Assessing Cervical Cancer Screening Coverage Using a Population-Based Behavioral Risk Factor Survey--Thailand, 2010

Disparities in the change of cervical cancer mortality rate between urban and rural Chiang Mai in the era of universal health care and the Thai national screening program

Background

The Ministry of Public Health of Thailand established universal health coverage (UHC) in 2002, which also included national-level screening for cervical cancer in 2005. This study examined the changes in mortality of cervical cancer in rural and urban areas in Chiang Mai Province of northern Thailand during the era of UHC and the immediately preceding period.

Methods

Data of cervical cancer patients in Chiang Mai in northern Thailand, who died from 1998 through 2012, were used to calculate the change in age-standardized rates of mortality (ASMR) using a joinpoint regression model and to calculate estimated annual percent changes (APC). The change in mortality rate by age groups along with changes by geographic area of residence were determined.

Results

Among the 1177 patients who died from cervical cancer, 13(1%), 713 (61%) and 451 (38%) were in the young age group (aged < 30), the screening target group (aged 30–59) and the elderly group (aged ≥60), respectively. The mortality rate among women aged 30–59 significantly declined by 3% per year from 2003 through 2012 (p < 0.001). By area of residence, the mortality rate in women targeted by the screening program significantly decreased in urban areas but remained stable in more rural areas, APC of − 7.6 (95% CI: − 12.1 to − 2.8) and APC of 3.7 (95% CI: − 2.1 to 9.9), respectively.

Conclusion

The UHC and national cervical cancer screening program in Thai women may have contributed to the reduction of the mortality rate of cervical cancer in the screening target age group. However, this reduction was primarily in urban areas of Chiang Mai, and there was no significant impact on mortality in more rural areas. These results suggest that the reasons for this disparity need to be further explored to equitably increase access to cervical cancer services of the UHC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01515-1.

CDC Activities for Improving Implementation of Human Papillomavirus Vaccination, Cervical Cancer Screening, and Surveillance Worldwide

Cervical cancer incidence and mortality rates are high, particularly in developing countries. Most cervical cancers can be prevented by human papillomavirus (HPV) vaccination, screening, and timely treatment. The US Centers for Disease Control and Prevention (CDC) provides global technical assistance for implementation and evaluation of HPV vaccination pilot projects and programs and laboratory-related HPV activities to assess HPV vaccines. CDC collaborates with global partners to develop global cervical cancer screening recommendations and manuals, implement screening, create standardized evaluation tools, and provide expertise to monitor outcomes. CDC also trains epidemiologists in cancer prevention through its Field Epidemiology Training Program and is working to improve cancer surveillance by supporting efforts of the World Health Organization in developing cancer registry hubs and assisting countries in estimating costs for developing population-based cancer registries. These activities contribute to the Global Health Security Agenda action packages to improve immunization, surveillance, and the public health workforce globally.

Significant variations in the cervical cancer screening rate in China by individual-level and geographical measures of socioeconomic status: a multilevel model analysis of a nationally representative survey dataset

Variations in cervical cancer screening rates in China have rarely been studied in depth. This study aimed to investigate cervical cancer screening rates in relation to both individual‐level and geographical measures of socioeconomic status (SES). Data were obtained from women aged 21 years or older by face‐to‐face interviews between August 2013 and July 2014 as part of the Chinese Chronic Diseases and Risk Factors Surveillance. The geographical variables were obtained from the 2010 Chinese population census. The cervical cancer screening rates and 95% confidence interval (CI) were estimated and mapped. Multilevel logistic regression models were fitted. Overall, only 21.4% (95% CI: 19.6–23.1%) of 91,816 women aged ≥21 years reported having ever been screened for cervical cancer and significant geographical variations at both province and county levels were identified (P < 0.01). The cervical cancer screening rates were the lowest among the poor [13.9% (95% CI: 12.1–15.7%)], uninsured [14.4% (95% CI: 10.3–18.4%)], less‐educated [16.0% (95% CI: 14.3–17.6%)], and agricultural employment [18.1% (95% CI: 15.8–20.4%)] women along with those residing in areas of low economic status [15.0% (95% CI: 11.8–18.2%)], of low urbanization [15.6% (95% CI: 13.4–17.7%)], and of low education status [16.0% (95% CI: 14.0–18.1%)]. The multilevel analysis also indicated that women with lower individual‐level measures of SES residing in areas with low geographical measures of SES were significantly less likely to receive cervical cancer screening (P < 0.0001). Despite the launch of an organized cancer screening program in China, cervical cancer screening rates remain alarmingly low and significant variations based on geographical regions and measures of SES still exist. It is therefore essential to adopt strategies to better direct limited available public resources to priority groups.

Agreement of self- and physician-collected samples for detection of high-risk human papillomavirus infections in women attending a colposcopy clinic in Thailand

Objective

To study the concordance between vaginal self- and endocervical physician-collected high-risk (hr) HPV testing in Thai women who attended a colposcopy clinic. Vaginal samples were obtained by self-sampling with a dry brush before endocervical samples were obtained by physicians. Both specimens were analyzed for hrHPV by Cobas4800 HPV test.

Results

Of the 247 pairs of samples, overall hrHPV prevalence from self- and physician-collected samples was 41.3 and 36.0%, respectively. The overall agreement between the methods was 74.5% with κ 0.46 (P < 0.001). Our study revealed moderate agreement between self- and physician-collected methods for hrHPV testing.

Effect of the national screening program on malignancy status of cervical cancer in Northern Thailand

OBJECTIVES

Cervical cancer has posed a serious problem in Thailand for decades. In 2002, a systematic screening program was implemented under universal healthcare coverage for all Thai women. However, there has been little research on how screening affected particular aspects of cervical cancer, such as stage distribution. This screening program has a target group; therefore, it is necessary to assess stage and incidence trends by age of those within and outside the screening target group.

METHODS

Using trend analysis, we assess in situ and malignant cervical cancers in Northern Thailand to measure changes after implementation of the national screening program.

RESULTS

While incidence of malignant cancers is decreasing and incidence of in situ tumors is increasing across all age groups, women above age 60 still experience a high incidence of malignant tumors.

CONCLUSIONS

The screening program is successful in the target group at downshifting the stage distribution of malignant tumors and reducing incidence of malignant tumors with in situ cases being captured. However, the high incidence of malignant tumors in women over age 60 will continue to be clinically relevant for cervical cancer management until younger generations undergoing screening enter this age group.

National and Subnational Population-Based Incidence of Cancer in Thailand: Assessing Cancers with the Highest Burdens

In Thailand, five cancer types-breast, cervical, colorectal, liver and lung cancer-contribute to over half of the cancer burden. The magnitude of these cancers must be quantified over time to assess previous health policies and highlight future trajectories for targeted prevention efforts. We provide a comprehensive assessment of these five cancers nationally and subnationally, with trend analysis, projections, and number of cases expected for the year 2025 using cancer registry data. We found that breast (average annual percent change (AAPC): 3.1%) and colorectal cancer (female AAPC: 3.3%, male AAPC: 4.1%) are increasing while cervical cancer (AAPC: -4.4%) is decreasing nationwide. However, liver and lung cancers exhibit disproportionately higher burdens in the northeast and north regions, respectively. Lung cancer increased significantly in northeastern and southern women, despite low smoking rates. Liver cancers are expected to increase in the northern males and females. Liver cancer increased in the south, despite the absence of the liver fluke, a known factor, in this region. Our findings are presented in the context of health policy, population dynamics and serve to provide evidence for future prevention strategies. Our subnational estimates provide a basis for understanding variations in region-specific risk factor profiles that contribute to incidence trends over time.

A Model Approach for Assessing the Benefits of HPV Testing against Cytology in Screening for Cervical Cancer Precursors in Thailand

Objective:

The aim of this study was to compare the efficacy of HPV 16/18 genotyping test, high risk HPV DNA testing, alone and in conjunction with the liquid-based cytology method in screening for cervical cancer precursors.

Methods:

A Markov model was used to describe the course of the cases of CIN2+ that had been detected over a 35 year period. Screening programs started at age 30 and were performed at an interval of once every five years. The model compared three strategies of HPV 16/18 genotyping with reflex cytology triage, high-risk HPV testing alone with referral to colposcopy and cytology-based screening with referral to colposcopy. We assumed the rate of patients lost to follow-up for those referred to colposcopy would be 0%. The clinical parameters were estimated using the data from a study conducted by the Thailand National Cancer Institute.

Result:

Of the three screening strategies evaluated, the high risk HPV DNA testing alone was the most effective for detecting CIN2+ over the 35 year study period. It detected 143 and 510 cases per 100,000 women more than the HPV 16/18 genotyping test and cytology-based strategy, respectively. The HPV genotyping test detected 368 cases per 100,000 women more than the cytology-based approach. In addition, when viewed with five year intervals, there were missed cases totaling approximately half of the detected cases screened by the cytology strategy and 10% of cases detected with screening by the HPV genotyping test.

Conclusion:

This study strongly indicates that HPV/DNA testing is preferable to cytology-based screening for cervical cancer precursors. However, the balance between the benefits, burdens and cost of each screening program should be considered.