Cancer Incidence In The Population Of Thua Thien Hue Province, Vietnam, 2001-2009 – Nguyen Dinh Tung

499 JOURNAL OF SCIENCE, Hue University, N0 61, 2010 CANCER INCIDENCE IN THE POPULATION OF THUATHIEN HUE PROVINCE, VIETNAM, 2001-2009 Nguyen Dinh Tung Oncology Department of Hue Central Hospital Lecturer of Hue College of Medicine & Pharmacy SUMMARY Hue Central Hospital is the place where the population-based cancer registry was carried out in Thua thien Hue Province. The purpose of this research was to determine the cancer incidence in the community, to contribute to the assessment of cancer burden in the whole country and to analyse the epidemiology characters of some popular cancers in this area. The active registering procedure has been performed, the data were collected from 14 hospitals and disposed of according to the international classification for oncology (ICD-O3). The data was stored in the CANREG software version 4 and was analyzed using EPI-INFO . It was estimated that 7,324 new cancer cases were registered in the period 2001-2009, which included 55.54% and 44.46% males and females respectively. The highest rate of cancer diseases belonged to Hue city (37.76%). There was 87.65% of cancer cases diagnosed by cytology or pathology. The crude rate (CR) was 123.9, the age -standardized rate (ASR) was 173.5 per100,000 inhabitants; those in males and females were 95.3 and 103.9 respectively. The cancers of liver, stomach, lung, oral cavity and non-Hodgkin lymphoma were the leading ones in males. Of these, the liver cancer rate is the highest (ARS 34.8).The leading cancers in females were breast, stomach, lung, liver and oral cavity; and the breast cancer rate is the highest (ARS 21.7). Cancer diseases have increased among inhabitants after the age of 40 years old in Thua thien Hue. These increased more rapidly in males than in females and the age-specific rate was highest among the group of 70-75 years old. Key words: cancer incidence, Thua Thien Hue 1. Introduction Vietnam is the second most populous country in South East Asia with 85 million people, and, it is also one of the poorest nations among developing countries in the world. There was not much information on the pattern of cancer incidence in Vietnam until recently. Data was limited to the description of relative frequencies in hospitals (Luong and Pham, 1964; Luong, 1986, NB Duc 1990, NC Hung 1995). The Hanoi 500 Cancer Registry (in the North of Vietnam) was founded in 1987 (Pham et al., 1993). In 1990, The Cancer Registry was set up in Ho Chi Minh City in the South of Vietnam to develop the hospital -based registry into a population -based cancer registry. Apart from this, the Vietnam Cancer Society was also established in 1989 and one of its objectives was to improve the organization of cancer control activities. The Oncology Department of Hue Central hospital was set up in 1996. The main responsibilities of this department are to organize the cancer control program in the Middle and Highland areas of Vietnam, provide diagnosis, treatment as well as conduct scientific research on cancers. Hue College of medicine and pharmacy and Hue Central Hospital are the training centers for medical staff for the whole region. The Hue Cancer Registry was founded in 2000 to assess the cancer burden in Thua thien Hue province and data collection of cancer patients was gradually expanded in the Middle area of Vietnam. We present in this report the results from this population-based registry for the period of 9 years between January 2001 and December 2009. During this time, 7,234 new cases were recorded among residents of Thua Thien Hue Province. These data are of interest not only in providing a picture of the contemporary cancer profile in the Middle area of Vietnam, but also in permitting a comparison with incidence rates from the North and the South Regions of Vietnam. 2. Methodology Thua Thien Hue is a place with diverse cultural heritage. Up to now, there is no place in Vietnam where so many originally historical vestiges have survived as in Hue - the ancient capital city. Hue is also one of the most important education centers in Vietnam. In December 1993, Hue was approved to be a World Cultural Heritage Site by UNESCO. Thua thien Hue is located in central Vietnam. It covers 5,054 km2 and is divided into 8 districts and 1 capital city (Hue). The estimated population in 2008 was about 1,119,800, comprising 89.9% of Vietnamese (Kinh). Other main ethnicities are Catu and Ta oi. The climate is tropical, with high humidity and an average temperature of about 26°C. It’s season of equatorial rains is between October and February. The population-based registry receives information from the Cancer Registry division of Hue Central Hospital, the Planning Division of Hue University Hospital, 3 private hospitals, 1 Military hospital and 08 district hospitals (among a total of 14 hospitals). The principal data sources are medical records, including outpatient records if they exist, logs and reports of diagnostic laboratories (including all histopathology and cytology services in the city), and the patient logs from polyclinic departments. Death certificates are not used as a source of information; since cause of death is very poorly specified (certification by a medical doctor is not required and is relatively rare, 501 except for hospital deaths). Any case with a permanent address in Thua thien Hue province which had a diagnosis of 'malignancy' made for the first time was registered. This includes cases diagnosed by clinical diagnosis alone, even in out patient departments of district hospitals. Although cancers and tumors without precise specification of whether they were benign or malignant (ICD-O behaviour codes /2 and /1) were registered, they were excluded from the analysis in this article - which included cases with tumors specified as malignant or invasive (behaviour code /3). The date of occurrence of a case is defined as the date of hospital admission or date of diagnosis. The registry uses a computer with the CANREG 04 system for data entry and management, which provides a range of checks on validity of entered data. The population of this 8-district areas and Hue city in 2008 was taken to represent the population at risk. The age-sex distribution of this population is shown in Table 5. Results are presented as numbers of cases by site, sex and age, with crude and age-standardized rates per 100,000 person-years. 3. Results Table 1. Number of cases by year and sex Years 2001 2002 2003 2004 2005 2006 2007 2008 2009 Total % Male 362 294 448 386 485 302 287 745 759 4,068 55.54 Female 311 226 280 321 450 312 219 573 564 3,256 44.46 Total 673 520 728 707 935 614 506 1,318 1,323 7,324 100.00 Table 2. Number of cases by year and Address Code No. Location 2001- 2007 2008 2009 Total % 1 Hue 1,868 472 426 2,766 37.76 2 Phongdien 366 116 105 587 08.01 3 Quangdien 327 96 111 534 07.29 4 Huongtra 440 123 120 683 09.32 5 Phuvang 632 191 237 1,060 14.47 6 Huongthuy 387 94 114 595 08.13 7 Phuloc 460 116 168 794 10.84 8 Aluoi 143 36 29 208 02.83 502 9 Namdong 60 24 13 97 01.32 Total 4,683 1,318 1,323 7,324 100.00 Table 3. Number of cases by Basis Diagnosis No Basis Diagnosis Number of Cases % 1 Cytology of Metastase 163 01.40 2 Clinical Only 367 03.65 3 Clinical Investigation (X ray, Ultrasound...) 645 08.80 4 Exploratory Surgery/ Endoscopy 2385 32.67 5 Cytology or Haematology 3828 52.14 6 Histology of Primary Tumor 106 01.44 Total 7,324 100.00 Table 4. ICD-O Classification ICD-O Sites Male Female Total n % n % % n C00-C14 Lip, oral cavity , Nasopharynx & Hypopharynx 398 09'82 265 8.17 663 9.09 C15-C26 Digestive Organ 1789 43.97 909 27.91 2698 36.83 C30-C39 Bronchus, lung & other thoracic organs 580 14.25 292 8.96 872 11.90 C40,41,45- 49 Bone, Connective, Soft tissue 166 04.08 173 5.31 339 4.62 C42,C77 Lympho malin & Leukaemia 358 08.80 207 06.35 565 07.72 C44 Skin 42 01.03 31 00.95 73 01.00 C50 Breast 14 00.34 585 17.96 599 08.17 C51-C58 Cervix, Corpus Uteri & others 0 00.00 458 14.06 458 06.25 503 C60-C63 Prostate, Testis , Penis 122 02.99 0 00.00 122 01.67 C64-C68 Kidney & other Urinary organs 187 04.60 75 02.30 262 03.59 C69-C72 Brain, Nervous system 87 02.13 53 01.62 140 01.91 C73-C75 Thyroid gland & other endocrines 53 01.30 98 03.00 151 02.06 C76-C80 Others 256 06.04 124 04.11 380 05.18 C00-C80 All sites total 4,068 100.00 3,256 100.00 7,324 100.00 Table 5.: Age Standard Population of Thua Thien Hue Province in 2008 Standard pop. : World Ages Male Female 0-4: 74093 70443 : 12000 5-9: 64507 61287 : 10000 10-14: 60581 57049 : 9000 15-19: 68489 63782 : 9000 20-24: 58245 52851 : 8000 25-29: 48949 45744 : 8000 30-34: 43863 41073 : 6000 35-39: 42312 40620 : 6000 40-44: 35771 36609 : 6000 45-49: 26831 29669 : 6000 50-54: 23348 26522 : 5000 55-59: 15378 18025 : 4000 60-64: 10083 13540 : 4000 65-69: 8763 12762 : 3000 70-74: 7950 12163 : 2000 75 + : 10942 17948 : 2000 ??? : 0 0 504 ------ ------ ------ Tot. : 600105 600087: 100000 Table 6. Cancer incidence in Thua Thien Hue Gender Population N. of Cases % Crude Rate Age Standard Rate Males 600,105,000 745 56.52 123.9 173.5 Females 600,087,000 573 43.48 95.3 103.9 Table 7. Ten of leading cancers in males No Sites N. of Cases Crude Rate ASR world ICD ( 10 th ) 1 Liver 138 22.9 34.8 C22 2 Stomach 137 22.8 31.3 C16 3 Bronchus, lung 101 16,8 24.6 C33- C34 4 Oral Cavity 50 08.3 11.5 C03-C06 5 Non-Hodgkin Lymphoma 36 06.0 07.5 C82-C85 6 Colon 26 04.3 06.4 C18 7 Esophagus 22 03.7 05.0 C15 8 Connective, Soft Tissue 20 03.3 03.8 C47-C49 9 Myeloid Leukaemia 18 03.0 03.9 C92- C94 10 Bladder 16 02.7 03.9 C67 Table 8. Ten of leading cancer in females No Sites N. of Cases Crude Rate ASR world ICD ( 10 th ) 1 Breast 111 18.5 21.7 C50 2 Stomach 58 09.6 09.9 C16 3 Bronchus, lung 50 08.3 08.9 C33- C34 4 Liver 35 05.8 06.7 C22 5 Oral Cavity 34 05.7 06.0 C03-C06 505 6 Cervix 30 05.0 05.8 C53 7 Rectum 24 04.0 04.3 C19-C20 8 Non- Hodgkin Lymphoma 23 03.8 04.0 C82-C85 9 Ovary 19 03.2 03.3 C56 10 Soft Tissue 14 02.3 02.5 C47- C49 Figure 1. Age - specific incidence rates : all sites, males and females Figure 2. Age- specific incidence rate for Liver cancer 506 0 50 100 150 200 250 300 350 A x is T it le Males Females Figure 3. Age-specific incidence rate for Stomach cancer Figure 4. Age -specific incidence rate for Lung cancer 0 10 20 30 40 50 60 70 80 90 A xi s Ti tl e Breast Cervix Figure 5. Age-specific incidence rate for Breast & Cervix Cancer 507 4. Discussion There were 7,324 cases specified as ‘‘malignant’’ [4,068 men (55.54%) and 3,256 women (44.46%)] in the 9 years period between 2001 and 2009 (table 1). The number of cases in 2008 and 2009 were higher than those in several years ago. From this fact, we have received funding for this research in the period between 2001 and 2004. Since 2008, we have established the National Cancer Control Program in Thua Thien Hue province, including Cancer Registry. To estimate the cancer incidence within a year in Thua Thien Hue, we have chosen the year 2008 for representative data with 1,318 cases, including 745 men (56.52% ) and 573 women (43.48%). The crude rate (CR) was 123.9 per 100,000 and Age Standardized rate (ASR) was 173.5 per 100,000 for men; CR was 95.3 per 100,000 and ASR was 103.9 per 100,000 for women (table 1,5 & 6).The cancer registry in Hanoi (1990) has found 1975 cases specified as 'malignant' (1163 men and 812 women) in the 3-year period ( 1988-1990). The estimated rates of incidence for all cancers were 86.7 per 100,000 (CR) and 105.1 per 100,000 (ASR)for men; 59.0 per 100,000 (CR) and 63.6 per 100,000 (ASR) for women. Additionally, the results from the population-based cancer registry in Ho Chi Minh City in the two year period between 1995 and 1996 provided the first information on the incidence of cancer in Southern Vietnam. A total of 4,080 cancer cases in males and 4,338 in females were registered with CR as 89.0 per 100,000, ASR as 130.9 per 100,000 for men and CR as 85.8 per 100,000, ASR as 100.7 per 100,000 for women. Table 3 shows the most valid basis of diagnosis of the cases registered by tumor site. Overall, 87,65% of cases have had some microscopic confirmation of the diagnosis, either histological or cytological and 3,65 % on the basis of clinical examination only. The sites with the lowest percentages of morphologically were liver and lung cancer. In 1988, the ability of cancer diagnosis in several cancer registries was: Hanoi 53,8%, Manila, Philippines 60,6%, and Khon Kean, Thailand 34, 5%. The low histological verification in Khon Kaen is the result of very high rates of liver cancer in males but, in general, is not very different from other Asian registries. In men, lung cancer (18,52% of cases, ASR 34.8 per 100,000) was the most frequent malignancy, followed by cancer of the stomach (18,38% of cancers, ASR 31.3). Both showed a progressive increase of incidence with the maximum increase in the oldest age-group. However, the liver cancer incidence was highest among the group between 60-64 years old. (Figure 2&3). Lung cancer is the third highest in frequency ( 13.55% of cases, ASR 24.6), but for this tumor the average age of incidence is rather less, with the maximum rate in the age-group 70-74 and a decline thereafter (Figure 4). The fourth highest in frequency is cancer of the oral cavity and nasopharynx (ASR 11.5 ) and the fifth highest is non- Hodgkin lymphoma (ASR 7.5). In 2001-2004, the 508 Hanoi cancer registry found that incidences of lung cancer (ASR 40.2), stomach cancer ( ASR 30.3) and liver cancer ( ASR 20.0 ) were very different from those from its cancer registry nearly 20 year ago ( ASR of lung 21.1, stomach 20.8, liver 14.0 ). In women, breast cancer is by far the most frequent malignancy (19,37% of cancers, an ASR of 21.7 per 100,000). Incidence rates increase to a maximum number among age group of 49-64, and then decline (Figure 5). Stomach cancer is the second highest in frequency (10,12 % of cancers, ASR 9.9), followed by lung cancer (6.8%, ASR 8.7). Cervical cancer was formerly reported to be extremely common in Vietnam, particularly in the South (ASR 26.0 ) which, while similar to that observed elsewhere in South East Asia and the first cancer in women, it was 4 times greater than that in Hanoi, but it now declines to the second highest, following by breast cancer. It now ranks the sixth in this report ( ASR 5.8 ), the fifth cancer in Hanoi in 2007 ( ASR 6.8 ) and the second cancer in HCM city in 2004 (ASR 16). Cervical cancer is now generally thought to be related to infection with human. Papillomavirus (HPV) especially HPV 16 and HPV 18. Cervical cancer incidence has decreased in the past 10 years. This can be explained by the success of the cervical cancer screening program in the main cities of Vietnam. Experiences from the cervix cancer screening program in US during the last 30 years has shown that PAP Smear can be useful for decreasing cervix cancer incidence, while mammography may just increase the ability of early detection for breast cancer. Breast cancer nowadays has become the leading cancer in Vietnam. Research in Hanoi shown that ASR was 30.0 and 21.7 in this report. This data was increased several times compare to 10 years ago ( ASR 14.0 and 9.1 ). Although breast cancer is the most common cancer in women, it is also several times lower when compare to US & Europe (ASR nearly 100 per 100,000). Thus the low rate currently observed may be associated with the reproductive factors accompanying previously high levels of fertility (early age at first pregnancy, multiple births), low caloric intake (relatively late age at menarche, low body mass) and prolonged breast feeding of infants. 5. Conclusions The data on cancer incidence confirms the increase of crude rates and ASR among the population in Thua thien Hue during the last 10 years. It also indicated a genuine risk for certain cancers, particularly those associated with 'western' lifestyles or consumption of alcohol and a certain relationship with some virus infection. Cancers of the digestive organs was the most frequently seen cancer, followed by bronchus -lung cancer. There was no difference, when compared with the whole country, in the incidence of breast cancer (the leading cancer in women) and cervical cancer is in the 509 process of decreasing. The difference, comparing with the North, is its higher incidence of liver cancer and, comparing with the South, is its higher incidence of nasopharynx, stomach cancer and especially lower incidence of cervical cancer. 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