*1.2.1 Improving life expectancy*

The culture of Vietnam is a combination between Chinese and French because the country was occupied by China for nearly 1000 years and by France for around 100 years in the past. As colorectal cancer is reported to have connection with Western dietary habits, it is a favorable condition to observe its distribution and etiologies in Vietnam.

Located in Southeast Asia, Vietnam is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the East Sea to the east. With a population of approximately 96,491,142 people in 2018 [4], Vietnam is the 13th most populous country in the world. The Socialist Republic of Vietnam has placed a significant emphasis on economic development since the introduction of the "Doi moi" (the economic reform) in 1986. As a result, Vietnam has achieved significantly in a short amount of time. For example, the percentage of the population living on less than a dollar a day has decreased from 58–29% over 10 years, and the life expectancy of Vietnamese people has reached 71 years for men and 75 years for women [5–7]. These progressing economics and urbanizations have changed lifestyles, dietary habits, increasing pollutions in living and working environments, which might be associated with the occurrence of colorectal cancer.

### *1.2.2 Developing descriptive cancer epidemiology*

Regarding the source of data of colorectal cancer, for many countries, civil registration and vital statistics systems are considered the main sources for mortality data [8]. Civil registration was initiated in Vietnam in 1956, and despite the 50 years of collecting data about cancer mortality, limited information was published [9]. However, a recent study assessed the civil registration and vital statistics system in Vietnam and reported that the system had significant restrictions including a lack of data particularly about early neonatal deaths, deaths of temporary residents, and/or migrants [9].

Beyond Vietnam's civil registration and vital statistics system, a national mortality reporting system was introduced in 1992 and periodic updating guidelines to improve the quality of data collecting [10]. Under the auspices of the Ministry of Health (MOH), the A6 mortality reporting system relies on commune-level health officials providing basic demographic data and information on the cause of death, which is recorded in an official book referred to as the A6. The data from the A6 is collated by the district-level health service and the information is then sent to the provincial and central level governments. The community plays a significant role in maintaining the current mortality reporting system, and in turn, can actively use the information to plan commune-level health services. Using the A6 system, mortality data regarding cancer were collected and analyzed [11–14]. Verbal autopsy designed by WHO was applied in the community to determine all causes of death, including cancer [15]. Using the verbal autopsy as a reference, the sensitivity and completeness of the system were observed to be about 80% and 94%, respectively [16]. These findings have suggested that the accuracy and completeness of cancer mortality are feasible, and therefore, it was a source of data for colorectal cancer presented in the present study. The A6 system, with the detailed recordings of deaths in all communes, can easily be conveniently used by health workers. In Vietnam, during the last decade, 7081 (65.1%) medical doctors were working at commune health stations (CHS) [6, 17, 18]. Health workers are trained and work at CHS and they will contribute to the improvement of the mortality data quality and registration completeness gradually soon. Cancer epidemiology and populationbased cancer registration were introduced by IARC during the 1980s, focused in the two biggest cities, Hanoi and Ho Chi Minh, representing the north and south of Vietnam, respectively. Cancer incidence during 1988–1997 in the Hanoi city and 1995–1998 in the Ho Chi Minh city was published by IACR [19–21]. Data on

**35**

deaths per year [4].

*Colorectal Cancer in Vietnam*

*DOI: http://dx.doi.org/10.5772/intechopen.93730*

*1.2.3 Developing analytical cancer epidemiology*

colorectal cancer incidence produced by these two population-based cancer registries include a database of cancer mortality extracted from MOH's national mortal-

Cancer was observed to be the second most common cause of death nationwide during 2005–2006 (about 16%) [11, 12, 14], after vascular heart diseases (about 25%). Colorectal cancer (ICD-10: C18–20) has occurred at a national level in Vietnam. This study aims to generate a comprehensive picture of the fatal disease in the eight regions of Vietnam, with the hope to facilitate epidemiological studies in our country. For data of risk factors of colorectal cancer, we conducted a molecular epidemiological case–control study on the incident cases of the disease from 2002 to 2011. The study was designed by the leading experts of cancer epidemiologists from Japan and Vietnam. The protocol was approved by the scientific and ethics committees of the MONBUKAGAKUSHO (Japan) and the Ministry of Science and Technology

(Vietnam). Initial results and findings were published elsewhere [22–24].

From 2005 to 2006, we reported 4646 cases of fatal colorectal cancer among all 93,719 cancer death cases. It was responsible for about 5% of all cancer cases. Colorectal cancer was distributed in all 671 districts within 63 provinces/cities of Vietnam. Among 4646 colorectal cases, there were 2450 men (52.7%). The average age at death was 62 in men and 66 in women [14]. In 2002, the estimated number of death from colorectal cancer was 1730 cases in men and 2401 cases in women, provided that the total number of cases was 4131 [25]. The average reported

number per year was 2323 cases in 2005–2006, which was only 56% of the estimated number of 4131 cases. According to GLOBOCAN 2018, colon ranked the fifth in the incidence and mortality among malignant diseases, with 5457 new cases and 3183

These characteristics suggest that an epidemiological study must be performed: Colorectal cancer caused thousands of deaths in Vietnam, and it was considered

Causality and risk factors of colorectal cancer were presented at nationwide because the cancer was observed in all 671 districts within all 63 provinces/cities. Therefore, we should observe and examine etiology and causality at the household

Registration of colorectal cancer mortality nationwide might be underreported for about 40% of total cases. Data on cancer mortality registration will promptly be improved and it will be used for cancer control and prevention in our country. Using referred data of cancer from China to estimate the cancer incidence and mortality of all sites as well as of colorectal cancer, it might be an overestimated

• Colorectal cancer caused premature death for an average of 7.3 years [18].

as one of the most important public health problems in our country.

and community levels in identifying and controlling risk factors.

**2. Characteristics of colorectal cancer cases in Vietnam**

**2.1 The occurrence of colorectal cancer at nationwide**

**2.2 Colorectal cancer caused a premature death**

colorectal cancer in 2002 for Vietnam [25].

ity reporting system that was also used to present in the study.

### *Colorectal Cancer in Vietnam DOI: http://dx.doi.org/10.5772/intechopen.93730*

*Colorectal Cancer*

etiologies in Vietnam.

and/or migrants [9].

100 years in the past. As colorectal cancer is reported to have connection with Western dietary habits, it is a favorable condition to observe its distribution and

might be associated with the occurrence of colorectal cancer.

*1.2.2 Developing descriptive cancer epidemiology*

Located in Southeast Asia, Vietnam is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the East Sea to the east. With a population of approximately 96,491,142 people in 2018 [4], Vietnam is the 13th most populous country in the world. The Socialist Republic of Vietnam has placed a significant emphasis on economic development since the introduction of the "Doi moi" (the economic reform) in 1986. As a result, Vietnam has achieved significantly in a short amount of time. For example, the percentage of the population living on less than a dollar a day has decreased from 58–29% over 10 years, and the life expectancy of Vietnamese people has reached 71 years for men and 75 years for women [5–7]. These progressing economics and urbanizations have changed lifestyles, dietary habits, increasing pollutions in living and working environments, which

Regarding the source of data of colorectal cancer, for many countries, civil registration and vital statistics systems are considered the main sources for mortality data [8]. Civil registration was initiated in Vietnam in 1956, and despite the 50 years of collecting data about cancer mortality, limited information was published [9]. However, a recent study assessed the civil registration and vital statistics system in Vietnam and reported that the system had significant restrictions including a lack of data particularly about early neonatal deaths, deaths of temporary residents,

Beyond Vietnam's civil registration and vital statistics system, a national mortality reporting system was introduced in 1992 and periodic updating guidelines to improve the quality of data collecting [10]. Under the auspices of the Ministry of Health (MOH), the A6 mortality reporting system relies on commune-level health officials providing basic demographic data and information on the cause of death, which is recorded in an official book referred to as the A6. The data from the A6 is collated by the district-level health service and the information is then sent to the provincial and central level governments. The community plays a significant role in maintaining the current mortality reporting system, and in turn, can actively use the information to plan commune-level health services. Using the A6 system, mortality data regarding cancer were collected and analyzed [11–14]. Verbal autopsy designed by WHO was applied in the community to determine all causes of death, including cancer [15]. Using the verbal autopsy as a reference, the sensitivity and completeness of the system were observed to be about 80% and 94%, respectively [16]. These findings have suggested that the accuracy and completeness of cancer mortality are feasible, and therefore, it was a source of data for colorectal cancer presented in the present study. The A6 system, with the detailed recordings of deaths in all communes, can easily be conveniently used by health workers. In Vietnam, during the last decade, 7081 (65.1%) medical doctors were working at commune health stations (CHS) [6, 17, 18]. Health workers are trained and work at CHS and they will contribute to the improvement of the mortality data quality and registration completeness gradually soon. Cancer epidemiology and populationbased cancer registration were introduced by IARC during the 1980s, focused in the two biggest cities, Hanoi and Ho Chi Minh, representing the north and south of Vietnam, respectively. Cancer incidence during 1988–1997 in the Hanoi city and 1995–1998 in the Ho Chi Minh city was published by IACR [19–21]. Data on

**34**

colorectal cancer incidence produced by these two population-based cancer registries include a database of cancer mortality extracted from MOH's national mortality reporting system that was also used to present in the study.
