Development of a semi-quantitative food frequency questionnaire for dietary studies--focus on vitamin C intake.

The present work aimed to provide a basis for examination of intake of selected food items determined with a semi-quantitative food frequency questionnaire (SQFFQ) and planned-food selection (PFS). From February to July of 2003, ninety one cancer patients and 90 matched (same sex and age within 5 years) non-cancer patients were directly interviewed by trained interviewers using the designed questionnaire at the inpatient-department of Viet Duc hospital, Ha Noi City, Viet Nam. Study subjects consumed more SQFFQ-food items than PFS-food items, so that the latter method might not accurately reflect dietary habits regarding estimation of nutrient intake, especially vitamins. Because these are beneficial factors acting against cancer development at many sites, the absence of food items selected by SQFFQ may result in a poor database regarding possible confounding factors. For futher clarification we then focused on vitamin C contributions of Vietnamese food and analyzed data of the National Nutritional Household Survey in 2000: 7,686 households throughout the country (vitamin C intake status) and 158 households with 741 persons of the population of Hanoi city (individual food items contributing to vitamin C). Direct interview using a validated questionnaire with an album of current Vietnamese food items-recipes and weighing checks was conducted to obtain information regarding all types of food intake over the last 24-hours. Contribution analysis using the Nutritive Composition Table of Vietnamese Foods, revision 2000, and stepwise regression analysis was applied. Average intake adjusted by ages of vitamin C per person per day was estimated. In total, the study subjects were found to currently consume 184 food items. Average intake of vitamin C was 72.5 mg per person per day at the national level: 57.9% from leafy vegetables, 33.4% from fresh fruits, and 6.4% from non-leafy vegetables. For vitamin C contribution, the highest 25 food items contributed to a cumulative 95.3% of vitamin C intake with a cumulative R2=0.99.

Gastric and colo-rectal cancer mortality in Viet Nam in the years 2005-2006.

BACKGROUND: The International Collaborative Epidemiological Study of Host and Environmental Factors for Stomach and Colorectal Cancers in Southeast Asian Countries (SEACs) has been conducted in Viet Nam from 2003 to 2008 on a case-control basis. For further effective primary prevention, we examined gastric and colorectal cancer mortality nationwide in eight regions of Viet Nam in 2005-06. METHODS: Both demographic data and lists of all deaths in 2005-06 were obtained from all 10,769 commune health stations in Viet Nam. Five indicators included name, age, sex, date of death and cause of death was collected for each case. We selected only communes having the list of deaths with clear cause for each case and crude mortality rate for all causes from 300-600/100,000 as published by the Ministry of Health for a reasonable accuracy and completeness. Obtained data for all causes, all cancers, stomach and colorectal cancer deaths as well as demographic information were processed using Excel software and exported to STATA 8.0 for estimation of world age-standardized cancer mortality rates per 100,000. RESULTS: Data were available for 1,246 gastric cases, (819 male and 427 female) with age-standardized mortality rates from 12.7 to 31.3 per 100,000 in males and from 5.9 to 10.3 per 100,000 in females in the 8 regions of the country. For colorectal cancers, 542 cases (268 male and 274 female) gave mortality rates from 4.0 to 11.3 per 100,000 in males and from 3.0 to 7.8 per 100,000 in females. DISCUSSION: Stomach cancer mortality in males in the region of North East in the North Viet Nam (2005-06) was higher than that in Japan (2002) (31.3 versus 28.7 per 100,000) while colorectal cancer in Viet Nam was lower. While prevalence of Helicobacter pyloris infection in Viet Nam was from 70-75% in both males and females, the stomach cancer rate in males was significantly higher than in females, 31.3 versus 6.8 per 100,000, suggesting an influence of other environmental risk factors. Whether protective factors are operating against colorectal cancer in Viet Nam now needs to be explored.

Cancer mortality pattern in Viet Nam.

BACKGROUND: Health information in general and cancer information in particular in Viet Nam is an basic data for decisions related to health planning prevent against cancer. However, very limited database of cancer information bas been available to date. The aim of the present study was to examine cancer mortality pattern nationwide in Viet Nam. METHODS: Descriptive cancer epidemiology was designed for the present study. Both demographic data and list of all deaths during the two years period, 2005-06, were obtained from all 10,769 commune health stations. Five indicators included name, age, sex, date of death and cause of death was collected for each case. A guideline to report demographic data of each commune and information of each case who has been lived at least 6 months in their commune was prepared in the designed form and sent by express mail service to all the heads of 10,769 commune health stations throughout country. The data comprises all cancer mortality records at the commune-level for the period 2005-06. All obtained data of cancer deaths as well as demographic information was computed using Excel software. The Excel data was exported to STATA 8.0 for cancer analysis. Cancer case was coded following ICD-10. RESULTS: To date, 94.6% of the 10,769 communes (from the 638 of 671 districts within the 64 provinces) have forwarded the required data and we currently have approximately 93,719 cancer deaths for the 2 years period. Number of person-year was 76,726,873 in 2005 and 77,902,688 in 2006. Number of cancer deaths was 45,413 (29,189 males and 16,224 females) in 2005 and 48,306 (31,447 males and 16,859 females) in 2006. Male to female ratios were 1.8 and 1.9 in 2005 and 2006, respectively. Three most common cancer sites numbered of 61,079 (65% of all 93,719 cancer deaths) included 25,410 liver cancer; 22,209 lung cancer; and 13,460 stomach cancer. Among both males and females, liver cancer was ranked in the first most common (31,04% and 19.91%), followed by lung cancer (26.69% and 18.21%) and stomach (14.42% and 14.26%). Among females, cervix and other female genital cancers were ranked in the four most common (9.13%) and breast cancer was about 5.69%. CONCLUSIONS: Participated proportion of nationwide administration units and population was over 90% to report about 93,719 deaths from cancer that suggested that cancer has been highly concerned by social as well as people due to a number of thousand life lost. This condition will accept well primary cancer prevention at commune level in Viet Nam to eliminate the ancient disease of cancer in human.

Population-based cancer survival in sites in Viet Nam.

BACKGROUND: Very few population-based cancer survival studies have been performed in Viet Nam. The aim of the present study was to estimate observed and relative cancer survival rates in populations of Phu Tho, Hanoi and Hue city. METHODS: A retrospective-cohort study was performed for all 12 districts of Phu Tho province (semi-highland area in the north), eight districts of Hanoi city (Capital) and four districts of Hue city in central area). Seven indicators were collected for each case of cancer death: name, age, sex, date of the first diagnosis having cancer, date of death, the cause of death and full address. Two steps were done. Firstly, we collected name, age, sex, date of death, the cause of death and full address; secondly, we collected date of the first diagnosis having cancer by a household visit by trained interviewer. Survival time was calculated from the date of death minus the date of diagnosis for each case of cancer. Observed survival rates for 1-year, 2-years, 3-years, 4-years and 5-years were estimated by the form of survival number multiplied by 100 then corrected for the registered number of cancer cases. For relative survival rates, the observed survival rates were corrected for the general population survival rate. RESULTS: Males and females combined, for all cancer sites, 1-year, 2-year, 3-year, 4-year and 5-year observed and relative survival rates were 23.8%-23.9%, 8.5%-8.5%, 3.8%-3.8%, 2.6%-2.6%, 1.7%-1.7%, respectively. The highest one-year relative cancer survival rate was seen in the capital, Hanoi city (49,8%), followed by Hue city in the central area (24,7%), and the lowest in Phu Tho, north-semi-highland (21.8%). CONCLUSIONS: The better cancer survival in Hanoi than in Phu Tho province, as well as the results overall, point to a need for greater efforts in early detection and treatment, especially in rural areas.

Anti-smoking initiative and decline in incidence rates of lung cancer in Viet Nam.

Viet Nam had the highest reported male smoking prevalence rate (72.8-74.3%) in the world in the 1990s. Production of tobacco products was about 0.44 kg or 600 cigarettes per capita per year in 1994 for domestic use. Population-attributable risk per cent of lung cancer due to smoking was about 69.7%. Males in the south have a lower reported smoking prevalence rate (OR=0.7) and a significant lower incidence rate of lung cancer, age-standardized-incidence-rate per 100,000 (ASR) 33.1 vs 24.6 when compared to males in the north. Incidence rates of lung cancer significantly declined in Hanoi (ASR 34.9-33.1 and 6.3-5.8) and Ho Chi Minh City (ASR 24.6-23.7 and 6.8-5.6) between 1991-1997 and at the national level between 1990-2000 (ASR 30.4-30.1 and 6.7-6.6) in males and females, respectively. This decline in incidence rate of lung cancer resulted from the great achievements of the National Tobacco Control Program over about a 10-year period from 1989 to help people stop smoking. The present finding should stimulate further primary cancer prevention efforts in developing countries, including Viet Nam. It also suggests that the method applied to translate scientific evidence of smoking harm to people and into health policy, is a useful tool to drive people's attitude to stop smoking and remove its human carcinogens from our society.

Development of population-based cancer mortality registration in the North of Viet Nam.

BACKGROUND: Regional cancer distributions provide useful pointers to potential environmental risk factors. Cancer death registration data are also basic for checking completeness of population-based registration of cancer incidence. The aim of the present project was to develop population-based cancer mortality registration in various regions in the North of Viet Nam. METHODS: Cancer data were accessed from the database of population-routine-based death registration performed by medical workers at commune health stations based on the guidelines of the Ministry of Health. All deaths occurring in the communities were registered and the registration process was monthly reviewed for each fatal case regarding the name, age, sex, address, occupation, date-place-cause of death, and information concerning to pre-death medical care during the study period from 1999 to 2005. The list of deaths and residents of the study population were carefully cross-checked with other information sources to avoid under or over registration. The study sites were Red River Delta areas and a high-mountain area. The world population structure was used to estimate age-standardized cancer mortality rates per 100,000 (ASR). RESULTS: During 4,330,620 person-years estimated during 1999 to 2005, 21,108 deaths were registered. The crude death rate from all causes was 487.4/100,000. Among them, 4,244 cancers in all sites (2,835 in males and 1,409 in females) were registered, giving mortality rates/100,000 of 134.6 and 63.3 (crude), and 155.7 and 54.3 (ASR), for males and females, respectively. The rate for the high-mountain area was only half (45.5) those in the Red River Delta (95.2-117.4). Male to female ratios were ranked from 2.2 to 3.1. Cancer accounted for about 20% of all causes of death. CONCLUSIONS: The present findings suggest that in Viet Nam, development of reliable population-based cancer mortality registration is feasible and practical.

Cancer mortality in a Hanoi population, Viet Nam, 1996-2005.

BACKGROUND: Hitherto, cancer mortality data have not been available in Viet Nam, so that the real public health problem with this disease has yet to be addressed and recognized in the country with a population of over 80 million in South East Asia. The aim of the present pilot study was to examine cancer mortality in a commune population of Hanoi city, 1996-2005. METHODS: Cancer data was accessed from the database of the population-routine-based death registration performed by medical workers at commune health stations based on the guidelines of the Ministry of Health at Hanoi city. All deaths occurring in the community were registered. This registration process was monthly reviewed for each fatal case regarding the name, age, sex, address, occupation, date-place-cause of death, and information concerning to pre-death medical care during the study period from Jan. 1996 to Dec. 2005. The list of death and residents of the study population was carefully cross-checked with other information sources to avoid under- or over-registration. The world population structure was used to estimate age-standardized cancer mortality rates per 100,000, (ASR). RESULTS: During 60,770 person-years estimated from Jan. 1996 to Dec. 2005, 320 deaths and their causes were registered. Among them, 100 cancer cases of all sites (66 males and 34 females) were included. Cancer mortality rates were 222 and 109 (Crude), 353 and 115 (ASR), for males and females, respectively. For both genders combined, lung cancer was the most common, 27 cases, followed by liver, 26 cases and stomach, with 19. Proportion of death from cancer was about 31% of all causes. CONCLUSIONS: The present findings suggest that in Viet Nam, a developing country, cancer is indeed an important public health problem.

Grand challenges in global health and the practical prevention program? Asian focus on cancer prevention in females of the developing world.

In response to the request for 'Breakthrough Questions' for 'Grand Challenges in Global Health' recently published in Nature, the Asian Pacific Organization for Cancer Prevention should focus its attention on what projects are of the highest priority for integration with its Practical Prevention Program (PPP). The most common female cancers in most of the countries of Asia are carcinoma of the breast, followed by the uterine cervix. While the incidences of breast adenocarcinomas are still generally lower than in the Western world they are rapidly increasing, and squamous cell carcinomas of the cervix are a major problem. Clearly there are many areas which would reward research. One factor which appears of major relevance in the mammary gland case is the diet, and particularly the phytoestrogens included in 'tofu', along with physical exercise. The age at which these could be operating needs to be elucidated, with reference to timing of menarche and menopause, and also breast mammographic density, another predictor of likelihood of neoplasia. In the cervix, the predominant influence is well established to be persistent infection with a high risk 'oncogenic' type of human papilloma virus (HPV). Vaccines therefore hold much promise, but a better understanding of the mechanisms underlying spontaneous clearance of both infection and cervical intraepithelial neoplasia (CIN) of different grades is also essential for optimal intervention. The roles of smoking and antioxidant intake in particular deserve emphasis. In Asia, with the considerable variation evident in both breast and cervical cancer incidence rates, as well as in cultural and other environmental factors, we are in a very favourable position to meet two specific challenges: 1). elucidation of how diet in adolescence determines susceptibility to neoplasia of the mammary glands; and 2). determination of what governs persistence of HPV infection. Realisation of these pivotal research aims, with especial emphasis on the context of the PPP, is our shared goal.