Screening For Asymptomatic Disease Research Articles

“First, Do No Harm”?

Screening for asymptomatic disease is a routine aspect of contemporary public health practice. However, it is also controversial, because it leads to overdiagnosis and overtreatment, with many arguing that programmes are “ineffective,” i.e., the “costs” outweigh the “benefits.” This paper explores a more fundamental objection to screening programmes: that, even if they are effective, they are ethically impermissible because they breach the principle of non-maleficence. In so doing, it suggests a new approach to the ethics of risk, justifying a concern with how policies affect individuals’ absolute ex-ante prospects. Part 1 sets up the tension between screening and non-maleficence. Part 2 introduces and motivates a novel interpretation of the non-maleficence principle, “ex-ante Do No Harm,” which resolves this tension. Part 3 defends and clarifies this principle by discussing its relationship to the ex-ante Pareto principle. Part 4 discusses the worry that risk estimates are too “subjective.”

Cost-effectiveness of breast cancer screening programme for women in rural China.

In low and middle-income countries mammographic breast cancer screening is prohibitively expensive and a cheaper alternative option is to use ultrasound as the primary screening test. In 2009, China launched a breast cancer screening programme for rural women aged 35-64 years with clinical breast examination coupled with ultrasound as the primary tool. Our study aimed to analyse the cost-effectiveness of breast screening compared to no screening among Chinese rural women. We developed a Markov model to estimate the lifetime costs and effects for rural women aged 35 years from a societal perspective. Asymptomatic women in the intervention arm were screened every 3 years before age 64 years. Breast cancer in the non-screening arm can only be diagnosed on presentation of symptoms. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. Compared to no screening, breast cancer screening cost $186.7 more and led to a loss of 0.20 quality-adjusted life years (QALYs). Breast screening was more expensive and did harm to health among rural women with an incremental cost-effectiveness ratio (ICER) of $-916/QALY. The sensitivity analysis identified utility loss from false positives as the factor that most influenced the results, but this did not affect the conclusions. In a rural setting with such low breast cancer incidence, screening for asymptomatic disease is not cost-effective with current screening tools. Priority should be given to ensure that symptomatic women have proper access to diagnosis and treatment at an early stage as this will lead to mortality reductions without the usual screening harms.

Breast cancer screening programme in China: does one size fit all? A cost-effectiveness analysis based on a Markov model

BackgroundIn China, breast cancer is the most frequently diagnosed cancer in women. Marked disparities between urban and rural populations have been reported for breast cancer incidence and survival. In 2009, China launched a breast cancer screening programme for women living in rural areas who were aged 35–64 years and at average risk. The programme used ultrasound combined with clinical breast examination as the primary screening tool. In 2012, breast cancer screening was done by use of ultrasound, and was followed by mammography among women living in urban areas aged 40–69 years, who were high risk and were identified through risk assessment questionnaires. To date, economic evidence is still scarce. This study aimed to analyse the cost-effectiveness of breast cancer screening compared with no screening among women in rural and urban China. MethodsWe developed a Markov model to estimate the lifetime costs and effects, from a societal perspective, for the general population-based cohorts, both in urban China with high incidence of breast cancer and rural China with low incidence of breast cancer. Analyses were done for women in rural areas aged 35 years and women in urban areas aged 40 years. Women who were asymptomatic in the intervention arm were screened every 3 years. Breast cancer in the non-screening arm could only be diagnosed on presentation of symptoms. The main outcome measure was cost per quality-adjusted life-year (QALY) gained with a 3% annual discount. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. FindingsCompared with no screening, the rural breast cancer screening programme cost US$186·72 more and led to a loss of 0·20 QALYs because of disutility from false positives. Breast cancer screening among women in rural China is more expensive, with an incremental cost-effectiveness ratio (ICER) of $-916 per QALY, compared with no screening. In urban areas, the breast cancer screening programme cost $84·99 and gained 0·01 QALYs, with an ICER of $6671 per QALY, well below the willingness-to-pay threshold of $23 050 per QALY at three times GDP per capita (2014) in China. The results are shown to be robust through the sensitivity analyses. InterpretationIn a rural setting, which has low breast cancer incidence, screening for asymptomatic disease among the general population using current screening tools is not cost-effective. Priority should be given to ensure that women who are symptomatic have access to diagnosis and treatment at an early stage. In urban China, a high-risk population-based screening method for breast cancer is very likely to be cost-effective compared with no screening. FundingNational Natural Science Foundation of China (71273016 and 71673004).

PMD25 - Cost Effectiveness of Breast Cancer Screening for Women in Rural China

In low and middle-income countries mammographic breast cancer screening is prohibitively expensive and a cheaper alternative option is to use ultrasound as the primary screening test. In 2009, China launched a breast cancer screening programme for rural women with ultrasound and clinical breast examination as the primary screening tool. This study aimed to analyse the cost-effectiveness of breast cancer screening compared to no screening among Chinese rural women. We developed a Markov model to estimate the lifetime costs and effects for rural women aged 35 years from a societal perspective. Asymptomatic women in the intervention arm were screened every three years before age 64 years. Breast cancer in the non-screening arm can only be diagnosed on presentation of symptoms. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. Compared to no screening, breast cancer screening cost $186·72 more and led to a loss of 0·20 quality-adjusted life years (QALYs). Breast cancer screening was more expensive and did harm to health among Chinese rural women with an incremental cost-effectiveness ratio (ICER) of $-916/QALY. The sensitivity analysis identified disutility from false positives as the factor that most influenced the results, but this did not affect the conclusions. In a rural setting with such low incidence, screening for asymptomatic disease is not cost-effective with current screening tools. Instead, priority should be given to ensure that symptomatic women have proper access to diagnosis and treatment at an early stage as this will lead to reductions in mortality from the disease without the usual harms associated with screening.

Abstract IS-3: IS-3 Overcoming obstacles to breast conservation surgery in Malaysia

Abstract The rates of breast conservation in breast cancer can vary from 75% in highly developed countries where mammographic breast screening programmes has led to detection of small tumours, to 0% in low income countries where there are no early detection programmes and women present with large tumours. Mastectomy is the only choice in countries where there are no radiation therapy facilities, an essential component of breast conservation surgery (BCS). Malaysia is a high middle income country in South East Asia, with population of 31 million and an incidence of breast cancer of 38.9 per 100 000. According to the International Atomic Energy Agency, 78.9% of the population in Malaysia have access to radiation facilities, so access to radiation does not pose a major barrier to BCS. However BCS is only suitable for women who present with small tumours. In Malaysia, 40-60% of women present with Stage 3 and 4 breast cancer, with a mean size of 4 cm. Hence the majority of patients are not suitable for BCS. In a tertiery urban institution, the BCS rate was reported as 22%. Early detection programmes are essential to improve the rates of BCS. However before any early detection programme can be implemented, the public must know the benefits of early detection. Early detection consists of screening for asymptomatic disease by mammography, and downstaging of symptomatic disease. Population-based mammographic screening is not recommended in low and middle income countries, where there have been no randomized controlled trials on mammographic screening to determine effectiveness in reducing breast cancer mortality, and may not be cost-effective in a country with a lower incidence of breast cancer. Malaysia does not have a population-based mammographic breast screening programme; however there are opportunistic programmes where mammograms are provided free of charge. Despite this, several surveys showed that only 5-15% of eligible women in Malaysia had a screening mammogram done. In addition, the same surveys show that women have poor knowledge of the signs and symptoms of breast cancer. Barriers to early detection (and treatment) appear to be at an individual level. A qualitative study on the reasons for late presentation showed that fear of mastectomy, a fatalistic attitude, belief in alternative therapy and poor decision making were seen in women who present late. Deconstructing why women present with advanced cancer and default treatment would provide opportunities for intervention, such as developing materials to assist in decision making and providing culturally sensitive educational materials. An important message is that early detection save lives and save breasts because BCS will be possible. Malaysia is a multi-ethnic country made up of three main races, ie, Chinese, Malays and Indians. Although there is no difference in overall survival between BCS and mastectomy, there are ethnic differences in BCS rates, with the Chinese women opting for mastectomy, with the misconception that more surgery gives them a better change of cure. In conclusion, the most important obstacle to BCS is the large size of the tumour. Psychosocial and cultural barriers to early detection and treatment programmes need to be addressed to reduce the mastectomy rate. Citation Format: Yip CH. IS-3 Overcoming obstacles to breast conservation surgery in Malaysia [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr IS-3.

Abstract ED06-02: Breast cancer screening in low- and middle-income countries

Abstract Breast cancer is the commonest cancer in the majority of low and middle income countries (LMIC's). Survival from breast cancer depends on two main factors – early detection and treatment. In LMICs, delayed presentation of breast cancer is a common occurrence. Barriers to early presentation are lack of access to optimal treatment, lack of financial resources, ignorance and psychosocial issues which include fatalism, fear of death, fear of mastectomy, and lack of autonomy on the part of the woman. Downsizing symptomatic disease as well as screening for asymptomatic disease can reduce mortality from breast cancer. Public education and awareness is a key first step as any early detection program is unlikely to succeed unless the public is aware of the potential benefits. The effectiveness and efficiency of screening modalities including screening mammography, clinical breast examination (CBE) and breast self-examination (BSE) are reviewed in the context of resource availability and population-based need. While mammographic screening is the gold standard for early detection of breast cancer, considerations regarding cost-effectiveness and quality assurance of such a program in LMICs is a concern. The identification of a target group for mammography screening in LMICs should be based on the burden of disease in the population, the potential to benefit from screening, and available resources. Although there may be exceptions, in the absence of such information, the preponderance of the evidence suggests that in most countries it would be reasonable to begin a breast cancer screening program by offering mammography every 2 years to women between the ages of 50 and 65. Although two observational studies on BSE provide evidence that this screening modality reduces breast cancer mortality, this has not been confirmed in two randomized trials. Currently, the evidence is not sufficiently conclusive to justify the recommendation for routine CBE in population-based screening programs, because CBE has not been shown to independently decrease breast cancer mortality, although there are current trials to evaluate this modality. It is also important that any screening program be accompanied by the development of resources required for diagnosis and treatment. The success of any early detection program can be measured by cancer stage at diagnosis, and eventually improvement in survival. Citation Information: Cancer Prev Res 2011;4(10 Suppl):ED06-02.

A clinical trial of tailored office systems for preventive service delivery: The Study to Enhance Prevention by Understanding Practice (STEP-UP)

Background: The potential of primary care practice settings to prevent disease and morbidity through health habit counseling, screening for asymptomatic disease, and immunizations has been incompletely met. This study was designed to test a practice-tailored approach to increasing preventive service delivery with particular emphasis on health habit counseling. Design: Group randomized clinical trial and multimethod process assessment. Setting/ Participants: Seventy-seven community family practices in northeast Ohio. Intervention: After a 1-day practice assessment, a nurse facilitator met with practice clinicians and staff and assisted them with choosing and implementing individualized tools and approaches aimed at increasing preventive service delivery. Main Outcome Measure: Summary scores of the health habit counseling, screening and immunization services recommended by the U.S. Preventive Services Task Force up to date for consecutive patients during randomly selected chart review days. Results: A significant increase ( p=0.015) in global preventive service delivery rates at the 1-year follow-up was found in the intervention group (31% to 42%) compared to the control group (35% to 37%). Rates specifically for health habit counseling ( p=0.007) and screening services ( p=0.048) were increased, but not for immunizations. Conclusions: An approach to increasing preventive service delivery that is individualized to meet particular practice needs can increase global preventive service delivery rates.

Early detection of cancer. Psychologic and social dimensions

Major strides in early detection research can be attributed to social and behavioral research. Social scientists have been involved in research determining the epidemiologic basis of and the cost-effectiveness of screening for asymptomatic disease. The availability of well accepted screening tests has been a barrier to early detection research, especially in the area of men's health. Early detection research has focused on the individual and system levels. Theoretical models are being adapted for early detection from smoking research and are a strength of current work. These models explain why people participate in early detection and how behavior change can occur. In studying system barriers to early detection, intervention efforts have been focused in the community and in the medical care delivery system. Methodologic issues are beginning to emerge, including measuring of program outcomes, and the appropriate research designs for community studies. Except for immigrant populations, initial screening rates are high, and the periodicity of screening becomes the outcome of choice. Some of these problems are the direct result of the success of research and public education efforts to increase cancer screening. The following are priorities for the next decade: theory driven research on behavior change and on interventions; the social determinants of physicians' participation in screening; process evaluation to relate community efforts to outcomes; and reductions in the stage at which cancer is diagnosed as an outcome measure.

The use of tumour markers in clinical practice

The value of any circulating tumour marker depends on its relative merits in screening for asymptomatic disease, use in diagnosis of a particular cancer, being able to predict extent of disease and hence prognosis, and in monitoring disease response to treatment. In this respect human chorionic gonadotrophin has all the attributes of the ideal tumour marker for the gestational trophoblastic tumours. It seems unlikely that a specific tumour marker will be found for colorectal cancer. Of the available colorectal tumour markers, CEA meets the requirements most closely when employed as a single agent, and as it has been around for 25 years all newer tumour markers are naturally compared to this standard. Monoclonal antibodies have proved to be disappointing as a screening agent, although they are associated with fewer false positive results. In view of the well known heterogeneity of antigen expression within a single tumour, panels of monoclonal antibodies (i.e. pre-defined antisera) may be more useful than a single antibody. Proteins, enzymes and other antigens are generally too non-specific to be of any clinical use in colorectal cancer.

Screening for asymptomatic disease: Principles and background

Screening for asymptomatic disease: Principles and background

The future of the miniature chest X-ray in screening for asymptomatic disease

The future of the miniature chest X-ray in screening for asymptomatic disease

Screening for asymptomatic disease by health departments

In conclusion, we believe the laboratory screening permits the application of a proved public health technique in the prevention of chronic diseases. Further, through early discovery and prompt treatment the cost of medical care can be reduced. In turn, rehabilitation may attain its proper place in the community's health and medical care facilities, and thus more easily demonstrate its true place restorative medicine. Last the multiple screening technique can serve as a valuable yardstick to measure the community's health problem when it is appropriately applied in selected population groups in which chronic diseases are known to be more prevalent.