No abstract available.
Chemoprevention ; Tuberculosis

No abstract available.
Chemoprevention* ; Head and Neck Neoplasms* ; Head*

Metformin is a first-line anti-diabetic drug that has been widely used in patients with type 2 diabetes. Many population-based epidemiologic studies have shown that metformin treatment is associated with decreased risk for various cancers. Recent epidemiologic studies showed that the use of metformin was associated with a reduction in gastric cancer risk, especially in patients with type 2 diabetes who used metformin for long periods of time (>2~3 years). Currently, there are no registered clinical trials investigating the anti-cancer effect of metformin in gastric cancer; hence, further well-designed clinical trials are required. Herein, we review the literature regarding the use of metformin for the prevention of gastric cancer.
Chemoprevention* ; Epidemiologic Studies ; Humans ; Metformin* ; Stomach Neoplasms*

No abstract available.
*Chemoprevention ; Colorectal Neoplasms/*prevention & control ; *Diet ; Humans

One of the best approaches against cancer is prevention. Inactivation of the p53 or p16INK4a genes has been extensively reported in most human cancer cells. Both p53 and p16INK4a function as tumor suppressors. Therefore, functional restoration of these molecules is considered to be one of the most useful methods for cancer prevention and therapy. We have proposed a concept termed ‘gene-regulating chemoprevention and chemotherapy’ regarding the above pathway. This concept assumes that transcriptional regulation by drugs on tumor-suppressor genes, downstream target genes or functionally similar genes (for example, family genes) of the tumor-suppressor genes would contribute to the prevention of human malignancies. Histone deacetylase (HDAC) inhibitors have been shown to be potent inducers of growth arrest, differentiation and apoptotic cell death. Previously, we demonstrated that HDAC inhibitors, such as sodium butyrate and trichostatin A (TSA), transcriptionally induce the cyclin-dependent kinase inhibitor p21WAF1/Cip1, a downstream target gene of p53, in a p53-independent manner. Furthermore, we have recently shown that HDAC inhibitors activate Gadd45, another downstream target gene of p53, and p19INK4d, a gene functionally similar to p16INK4a. Our results, taken together with previous findings, suggest that HDAC inhibitors may be one of the most attractive and promising agents for ‘gene-regulating chemoprevention’ and ‘molecular-targeting prevention’ of cancer.
Prevention ; Malignant Neoplasms ; Chemoprevention ; inhibitors ; Genes

Background: Administration of chemotherapy to prevent postmolar gestational trophoblastic neoplasia was first implemented in the 1960’s. However, its use has remained controversial. Objectives: This study aimed to describe the effect of chemoprophylaxis in preventing progression of hydatidiform mole to gestational trophoblastic neoplasia among patients managed in a tertiary hospital in Davao City from 2011 to 2015. Materials & Method: This retrospective cross-sectional study evaluated 123 cases of hydatidiform mole who were managed at a tertiary hospital in Davao City from the years 2011 to 2015. The patients’ charts were retrieved to get the clinicodemographic profile, progression to gestational trophoblastic neoplasia, and occurrence of adverse effects secondary to chemoprophylaxis. Patients with rising or plateauing beta human chorionic gonadotropin titer were identified within the 3-year period from molar evacuation. Collected data were analyzed using frequency and percentage distribution. Results: The mean age of the patients was 30.5 years, 24% of whom were noted in women more than 40 years of age. The average age of gestation on admission was 14.89 weeks. All patients had a histopathologic diagnosis of complete mole and at least one risk factor for developing postmolar gestational trophoblastic neoplasia. Patients did not experience any significant side effect to chemoprophylaxis. None of the patients developed gestational trophoblastic neoplasia within the 3-year period of monitoring. Conclusion The administration of chemoprophylaxis to patients diagnosed with hydatidiform mole may be effective against the development of postmolar gestational trophoblastic neoplasia.
Pregnancy ; Female ; Gestational Trophoblastic Disease ; Hydatidiform Mole ; Neoplasms ; Chemoprevention

Approximately 7% of all breast cancer cases are associated with hereditary predisposition and BRCA1 and BRCA2 gene, which accounts for half of the hereditary breast cancer (HBC). Although majority of breast cancer occur sporadically, identification of HBC is important in that active adoption of preventive strategies such as surveillance, chemoprevention, and riskreducing surgery will result in the gain of life-expectancy. According to the recent studies, the prevalence and penetrance of BRCA mutation in Korean breast cancer patients are comparable to that of western countries. Genetic testing should be done in the setting of genetic counseling, which provides the patients with comprehensive information about the test procedure, the interpretation of the test result, and possible options when the test results were positive for mutation. The management of HBC is not different from that of sporadic cancer and many clinical trials investigating the chemoprevention and targeted therapy of HBC are underway. The Korean Hereditary Breast Cancer (KOHBRA) study is a nationwide multicenter study to reveal the prevalence of BRCA mutation in Korean breast cancer patients. After the completion of the KOHBRA study, we expect important basic data which will be the backbone of clinical practice guideline for Korean HBC patients.
Adoption ; Breast ; Breast Neoplasms ; Chemoprevention ; Genes, BRCA2 ; Genetic Counseling ; Genetic Testing ; Humans ; Penetrance ; Prevalence

Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment.
Carcinogenesis ; Chemoprevention* ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Nitric Oxide*

Malaria is the world's most important parasitic infec tion. Although it has been eradicated from temperate zones including Korea , increasing numbers of travellers visit tropical malarious countries and imported malaria becomes important medical problem in the developed countries. In Korea with increasing travellers to malaria endemic area, the incidence of imported malaria shows rising tendency same as the developed countries. It beco mes important to provide general personal protective me asures and chemoprophylaxis to trevellers, when employed in appropriate manner, that can be highly effective in preventing malaria . We recently experienced a case of imported Plasmodium vivax malaria with delayed mani festations due to inadequate chemoprophylaxis. A 53- year-old woman with history of trevel to East Africa 4 months ago and chief complaint of fever was diagnosed as tertian malaria. She had irregularly taken prophylatic antimalarial during travel and had not taken it after return but should have taken it at least 4 weeks after return.
Africa, Eastern ; Chemoprevention* ; Developed Countries ; Female ; Fever ; Humans ; Incidence ; Korea ; Malaria ; Malaria, Vivax* ; Plasmodium vivax* ; Plasmodium*

Selenium is an essential microelement in animals including human. Selenium plays an important role in cellular functions such as deoxygenation and detoxification. Also, it can be used in treatment of cardiac disease, hepatic disease, AIDS and various cancers. Recent meta-analysis showed that high selenium exposure was associated with decreased risk of several cancers. Selenium has an effect on anticarcinogesis through several mechanisms, which are regulation of cell cycles, apoptosis, DNA damage and repair, inhibition of cellular adhesion and migration, anti-angiogenesis and immune modulation. Even though many laboratory studies have provided convincing evidence of these mechanisms, results from epidemiologic and clinical studies of selenium does not coincide with each other. Well-designed trials considering dosage and chemical form of selenium supplement as well as confounding factors and long-term follow-up of them would be needed to use selenium in chemoprevention and therapy of cancers.
Animals ; Apoptosis ; Cell Cycle ; Chemoprevention ; DNA Damage ; Follow-Up Studies ; Heart Diseases ; Humans ; Selenium*