Cancer incidence in Ho Chi Minh City, Viet Nam, 1995-1996

Colorectal Cancer in Vietnam

In this chapter, we focus on the up-to-date status of colorectal cancer occurrence in an Asian country with nearly 100 million in population. Protective and risk factors, time trend of colorectal cancer from 2005 to 2018 will be presented. Perspective of colorectal cancer prevention and research will be highlighted. Data will be derived and based out of current running research projects of prospective cohort study, case-control study, and population-based mortality registration in Vietnam from 2005 to 2020. The association colorectal cancer with lifestyle, diet, cooking methods, demographic factors is taken into analysis. Time trend, colorectal cancer survival, mortality will be presented.

Trends in breast cancer incidence in Ho Chi Minh City 1996-2015: A registry-based study

The burden of breast cancer in Vietnam has not been documented. This study sought to estimate the incidence of breast cancer in Ho Chi Minh City, the largest economic center of Vietnam, from 1996 to 2015. This was a population-based study using the Ho Chi Minh City Cancer Registry as a source of data (coverage period: 1996-2015). The Registry adopted the International Classification of Diseases for Oncology, 3rd Edition for the classification of primary sites and morphology, and guidelines from the International Agency for Research on Cancer and the International Association of Cancer Registries. Using the population statistics from census data of Ho Chi Minh City, the point incidence of breast cancer for 5-year period was estimated. Based on the national population, we calculated the age-standardized rate (ASR) of breast cancer between 1996 and 2015. Overall 14,222 new cases of breast cancer (13,948 women, or 98%) had been registered during the 1996-2015 period; among whom, just over half (52%) were in the 2nd stage and 26% in the 3rd and 4th stages. In women, the median age at diagnosis was 50 years and there was a slight increase over time. The ASR of breast cancer during the 2011-2015 period was 107.4 cases per 100,000 women, representing an increase of 70% compared to the rate during the 1996-2000 period. In men, there was also a significant increase in the ASR: from 1.13 during the 1996-2001 period to 2.32 per 100,000 men during the 2011-2015 period. These very first data from Vietnam suggest that although the incidence of breast cancer in Vietnam remains relatively low, it has increased over time.

Projecting Cancer Incidence for 2025 in the 2 Largest Populated Cities in Vietnam

The population size and projected demographics of Vietnam's 2 largest cities, Ho Chi Minh City (HCMC) and Hanoi, will change dramatically over the next decade. Demographic changes in an aging population coupled with income growth and changes in lifestyle will result in a very different distribution of common cancers in the future. The study aimed to project the number of cancer incidence in the 2 largest populated cities in Vietnam for the year 2025. Cancer incidence data from 2004 to 2013 collected from population-based cancer registries in these 2 cities were provided by Vietnam National Cancer Institute. Incidence cases in 2013 and the previous decades average annual percent changes of age-standardized cancer incidence rates combined with expected population growth were modeled to project cancer incidence for each cancer site by gender to 2025. A substantial double in cancer incidence from 2013 to 2025 resulted from a growing and aging population in HCMC and Hanoi. Lung, colorectum, breast, thyroid, and liver cancers, which represent 67% of the overall cancer burden, are projected to become the leading cancer diagnoses by 2025 regardless of genders. For men, the leading cancer sites in 2025 are predicted to be lung, colorectum, esophagus, liver, and pharynx cancer, and among women, they are expected to be breast, thyroid, colorectum, lung, and cervical cancer. We projected an epidemiological transition from infectious-associated cancers to a high burden of cancers that have mainly been attributed to lifestyle in both cities. We predicted that with 16.9% growth in the overall population and dramatic aging with these 2 urban centers, the burdens of cancer incidence will increase sharply in both cities over the next decades. Data on projections of cancer incidence in both cities provide useful insights for directing appropriate policies and cancer control programs in Vietnam.

Magnetic Resonance Imaging Features of Common Posterior Fossa Brain Tumors in Children: A Preliminary Vietnamese Study

BACKGROUND:

Magnetic Resonance Imaging (MRI) nowadays plays an important role in the evaluation of posterior fossa brain tumours in children for appropriate diagnosis, treatment planning, and follow-up.

AIM:

To assess the MRI features of common posterior fossa brain tumours including medulloblastomas, ependymomas, and pilocytic astrocytomas along with the postoperative parameters to contribute the local knowledge to the neuroradiology and neurosurgery fields.

METHODS:

The study was performed at Children’s Hospital 02 from January 2016 to June 2019. In this study, all pediatric patients adopted MRI to evaluate the posterior fossa brain tumours’ characteristics and then underwent surgery to eradicate the posterior fossa tumours. We retrospectively compared the baseline parameters, MRI parameters, and postoperative parameters among medulloblastomas, ependymomas, and pilocytic astrocytomas.

RESULTS:

There were 62 patients (27 medulloblastomas, 20 ependymomas, and 15 pilocytic astrocytomas) in this research. The main structure of medulloblastomas and ependymomas was predominantly solid, whereas the main structure of pilocytic astrocytomas was superiorly cystic (p < 0.05). Ependymoma tended to extend tumour through foramina of Luschka and Magendie (p < 0.05). Medulloblastomas chiefly showed iso intensity on T2W and FLAIR images meanwhile ependymomas and pilocytic astrocytomas predominantly appeared hyperintensity on T2W and FLAIR images. Medulloblastomas and ependymomas were mostly high intensity on DWI, and low intensity on ADC whereas pilocytic astrocytomas were usually low intensity on DWI and high intensity on ADC. After injecting CE, pilocytic astrocytomas showed a mixed intensity whereas the signal intensity of medulloblastoma and ependymoma on T1CE was generally strong. There were positive correlations between FH diameter and estimated blood loss (r = 0.289, p < 0.05); and surgical time (r = 0.312, p < 0.05).

CONCLUSION:

MRI plays a crucial role in demonstrating the features of posterior fossa brain tumours for appropriate diagnosis of medulloblastomas, ependymomas, and pilocytic astrocytomas. Medulloblastomas are problematic tumours and the clinicians should also take into consideration in cases of larger feet-to-head diameter of tumours to ensure the efficacy and safety surgery for patients.

Medical costs for the treatment of cervical cancer at central hospitals in Vietnam

Cervical cancer remains the second most common cancer amongst female aged 15 to 44 years old in Vietnam. We estimated medical costs for the treatment of cervical cancer patients. We employed the standard costing approach and health care provider perspective. We first computed the unit cost of 22 medical services related to cervical cancer treatments and then, based on standard cervical cancer treatment protocols, we estimated the cost of nine treatment scenarios for cervical cancer patients. We found that the medical costs for treatment of cervical cancers at central hospitals in Vietnam increased as the cancer progresses into later stages.

Cervical cancer treatment costs and cost-effectiveness analysis of human papillomavirus vaccination in Vietnam: a PRIME modeling study

Background

Cervical cancer is currently the leading cause of cancer mortality among women in South Vietnam and the second leading cause of cancer mortality in North Vietnam. Human papillomavirus (HPV) vaccination has the potential to substantially decrease this burden. The World Health Organization (WHO) recommends that a cost-effectiveness analysis of HPV vaccination is conducted before nationwide introduction.

Methods

The Papillomavirus Rapid Interface for Modeling and Economics (PRIME) model was used to evaluate the cost-effectiveness of HPV vaccine introduction. A costing study based on expert panel discussions, interviews and hospital case note reviews was conducted to explore the cost of cervical cancer care.

Results

The cost of cervical cancer treatment ranged from US$368 – 11400 depending on the type of hospital and treatment involved. Under Gavi-negotiated prices of US$4.55, HPV vaccination is likely to be very cost-effective with an incremental cost per disability-adjusted life year (DALY) averted in the range US$780 - 1120. However, under list prices for Cervarix and Gardasil in Vietnam, the incremental cost per DALY averted for HPV vaccination can exceed US$8000.

Conclusion

HPV vaccine introduction appears to be economically attractive only if Vietnam is able to procure the vaccine at Gavi prices. This highlights the importance of initiating a nationwide vaccination programme while such prices are still available.

Evaluation of Risk Factors for Nasopharyngeal Carcinoma in a High-risk Area of India, the Northeastern Region

Northeastern India is a major nasopharyngeal carcinoma (NPC) high risk-area although the rest of the country has very low incidence. A case-control study of 105 NPC cases and 115 controls was conducted to identify the potential risk factors for NPC development in this region. Information was collected by interviewer about socio-demographic characteristics, cigarette smoking, alcohol consumption, dietary history, occupational history, and a family history of cancer. Epstein-Barr viral load was assayed from the blood DNA by real time PCR. Associations between GSTs genotypes, cytochrome P450 family including CYP1A1, CYP2E1 and CYP2A6 polymorphisms and susceptibility to relationship between the diseases were studied using PCR-RFLP assay. Results indicate that Epstein-Barr virus load was significantly higher in patients compared to controls (p<0.0001). Furthermore, concentration of blood EBV-DNA was significantly higher in advanced stage disease (Stage III and IV) than in early stage disease (Stage I and II) (p<0.05). Presence of CYP2A6 variants that reduced the enzyme activity was significantly less frequent in cases than controls. Smoked meat consumption, exposure to smoke, living in poorly ventilated house and alcohol consumption were associated with NPC development among the population of Northeastern India. Thus, overall our study revealed that EBV viral load and genetic polymorphism of CYP2A6 along with living practices which include smoked meat consumption, exposure to smoke, living in poorly ventilated houses and alcohol consumption are the potential risk factors of NPC in north eastern region of India. Understanding of the risk factors and their role in the etiology of NPC are helpful forpreventive measures and screening.

Female breast cancer in Vietnam: a comparison across Asian specific regions

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death of women over the world. A large number of females with breast cancer in Vietnam and other Southeast Asian (SEA) countries present at an early age with more aggressive tumors compared with women in Australia. Despite experiencing a low incidence rate, the increasing incidence rate among SEA countries exceeds that of the Westernized world. Changes in reproductive factors, environmental exposures, and lifestyle are the possible causes of this trend. However, limited evidence shows that these factors are associated with breast cancer in the Vietnamese population. Breast cancer incidence rates within Vietnam are not uniform and appear to be dependent on geographic location. Findings from this review have important implications for breast cancer control and treatment in Vietnam. A good understanding of the morphology of the breast and the type and nature of breast cancers presenting in Vietnam is required to facilitate the introduction of an effective national breast screening program.

Lessons learned from successful Papanicolaou cytology cervical cancer prevention in the Socialist Republic of Vietnam

In 1996, we documented that the burden of cervical cancer in Vietnam was associated with troop movements during the Vietnam War. Subsequently, establishment of Papanicolaou screening in southern Vietnam was associated with reductions in cervical cancer incidence from 29.2/100,000 in 1998 to 16/100,000 in 2003. This is one of the first English-language reports of a real-world cervical cancer prevention effort associated with a decisive impact on health outcomes in a contemporary developing country.

LESSONS LEARNED

if our ideological commitment is to improve health outcomes as rapidly as possible among as many people as possible, then Papanicolaou screening (with or without HPV or visual screening) must be implemented without further delay in any setting where cervical screening is appropriate but unavailable; consideration must be given to HPV vaccination after, rather than before, full coverage of target demographic groups by screening services has been achieved and/or the possibility has been excluded that HPV vaccination may be ineffective for cancer prevention. Competing ideological commitments engender imprudent yet commercially useful alternative strategies prone to decelerate global reductions in mortality by suppressing the more-rapid uptake of less-expensive open-source technology in favor of the less-rapid uptake of more-expensive proprietary technologies with uncertain real-world advantages and unfavorable real-world operational limitations. Global cervical cancer prevention efforts will become more effective if global health leaders, including the Bill & Melinda Gates Foundation, embrace an ideological commitment to improving health outcomes as rapidly as possible among as many people as possible and assimilate the policy implications of that commitment.

Hepatitis B infection in Vietnam: current issues and future challenges

Hepatitis B virus (HBV) infection remains a major public health problem in Vietnam. Recent studies have found that prevalence of current HBV infection (HBsAg+) ranges from 10% to 20% in the general population and 20% to 40% among injecting drug users and HIV+ patients. However, HBV prevention and control in Vietnam relies heavily on universal infant vaccination program and HBsAg screening for blood donors. Currently, HBV prevention and control is underfunded by the government and receives little support from international agencies. HBV-related liver disease will continue to create a heavy burden for public health in Vietnam in the next several decades unless appropriate interventions are undertaken urgently. Establishment of a national strategy for HBV prevention and control is crucial to develop and implement effective interventions.

Herpes simplex virus type-2 seropositivity among ever married women in South and north Vietnam: a population-based study

OBJECTIVE

To investigate herpes simplex virus type-2 (HSV-2) seropositivity and associated risk factors in Vietnamese women.

METHODS

Cross-sectional study with personal interviews and gynecological examinations among population-based samples of ever married women, aged 15 to 69 years, living in Ho Chi Minh City (HCMC) and Hanoi in 1997. Type-specific IgG antibodies against HSV-2 were detected using HerpeSelect ELISA (Focus Diagnostics). Adjusted prevalence ratios were estimated with log-binomial regression.

RESULTS

HSV-2 seroprevalence was higher in 1106 women from HCMC (30.8%, 95% CI: 28.1-33.4, age-standardized to 2000 world standard population) than in 1170 women from Hanoi (8.8%, 95% CI: 7.1-10.5). In HCMC, HSV-2 seroprevalence was higher for women who were not married, HPV DNA positive, current hormonal contraceptive users, or had a history of multiple sexual partners or spontaneous abortion. HCMC seroprevalence was inversely associated with educational attainment, age at first intercourse, and age at first pregnancy. In the multivariable model for HCMC, a trend of increasing HSV-2 seroprevalence with age was observed, and prevalence ratios were nearly identical to age-adjusted prevalence ratios for marital status, age at first pregnancy, and HPV DNA positivity.

CONCLUSIONS

HSV-2 was notably less prevalent in Hanoi than HCMC, where it was associated with traditional HSV-2 risk factors. These results are likely explained by socio-cultural, historical, economic, and demographic factors related to urban-rural and regional differences. Future population-based studies should include men and never-married women as a next step toward obtaining a more nearly complete picture of HSV-2 epidemiology in Vietnam.

Exploring the cost-effectiveness of HPV vaccination in Vietnam: insights for evidence-based cervical cancer prevention policy

Using mathematical models of cervical cancer for the northern and southern regions of Vietnam, we assessed the cost-effectiveness of cervical cancer prevention strategies and the tradeoffs between a national and region-based policy in Vietnam. With 70% vaccination and screening coverage, lifetime risk of cancer was reduced by 20.4-76.1% with vaccination of pre-adolescent girls and/or screening of older women. Only when the cost per vaccinated girl was low (i.e., <I$25) was vaccination combined with screening (three times per lifetime or every 5 years) favored in both regions; at high costs per vaccinated girl (i.e., >I$100), screening alone was most cost-effective. When optimal policies differed between regions, implementing a national strategy resulted in health and economic inefficiencies. HPV vaccination appears to be an attractive cervical cancer prevention strategy for Vietnam, provided high coverage can be achieved in young pre-adolescent girls, cost per vaccinated girl is <I$25 (i.e., <$5 per dose), and screening is offered at older ages.

Cervical human papillomavirus infection among female sex workers in southern Vietnam

Background

Cervical cancer is the most frequently diagnosed malignancy among women in southern Vietnam where its incidence is one of the highest observed worldwide.

Results

Cervical HPV DNA infection was measured in a cross-sectional sample of 282 female sex workers (FSW) in Soc Trang province in southern Vietnam. HPV DNA was detected in 85% of FSW and prevalence did not vary by age. Thirty-five HPV genotypes were detected; HPV 52 was the most common type. Half of HPV-positive women were infected with oncogenic types and 37% were infected with multiple genotypes. The prevalence of oncogenic HPV infection was lower among FSW with more formal education (adj. prevalence ratio = 0.63, 95% CI 0.42–0.93), those servicing 25 or more clients per month (adj. PR = 0.66 95% CI 0.48–0.92), and those engaging in withdrawal prior to ejaculation (adj. PR = 0.68, 95% CI 0.53–0.87). Oncogenic HPV prevalence was higher among FSW with regular male partners who had other female partners (adj. PR = 1.75, 95% CI 1.34–2.28) and FSW who were HIV+ (adj. PR = 1.42, 95% CI 1.08–1.88).

Conclusion

Our results demonstrate that although cervical HPV infection is extremely common among FSW in southern Vietnam, prevalence varies by education level, sexual activity, habits of regular partners, and HIV status.

An enormous hepatitis B virus-related liver disease burden projected in Vietnam by 2025

BACKGROUND

Hepatitis B virus (HBV) is the major cause of chronic liver disease in Vietnam. This study aimed to estimate and project chronic HBV prevalence and HBV-related liver cirrhosis (LC) and hepatocellular carcinoma (HCC) for the period 1990-2025.

METHOD

The Vietnamese population for the period 1990-1999 was derived from census data to 1999 and from 2000 to 2025 based on projection data from the United States Census Bureau. Population chronic HBV prevalence for males and females was estimated based on age-specific HBV prevalence from Vietnamese community-based studies. Universal infant HBV vaccination from 2003 was assumed to reduce HBV infection by 90% in subsequent birth cohorts. Incidences of HBV-related LC and HCC by HBV DNA levels from the Taiwanese REVEAL studies were applied to the chronic HBV population to estimate and project HBV-related liver disease burden.

RESULTS

Estimated chronic HBV prevalence increased from 6.4 million cases in 1990 to around 8.4 million cases in 2005 and was projected to decrease to 8.0 million by 2025. Estimated HBV-related LC and HCC incidence increased linearly from 21,900 and 9400 in 1990 to 58,650 and 25,000 in 2025. Estimated HBV-related mortality increased from 12,600 in 1990 to 40,000 in 2025.

CONCLUSION

Over the next two decades, universal infant HBV vaccination will reduce chronic HBV prevalence in Vietnam but HBV-related liver disease burden will continue to rise. A national HBV strategy is required to address this expanding burden of liver disease.

The enigmatic epidemiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has a unique and complex etiology that is not completely understood. Although NPC is rare in most populations, it is a leading form of cancer in a few well-defined populations, including natives of southern China, Southeast Asia, the Arctic, and the Middle East/North Africa. The distinctive racial/ethnic and geographic distribution of NPC worldwide suggests that both environmental factors and genetic traits contribute to its development. This review aims to summarize the current knowledge regarding the epidemiology of NPC and to propose new avenues of research that could help illuminate the causes and ultimately the prevention of this remarkable disease. Well-established risk factors for NPC include elevated antibody titers against the Epstein-Barr virus, consumption of salt-preserved fish, a family history of NPC, and certain human leukocyte antigen class I genotypes. Consumption of other preserved foods, tobacco smoking, and a history of chronic respiratory tract conditions may be associated with elevated NPC risk, whereas consumption of fresh fruits and vegetables and other human leukocyte antigen genotypes may be associated with decreased risk. Evidence for a causal role of various inhalants, herbal medicines, and occupational exposures is inconsistent. Other than dietary modification, no concrete preventive measures for NPC exist. Given the unresolved gaps in understanding of NPC, there is a clear need for large-scale, population-based molecular epidemiologic studies to elucidate how environmental, viral, and genetic factors interact in both the development and the prevention of this disease.

Systems analysis of real-world obstacles to successful cervical cancer prevention in developing countries

Papanicolaou screening is feasible anywhere that screening for cervical cancer, the leading cause of cancer-related death among women in developing countries, is appropriate. After documenting that the Vietnam War had contributed to the problem of cervical cancer in Vietnam, we participated in a grass roots effort to establish a nationwide cervical cancer prevention program in that country and performed root cause analyses of program deficiencies. We found that real-world obstacles to successful cervical cancer prevention in developing countries involve people far more than technology and that such obstacles can be appropriately managed through a systems approach focused on programmatic quality rather than through ideological commitments to technology. A focus on quality satisfies public health goals, whereas a focus on technology is compatible with market forces.

The global breast cancer burden: variations in epidemiology and survival

Breast cancer is the most common type of cancer and the most common cause of cancer-related mortality among women worldwide. However, the burden is not evenly distributed, and, according to the best available data, there are large variations in the incidence, mortality, and survival between different countries and regions and within specific regions. Many complex factors underlie these variations, including population structure (eg, age, race, and ethnicity), lifestyle, environment, socioeconomic status, risk factor prevalence, mammography use, disease stage at diagnosis, and access to high-quality care. We review recent breast cancer incidence and mortality statistics and explore why these vary so greatly across the world. Further research is needed to fully understand the reasons for variations in breast cancer outcomes. This will aid the development of tailored strategies to improve outcomes in general as well as the standard of care for underserved populations and reduce the burden of breast cancer worldwide.

Human papillomavirus and abnormal Pap test results in Vietnamese-American women: a pilot case-control study

OBJECTIVE

To evaluate the relationship between abnormal Pap test results and human papillomavirus (HPV) in Vietnamese-American women, who have the highest cervical cancer incidence in the United States.

MATERIALS AND METHODS

In 2001, we obtained specimens from 117 Vietnamese women, 24 with abnormal Pap test results including atypical squamous cells of undetermined significance (cases) and 93 with normal Pap test results (controls), as classified by the 1991 Bethesda System. We used L1 consensus primers MY09/MY11 to perform HPV polymerase chain reaction analysis and type-specific probes to perform genotyping.

RESULTS

Thirteen cases (54%) and 6 controls (6%) were HPV positive (p < .001). Ten of 24 cases (42%) and 0 controls (0%) had high-risk HPV types (16, 18, 45, 53, 56, or 66; p < .001). High-risk HPV types were significantly associated with increasing severity of Pap test results.

CONCLUSIONS

Compared with those with normal Pap test results, Vietnamese-American women with abnormal Pap test results were more likely to have high-risk HPV types. Higher cervical cancer incidence among these women is likely the result of less frequent Pap screening rates and not different biology.

Differences in Breast Cancer Risk Factors by Tumor Marker Subtypes among Premenopausal Vietnamese and Chinese Women

We evaluated associations between reproductive and lifestyle risk factors with breast cancer tumor marker status in a case-control study. Cases were premenopausal women living in Vietnam and China who were eligible for a clinical trial of oophorectomy and tamoxifen as treatment for breast cancer (n = 682). Controls were nonrelative hospital visitors, matched on age to the cases (n = 649). Immunohistochemical analysis was used to identify the presence of estrogen receptor (ER) and progesterone receptor and the overexpression of HER-2/neu oncogene. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using unconditional logistic regression, adjusted for known confounders. Overall, 280 (61%) tumor samples were ER positive and 176 (38%) were ER negative. HER-2/neu overexpression was detected in 161 (35%) samples, whereas 286 (26%) samples were HER-2/neu negative. We observed an inverse trend between increasing parity and decreasing breast cancer risk (P = 0.002). Women ages ≥25 years at first birth had increased breast cancer risk compared with women ages &lt;25 years at first birth (OR, 1.53; 95% CI, 1.20-1.95). Women who consumed alcohol had increased risk of breast cancer compared with women who did not (OR,1.85; 95% CI, 1.32-2.61). Compared with controls, OR estimates for breast cancer by parity and age at first birth were significantly associated with ER and/or HER-2/neu tumor status by Wald test (P &lt; 0.05). Family history, age at menarche, cumulative lactation, body mass index, and education were not significantly related to breast cancer risk. Our findings support the hypothesis that some breast cancer risk factors differ by ER and HER-2/neu tumor marker subtypes.

Crossing the quality chasm: a requirement for successful cervical cancer prevention in developing countries

Disease prevention requires sociopolitical change, which in turn requires the participation of those for whom the change is intended, including demographic groups at high risk for disease, appropriate governmental authorities, and essential health care personnel. Multiparous women of lowest socioeconomic status, the demographic group at highest risk for the development of cervical cancer, lack sociopolitical leverage almost by definition. Pap screening in developing countries is an idea whose time has come, but it is also an ethical imperative currently lacking a substantial sociopolitical constituency. Noncytologic screening methods currently benefit from sponsorship by corporate manufacturers and by donor organizations such as the Bill and Melinda Gates Foundation. Pap screening efforts in developing countries will benefit from the involvement of cytology organizations based in developed countries. Future assessments of the progress of cervical cancer prevention efforts in developing countries will benefit from additional examination of the interactions between quality and sociopolitical obstacles to change. Many of these obstacles will be elucidated by following the money, as well as the science, involved in cervical screening activities.

Association between war and cervical cancer among Vietnamese women

Decades ago, cervical cancer was the leading form of cancer among women in both North Vietnam and South Vietnam. Currently, cervical cancer rates are considerably lower in the northern region of the country. We performed a case-control study to measure factors associated with the development of cervical cancer among Vietnamese women. Questionnaire-based interviews were conducted with 202 women in southern Vietnam and 97 women in northern Vietnam. Case subjects were women hospitalized with cervical cancer. Control subjects were women hospitalized with extrauterine neoplasms. Data were analyzed using logistic regression, and odds ratios for the development of invasive cervical cancer were measured. The development of invasive cervical cancer was significantly associated with military service by husbands during the Second Indochinese War and with parity status. Odds ratio for the development of cervical cancer among southern Vietnamese women whose husbands had served in the armed forces was 2.6 (95% CI = 1.2-5.5). Odds ratio for the development of cervical cancer among northern women whose husbands had served in the armed forces was 3.9 (95% CI = 1.5-10.4) if their husbands had been stationed in South Vietnam during the war years. Northern women whose husbands had served in the military experienced no significant increase in cervical cancer risk if their husbands had been stationed in North Vietnam during the war years. Geographic and temporal variation in cervical cancer rates among Vietnamese women was associated with the movement of soldiers. These findings may be useful for cervical cancer prevention efforts in Vietnam and in other countries.

Human papillomavirus infection among women in South and North Vietnam

The incidence rate of invasive cervical carcinoma (ICC) is 4-fold higher in Ho Chi Minh City, in the South of Vietnam, than in Hanoi, in the North. Thus, we explored the prevalence of and the risk factors for human papillomavirus (HPV) infection in these 2 areas. A population-based random sample of married women aged 15-69 years were interviewed and had a gynaecological examination in the urban district of Ho Chi Minh City and in a peri-urban district in Hanoi. HPV DNA detection was performed using a GP5+/6+ primer-mediated PCR enzyme immunoassay. A total of 922 women from Ho Chi Minh and 994 from Hanoi, for whom a Pap smear and HPV-status were available, were evaluated. HPV DNA was detected among 10.9% of women in Ho Chi Minh City and 2.0% in Hanoi (age standardized prevalence, world standard population: 10.6% and 2.3%, respectively). In the 2 areas combined, 30 different HPV types were found, the most common being HPV 16 (in 14 single and 18 multiple infections), followed by HPV 58, 18 and 56. A peak of HPV DNA detection in women younger than age 25 was found in Ho Chi Minh City (22.3%) but not in Hanoi. Major risk factors for HPV DNA detection were indicators of sexual habits, most notably the presence of HSV-2 antibodies, nulliparity and the current use of oral contraceptives. Women in Hanoi showed the lowest HPV prevalence ever reported so far, suggesting that HPV has not spread widely in this population. As expected, HPV prevalence in a population seemed to be closely correlated with ICC incidence rates.

Cancer incidence patterns among Vietnamese in the United States and Ha Noi, Vietnam

Nearly 600,000 persons have immigrated to the United States from Vietnam since the end of the Vietnam War. Despite the rapid growth of the U.S. Vietnamese population, little is known about cancer incidence in this migrant group. Using population-based data from the Surveillance, Epidemiology and End Results program, California Cancer Registry and International Agency for Research on Cancer, we compared cancer incidence rates for Vietnamese in the United States (1988-1992) to rates for residents of Ha Noi, Vietnam (1991-1993); non-Hispanic whites were included to serve as the U.S. reference rates. Lung and breast cancers were the most common among Vietnamese males and females, respectively, regardless of geographic region. Rates of cancers more common to U.S. whites, such as breast, prostate and colon cancers, were elevated for U.S. Vietnamese compared to residents in Ha Noi but still lower than rates for U.S. whites. Rates of cancers more common to Asian countries, such as stomach, liver, lung and cervical cancers, were likewise elevated for U.S. Vietnamese compared to residents of Ha Noi and exceeded corresponding rates for whites. Incidence patterns for stomach, liver, lung and cervical cancers may reflect increased risk of exposures in this migrant population and should be further explored to uncover the relative contributions of environmental and genetic factors to cancer etiology.

The situation with cancer control in Vietnam

Vietnam is one of the poor, developing countries. Malnutrition and infectious diseases are still major health problems. Cancer ranks in a relatively modest position of priority. The reason is partly explained by a shortage of treatment facilities and poor quality of health and vital statistics. The leading cancers in the country are lung, liver, stomach, colon-rectum and nasopharynx in males and breast, cervix, stomach, liver, colon-rectum and lung in females. Although the country has some common patterns of cancer such as a relatively high incidence of nasopharynx, liver and stomach and a relatively low incidence of breast and prostate cancer compared with international data, the geographical distribution of cancer is not homogenous within the country. The most remarkable difference is observed in cancer of the cervix uteri, of which the incidence in the South is, at least four times higher than that in the North. Other less extensive differences are observed in cancer of the lung, stomach, nasopharynx and breast, the incidence of which seems to be higher in the North than in the South, and the liver, which seems to be more frequent in the South than in the North. It was estimated that in 1990 the cancer incidence in Vietnam was about 133 per 100 000 in males and 91.7 per 100 000 in females and that the mortality was 105.9 and 58.5 per 100 000, respectively (standardization to the world's population). In that year, Vietnam had at least 52 700 new cancer cases and 37 700 dead from cancer. Although the National Cancer Control Program is still in preparation, some efforts by the government have already been made with tobacco control, improving the cancer treatment net, mass media education and production of vaccine against HBV. Cancer control in Vietnam still has to deal with challenges such as poor quality of cancer morbidity and mortality data, shortage of resources for establishing a comprehensive cancer control network from the center to the peripheries, lack of data for an anti-tobacco program and misunderstanding or limited knowledge of general practitioners and the public about the disease.

Hepatitis B immunization coverage among Vietnamese-American children 3 to 18 years old

OBJECTIVE

Persons with chronic hepatitis B virus (HBV) infection are at increased risk of chronic hepatitis, cirrhosis, and liver cancer. Although HBV infection is relatively uncommon in the United States, the disease is endemic in persons born in Southeast Asia, including Vietnamese-Americans. Current US infant immunization recommendations and state-mandated school-entry programs have left many nontargeted age-cohorts unvaccinated and at risk of infection. To assess the need for catch-up hepatitis B immunizations, this study reports the hepatitis B immunization rates of Vietnamese-American children 3 to 18 years old living in the metropolitan areas of Houston and Dallas, Texas, and the Washington, DC, area.

DESIGN

We conducted 1508 telephone interviews with random samples of Vietnamese households in each of the 3 study sites. We asked for hepatitis B immunization dates for a randomly selected child in each household. Attempts were made to verify immunization dates through direct contact with each child's providers. Low and high estimates of coverage were calculated using reports from providers when reached (n = 720) and for the entire sample (n = 1508).

RESULTS

Rates of having 3 hepatitis B vaccinations ranged from 13.6% (entire sample) to 24.1% (provider reports, Dallas), 10. 3% to 26.4% (Houston), and 18.1% to 37.8% (Washington, DC). Children living in the Texas sites, older children, children whose families had lived in the United States for a longer time, and children whose provider was Vietnamese or who had an institutional provider were less likely to have been immunized. The odds of being immunized were greater, however, for children who had had at least 1 diphtheria, tetanus toxoid, and pertussis shot, and whose parents had heard about HBV infection, and were married.

CONCLUSIONS

The low rates of hepatitis B vaccine coverage among children and adolescents portend a generation which, too old to benefit from infant programs and school entry laws, will grow into adulthood without the protection of immunization. Increased efforts are needed to design successful catch-up campaigns for this population.

Incidence of childhood cancer in Ho Chi Minh City, Vietnam, 1995-97

Incidence rates of childhood cancer for the city of Ho Chi Minh are presented for the first time. For the 3-year period 1995-97, a total of 302 cancer cases were registered in children under 15 years of age, with a male to female ratio of 1.1. The overall crude rate was 78.8 and the age-standardised incidence rate was 88.4 per million person-years, which was low in comparison with other countries in eastern Asia and with the predominantly white population of Australia. Leukaemia (principally acute lymphocytic), brain tumours and lymphomas were the most common childhood neoplasms, which is consistent with the pattern observed in other registries of the region. The rate of retinoblastoma was higher than in the other regional registries. On the other hand, no cases of hepatocellular carcinoma were registered.

Estimates of the worldwide incidence of 25 major cancers in 1990

The annual incidence rates (crude and age-standardized) and numbers of new cases of 25 different cancers have been estimated for the year 1990 in 23 areas of the world. The total number of new cancer cases (excluding non-melanoma skin cancer) was 8.1 million, just over half of which occur in the developing countries. The most common cancer in the world today is lung cancer, accounting for 18% of cancers of men worldwide, and 21% of cancers in men in the developed countries. Stomach cancer is second in frequency (almost 10% of all new cancers) and breast cancer, by far the most common cancer among women (21% of the total), is third. There are large differences in the relative frequency of different cancers by world area. The major cancers of developed countries (other than the 3 already named) are cancers of the colon-rectum and prostate, and in developing countries, cancers of the cervix uteri and esophagus. The implications of these patterns for cancer control, and specifically prevention, are discussed. Tobacco smoking and chewing are almost certainly the major preventable causes of cancer today.

Estimates of the worldwide incidence of 25 major cancers in 1990

The annual incidence rates (crude and age-standardized) and numbers of new cases of 25 different cancers have been estimated for the year 1990 in 23 areas of the world. The total number of new cancer cases (excluding non-melanoma skin cancer) was 8.1 million, just over half of which occur in the developing countries. The most common cancer in the world today is lung cancer, accounting for 18% of cancers of men worldwide, and 21% of cancers in men in the developed countries. Stomach cancer is second in frequency (almost 10% of all new cancers) and breast cancer, by far the most common cancer among women (21% of the total), is third. There are large differences in the relative frequency of different cancers by world area. The major cancers of developed countries (other than the 3 already named) are cancers of the colon-rectum and prostate, and in developing countries, cancers of the cervix uteri and esophagus. The implications of these patterns for cancer control, and specifically prevention, are discussed. Tobacco smoking and chewing are almost certainly the major preventable causes of cancer today.