The economic evaluation of human papillomavirus vaccination strategies against cervical cancer in women in Lao PDR: a mathematical modelling approach.

BACKGROUND: Cervical cancer, a preventable disease, is the third leading cause of cancer morbidity and mortality in the Lao People's Democratic Republic (Lao PDR). Since many cervical cancers are linked to human papilloma virus (HPV) infection, vaccination against this virus may lead to a reduction in these types of cancer. The study described here is the first to compare the cost-effectiveness of different HPV vaccination options in Lao PDR. METHODS: A dynamic compartment model was created. The model included routine screening activities already in place, as well as theoretical interventions that included a 10-year old girl-only vaccination programme combined with/without a 10-year old boy vaccination programme and/or a catch-up component. The simulation was run over 100 years. In base case analyses, we assumed 70 % vaccination coverage with lifelong protection and 100 % efficacy against HPV types 16/18. The outcomes of interest were the incremental cost per Disability-Adjusted Life Year (DALY) averted. RESULTS: In base case analyses, according to the WHO definition of cost-effectiveness thresholds, vaccinating 10-year-old girls was very cost-effective. Adding a catch-up vaccination element for females aged 11-25 years was also very cost-effective, costing 1559 international dollars (I$) per DALY averted. Increasing the age limit of the catch-up vaccination component to 75 years old showed that this remained a cost-effective option (I$ 5840 per DALY averted). Adding a vaccination programme for 10-year-old boys was not found to be cost-effective unless a short time simulation (30 years or less) was considered, along with a catch-up vaccination component for both males and females. CONCLUSIONS: Adding a catch-up female vaccination component is more attractive than adding a 10-year-old boy vaccination component.

Awareness and attitudes towards emergency contraceptive pills among young people in the entertainment places, Vientiane City, Lao PDR.

BACKGROUND: Emergency Contraception is not officially available to the public sector in Laos. The potential of emergency contraception to prevent unwanted pregnancies is well documented in developed countries, but in Laos no studies of ECPs exist. This study aimed to assess knowledge of and attitudes towards emergency contraceptive pills (ECPs) in Vientiane, the capital city of the Lao PDR. METHODS: A cross-sectional survey was conducted among 500 young adults in entertainment venues by using the convenience sampling between May to July, 2007. Data were obtained through face-to-face interview. Participants were asked about socio- demographic characteristics, knowledge, attitudes related to ECPs, and source of information about ECPs. Data analysis was performed with chi-square test and logistic regression (p < .05). RESULTS: Only 22.4 percent of respondents had heard of ECPs and of these only 17.9 percent knew the correct time-frame for effective use. Most of the respondents (85%) agreed on the need for ECPs to be available in Laos and 66.8 percent stated that they would use them should the need arise, if they were available. Among those who said they would not use ECPs, 63.8 percent were concerned about possible health effects, or other side effects. Awareness of ECPs was associated with increasing age (OR = 2.78, p = .025) and male sex (OR = 2.91, p = .010). CONCLUSIONS: There is needed to provide effective health education about the method, timing of use, and how to obtain ECPs through both informal, peer channels, and also through formal channels such as health care providers.

Detection of human papillomavirus among women in Laos: feasibility of using filter paper card and prevalence of high-risk types.

BACKGROUND: Persistent infection with high-risk (HR) human papillomavirus (HPV) is a well-recognized cause of cervical cancer, but little is known about the situation in Laos. The aims of the study were to determine the prevalence of HR-HPV among Lao women and to evaluate the use of a filter paper card (FTA Elute Micro Card) for collection of cervical cells in the humid tropical climate. METHODS: This is a cross-sectional study including 1922 women from 3 provinces in Laos. During a gynecological examination, cervical cells were collected and applied to the FTA card followed by HPV typing using a real-time polymerase chain reaction (PCR)-based assay. RESULTS: Overall, 213 of the 1922 women were positive for HR-HPV (11%). The most common type was the group HPV33/52/58 (3%), followed by the single type 16 (2%) and the group 18/45 (1%), respectively. Only 11 cards (0.6%) did not contain a sufficient amount of genomic DNA for polymerase chain reaction-based analysis. CONCLUSIONS: The prevalence of HR-HPV infections in Laos is similar to other Asian countries, and 40% of the women with an HR-HPV infection will be target of the present HPV vaccines. The FTA card is suitable for collection of cervical cells for HR-HPV typing in tropical conditions. This information is important for planning and establishing primary and secondary prevention of cervical cancer in Laos.

Efficacy of careHPV™ human papillomavirus screening versus conventional cytology tests for the detection of precancerous and cancerous cervical lesions among women living with HIV-1 in Lao People's Democratic Republic.

BACKGROUND: In the Lao People's Democratic Republic (Lao PDR), cervical cancer is the third leading cause of women cancer. AIMS: The objective of this cross-sectional study was to compare the efficacy of careHPV™ test versus conventional Pap smear or Siriraj liquid-based cytology in the detection of cervical cancer in women living with human immunodeficiency virus type 1 (HIV-1). MATERIALS & METHODS: Overall, 631 women consented to participate. Four cervical specimens were taken for the purpose of conventional Pap smear, Siriraj liquid-based cytology, careHPV™ test, and HPV-16 genotyping. The exact McNemar test was used to compare the efficacy and diagnostic performance of the tests. RESULTS: Of the 631 women with follow-up, 331 were human papillomavirus (HPV) negative. High-grade squamous intraepithelial lesions were found in 37 women, biopsy-proven high-grade cervical intraepithelial neoplasia in 50 women, and invasive carcinoma in seven women. The proportion of women with high-grade cervical lesion or carcinoma detected after abnormal careHPV™ test was higher (6.02%; 95% confidence interval [CI]: 4.4-8.1) than that detected by conventional Pap smear (4.59%; 95% CI: 3.2-6.5). careHPV™ and HPV-16 genotyping had, respectively, the highest sensitivity (80.8%; 95% CI: 67.4-89.5) and specificity (92.2%; 95% CI: 89.8-94.2). HPV-16 was the most frequently detected genotype. CONCLUSIONS: careHPV™ test represents a screening option in Lao PDR, particularly in women living with HIV-1 because of higher prevalence of chronic HPV in this population.

Women's perception of cervical cancer and its prevention in rural Laos.

BACKGROUND: Cervical cancer is the second most common cancer of women in the world, and it becomes a major cause of cancer mortality in low-income countries. Currently, little is known regarding cervical cancer incidence in Laos, although it is anticipated to be high like in neighboring countries. To be able to develop a screening program in the country, it is essential to explore women's perception of the disease. The purpose of this study was therefore to describe knowledge, awareness, and attitudes regarding cervical cancer among rural women of Laos. METHODS: In a descriptive cross-sectional study, women were interviewed using a structured questionnaire covering sociodemographic factors, knowledge of the disease and its risk factors, awareness, and attitudes toward cervical cancer and its prevention. RESULTS: Eight hundred women were included in the study, and 58% claimed to know about cervical cancer. Approximately one third (38%) considered themselves to be at risk, but less than 5% had ever had a Papanicolau test. Sixty-two percent believed it was possible to prevent cervical cancer and that vaccination may be a suitable method, but only 14% know about risk factors. Another method for prevention was frequent vaginal douching, which was suggested by 70% of the women. Symptoms like bleeding and discharge were correctly identified as possible indicators of cervical cancer, but only 57 women (7%) knew that an early stage of the disease could be symptom-free. Lack of subjective symptoms was the main reason for women to refrain from gynecological examinations. CONCLUSIONS: This study indicates that rural women in Laos have limited knowledge about cervical cancer and even less about screening and prevention. There is a need to educate the general community about the disease and its prevention.

Policy maker and provider knowledge and attitudes regarding the provision of emergency contraceptive pills within Lao PDR.

BACKGROUND: The Ministry of Health (MOH) launched the National Reproductive Health Policy in 2005, which included recommendations regarding the use of emergency contraceptive pills (ECP). However, ECP have not yet been introduced officially in the public sector of the Lao PDR. Thus, their availability is limited. Understanding the knowledge of ECP and attitudes about their provision, barriers to use, and availability among health providers and policy makers is essential to successfully incorporate ECP into reproductive health services. METHODS: Qualitative research methods using in-depth interviews were employed to collect data from policy makers and health providers (auxiliary medical staff, nurses, and medical doctors). Altogether, 10 policy makers, 22 public providers, and 10 providers at private clinics were interviewed. Content analysis was applied to analyze the transcribed data. RESULTS: The majority of policy makers and health care providers had heard about ECP and supported their introduction in the public sector. However, their knowledge was poor, many expressed inconsistent attitudes, and their ability to meet the demand of potential users is limited. CONCLUSIONS: There is a need to train health providers and policy makers on emergency contraception and improve their knowledge about ECP, especially regarding the correct timing of use and the availability of methods. In addition, the general public must be informed of the attributes, side effects, and availability of ECP, and policy makers must facilitate the approval of ECP by the Lao Food and Drug Administration. These interventions could lead to increased access to and demand for ECP.

Subtypes of Breast Cancer in Lao P.D.R.: A Study in a Limited-Resource Setting

Aim: The purpose of this study is to evaluate the prevalence of the immunohistochemical subtypes of breast cancer among Lao women by using immunohistochemistry (according to the St. Gallen 2017 guidelines) and to study their correlation to clinicopathological features in order to help guide better treatment plans for patients. Materials and methods: Formalin-fixed and paraffin embedded tissue blocks of 76 cases of primary invasive breast cancer were retrieved from the University of Health Sciences, Vientiane, Lao PDR, from 2013 to 2016. Patients' information and previous histological reports were reviewed. Immunohistochemistry was done using antibodies against estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu) and Ki-67 (MIB-1). Results: The mean age of the patients was 49 years, and the major histologic type was invasive ductal carcinoma, NOS (90.7%). The proportion of each subtype was hormone receptor-positive and HER2-negative, 44.7%; hormone receptor-positive and HER2-positive, 3.9%; hormone receptor-negative and HER2-positive, 13.2%; and triple-negative, 38.2%. ER was positive in 40.8% of the cases, while PR was positive in 47.4%. More than half of the cases were poorly differentiated cancer (65.8%), followed by moderately differentiated (34.2%). Tumors presented with pT2 (60.5%), followed by pT3 (25.0%) and pT4 (7.9%). Conclusion: Breast cancer among Lao women is characterized by a large percentage of the triple-negative subtype that is less susceptible to hormonal treatments. The empirical treatment with tamoxifen should be reconsidered since it would be less effective to these patients. More importantly, basic pathology services should be the first requirement in Lao PDR in order to provide adequate care.

Economic Evaluation of Screening Strategies Combined with HPV Vaccination of Preadolescent Girls for the Prevention of Cervical Cancer in Vientiane, Lao PDR.

BACKGROUND: Several approaches to reduce the incidence of invasive cervical cancers exist. The approach adopted should take into account contextual factors that influence the cost-effectiveness of the available options. OBJECTIVE: To determine the cost-effectiveness of screening strategies combined with a vaccination program for 10-year old girls for cervical cancer prevention in Vientiane, Lao PDR. METHODS: A population-based dynamic compartment model was constructed. The interventions consisted of a 10-year old girl vaccination program only, or this program combined with screening strategies, i.e., visual inspection with acetic acid (VIA), cytology-based screening, rapid human papillomavirus (HPV) DNA testing, or combined VIA and cytology testing. Simulations were run over 100 years. In base-case scenario analyses, we assumed a 70% vaccination coverage with lifelong protection and a 50% screening coverage. The outcome of interest was the incremental cost per Disability-Adjusted Life Year (DALY) averted. RESULTS: In base-case scenarios, compared to the next best strategy, the model predicted that VIA screening of women aged 30-65 years old every three years, combined with vaccination, was the most attractive option, costing 2 544 international dollars (I$) per DALY averted. Meanwhile, rapid HPV DNA testing was predicted to be more attractive than cytology-based screening or its combination with VIA. Among cytology-based screening options, combined VIA with conventional cytology testing was predicted to be the most attractive option. Multi-way sensitivity analyses did not change the results. Compared to rapid HPV DNA testing, VIA had a probability of cost-effectiveness of 73%. Compared to the vaccination only option, the probability that a program consisting of screening women every five years would be cost-effective was around 60% and 80% if the willingness-to-pay threshold is fixed at one and three GDP per capita, respectively. CONCLUSIONS: A VIA screening program in addition to a girl vaccination program was predicted to be the most attractive option in the health care context of Lao PDR. When compared with other screening methods, VIA was the primary recommended method for combination with vaccination in Lao PDR.

Accuracy of Combined Visual Inspection with Acetic Acid and Cervical Cytology Testing as a Primary Screening Tool for Cervical Cancer: a Systematic Review and Meta-Analysis.

BACKGROUND: The performance of combined testing visual inspection with acetic acid (VIA) and cervical cytology tests might differ from one setting to another. The average estimate of the testing accuracy across studies is informative, but no meta-analysis has been carried out to assess this combined method. OBJECTIVE: The objective of this study was to estimate the average sensitivity and specificity of the combined VIA and cervical cytology tests for the detection of cervical precancerous lesions. MATERIALS AND METHODS: We conducted a systematic review and a meta-analysis, according to the Cochrane Handbook for Systematic Review of Diagnostic Test Accuracy. We considered two cases. In the either-positive result case, a positive result implies positivity in at least one of the tests. A negative result implies negativity in both tests. In the both-positive case, a positive result implies having both tests positive. Eligible studies were identified using Pubmed, Embase, Website of Science, CINHAL and COCRANE databases. True positive, false positive, false negative and true negative values were extracted. Estimates of sensitivity and specificity, positive and negative likelihood (LR) and diagnostic odds ratios (DOR) were pooled using a hierarchical random effect model. Hierarchical summary receiver operating characteristics (HSROC) were generated and heterogeneity was verified through covariates potentially influencing the diagnostic odds ratio. FINDINGS: Nine studies fulfilled inclusion criteria and were included in the analysis. Pooled estimates of the sensitivities of the combined tests in either-positive and both-positive cases were 0.87 (95% CI: 0.83-0.90) and 0.38 (95% CI: 0.29-0.48), respectively. Corresponding specificities were 0.79 (95% CI: 0.63-0.89) and 0.98 (95% CI: 0.96-0.99) respectively. The DORs of the combined tests in either-positive or both-positive result cases were 27.7 (95% CI: 12.5-61.5) and 52 (95% CI: 22.1-122.2), respectively. When including only articles without partial verification bias and also a high-grade cervical intraepithelial neoplasia as a threshold of the disease, DOR of combined test in both-positive result cases remained the highest. However, DORs decreased to 12.1 (95% CI: 6.05-24.1) and 13.8 (95% CI: 7.92-23.9) in studies without partial verification bias for the combined tests in the either-positive and both-positive result cases, respectively. The screener, the place of study and the size of the population significantly influenced the DOR of combined tests in the both-positive result case in restriction analyses that considered only articles with CIN2+ as disease threshold. CONCLUSIONS: The combined test in the either-positive result case has a high sensitivity, but a low specificity. These results suggest that the combined test should be considered in developing countries as a primary screening test if facilities exist to confirm, through colposcopy and biopsy, a positive result.

Safety, feasibility, and acceptability of visual inspection with acetic acid and immediate treatment with cryotherapy in rural Laos.

OBJECTIVE: To assess the safety, acceptability, and feasibility of visual inspection with acetic acid (VIA) followed by immediate treatment with cryotherapy as a single-visit approach for the prevention of cervical cancer among women in rural Laos. METHODS: In 2009, women from 2 provinces in Laos were recruited for cervical cancer screening using VIA. If the inspection of the cervix showed a well-defined acetowhite lesion close to the os, immediate cryotherapy was offered. RESULTS: Of the 1926 women who were included, 134 (7.0%) tested positive on VIA. Of these, 113 (84.3%) underwent immediate cryotherapy and none declined treatment. One year after immediate cryotherapy, 77 (68.1%) women returned for a follow-up assessment and 68 (88.3%) were now VIA-negative. There was no report of a major complication during or after treatment. The acceptance of both VIA and cryotherapy was high. CONCLUSION: Visual inspection with acetic acid is a simple test that requires minimal infrastructure and expenditure. Integration of VIA with cryotherapy at the primary care level may constitute a feasible program for the prevention of cervical cancer in Laos.