Hepatocellular carcinoma in Asia: Prevention strategy and planning

AIM: To review all of epidemiological and etiological aspects of hepatocellular carcinoma(HCC) and examined the prevention of this disease in Asia.METHODS: We conducted a systematic review according to the PRISMA guidelines. We were chosen articles that published previously, from Pub Med(MEDLINE), the Cochrane database and Scopus. The key words used in this research were as follows: HCC in Asia and the way of prevention of this disease, with no language limitations. We selected those papers published before 2014 that we considered to be most important and appropriate. All relevant articles were accessed in full text and all relevant materials was evaluated and reviewed.RESULTS: More than 70% of all new cases of liver cancer were diagnosed in Asia, a region that 75% of all those chronically infected with hepatitis B virus(HBV) in the world. Chronic HBV infection is the main cause of HCC in Asia, where the virus is endemic and vertical transmission is common. Japan, Saudi Arabia, Egypt and Pakistan are exception because of high prevalence of HCV infection in these regions. The prevalence of this cancer is high in Eastern and South-Eastern Asia, But Middle Eastern countries are characterized as moderate prevalence rate of HCC region and Central Asia and some part of Middle Eastern countries are known as low prevalence rate of HCC. In addition of HBV and HCV the other factors such as aflatoxin, alcohol, obesity, diabetes and non-alcoholic fatty liver disease(NAFLD) might be responsible for a low prevalence of HCC in Asian countries. Currently available HCC therapies, chemotherapy, surgical are inefficient, mainly due to usually late diagnosis and high recurrence rates after surgical resection, and usually end with treatment failure. Liver transplantation also remains as a difficult strategy in patients with HCC. Thus prevention of HCC by treating and prevention HBV and HCV infection, the major causative agents of HCC, and the other riskfactors such as aflatoxin, alcohol, obesity, diabetes and NAFLD is of a great medical importance. CONCLUSION: The main challenge which still present in Asia, is the high prevalence of chronic hepatitis.So, prevention of HBV and HCV is the key strategy to reduce the incidence of HCC in Asia.

Increased burden of colorectal cancer in Asia

The incidence and mortality of colorectal cancer(CRC) is rising rapidly in Asia.It seems that ethnicity has an important etiological role in CRC in Asia.However the incidence,anatomical distribution and mortality of CRC among Asian populations are not different from those in Western countries.There is little support by health authorities for CRC screening and very low public awareness of this emerging epidemic in Asia.The increasing rate of CRC in Asia means that we need to take action immediately to prevent CRC and to diagnose the disease at the early stages by introducing CRC screening in countries at high risk of an increasing burden of CRC.

Non-alcohol fatty liver disease in Asia:Prevention and planning

AIM:To review all of epidemiological aspects of nonalcoholic fatty liver disease(NAFLD) and also prevent this disease is examined.METHODS:We conducted a systematic review according to the PRISMA guidelines.All searches for writing this review is based on the papers was found in Pub Med(MEDLINE),Cochrane database and Scopus in August and September 2014 for topic of NAFLD in Asia and the way of prevention of this disease,with no language limitations.All relevant articles were accessed in full text and all relevant materials was evaluated and reviewed.RESULTS:NAFLD is the most common liver disorder in worldwide,with an estimated with 20%-30% prevalence in Western countries and 2%-4% worldwide.The prevalence of NAFLD in Asia,depending on location(urban vs rural),gender,ethnicity,and age is variable between 15%-20%.According to the many studies in the world,the relationship between NAFLD,obesity,diabetes mellitus,and metabolic syndrome(MS) is quiet obvious.Prevalence of NAFLD in Asian countries seems to be lower than the Western countries but,it has increased recently due to the rise of obesity,type 2 diabetes and MS in this region.One of the main reasons for the increase in obesity,diabetes and MS in Asia is a lifestyle change and industrialization.Today,NAFLD is recognized as a major chronic liver disease in Asia.Therefore,prevention of this disease in Asian countries is very important and the best strategy for prevention and control of NAFLD is lifestyle modifications.Lifestyle modification programs are typically designed to change bad eating habits and increase physical activity that is associated with clinically significant improvements in obesity,type 2 diabetes and MS.CONCLUSION:Prevention of NAFLD is very importantin Asian countries particularly in Arab countries because of high prevalence of obesity,diabetes and MS.

Colorectal cancer screening:Time for action in Iran

Colorectal cancer(CRC) is now the third most common cause of cancer-related deaths in the world.According to the Iranian Annual National Cancer Registration Report,CRC is the third most common cancer in Iranian women and fifth in men.The incidence of CRC has increased during the last 25 years.CRC screening is an efficient way to reduce the burden of CRC through detection of precursor lesions of cancer or early stage cancer.Iran may benefit even more from screening programs.According to recent studies,the prevalence of colorectal adenoma in first degree relatives of patients diagnosed with CRC is significantly higher than in the average risk population.So,appropriate screening strategies,especially in relatives of patients,should be considered as the first step of CRC screening in Iran.

Bayesian adjustment for over-estimation and under-estimation of gastric cancer incidence across Iranian provinces

AIM To correct the misclassification in registered gastric cancer incidence across Iranian provinces in cancer registry data. METHODS Gastric cancer data is extracted from Iranian annual of national cancer registration report 2008. A Bayesian method with beta prior is implemented to estimate the rate of misclassification in registering patient'spermanent residence in neighboring province. Each time two neighboring provinces with lower and higher than 100% expected coverage of cancer cases are selected to be entered in the model. The expected coverage of cancerous patient is reported by medical university of each province. It is assumed that some cancer cases from a province with a lower than 100% expected coverage are registered in their neighboring province with more than 100% expected coverage. RESULTS The condition was true for 21 provinces from a total of 30 provinces of Iran. It was estimated that 43% of gastric cancer cases of North and South Khorasan provinces in north-east of Iran was registered in Razavi Khorasan as the neighboring facilitate province; also 72% misclassification was estimated between Sistan and balochestan province and Razavi Khorasan. The misclassification rate was estimated to be 36% between West Azerbaijan province and East Azerbaijan province, 21% between Ardebil province and East Azerbaijan, 63% between Hormozgan province and Fars province, 8% between Chaharmahal and bakhtyari province and Isfahan province, 8% between Kogiloye and boyerahmad province and Isfahan, 43% Golestan province and Mazandaran province, 54% between Bushehr province and Khozestan province, 26% between Ilam province and Khuzestan province, 32% between Qazvin province and Tehran province(capital of Iran), 43% between Markazi province and Tehran, and 37% between Qom province and Tehran. CONCLUSION Policy makers should consider the regional misclassification in the time of programming for cancer control, prevention and resource allocation.

Bayesian adjustment of gastric cancer mortality rate in the presence of misclassification

To correct for misclassification error in registering causes of death in Iran death registry using Bayesian method. METHODSNational death statistic from 2006 to 2010 for gastric cancer which reported annually by the Ministry of Health and Medical Education included in this study. To correct the rate of gastric cancer mortality with reassigning the deaths due to gastric cancer that registered as cancer without detail, a Bayesian method was implemented with Poisson count regression and beta prior for misclassified parameter, assuming 20% misclassification in registering causes of death in Iran. RESULTSRegistered mortality due to gastric cancer from 2006 to 2010 was considered in this study. According to the Bayesian re-estimate, about 3%-7% of deaths due to gastric cancer have registered as cancer without mentioning details. It makes an undercount of gastric cancer mortality in Iranian population. The number and age standardized rate of gastric cancer death is estimated to be 5805 (10.17 per 100000 populations), 5862 (10.51 per 100000 populations), 5731 (10.23 per 100000 populations), 5946 (10.44 per 100000 populations), and 6002 (10.35 per 100000 populations), respectively for years 2006 to 2010. CONCLUSIONThere is an undercount in gastric cancer mortality in Iranian registered data that researchers and authorities should notice that in sequential estimations and policy making.

Trend of hepatocellular carcinoma incidence after Bayesian correction for misclassified data in Iranian provinces

To study the trend of hepatocellular carcinoma incidence after correcting the misclassification in registering cancer incidence across Iranian provinces in cancer registry data. METHODSIncidence data of hepatocellular carcinoma were extracted from Iranian annual of national cancer registration reports 2004 to 2008. A Bayesian method was implemented to estimate the rate of misclassification in registering cancer incidence in neighboring province. A beta prior is considered for misclassification parameter. Each time two neighboring provinces were selected to be entered in the Bayesian model based on their expected coverage of cancer cases which is reported by medical university of the province. It is assumed that some cancer cases from a province that has an expected coverage of cancer cases lower than 100% are registered in their neighboring facilitate province with more than 100% expected coverage. RESULTSThere is an increase in the rate of hepatocellular carcinoma in Iran. Among total of 30 provinces of Iran, 21 provinces were selected to be entered to the Bayesian model for correcting the existed misclassification. Provinces with more medical facilities of Iran are Tehran (capital of the country), Razavi Khorasan in north-east of Iran, East Azerbaijan in north-west of the country, Isfahan in central part and near to Tehran, Khozestan and Fars in south and Mazandaran in north of the Iran, had an expected coverage more than their expectation. Those provinces had significantly higher rates of hepatocellular carcinoma than their neighboring provinces. In years 2004 to 2008, it was estimated to be on average 34% misclassification between North Khorasan province and Razavi Khorasan, 43% between South Khorasan province and Razavi Khorasan, 47% between Sistan and balochestan province and Razavi Khorasan, 23% between West Azerbaijan province and East Azerbaijan province, 25% between Ardebil province and East Azerbaijan province, 41% between Hormozgan province and Fars province, 22% betweenChaharmahal and bakhtyari province and Isfahan province, 22% between Kogiloye and boyerahmad province and Isfahan, 22% between Golestan province and Mazandaran province, 43% between Bushehr province and Khozestan province, 41% between Ilam province and Khuzestan province, 42% between Qazvin province and Tehran province, 44% between Markazi province and Tehran, and 30% between Qom province and Tehran. CONCLUSIONAccounting and correcting the regional misclassification is necessary for identifying high risk areas and planning for reducing the cancer incidence.