Level of Implementation of Seasonal Malaria Chemoprevention in Children Aged between 3 to 59 Months in Koza, Far North Region of Cameroon

Background: Seasonal Malaria Chemoprevention (SMC) is a strategy put in place by World Health Organisation (WHO) to fight against malaria in zones of high seasonal malaria transmission since the year 2012. This strategy has been implemented in the Far North and North regions of Cameroon since the year 2016. Despite the implementation of this program the number of cases and deaths from seasonal malaria among the under 5 seems to be rising in Koza health area. Objective: To determine the level of implementation of the SMC Program and its impact on the mortality of children aged 03 to 59 months during the season of high transmission. Methods: This was a community-based cross-sectional and 7-years retrospective study. Data was surveyed for 3 months in 3 health areas of Koza health area. Data were collected and typed in Kobo collect, cleaned in MS Excel and analyzed in SPSS version 25 to come out with descriptive statistics. Results: Among the 172 households, female children were mostly represented 99 (57%) The age group mostly represented was 2 years. The population knowledge on SMC’s overall score was above average. The overall coverage rate (4 cycles) was 84% from interviewed parents and 67.5% from SMC cards. More than 23% of children experienced at least one side effect with the most common being vomiting (72%). The population’s overall impression of the program was good at 85%. The trends SMC coverage showed a sinusoidal fluctuation from 2015 to 2021, 2016 to 2019 and 2020 to 2021. Conclusion: The coverage rate of SMC was high thus the program is well implemented.

Carcinoma of the stomach: A review of epidemiology, pathogenesis, molecular genetics and chemoprevention

Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitationand hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.

Chemoprevention of tea on colorectal cancer induced by dimethylhydrazine in Wistar rats

AIM To investigate the chemopreventiveeffects of green tea and tea pigment on 1,2-dimethylhydrazine(DMH)-induced rat colorectalcarcinogenesis.METHODS Male weaning Wistar rats wererandomly allocated into four groups.Rats in thepositive control group were given s.c.injectionof DMH,once a week for ten weeks;rats in tea-treated groups,with the same DMH treatment asin the positive group,received 2% green tea and0.1% tea pigments;rats in the negative controlgroup were given s.c.injection of the samevolume of saline as well as DMH in the positivegroup.Animals were sacrified and necropsied atthe end of week 16 and week 32.RESULTS Aberrant cryptic foci(ACF)wereformed in animals in DMH-treated groups at theend of week 16.Compared to the DMH group,green tea and tea pigments groups had less ACF(148.25 and 204.25,respectively,P【0.01).Atthe end of week 32,all rats in DMH groupdeveloped large intestinal tumors.The resultsalso showed that DMH increased labeling index(LI)of proliferating cell nuclear antigen(PCNA)of intestinal mucosa and the expression of ras-p21.However,in the tea-treated groups,PCNA-LI was significantly reduced as compared withthe positive control group(36.63 and 40.36 inthe green tea group and tea pigment group,respectively,at the end of the experiment,P【0.01).ras-p21 expression was alsosignificantly reduced(2.07 and 2.36 in the colontumors of rats in the green tea group and teapigments group,respectively at the end of theexperiment,P【0.01).Furthermore,green tea and tea pigment inhibited the expression of Bcl-2protein(2,5,1,0 and 2,4,1,0,respectively,at the end of the experiment P【0.01),andinduced expression of Bax protein(0,1,3,4and 0,1,4,3,respectively,P【0.01).CONCLUSION Chinese green tea drinkinginhibited ACF and colonic tumors formation inrats,which showed that tea had a significantchemopreventive effect on DMH-inducedcolorectal carcinogenesis.Such effects may bedue to suppression of cell proliferation andinduction of apoptosis in the intestinal crypts.

Carcinogenesis and chemoprevention of biliary tract cancer in pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is a high risk factor for biliary tract cancer. In PBM, since the pancreatic duct and bile duct converge outside the duodenal wall beyond the influence of the sphincter of Oddi, pancreatic juice and bile are constantly mixed, producing a variety of harmful substances. Because of this, the biliary mucosa is repeatedly damaged and repaired, which causes an acceleration of cell proliferative activity and multiple gene mutations. Histological changes such as hyperplasia, metaplasia, and dysplasia ultimately result in a high incidence of carcinogenesis. In a nationwide survey by the Japanese Study Group on PBM, coexisting biliary tract cancer was detected in 278 of the 1627 registered cases of PBM (17.1%). Of these cases, in those with dilatation of the extrahepatic bile duct, cancer was often detected not only in the gallbladder but also in the bile ducts. More than 90% of cancer cases without dilatation of the extrahepatic bile duct develop in the gallbladder. Standard treatment for PBM is a cholecystectomy and resection of the extrahepatic bile duct. However, cholecystectomy alone is performed at nearly half of institutions in Japan. Conversely, reports of carcinogenesis in the remnant bile duct or pancreas after diversion surgery are steadily increasing. One of the causes for this is believed to be an accumulation of gene mutations which were present before surgery. Anticancer drugs are ineffective in preventing such carcinogenesis following surgery, thus the postoperative administration of chemopreventive agents may be necessary.

Colon cancer and the epidermal growth factor receptor:Current treatment paradigms,the importance of diet,and the role of chemoprevention

Colorectal cancer represents the third most common and the second deadliest type of cancer for both men and women in the United States claiming over 50000 lives in 2014. The 5-year survival rate for patients diagnosed with metastatic colon and rectal cancer is < 15%. Early detection and more effective treatments are urgently needed to reduce morbidity and mortality of patients afflicted with this disease. Here we will review the risk factors and current treatment paradigms for colorectal cancer, with an emphasis on the role of chemoprevention as they relate to epidermal growth factor receptor(EGFR) blockade. We will discuss how various EGFR ligands are upregulated in the presence of Western diets high in saturated and N-6 polyunsaturated fats. We will also outline the various mechanisms of EGFR inhibition that are induced by naturally occurring chemopreventative agents such as ginseng, green tea, and curcumin. Finally, we will discuss the current role of targeted chemotherapy in colon cancer and outline the limitations of our current treatment options, describing mechanisms of resistance and escape.

Azoxymethane-induced rat aberrant crypt foci:Relevance in studying chemoprevention of colon cancer

The pathogenesis of colon cancer involves sequential and multistep progression of epithelial cells initiated to a cancerous state with defined precancerous intermediaries. Aberrant crypt foci （ACF） represent the earliest identifiable intermediate precancerous lesions during colon carcinogenesis in both laboratory animals and humans. ACF are easily induced by colon-specific carcinogens in rodents and can be used to learn more about the process of colon carcinogenesis. For over two decades, since its first discovery, azoxymethane （AOM）-induced rodent ACF have served as surrogate biomarkers in the screening of various anticarcinogens and carcinogens. Several dietary constituents and phytochemicals have been tested for their colon cancer chemopreventive efficacy using the ACF system. There has been substantial effort in defining and refining ACF in terms of understanding their molecular make-up, and extensive research in this field is currently in progress. In chemoprevention studies, AOM-induced rat ACF have been very successful as biomarkers, and have provided several standardized analyses of data. There have been several studies that have reported that ACF data do not correlate to actual colon tumor outcome, however, and hence there has been an ambiguity about their role as biomarkers. The scope of this mini-review is to provide valuable insights and limitations of AOM-induced rat ACF as biomarkers in colon cancer chemoprevention studies. The role of the dynamics and biological heterogeneity of ACF is critical in understanding them as biomarkers in chemoprevention studies.

Cancer chemoprevention through dietary avonoids: what's limiting?

Flavonoids are polyphenols that are found in numerous edible plant species. Data obtained from preclinical and clinical studies suggest that specific flavonoids are chemo-preventive and cytotoxic against various cancers via a multitude of mechanisms. However, the clinical use of flavonoids is limited due to challenges associated with their e ective use, including(1) the isolation and purification of flavonoids from their natural resources;(2) demonstration of the e ects of flavonoids in reducing the risk of certain cancer, in tandem with the cost and time needed for epidemiological studies, and(3) numerous pharmacokinetic challenges(e.g., bioavailability, drug–drug interactions, and metabolic instability). Currently, numerous approaches are being used to surmount some of these challenges, thereby increasing the likelihood of flavonoids being used as chemo-preventive drugs in the clinic. In this review, we summarize the most important challenges and e orts that are being made to surmount these challenges.

Chemoprevention of hepatocellular carcinoma in patients with hepatitis C virus related cirrhosis

Interferon(IFN) therapy has been reported to decrease the risk of hepatocellular carcinoma(HCC) and improve survival by preventing liver-related deaths in patients with chronic hepatitis C virus(HCV) infection, while the role of IFN therapy on the natural history of hepatitis C related cirrhosis is still under debate. The ideal goal of therapy is to prevent the progression into end-stage disease. The use of IFN in patients with HCV compensated cirrhosis reduces the negative clinical evolution independently of the type of laboratoristic and virological response. In our experience, IFN therapy in HCV compensated cirrhosis is barely useful in prevention of HCC, as cirrhosis itself represents a risk of cancer.Some authors noted that IFN treatment reduces the risk of HCC independently of the virological response. It would probably be interesting to evaluate the efficacy of weekly low-dose pegylated(PEG)-IFN therapy in patients with HCV cirrhosis and to assess potential benefits of long-term PEG-IFN plus Ribavirin treatment.

Chemoprevention of colorectal cancer by targeting obesity-related metabolic abnormalities

Obesity and its related metabolic disorders, including insulin resistance and chronic inflammation, increase the risk of colorectal cancer(CRC). This observation suggests that the metabolic abnormalities associated with obesity can be effective targets for preventing the development of CRC in obese individuals. In recent years, many studies using obese and diabetic animal models have been conducted to investigate the chemoprevention of CRC using pharmaceutical or nutritional interventions. Pitavastatin, a medicine used to treat hyperlipidemia, prevents the development of obesityrelated colorectal carcinogenesis by attenuating chronic inflammation. Anti-hypertensive medicines, such as captopril and telmisartan, also suppress the formation of colonic preneoplastic lesions in obese and diabetic mice. In addition, several phytochemicals, including green tea catechins, have been reported to improve metabolic disorders and prevent the development of various cancers, including CRC. Moreover, the administration of branched-chain amino acids, which improves protein malnutrition and prevents the progression of hepatic failure, is effective for suppressing obesityrelated colon carcinogenesis, which is thought to be associated with improvements in insulin resistance. In the present article, we summarize the detailed relationship between metabolic abnormalities and the development of CRC. This review also outlines recent evidence, in particular drawing from basic and clinical examinations using either pharmaceutical or nutritional intervention that suggests that targeting metabolic alterations may be an effective strategy for preventing the development of CRC in obese individuals.

Cancer chemoprevention through the induction of apoptosis by natural compounds

As cell and tissue homeostasis are mediated by the balance between proliferation and apoptosis, controlling this balance is important for cancer chemoprevention. Cancer chemoprevention can be achieved by the use of natural, synthetic or biologic compounds that reverse, suppress or prevent the development of epithelial malignancies. Natural compounds including flavonoids are able to reduce oxidative stress, which is the most likely mechanism mediating the protective effects against cancer development. In addition, in vitro and in vivo studies have suggested that flavonoids, such as (-)-epigallocatechin-3-gallete (EGCG), quercetin, and curcumin, act by induction of apoptosis. Several natural compounds inhibit cell proliferation and angiogenesis. Certain natural products have been shown to inhibit the activation of nuclear factor kappa B (NF-κB) and Akt signaling pathways, both of which are known to maintain a homeostatic balance between cell survival and apoptosis. Understanding the mechanism of these natural products will contribute to the development of more specific preventive strategies against cancer development. Here we focus on the ability of natural cancer chemopreventive agents to induce apoptosis, and attempt to provide evidence for the preventive and therapeutic effects of natural compounds, EGCG, quercetin, and curcumin, in a succinct manner highlightingκand Akt signaling pathways in vivo.

Silibinin and colorectal cancer chemoprevention:a comprehensive review on mechanisms and efficacy

Globally,the risk of colorectal cancer（CRC） as well as the incidence of mortality associated with CRC is increasing.Thus,it is imperative that we look at alternative approaches involving intake of non-toxic natural dietary/non-dietary agents,for the prevention of CRC.The ultimate goal of this approach is to reduce the incidence of pre-neoplastic adenomatous polyps and prevent their progression to more advanced forms of CRC,and use these natural agents as a safe intervention strategy during the clinical course of this deadly malignancy.Over the years,pre-clinical studies have shown that silibinin（a flavonolignan isolated from the seeds of milk thistle,Silybum marianum） has strong preventive and therapeutic efficacy against various epithelial cancers,including CRC.The focus of the present review is to provide a comprehensive tabular summary,categorically for an easy accessibility and referencing,pertaining to the efficacy and associated mechanisms of silibinin against CRC growth and progression.

Chemoprevention of cancer:opportunities and challenges,with special emphasis on selenium

Michael Spom over 2 decades ago introduced the concept of chemoprevention： the use of compounds intended to decrease the risk of cancer for broad proportions of the world＇ s population. Evidence that this was possible came from epidemiologic literature, as well as from basic science. A wide range of compounds has been investigated, and much of this investigation is under way.

Concept of chemoprevention in colorectal cancer

Colorectal cancer remains a significant cause of morbidity and mortality throughout the world.The incidence of colorectal cancer is nearly four-fold higher in more-developed as compared with less-developed regions of the world.At present an early detection of colorectal cancer remains a crucial step in determining the therapeutic outcomes.Screening programmes have been introduced in an effort to detect colorectal cancer at an early stage or at a precancerous colonic polyp stage.These programmes should be used by the health professionals as an opportunity to educate the public regarding the use of chemoprevention in colorectal cancer,which is the main focus of this review and an attractive concept needing further evaluation.

Chemoprevention of gastrointestinal cancers by natural honey

Gastrointestinal cancers are the most common human cancers in both men and women worldwide. Several epidemiological and experimental studies suggest a relationship between gastrointestinal cancers risk and dietary factors. Natural honey has been widely used in traditional medicine for many centuries to treat a wide range of ailments and complaints. Honey contains various components that exhibit wide activities including antibacterial, anti-inflammatory, antioxidant and anticancer properties. The anticancer effects of honey are mediated via diverse mechanisms,including inhibition of proliferation, induction of apoptosis, suppression of free radicals and modulation of inflammatory signalling pathways. The present review assesses the chemopreventive effects of natural honey and its components in the modulation of gastrointestinal cancers and its modes of action in the prevention of the development of gastrointestinal tumors. Honey can be an approach as a cancer-preventive strategy which merits further experimental and clinical research in the near future.

CHEMOPREVENTION OF LUNG CANCER IN THE HIGH INCIDENCE AREA

Since 1984, mass screening for cancer and chemopreventive trials in the two high incidence areas of lung cancer have been carried out. Chemo preventive trials on the subjects having moderate or severe atypical hyperplasia cells in the sputum were done by treatment with R1 [N-(p-ethoxycarbophenyl) retinamide] and R2 [N-(p-carboxyphenyl) retina-mide]. Results showed that the general status of the patients had improved. IgA and IgM in the serum were increased and the arsenic skin lesions were relieved after the treatment with Rl and R2. The ratio of the incidence of lung cancer for the treated group and the control group was 1:4, and the mean degree of hyperplasia in the sputum had dropped. It is suggested that these drugs are both safe and effective in the chemoprevention of lung cancer.

Astragaloside in cancer chemoprevention and therapy

Tumor chemoprevention and treatment are two approaches aimed at improving the survival of patients with cancers.An ideal anti-tumor drug is that which not only kills tumor cells but also alleviates tumor-causing risk factors,such as precancerous lesions,and prevents tumor recurrence.Chinese herbal monomers are considered to be ideal treatment agents due to their multi-target effects.Astragaloside has been shown to possess tumor chemoprevention,direct anti-tumor,and chemotherapeutic drug sensitization effects.In this paper,we review the effects of astragaloside on tumor prevention and treatment and provide directions for further research.

Chemoprevention of colorectal cancer in general population and high-risk population: a systematic review and network meta-analysis

Background:Many nutritional supplements and pharmacological agents have been reported to show preventive effects on colorectal adenoma and colorectal cancer(CRC).We performed a network meta-analysis to summarize such evidence and assess the efficacy and safety of these agents.Methods:We searched PubMed,Embase,and the Cochrane Library for studies published in English until October 31,2021 that fit our inclusion criteria.We performed a systematic review and network meta-analysis to assess the comparative efficacy and safety of candidate agents(low-dose aspirin[Asp],high-dose Asp,cyclooxygenase-2 inhibitors[coxibs],calcium,vitamin D,folic acid,ursodeoxycholic acid[UDCA],estrogen,and progesterone,alone or in combination)for preventing colorectal adenoma and CRC.Cochrane risk-of-bias assessment tool was employed to evaluate the quality of each included study.Results:Thirty-two randomized controlled trials(278,694 participants)comparing 13 different interventions were included.Coxibs significantly reduced the risk of colorectal adenoma(risk ratio[RR]:0.59,95%confidence interval[CI]:0.44–0.79,six trials involving 5486 participants),advanced adenoma(RR:0.63,95%CI:0.43–0.92,four trials involving 4723 participants),and metachronous adenoma(RR:0.58,95%CI:0.43–0.79,five trials involving 5258 participants)compared with placebo.Coxibs also significantly increased the risk of severe adverse events(RR:1.29,95%CI:1.13–1.47,six trials involving 7109 participants).Other interventions,including Asp,folic acid,UDCA,vitamin D,and calcium,did not reduce the risk of colorectal adenoma in the general and high-risk populations compared with placebo.Conclusions:Considering the balance between benefits and harms,regular use of coxibs for prevention of colorectal adenoma was not supported by the current evidence.Benefit of low-dose Asp for chemoprevention of colorectal adenoma still requires further evidence.

Seasonal malaria chemoprevention in Africa and China's upgraded role as a contributor:a scoping review

Background Children under five are the vulnerable population most at risk of being infected with Plasmodium para-sites,especially in the Sahel region.Seasonal malaria chemoprevention(SMC)recommended by World Health Organi-zation(WHO),has proven to be a highly effective intervention to prevent malaria.Given more deaths reported during the COVID-19 pandemic than in previous years due to the disruptions to essential medical services,it is,therefore,necessary to seek a more coordinated and integrated approach to increasing the pace,coverage and resilience of SMC.Towards this end,fully leverage the resources of major players in the global fight against malaria,such as China could accelerate the SMC process in Africa.Methods We searched PubMed,MEDLINE,Web of Science,and Embase for research articles and the Institutional Repository for Information Sharing of WHO for reports on SMC.We used gap analysis to investigate the challenges and gaps of SMC since COVID-19.Through the above methods to explore China's prospective contribution to SMC.Results A total of 68 research articles and reports were found.Through gap analysis,we found that despite the delays in the SMC campaign,11.8 milion children received SMC in 2020.However,there remained some challenges:(1)a shortage of fully covered monthly courses;(2)lack of adherence to the second and third doses of amodiaquine;(3)four courses of SMC are not sufficient to cover the entire malaria transmission season in areas where the peak transmission lasts longer;(4)additional interventions are needed to consolidate SMC efforts.China was certified malaria-free by WHO in 2021,and its experience and expertise in malaria elimination can be shared with high-burden countries.With the potential to join the multilateral cooperation in SMC,including the supply of quality-assured health commodities,know-how transfer and experience sharing,China is expected to contribute to the ongoing Scale-up of SMC.Conclusions A combination of necessary preventive and curative activities may prove beneficial both for targeted populations and for health system strengthening in the long run.More actions are entailed to promote the partner-ship and China can be one of the main contributors with various roles.

Chemoprevention of neuroblastoma: progress and promise beyond uncertainties

Neuroblastoma is the most common extracranial solid tumor in children and comprises one-tenth of all childhood cancer deaths.The current clinical therapy for this deadly disease is multimodal,involving an induction phase with alternating regimens of high-dose chemotherapeutic drugs and load reduction surgery;a consolidation phase with more intensive chemotherapy,radiotherapy,and stem cell transplant;and a maintenance phase with immunotherapy and immune-activating cytokine treatment.Despite such intensive treatment,children with neuroblastoma have unacceptable life quality and survival,warranting preventive measures to regulate the cellular functions that orchestrate tumor progression,therapy resistance,metastasis,and tumor relapse/recurrence.Globally,active efforts are underway to identify novel chemopreventive agents,define their mechanism(s)of action,and assess their clinical benefit.Some chemoprevention strategies(e.g.,retinoids,difluoromethylornithine)have already been adopted clinically as part of maintenance phase therapy.Several agents are in the pipeline,while many others are in preclinical characterization.Here we review the classes of chemopreventive agents investigated for neuroblastoma,including cellular events targeted,mode(s)of action,and the level of development.Our review:(i)highlights the pressing need for new and improved chemopreventive strategies for progressive neuroblastoma;(ii)lists the emerging classes of chemopreventive agents for neuroblastoma;and(iii)recognizes the relevance of targeting dynamically evolving hallmark functions of tumor evolution(e.g.,survival,differentiation,lineage transformation).With recent gains in the understanding of tumor evolution processes and preclinical and clinical efforts,it is our strong opinion that effective chemopreventive strategies for aggressive neuroblastoma are a near reality.

An update on clinical trials for chemoprevention of human skin cancer

The pathophysiology of skin cancer is complex,with multiple factors contributing to its development.The proactive treatment of skin cancer has been investigated in the form of chemoprevention of cutaneous malignancies in clinical trials.Chemoprevention is the use of natural or pharmacologic agents that prevent or reverse skin cancer development.Multiple trials have arisen over the past decades to explore the efficacy of specific agents to halt the progression of UV radiation damage.This comprehensive review article aims to assess clinical trials performed with chemopreventive agents for melanoma and nonmelanoma skin cancers.The following compounds were most often used in these trials:nicotinamide,retinoids,polyphenolic antioxidants,COX-2 selective inhibitors,non-steroidal anti-inflammatory drugs,difluoromethylornithine,and 5-fluorouracil.Many agents show promise in their ability to prevent nonmelanoma skin cancer formation,with few melanoma trials demonstrating efficacy.The chemoprevention efforts aimed at skin cancer are complex;current and future trials will be instrumental in identifying therapeutic agents that pose efficacy in halting cancer development and assessing whether long-term administration is tolerable.