Journal Mar 2022Chemoprevention strategies reduce malaria disease and death, but the efficacy of anti-malarial drugs used for chemoprevention is perennially threatened by drug... (Review)
Review
Chemoprevention strategies reduce malaria disease and death, but the efficacy of anti-malarial drugs used for chemoprevention is perennially threatened by drug resistance. This review examines the current impact of chemoprevention on the emergence and spread of drug resistant malaria, and the impact of drug resistance on the efficacy of each of the chemoprevention strategies currently recommended by the World Health Organization, namely, intermittent preventive treatment in pregnancy (IPTp); intermittent preventive treatment in infants (IPTi); seasonal malaria chemoprevention (SMC); and mass drug administration (MDA) for the reduction of disease burden in emergency situations. While the use of drugs to prevent malaria often results in increased prevalence of genetic mutations associated with resistance, malaria chemoprevention interventions do not inevitably lead to meaningful increases in resistance, and even high rates of resistance do not necessarily impair chemoprevention efficacy. At the same time, it can reasonably be anticipated that, over time, as drugs are widely used, resistance will generally increase and efficacy will eventually be lost. Decisions about whether, where and when chemoprevention strategies should be deployed or changed will continue to need to be made on the basis of imperfect evidence, but practical considerations such as prevalence patterns of resistance markers can help guide policy recommendations.
Topics: Chemoprevention; Drug Combinations; Drug Resistance; Female; Humans; Infant; Malaria; Policy; Pregnancy; Pyrimethamine; Sulfadoxine
PubMed: 35331231
DOI: 10.1186/s12936-022-04115-8 -
Molecules (Basel, Switzerland) Dec 2022Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that... (Review)
Review
Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that uses drugs with chemopreventive properties to promote antioxidation, regulate cancer cell cycle, suppress proliferation, and induce cellular apoptosis, so as to improve cancer treatment outcomes. Natural polyphenols are currently recognized as a class of chemopreventive agents that have shown remarkable anticarcinogenic properties. Numerous in vitro and in vivo studies have elucidated the anti-CRC mechanisms of natural polyphenols, such as regulation of various molecular and signaling pathways. Natural polyphenols are also reportedly capable of modulating the gut microbiota and cancer stem cells (CSCs) to suppress tumor formation and progression. Combined use of different natural polyphenols is recommended due to their low bioavailability and instability, and combination treatment can exert synergistical effects, reduce side effects, and avoid drug resistance in CRC treatment. In summary, the application of polyphenols in the chemoprevention and treatment of CRC is promising. Further clinical evaluation of their effectiveness is warranted and anticipated.
Topics: Humans; Polyphenols; Anticarcinogenic Agents; Chemoprevention; Signal Transduction; Colorectal Neoplasms
PubMed: 36557939
DOI: 10.3390/molecules27248810 -
Gastrointestinal Endoscopy Clinics of... Jul 2021Gastric cancer is the fifth most common cause of cancer and the third leading cause of cancer-related deaths globally. The number of gastric cancer-related deaths is... (Review)
Review
Gastric cancer is the fifth most common cause of cancer and the third leading cause of cancer-related deaths globally. The number of gastric cancer-related deaths is only projected to increase, attributable primarily to the expanding aging population. Prevention is a mainstay of gastric cancer control programs, particularly in the absence of accurate, noninvasive modalities for screening and early detection, and the absence of an infrastructure for this purpose in the majority of countries worldwide. Herein, we discuss the evidence for several chemopreventive agents, along with putative mechanisms. There remains a clear, unmet need for primary chemoprevention trials for gastric cancer.
Topics: Aged; Chemoprevention; Helicobacter Infections; Helicobacter pylori; Humans; Stomach Neoplasms
PubMed: 34053637
DOI: 10.1016/j.giec.2021.03.006 -
International Journal of Molecular... Apr 2023Colorectal cancer (CRC) is one of the deadliest forms of cancer worldwide. CRC development occurs mainly through the adenoma-carcinoma sequence, which can last decades,... (Review)
Review
Colorectal cancer (CRC) is one of the deadliest forms of cancer worldwide. CRC development occurs mainly through the adenoma-carcinoma sequence, which can last decades, giving the opportunity for primary prevention and early detection. CRC prevention involves different approaches, ranging from fecal occult blood testing and colonoscopy screening to chemoprevention. In this review, we discuss the main findings gathered in the field of CRC chemoprevention, focusing on different target populations and on various precancerous lesions that can be used as efficacy evaluation endpoints for chemoprevention. The ideal chemopreventive agent should be well tolerated and easy to administer, with low side effects. Moreover, it should be readily available at a low cost. These properties are crucial because these compounds are meant to be used for a long time in populations with different CRC risk profiles. Several agents have been investigated so far, some of which are currently used in clinical practice. However, further investigation is needed to devise a comprehensive and effective chemoprevention strategy for CRC.
Topics: Humans; Colorectal Neoplasms; Early Detection of Cancer; Chemoprevention; Colonoscopy; Adenoma
PubMed: 37108756
DOI: 10.3390/ijms24087597 -
Cancer Prevention Research... Jun 2014Melanoma incidence is increasing and, despite recent therapeutic advances, the prognosis for patients with metastatic disease remains poor. Thus, early detection and... (Review)
Review
Melanoma incidence is increasing and, despite recent therapeutic advances, the prognosis for patients with metastatic disease remains poor. Thus, early detection and chemoprevention are promising strategies for improving patient outcomes. Aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAID) have demonstrated chemoprotective activity in several other cancers, and have been proposed as chemopreventive agents for melanoma. Throughout the last decade, however, a number of case-control, prospective, and interventional studies of NSAIDs and melanoma risk have yielded conflicting results. These inconsistent findings have led to uncertainty about the clinical utility of NSAIDs for melanoma chemoprevention. This mini-review highlights current knowledge of NSAID mechanisms of action and rationale for use in melanoma, provides a comparative review of outcomes and limitations of prior studies, and discusses the future challenges in demonstrating that these drugs are effective agents for mitigating melanoma risk.
Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Case-Control Studies; Chemoprevention; Humans; Melanoma; Risk Factors; Skin Neoplasms
PubMed: 24694780
DOI: 10.1158/1940-6207.CAPR-14-0018