Benefit-to-harm ratio of the Danish breast cancer screening programme

Lost in the loop - a qualitative study on patient experiences of care in standardized cancer patient pathways

BACKGROUND

The Norwegian health authorities introduced standardized cancer patient pathways (CPPs) in 2015, aiming to reduce practice variations across hospitals and regions, and improve the continuity, coordination and overall quality of the health care service provided to cancer patients. There has been few studies investigating this change, and that have looked into the organisational and economic benefits of standardized pathways, however the element of care and the patient perspective has been especially neglected. This study explored the care element in cancer patient pathways through an in-depth study of patient experiences.

METHODS

The patients were enrolled approximately three years after the introduction of standardized CPPs in Norway. Through a qualitative design with in-depth interviews, a total of 21 interviews were conducted with seven patients between 2018 and 2020. The first interview took place after the diagnosis was established and before treatment, the second interview during treatment, and the final interview approximately one year after the completion of active treatment. The empirical catchment area was eastern Norway. Data were analysed using a theoretical thematic analysis.

RESULTS

This study sheds light on the complex challenges patients' faces, while navigating CPPs, including the need for better transition support, improved coordination and continuity in care, and a more holistic approach that encompasses emotional well-being and family support. Three overarching themes were identified: [1] Navigating CPPs: patient care and transition challenges, [2] Fragmented cancer care: challenges in coordination and continuity [3] Unmet needs and overlooked opportunities in CPPs.

CONCLUSIONS

Patients experience that cancer patient pathways offer good medical treatment, but that the care element deserves more attention. Current CPPs are trapped in a logic of choice, preventing room for the element of care to receive the attention it requires for the patient to truly experience holistic person-centred care and continuous, well-coordinated services. Based in our study we argue there is a need to look into the missed opportunities for using the CPPs as points of departure for more holistic collaborative models for cancer care.

Benefits and harms of breast cancer screening: Cohort study of breast cancer mortality and overdiagnosis

BACKGROUND

Quantifying the benefits and harms of breast cancer screening accurately is important for planning and evaluating screening programs and for enabling women to make informed decisions about participation. However, few cohort studies have attempted to estimate benefit and harm simultaneously.

AIMS

We aimed to quantify the impact of mammographic screening on breast cancer mortality and overdiagnosis using a cohort of women invited to attend Australia's national screening program, BreastScreen.

METHODS

In a cohort of 41,330 women without prior breast cancer diagnosis, screening, or diagnostic procedures invited to attend BreastScreen Western Australia in 1994-1995, we estimated the cumulative risk of breast cancer mortality and breast cancer incidence (invasive and ductal carcinoma in situ) from age 50 to 85 years for attenders and non-attenders. Data were obtained by linking population-based state and national health registries. Breast cancer mortality risks were estimated from a survival analysis that accounted for competing risk of death from other causes. Breast cancer risk for unscreened women was estimated by survival analysis, while accounting for competing causes of death. For screened women, breast cancer risk was the sum of risk of being diagnosed at first screen, estimated using logistic regression, and risk of diagnosis following a negative first screen estimated from a survival analysis.

RESULTS

For every 1,000 women 50 years old at first invitation to attend BreastScreen, there were 20 (95% CI 12-30) fewer breast cancer deaths and 25 (95% CI 15-35) more breast cancers diagnosed for women who attended than for non-attendees by age 85. Of the breast cancers diagnosed in screened women, 21% (95% CI 13%-27%) could be attributed to screening.

DISCUSSION

The estimated ratio of benefit to harm was consistent with, but slightly less favourable to screening than most other estimates from cohort studies.

CONCLUSION

Women who participate in organised screening for breast cancer in Australia have substantially lower breast cancer mortality, while some screen-detected cancers may be overdiagnosed.

Incidence, Mortality and Survival Trends in Breast Cancers Coincident with Introduction of Mammography in the Nordic Countries

Survival in female breast cancers has generally improved but the relative contribution of early detection or treatment in this positive development is not known. Our aim was to assess the possible role of national mammography screening programs in survival improvement. Such screening has been offered to women, usually at 50-69 years of age, in Finland and Sweden since the 1980s and in Denmark and Norway since the 1990s. Participation rates have been high, ranging from 60% to 90%. We analyzed incidence and mortality changes and relative 5- and 10-year survival trends in breast cancer as novel measures in these countries using the NORDCAN database. Survival trends were compared in age groups of women who were screened to those who were not screened. We observed a relative survival advantage in 5-year and 10-year survival in the screened age groups after the period of national mammography screening was in place and this was consistent in each country. Timing and age-specific targeting of the improvements suggest that mammography may have contributed to the survival benefits. However, as we had no individual data on women who used the service, more detailed studies are needed to confirm the suggested survival advantage, particularly concerning mortality in stage-specific breast cancer.

Extending Age Ranges in Breast Cancer Screening in Four European Countries: Model Estimations of Harm-to-Benefit Ratios

Simple Summary

Breast cancer screening causes harms and benefits. The balance between the two varies by age. By applying microsimulation modelling, we compared several age ranges of screening in four European countries (the Netherlands, Finland, Italy and Slovenia) and evaluated the respective harm-to-benefit ratios. In all countries, adding screening between the ages 45 and 49 or 70 and 74 resulted in more life-years gained and more breast cancer deaths averted, but at the expense of increases in harms. Adapting the age range of breast cancer screening is an option to improve harm-to-benefit ratios in all four countries. The prioritization of considered harms and benefits affects the interpretation of results.

Abstract

The main benefit of breast cancer (BC) screening is a reduction in mortality from BC. However, screening also causes harms such as overdiagnosis and false-positive results. The balance between benefits and harms varies by age. This study aims to assess how harm-to-benefit ratios of BC screening vary by age in the Netherlands, Finland, Italy and Slovenia. Using microsimulation models, we simulated biennial screening with 100% attendance at varying ages for cohorts of women followed over a lifetime. The number of overdiagnoses, false-positive diagnoses, BC deaths averted and life-years gained (LYG) were calculated per 1000 women. We compared four strategies (50–69, 45–69, 45–74 and 50–74) by calculating four harm-to-benefit ratios, respectively. Compared to the reference strategy 50–69, screening women at 45–74 or 50–74 years would be less beneficial in any of the four countries than screening women at 45–69, which would result in relatively fewer overdiagnoses per death averted or LYG. At the same time, false-positive results per death averted would increase substantially. Adapting the age range of BC screening is an option to improve harm-to-benefit ratios in all four countries. Prioritization of considered harms and benefits affects the interpretation of results.

In situ breast cancer incidence patterns in Iceland and differences in ductal carcinoma in situ treatment compared to Sweden

The purpose was to review the incidence of in situ carcinoma in Iceland after initiating population-based mammography screening in 1987 and to compare management of ductal carcinoma in situ (DCIS) between Iceland and the Uppsala-Örebro region (UÖR) in Central Sweden. The Icelandic Cancer Registry provided data on in situ breast carcinomas for women between 1957 and 2017. Clinical data for women with DCIS between 2008 and 2014 was extracted from hospital records and compared to women diagnosed in UÖR. In Iceland, in situ carcinoma incidence increased from 7 to 30 per 100 000 women per year, following the introduction of organised mammography screening. The proportion of in situ carcinoma of all breast carcinomas increased from 4 to 12%. More than one third (35%) of women diagnosed with DCIS in Iceland were older than 70 years versus 18% in UÖR. In Iceland, 49% of all DCIS women underwent mastectomy compared to 40% in UÖR. The incidence of in situ carcinoma in Iceland increased four-fold after the uptake of population-based mammography screening causing considerable risk of overtreatment. Differences in treatment of DCIS were seen between Iceland and UÖR, revealing the importance of quality registration for monitoring patterns of management.

Breast cancer mortality and overdiagnosis after implementation of population-based screening in Denmark

Introduction

Service breast cancer screening is difficult to evaluate because there is no unscreened control group. Due to a natural experiment, where 20% of women were offered screening in two regions up to 17 years before other women, Denmark is in a unique position. We utilized this opportunity to assess outcome of service screening.

Materials and methods

Screening was offered in Copenhagen from 1991 and Funen from 1993 to women aged 50–69 years. We used difference-in-differences methodology with a study group offered screening; a historical control group; a regional control group; and a regional–historical control group, comparing breast cancer mortality and incidence, including ductal carcinoma in situ, between study and historical control group adjusted for changes in other regions, and calculating ratios of rate ratios (RRR) with 95% confidence intervals (CI). Data came from Central Population Register; mammography screening databases; Cause of Death Register; and Danish Cancer Register.

Results

For breast cancer mortality, the study group accumulated 1,551,465 person-years and 911 deaths. Long-term breast cancer mortality in Copenhagen was 20% below expected in absence of screening; RRR 0.80 (95% CI 0.71–0.90), and in Funen 22% below; RRR 0.78 (95% CI 0.68–0.89). Combined, cumulative breast cancer incidence in women followed 8+ years post-screening was 2.3% above expected in absence of screening; RRR 1.023 (95% CI 0.97–1.08).

Discussion

Benefit-to-harm ratio of the two Danish screening programs was 2.6 saved breast cancer deaths per overdiagnosed case. Screening can affect only breast cancers diagnosed in screening age. Due to high breast cancer incidence after age 70, only one-third of breast cancer deaths after age 50 could potentially be affected by screening. Increasing upper age limit could be considered, but might affect benefit-to-harm ratio negatively.

Online information about risks and benefits of screening mammography in 10 European countries: An observational Web sites analysis

Most publications about breast cancer do not provide accurate and comprehensive information, giving few or no data about risk/benefit ratios. We conducted a comparative study among 10 European countries about health information on breast cancer screening, assessing the first 10 Web sites addressing the general public that appeared following an Internet search.With the help of medical residents involved in the EuroNet MRPH Association, we analyzed the first 30 results of an Internet search in 10 European countries to determine the first 10 sites that offered screening mammography. We searched for the following information: source of information, general information on mammography and breast cancer screening, potential harms and risks (false positives, false positives after biopsy, false negatives, interval cancer, overdiagnosis, lead-time bias, and radiation exposure), and potential benefits (reduced mortality and increased survival).The United Kingdom provided the most information: 39 of all 70 possible identified risks (56%) were reported on its sites. Five nations presented over 35% of the possible information (United Kingdom, Spain, France, Ireland, and Italy); the others were under 30% (Portugal, Poland, Slovenia, Netherlands, and Croatia). Regarding the benefits, sites offering the most complete information were those in France (95%) and Poland (90%).Our results suggest that, despite consensus in the scientific community about providing better information to citizens, further efforts are needed to improve information about breast cancer screening. That conclusion also applies to countries showing better results. We believe that there should be greater coordination in this regard throughout Europe.

Outcome of breast cancer screening in Denmark

BACKGROUND

In Denmark, national roll-out of a population-based, screening mammography program took place in 2007-2010. We report on outcome of the first four biennial invitation rounds.

METHODS

Data on screening outcome were retrieved from the 2015 and 2016 national screening quality reports. We calculated coverage by examination; participation after invitation; detection-, interval cancer- and false-positive rates; cancer characteristics; sensitivity and specificity, for Denmark and for the five regions.

RESULTS

At the national level coverage by examination remained at 75-77%; lower in the Capital Region than in the rest of Denmrk. Detection rate was slightly below 1% at first screen, 0.6% at subsequent screens, and one region had some fluctuation over time. Ductal carcinoma in situ (DCIS) constituted 13-14% of screen-detected cancers. In subsequent rounds, 80% of screen-detected invasive cancers were node negative and 40% ≤10 mm. False-positive rate was around 2%; higher for North Denmark Region than for the rest of Denmark. Three out of 10 breast cancers in screened women were diagnosed as interval cancers.

CONCLUSIONS

High coverage by examination and low interval cancer rate are required for screening to decrease breast cancer mortality. Two pioneer local screening programs starting in the 1990s were followed by a decrease in breast cancer mortality of 22-25%. Coverage by examination and interval cancer rate of the national program were on the favorable side of values from the pioneer programs. It appears that the implementation of a national screening program in Denmark has been successful, though regional variations need further evaluation to assure optimization of the program.