Trends in socioeconomic inequalities in cervical,breast, and colorectal cancer screening participation among women in Japan, 2010–2019

BackgroundIt is known that socioeconomic status (SES) influences the outcome of cancer treatment and this could partly be explained by decreased use of cancer screening services by people of lower SES. Many studies have indicated that low SES, including low educational attainment or unstable employment, was related to nonparticipation in cancer screening. However, studies investigating trends in SES inequalities within cancer screening participation are limited. Our objective was to examine trends in SES inequalities in cervical, breast, and colorectal cancer screening participation among women in Japan between 2010 and 2019.MethodsWe analyzed 189,442, 168,571, 163,341, and 150,828 women in 2010, 2013, 2016, and 2019 respectively, using nationally representative cross-sectional surveys. The main outcome variables are participation in each cancer screening. We used educational attainment and employment status as measures for SES. Multivariable logistic regression analysis, adjusted for age, marital status, educational attainment, and employment status was performed to evaluate the associations between SES and nonparticipation in each cancer screening.ResultsOverall participation rates in each cancer screening increased between 2010 and 2019. Low educational attainment and non-permanent employment status were related to nonparticipation in each cancer screening and inequality according to employment status increased within each screening participation during the study period. For example, dispatched workers were more likely to not participate in cervical cancer screening than permanent workers: in 2010, [aOR 1.11 95 %CI: 1.01 –1.21], and in 2019, [aOR 1.46 95 %CI: 1.34–1.60]. The inequality was greatest in colorectal cancer screening nonparticipation, followed by breast and cervical screening.ConclusionsAlthough the participation rates in each cancer screening have increased, inequality in participation in terms of employment status widened among women in Japan between 2010 and 2019. Reducing inequalities in cancer screening participation is essential for cancer screening intervention policies.     

Quantification of overdiagnosis in randomised trials of cancer screening: an overview and re-analysis of systematic reviews

The degree of overdiagnosis in common cancer screening trials is uncertain due to inadequate design of trials, varying definition and methods used to estimate overdiagnosis. Therefore, we aimed to quantify the risk of overdiagnosis for the most widely implemented cancer screening programmes and assess the implications of design limitations and biases in cancer screening trials on the estimates of overdiagnosis by conducting an overview and re-analysis of systematic reviews of cancer screening. We searched PubMed and the Cochrane Library from their inception dates to November 29, 2021. Eligible studies included systematic reviews of randomised trials comparing cancer screening interventions to no screening, which reported cancer incidence for both trial arms. We extracted data on study characteristics, cancer incidence and assessed the risk of bias using the Cochrane Collaboration’s risk of bias tool. We included 19 trials described in 30 articles for review, reporting results for the following types of screening: mammography for breast cancer, chest X-ray or low-dose CT for lung cancer, alpha-foetoprotein and ultrasound for liver cancer, digital rectal examination, prostate-specific antigen, and transrectal ultrasound for prostate cancer, and CA-125 test and/or ultrasound for ovarian cancer. No trials on screening for melanoma were eligible. Only one trial (5%) had low risk in all bias domains, leading to a post-hoc meta-analysis, excluding trials with high risk of bias in critical domains, finding the extent of overdiagnosis ranged from 17% to 38% across cancer screening programmes. We conclude that there is a significant risk of overdiagnosis in the included randomised trials on cancer screening. We found that trials were generally not designed to estimate overdiagnosis and many trials had high risk of biases that may draw the estimates of overdiagnosis towards the null. In effect, the true extent of overdiagnosis due to cancer screening is likely underestimated.     

Significance tests for cancer screening trials

The goal of a cancer screening program is to reduce cancer mortality by detecting tumors at earlier stages of their development. For some types of cancer, screening tests may allow the preclinical detection of benign precursors of a tumor, and thus a screening program could result in reductions in both cancer incidence and mortality. For other types of cancer, a screening program will not reduce cancer incidence, and thus the expected outcome in a randomized cancer screening trial would be equal cancer incidence rates in control and study groups, but reduced cancer mortality in the study group. For the latter situation, we employ a variety of Poisson models for cancer incidence and mortality to derive optimal tests for equality of cancer mortality rates in a cancer screening trial, and we compare the asymptotic relative efficiencies of the test statistics under various alternatives. We demonstrate that testing equality of case mortality rates using Fisher's exact test or its Pearson chi-square approximation is nearly optimal when cancer incidence rates are equal and is fully efficient when cancer incidence rates are unequal. When valid, this comparison of case mortality rates in the study and control groups can be considerably more powerful than the standard comparison of population mortality rates. We illustrate the results using data from a clinical trial of a breast cancer screening program.     

Screening for cancer.

Screening has proved effective for only two cancer sites, the breast and the cervix uteri. Only for these, therefore, should screening be a part of routine clinical practice. The degree to which screening is effective depends on whether appropriate groups are screened. For cancer of the breast, current evidence justifies mammographic screening every two years only from the age of 50, continuing at least to the age of 70. The place of breast self-examination and physical examination of the breasts is under investigation, but these procedures should probably be used in all women after the age of 40. For cancer of the cervix, nearly maximal efficacy is obtained by screening sexually active women every three years from the age of 25 to 60. Older women who have not been screened regularly should be screened. Other screening techniques to detect cancers, such as the rectal examination, sigmoidoscopy, and fecal occult blood tests for colorectal cancer, are still experimental. Organizational and other difficulties will prevent screening programs from making a major contribution to reducing overall cancer mortality by the year 2000. If organizational problems can be overcome, however, screening may control invasive cancer of the cervix and make a major contribution in reducing breast cancer mortality in the future.     

Print news coverage of cancer: What prevention messages are conveyed when screening is newsworthy?

Background: Americans are generally favorable towards cancer screening, but fatalistic about cancer prevention. News coverage shapes perceptions of cancer control in meaningful ways, but there is little consensus as to the impact of news on our understanding of and engagement in cancer screening practices. Our analysis of cancer screening-related print news coverage during a four month period in 2005 suggests that the newsworthiness of new screening technologies may undermine public confidence in currently available and effective secondary prevention programs, while promoting tests whose effectiveness is debated or not yet established. Methods and results: We conducted a structured text analysis of 517 cancer-related news articles from 15 leading daily newspapers and a subsequent qualitative analysis of the 79 screening news articles. Screening articles were analyzed for content related to criteria for screening effectiveness. Content patterns for each type of screening and cancer were also noted. News coverage consistently conveyed screening as important and highlighted the need to protect and expand access to screening. At the same time, to the extent that story content was framed by the newsworthiness of new tests and technologies this often indirectly called into question effective and established protocols and programs without providing any actionable alternative. Conclusion: This analysis revealed unexpected messages about screening that are potentially problematic for cancer control. The cancer control community should continue efforts to understand and shape news coverage of screening in order to promote balanced and action-oriented content. Research has shown that Americans hold conflicting views regarding cancer—having a favorable opinion of screening while simultaneously feeling fatalistic about prevention. Our analysis of print news stories on cancer screening suggests that the determination of screening's “newsworthiness” is related to newly developed tests and protocols, which may create demand for new tests whose effectiveness is unknown and undermine confidence in established and effective screening programs.     

Screening and genetic counselling for relatives of patients with colorectal cancer in a family cancer clinic.

OBJECTIVE--To introduce and monitor a screening programme for first degree relatives of patients with colorectal cancer based on their calculated lifetime risk. DESIGN--Lifetime risks were calculated for first degree relatives of patients with colorectal cancer and used to offer screening based on estimated risk. SETTING--A family cancer clinic was set up as part of the North East Thames Regional Genetic Service for relatives of patients who had developed colorectal cancer before the age of 45 and members of families in which multiple cancer had occurred. PATIENTS--Self referrals as well as patients referred by general and hospital practitioners. INTERVENTION--Relatives with a lifetime risk of 1 in 10 or greater (high risk group) were offered screening five yearly by colonoscopy, and those whose risk was between 1 in 10 and 1 in 17 were offered yearly screening for faecal occult blood. Women with family histories compatible with Lynch type II cancer family syndrome were offered screening for breast and pelvic tumours. RESULTS--In four years 715 patients were seen. Acceptance of screening was 90% (644 patients). Of 151 patients screened for faecal occult blood, two were found to have polyps. This screening test was unsatisfactory for the high risk group, having a negative predictive value of 78% in 59 patients tested. Regular screening by colonoscopy was offered to 382 high risk patients; 62 patients with polyps and five with colonic cancer were found. One hundred and ten pedigrees were identified with the Lynch type II cancer family syndrome, and four of 35 women screened were found to have breast cancer. Of 14 relatives aged over 65 with a 1 in 2 risk of site specific colonic cancer or Lynch type II cancer family syndrome, seven were found to have polyps, one of whom had carcinoma in situ. CONCLUSIONS--Family history can be used to identify those at risk of colonic cancer and to target appropriate screening. Colonoscopy detected a high number of premalignant colonic polyps, but faecal occult blood testing was unsatisfactory for those at high risk of colorectal cancer.     

Screening and self examination for breast cancer.

Breast cancer is the major form of cancer in women, with nearly 30,000 new cases and over 15,000 deaths in the United Kingdom each year. Breast screening by mammography has been shown in randomised trials to reduce mortality from breast cancer in women aged 50 and over. An NHS breast screening programme has been in operation in the United Kingdom since 1988. Its aim is to reduce mortality from breast cancer by 25% in the population of women invited to be screened. The uptake of mammography among the eligible population may be the single most important determinant if the programme is to be effective. Primary care teams have an important part to play in encouraging women to attend for screening and in providing information, advice, and reassurance at all stages of the screening process. To date, routine breast self examination has not been shown to be an effective method of screening for breast cancer and should not therefore be promoted as a primary screening procedure. There is, however, a case to be made for women to become more "breast aware."     

Prevalence screening for ovarian cancer in postmenopausal women by CA 125 measurement and ultrasonography.

OBJECTIVE--To assess the performance of the sequential combination of serum CA 125 measurement and ultrasonography in screening for ovarian cancer. DESIGN--The serum CA 125 concentration of each subject was determined and those with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. If ultrasonography gave abnormal results surgical investigation was arranged. Volunteers were followed up by annual postal questionnaire. SETTING--General practice, occupational health departments, ovarian cancer screening clinic. SUBJECTS--22,000 women volunteers who were postmenopausal and aged over 45 years. MAIN OUTCOME MEASURES--Apparent sensitivity, specificity, positive predictive value, years of cancer detected. RESULTS--41 women had a positive screening result and were investigated surgically. 11 had ovarian cancer (true positive result) and 30 had other disorders or no abnormality (false positive result). Of the 21,959 volunteers with a negative screening result, eight subsequently presented clinically with ovarian cancer (false negative result) and 21,951 had not developed ovarian cancer during follow up (apparent true negative result). The screening protocol achieved a specificity of 99.9%, a positive predictive value of 26.8%, and an apparent sensitivity of 78.6% and 57.9% at one year and two year follow up respectively. The estimated number of years of cancer detected by the prevalence screen was 1.4 years. CONCLUSIONS--This screening protocol is highly specific for ovarian cancer and can detect a substantial proportion of cases at a preclinical stage. Further investigation is required to determine the effect of the screening protocol on the ratio of early to late stage disease detected and on mortality from ovarian cancer.     

Effectiveness of mass screening for endometrial cancer

OBJECTIVE: To investigate the effectiveness of mass screening for endometrial cancer using Endocyte (Laboratoire CCD, Paris, France) endometrial smears. STUDY DESIGN: The study subjects were consecutive patients with documented endometrial cancer diagnosed between January 1, 1989, and December 31, 1997, at 22 hospitals in Japan. One hundred twenty-six cases were detected by mass screening and 1,069 diagnosed in outpatient clinics. We compared the stage of cancer at diagnosis and survival rate of patients in the two groups. RESULTS: Early stage was significantly more frequent in the screening group (P < .001); stage I comprised 88.1% of the screening group as compared with 65.3% of the outpatient group. Well-differentiated adenocarcinoma was significantly more frequent in the screening group (P < .01); grade 1 constituted 74.7% of the screening group as compared with 61.0% of the outpatient group. The five-year survival rate was significantly higher in the screening group than in the outpatient group (94.0% vs. 84.3%, P = .041). The crude hazard ratio (HR) of dying of endometrial cancer for the screening group as compared to the outpatient group was .47 (95% CI .22-.99, P = .048). HR became .96 (95% CI .45-2.08, P = .925) after adjustment for age, study area and cancer stage. CONCLUSION: The results suggest that an endometrial cancer screening program would lead to early detection and improved survival among women with endometrial cancer.     

Demands on surgical inpatient services after mass mammographic screening.

The changes in the demand for surgical inpatient care created by mammographic screening for breast cancer were analysed by comparing two counties, one with and one without a mass screening campaign. A comprehensive computerised register of inpatient care in the region was used. The results indicate that population based screening offered to women above 40 years and repeated every two to three years will increase the number of operations required for breast cancer and inpatient days by at least 150% during the initial screening round. During the second round the figures tend to return to previous levels. Of decisive importance for the demands on health service resources are the specificity of screening, the duration of the first screening round, and the age groups included.     

A Cost-Utility Analysis of Lung Cancer Screening and the Additional Benefits of Incorporating Smoking Cessation Interventions

Background

A 2011 report from the National Lung Screening Trial indicates that three annual low-dose computed tomography (LDCT) screenings for lung cancer reduced lung cancer mortality by 20% compared to chest X-ray among older individuals at high risk for lung cancer. Discussion has shifted from clinical proof to financial feasibility. The goal of this study was to determine whether LDCT screening for lung cancer in a commercially-insured population (aged 50–64) at high risk for lung cancer is cost-effective and to quantify the additional benefits of incorporating smoking cessation interventions in a lung cancer screening program.

Methods and Findings

The current study builds upon a previous simulation model to estimate the cost-utility of annual, repeated LDCT screenings over 15 years in a high risk hypothetical cohort of 18 million adults between age 50 and 64 with 30+ pack-years of smoking history. In the base case, the lung cancer screening intervention cost $27.8 billion over 15 years and yielded 985,284 quality-adjusted life years (QALYs) gained for a cost-utility ratio of $28,240 per QALY gained. Adding smoking cessation to these annual screenings resulted in increases in both the costs and QALYs saved, reflected in cost-utility ratios ranging from $16,198 per QALY gained to $23,185 per QALY gained. Annual LDCT lung cancer screening in this high risk population remained cost-effective across all sensitivity analyses.

Conclusions

The findings of this study indicate that repeat annual lung cancer screening in a high risk cohort of adults aged 50–64 is highly cost-effective. Offering smoking cessation interventions with the annual screening program improved the cost-effectiveness of lung cancer screening between 20% and 45%. The cost-utility ratios estimated in this study were in line with other accepted cancer screening interventions and support inclusion of annual LDCT screening for lung cancer in a high risk population in clinical recommendations.     

Effectiveness of the public health policy for breast cancer screening in Finland: population based cohort study.

OBJECTIVE: To evaluate the effectiveness of screening for breast cancer as a public health policy. DESIGN: Follow up in 1987-92 of Finnish women invited to join the screening programme in 1987-9 and of the control women (balanced by age and matched by municipality of residence), who were not invited to the service screening. SETTING: Finland. SUBJECTS: Of the Finnish women born in 1927-39, 89893 women invited for screening and 68862 controls were followed; 1584 breast cancers were diagnosed. MAIN OUTCOME MEASURES: Rate ratio of deaths from breast cancer among the women invited for screening to deaths among those not invited. RESULTS: There were 385 deaths from breast cancer, of which 127 were among the 1584 incident cases in 1987-92. The rate ratio of death was 0.76 (95% confidence interval 0.53 to 1.09). The effect was larger and significant (0.56; 0.33 to 0.95) among women aged under 56 years at entry. 20 cancers were prevented (one death prevented per 10000 screens). CONCLUSIONS: A breast screening programme can achieve a similar effect on mortality as achieved by the trials for breast cancer screening. However, it may be difficult to justify a screening programme as a public health policy on the basis of the mortality reduction only. Whether to run a screening programme as a public health policy also depends on its effects on the quality of life of the target population and what the resources would be used for if screening was not done. Given all the different dimensions in the effect, mammography based breast screening is probably justifiable as a public health policy.     

Survival Analysis of Patients with Interval Cancer Undergoing Gastric Cancer Screening by Endoscopy

AimsInterval cancer is a key factor that influences the effectiveness of a cancer screening program. To evaluate the impact of interval cancer on the effectiveness of endoscopic screening, the survival rates of patients with interval cancer were analyzed.MethodsWe performed gastric cancer-specific and all-causes survival analyses of patients with screen-detected cancer and patients with interval cancer in the endoscopic screening group and radiographic screening group using the Kaplan-Meier method. Since the screening interval was 1 year, interval cancer was defined as gastric cancer detected within 1 year after a negative result. A Cox proportional hazards model was used to investigate the risk factors associated with gastric cancer-specific and all-causes death.ResultsA total of 1,493 gastric cancer patients (endoscopic screening group: n = 347; radiographic screening group: n = 166; outpatient group: n = 980) were identified from the Tottori Cancer Registry from 2001 to 2008. The gastric cancer-specific survival rates were higher in the endoscopic screening group than in the radiographic screening group and the outpatients group. In the endoscopic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer and the patients with interval cancer were nearly equal (P = 0.869). In the radiographic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer was higher than that of the patients with interval cancer (P = 0.009). For gastric cancer-specific death, the hazard ratio of interval cancer in the endoscopic screening group was 0.216 for gastric cancer death (95%CI: 0.054-0.868) compared with the outpatient group.ConclusionThe survival rate and the risk of gastric cancer death among the patients with screen-detected cancer and patients with interval cancer were not significantly different in the annual endoscopic screening. These results suggest the potential of endoscopic screening in reducing mortality from gastric cancer.     

Progress and challenges in screening for early detection of ovarian cancer

Ovarian cancer is characterize by few early symptoms, presentation at an advanced stage, and poor survival. As a result, it is the most frequent cause of death from gynecological cancer. During the last decade, a research effort has been directed toward improving outcomes for ovarian cancer by screening for preclinical, early stage disease using both imaging techniques and serum markers. Numerous biomarkers have shown potential in samples from clinically diagnosed ovarian cancer patients, but few have been thoroughly assessed in preclinical disease and screening. The most thoroughly investigated biomarker in ovarian cancer screening is CA125. Prospective studies have demonstrated that both CA125 and transvaginal ultrasound can detect a significant proportion of preclinical ovarian cancers, and refinements in interpretation of results have improved sensitivity and reduced the false-positive rate of screening. There is preliminary evidence that screening can improve survival, but the impact of screening on mortality from ovarian cancer is still unclear. Prospective studies of screening are in progress in both the general population and high-risk population, including the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), a randomized trial involving 200,000 postmenopausal women designed to document the impact of screening on mortality. Recent advances in technology for the study of the serum proteome offer exciting opportunities for the identification of novel biomarkers or patterns of markers that will have greater sensitivity and lead time for preclinical disease than CA125. Considerable interest and controversy has been generated by initial results utilizing surface-enhanced laser desorption/ionization (SELDI) in ovarian cancer. There are challenging issues related to the design of studies to evaluate SELDI and other proteomic technology, as well as the reproducibility, sensitivity, and specificity of this new technology. Large serum banks such as that assembled in UKCTOCS, which contain preclinical samples from patients who later developed ovarian cancer and other disorders, provide a unique resource for carefully designed studies of proteomic technology. There is a sound basis for optimism that further developments in serum proteomic analysis will provide powerful methods for screening in ovarian cancer and many other diseases.     

Cervical Cancer—Use of a Non-Physician Health Team for Screening Procedures

A team of non-physician personnel has been trained in cytologic screening for cervical cancer. In a county hospital clinic setting among low income women whose annual pelvic examinations were being by-passed by physicians, this three-person team has performed pelvic examinations and screening under physician supervision for one year.Results of the first year''s experience, measured in cancer detection and in recognition and referral of benign gynecological disease as well, would suggest that a non-physician team, with a registered nurse doing a pelvic examination of screening type, can screen for cervical cancer and other pelvic disease efficiently and without a significant lowering of the quality of medical care.The training and use of teams of allied health care personnel directed by physicians is suggested as a practical means of overcoming the increasing shortage of physician services in annual screening for cervical cancer among low income women.     

Bayesian inference for the lead time in periodic cancer screening

This article develops a probability distribution for the lead time in periodic cancer screening examinations. The general aim is to allow statistical inference for a screening program's lead time, the length of time the diagnosis is advanced by screening. The program's lead time is distributed as a mixture of a point mass and a piecewise continuous distribution. Simulation studies using the HIP (Health Insurance Plan for Greater New York) study's data provide estimates of different characteristics of a screening program under different screening frequencies. The components of this mixture represent two aspects of screening's benefit, namely, a reduction in the number of interval cases and the extent by which screening advanced the age of diagnosis. We present estimates of these two measures for participants in a breast cancer screening program. We also provide the mean, mode, variance, and density curve of the program's lead time. The model can provide policy makers with important information regarding the screening period, frequency, and the endpoints that may serve as surrogates for the benefit to women who take part in a periodic screening program. Though the study focuses on breast cancer screening, it is also applicable to other kinds of chronic disease.     

Cervical cancer screening and demonstration projects to identify barriers to preventing cervical cancer mortality

Cervical cancer screening and demonstration projects to identify barriers to optimal screening are discussed. Interview surveys showed that older women and women in low-income groups tended to have lower rates of Papanicolaou smear screening. Data produced by demonstration projects established by the Centers for Disease Control in collaboration with state and local authorities and private institutions will be used to design and implement strategies for increasing screening levels to further reduce cervical cancer mortality.     

Association between lung cancer screening and smoking cessation

IntroductionAdults with high-risk smoking histories benefit from annual lung cancer screening. It is unclear if there is an association between lung cancer screening and smoking cessation among U.S. adults who receive screening.MethodsWe performed this population-based cross-sectional study using data from the Behavioral Risk Factor Surveillance System (2017–2020). We defined individuals eligible for lung cancer screening as adults 55–80 years old with ≥ 30 pack-year smoking history who were currently smoking or quit within the last 15 years. We assessed the association between lung cancer screening and current smoking status.ResultsBetween 2017 and 2020, 12,382 participants met screening criteria. Current smoking was reported by 5685 (45.9 %) participants, of whom 40.4 % (2298) reported a cessation attempt in the prior year. Lung cancer screening was reported by only 2022 (16.3 %) eligible participants. Lung cancer screening was associated with lower likelihood of currently smoking (odds ratio [OR] 0.705, 95 % CI 0.626–0.793) compared to individuals who did not receive screening. Screening was also associated with higher likelihood of reporting a cessation attempt in the prior year (OR 1.562, 95 % CI 1.345–1.815) compared to individuals who did not receive screening.ConclusionsReceipt of lung cancer screening was associated with lower smoking rates and more frequent cessation attempts among U.S. adults. Better implementation of lung cancer screening programs is critical and may profoundly increase smoking cessation in this population at risk of developing lung cancer.     

The Prevalence and Factors for Cancer Screening Behavior among People with Severe Mental Illness in Hong Kong

Objectives

Screening is useful in reducing cancer incidence and mortality. People with severe mental illness (PSMI) are vulnerable to cancer as they are exposed to higher levels of cancer risks. Little is known about PSMI''s cancer screening behavior and associated factors. The present study examined the utilization of breast, cervical, prostate, and colorectal cancer screening among PSMI in Hong Kong and to identify factors associated with their screening behaviors.

Method

591 PSMI from community mental health services completed a cross-sectional survey.

Results

The percentage of cancer screening behavior among those who met the criteria for particular screening recommendation was as follows: 20.8% for mammography; 36.5% for clinical breast examination (CBE); 40.5% for pap-smear test; 12.8% for prostate examination; and 21.6% for colorectal cancer screening. Results from logistic regression analyses showed that marital status was a significant factor for mammography, CBE, and pap-smear test; belief that cancer can be healed if found early was a significant factor for pap-smear test and colorectal screening; belief that one can have cancer without having symptoms was a significant factor for CBE and pap-smear test; belief that one will have a higher risk if a family member has had cancer was a significant factor for CBE; and self-efficacy was a significant factor for CBE and pap-smear test behavior.

Conclusions

Cancer screening utilization among PSMI in Hong Kong is low. Beliefs about cancer and self-efficacy are associated with cancer screening behavior. Health care professionals should improve the knowledge and remove the misconceptions about cancer among PSMI; self-efficacy should also be promoted.     

Performance of Different Gastric Cancer Screening Methods in Korea: A Population-Based Study

Background

There is a lack of agreement on which gastric cancer screening method is the most effective in the general population. The present study compared the relative performance of upper-gastrointestinal series (UGIS) and endoscopy screening for gastric cancer.

Methods

A population-based study was conducted using the National Cancer Screening Program (NCSP) database. We analyzed data on 2,690,731 men and women in Korea who underwent either UGIS or endoscopy screening for gastric cancer between January 1, 2002 and December 31, 2005. Final gastric cancer diagnosis was ascertained through linkage with the Korean Central Cancer Registry. We calculated positivity rate, gastric cancer detection rate, interval cancer rate, sensitivity, specificity, and positive predictive value of UGIS and endoscopy screening.

Results

The positivity rates for UGIS and endoscopy screening were 39.7 and 42.1 per 1,000 screenings, respectively. Gastric cancer detection rates were 0.68 and 2.61 per 1,000 screenings, respectively. In total, 2,067 interval cancers occurred within 1 year of a negative UGIS screening result (rate, 1.17/1,000) and 1,083 after a negative endoscopy screening result (rate, 1.17/1,000). The sensitivity of UGIS and endoscopy screening to detect gastric cancer was 36.7 and 69.0%, respectively, and specificity was 96.1 and 96.0%. The sensitivity of endoscopy screening to detect localized gastric cancer was 65.7%, which was statistically significantly higher than that of UGIS screening.

Conclusion

Overall, endoscopy performed better than UGIS in the NCSP for gastric cancer. Further evaluation of the impact of these screening methods should take into account the corresponding costs and reduction in mortality.