Impact of Overdiagnosis on Long-Term Breast Cancer Survival

Data-driven overdiagnosis definitions: A scoping review

INTRODUCTION

Adequate methods to promptly translate digital health innovations for improved patient care are essential. Advances in Artificial Intelligence (AI) and Machine Learning (ML) have been sources of digital innovation and hold the promise to revolutionize the way we treat, manage and diagnose patients. Understanding the benefits but also the potential adverse effects of digital health innovations, particularly when these are made available or applied on healthier segments of the population is essential. One of such adverse effects is overdiagnosis.

OBJECTIVE

to comprehensively analyze quantification strategies and data-driven definitions for overdiagnosis reported in the literature.

METHODS

we conducted a scoping systematic review of manuscripts describing quantitative methods to estimate the proportion of overdiagnosed patients.

RESULTS

we identified 46 studies that met our inclusion criteria. They covered a variety of clinical conditions, primarily breast and prostate cancer. Methods to quantify overdiagnosis included both prospective and retrospective methods including randomized clinical trials, and simulations.

CONCLUSION

a variety of methods to quantify overdiagnosis have been published, producing widely diverging results. A standard method to quantify overdiagnosis is needed to allow its mitigation during the rapidly increasing development of new digital diagnostic tools.

Overdiagnosis Due to Screening Mammography for Breast Cancer among Women Aged 40 Years and Over: A Systematic Review and Meta-Analysis

The current systematic review and meta-analysis was conducted to estimate the incidence of overdiagnosis due to screening mammography for breast cancer among women aged 40 years and older. A PRISMA systematic search appraisal and meta-analysis were conducted. A systematic literature search of English publications in PubMed, Web of Science, EMBASE, Scopus, and Google Scholar was conducted without regard to the region or time period. Generic, methodological, and statistical data were extracted from the eligible studies. A meta-analysis was completed by utilizing comprehensive meta-analysis software. The effect size estimates were calculated using the fail-safe N test. The funnel plot and the Begg and Mazumdar rank correlation tests were employed to find any potential bias among the included articles. The strength of the association between two variables was assessed using Kendall’s tau. Heterogeneity was measured using the I-squared (I2) test. The literature search in the five databases yielded a total of 4214 studies. Of those, 30 articles were included in the final analysis, with sample sizes ranging from 451 to 1,429,890 women. The vast majority of the articles were retrospective cohort designs (24 articles). The age of the recruited women ranged between 40 and 89 years old. The incidence of overdiagnosis due to screening mammography for breast cancer among women aged 40 years and older was 12.6%. There was high heterogeneity among the study articles (I2 = 99.993), and the pooled event rate was 0.126 (95% CI: 15 0.101–0.156). Despite the random-effects meta-analysis showing a high degree of heterogeneity among the articles, the screening tests have to allow for a certain degree of overdiagnosis (12.6%) due to screening mammography for breast cancer among women aged 40 years and older. Furthermore, efforts should be directed toward controlling and minimizing the harmful consequences associated with breast cancer screening.

Quality of Informed Consent in Mammography Screening-The Polish Experience

Breast cancer is one of the leading forms of cancers in women worldwide. In Poland, it accounts for approx. 20% of all cancers diagnosed, with approximately 11,000 new cases and 5000 deaths from this disease annually. To prevent unfavourable statistics, Poland introduced free breast cancer screening programmes, available to women aged 50-69. Over a million women take advantage of this programme each year. The aim of the research was to assess the quality of consent women give prior to mammography screening and address the question of whether this quality is sufficient to make an informed choice. The study was conducted on a representative group of 600 Polish women over 50 years old (475 of them had undergone mammography screening), who agreed to take part in the study. Using the computer-assisted interview technology (CATI) method, all women were asked about their perception of breast cancer and screening and those who had undergone mammography were quizzed about the consent process. They will form the focus of this research. The validated tool contained items on both the benefits and risks of screening. The results indicate that the quality of informed consent was insufficient. A discrepancy was observed in the awareness between the benefits and risks of mammography screening. The main motivations to undergo screening were: prophylactic purposes and the free-of-charge nature of this health service. Population-based screening programmes for breast cancer should be reconsidered in terms of information policy, and the quality of informed consent should be increased.

Evaluating the effectiveness of population-based breast cancer service screening: an analysis of parsimonious patient survival information with the time-varying Cox model

BACKGROUND

This study is aimed at estimating the unbiased effectiveness of population-based breast cancer service screening based on case survival information alone rather than large-scale individual screening data pursuant to the intention-to-treat principle of a randomized-controlled trial.

METHODS

A novel time-dependent switched design with two modalities of cancer detection (screen-detected vs clinically detected) was proposed to evaluate the effectiveness of breast cancer screening. We used data on 767 patients from Kopparberg in the Swedish Two-County trial and on 78 587 patients in the Taiwan population-based service screening. We estimated the relative rate of the screen-detected vs the clinically detected with adjustment for both truncation and lead-time biases. The absolute effectiveness in terms of the number needed to screen (NNS) for averting one death from breast cancer was estimated.

RESULTS

The relative rate of effectiveness was estimated as 33%, which was consistent with the 37% reported from the original Swedish randomized-controlled trial. The corresponding estimate for the Taiwan screening programme was 42%, which was also very close to that estimated using individual screening history data (41%). Both relative estimates were further applied to yield 446 and 806 of NNS for averting one death from breast cancer for the corresponding two data sets.

CONCLUSION

The proposed time-dependent switched design and analysis with two modalities of case survival information provides a very efficient means for estimating the unbiased estimates of relative and absolute effectiveness of population-based breast cancer service screening dispensing with a large amount of individual screening history data.

SCREENING MAMMOGRAPHY: DIAGNOSTIC EFFICACY-ISSUES AND CONSIDERATIONS FOR THE 2020S

Diagnostic efficacy in medical imaging is ultimately a reflection of radiologist performance. This can be influenced by numerous factors, some of which are patient related, such as the physical size and density of the breast, and machine related, where some lesions are difficult to visualise on traditional imaging techniques. Other factors are human reader errors that occur during the diagnostic process, which relate to reader experience and their perceptual and cognitive oversights. Given the large-scale nature of breast cancer screening, even small increases in diagnostic performance equate to large numbers of women saved. It is important to identify the causes of diagnostic errors and how detection efficacy can be improved. This narrative review will therefore explore the various factors that influence mammographic performance and the potential solutions used in an attempt to ameliorate the errors made.

Divergent Patterns and Trends in Breast Cancer Incidence, Mortality and Survival Among Older Women in Germany and the United States

Background: Breast cancer treatment has changed tremendously over the last decades. In addition, the use of mammography screening for early detection has increased strongly. To evaluate the impact of these developments, long-term trends in incidence, mortality, stage distribution and survival were investigated for Germany and the United States (US). Methods: Using population-based cancer registry data, long-term incidence and mortality trends (1975–2015), shifts in stage distributions (1998–2015), and trends in five-year relative survival (1979–2015) were estimated. Additionally, trends in five-year relative survival after standardization for stage were explored (2004–2015). Results: Age-standardized breast cancer incidence rates were much higher in the US than in Germany in all periods, whereas age-standardized mortality began to lower in the US from the 1990s on. The largest and increasing differences were observed for patients aged 70+ years with a 19% lower incidence but 45% higher mortality in Germany in 2015. For this age group, large differences in stage distributions were observed, with 29% (Germany) compared to 15% (US) stage III and IV patients. Age-standardized five-year relative survival increased strongly between 1979–1983 and 2013–2015 in Germany (+17% units) and the US (+19% units) but was 9% units lower in German patients aged 70+ years in 2013–2015. This difference was entirely explained by differences in stage distributions. Conclusions: Overall, our results are in line with a later uptake and less extensive utilization of mammography screening in Germany. Further studies and efforts are highly needed to further explore and overcome the increased breast cancer mortality among elderly women in Germany.

Patient satisfaction and quality of life in breast reconstruction: assessment of outcomes of immediate, delayed, and nonreconstruction

Objectives

This study was conducted aiming to assess the quality of life and satisfaction of women who had mastectomy treated with and without breast reconstruction.

Results

A total of 81 women who had mastectomy were included, of whom 53 (65.4%) underwent breast reconstruction. Quality of life was not significantly better in the reconstruction group than the nonreconstruction group. Satisfaction with the surgically operated breast, whether reconstructed or not, was positively correlated with quality of life (p = 0.004). There was no significant difference in quality of life between women with immediate and late reconstruction. This study showed that the satisfaction of patients with the operated breast, reconstructed or not, is more important in quality of life than whether the breast was reconstructed or not. When we analyzed the quality of life of women who had mastectomy who were dissatisfied with their unreconstructed breasts, we observed that nonreconstruction had a negative impact on the quality of life.