Effect of mammography screening and sociodemographic factors on stage of female breast cancer at diagnosis in New South Wales

Protocol for evaluating the fitness for purpose of an artificial intelligence product for radiology reporting in the BreastScreen New South Wales breast cancer screening programme

INTRODUCTION

Radiologist shortages threaten the sustainability of breast cancer screening programmes. Artificial intelligence (AI) products that can interpret mammograms could mitigate this risk. While previous studies have suggested this technology has accuracy comparable to radiologists most have been limited by using 'enriched' datasets and/or not considering the interaction between the algorithm and human readers. This study will address these limitations by comparing the accuracy of a workflow using AI alongside radiologists on a large consecutive cohort of examinations from a breast cancer screening programme. The study will combine the strengths of a large retrospective design with the benefit of prospective data collection. It will test this technology without risk to screening programme participants nor the need to wait for follow-up data. With a sample of 2 years of consecutive screening examinations, it is likely the largest test of this technology to date. The study will help determine whether this technology can safely be introduced into the BreastScreen New South Wales (NSW) population-based screening programme to address radiology workforce risks without compromising cancer detection rates or increasing false-positive recalls.

METHODS AND ANALYSIS

A retrospective, consecutive cohort of digital mammography screens from 658 207 examinations from BreastScreen NSW will be reinterpreted by the Lunit Insight MMG AI product. The cohort includes 4383 screen-detected and 1171 interval cancers. The results will be compared with radiologist single reading and the AI results will also be used to replace the second reader in a double-reading model. New adjudication reading will be performed where the AI disagrees with the first reader. Recall rates and cancer detection rates of combined AI-radiologist reading will be compared with the rates obtained at the time of screening.

ETHICS AND DISSEMINATION

This study has ethical approval from the NSW Health Population Health Services Research Ethics Committee (2022/ETH02397). Findings will be published in peer-reviewed journals and presented at conferences. The findings of this evaluation will be provided to programme managers, governance bodies and other stakeholders in Australian breast cancer screening programmes.

Breast cancer screening participation in women using mental health services in NSW, Australia: a population study

PURPOSE

Population screening programs have contributed to reduced breast cancer mortality, but disadvantaged or vulnerable groups may not have shared these improvements. In North American and European studies, women living with mental health conditions have reduced breast screening rates. There are no current Australasian data to support health system planning and improvement strategies.

METHODS

The New South Wales (NSW) BreastScreen program offers free screening to NSW women aged 50-74. We compared 2-year breast screening rates for mental health service users (n = 33,951) and other NSW women (n = 1,051,495) in this target age range, after standardisation for age, socioeconomic status and region of residence. Mental health service contacts were identified through linkage to hospital and community mental health data.

RESULTS

Only 30.3% of mental health service users participated in breast screening, compared with 52.7% of other NSW women (crude incidence rate ratio 0.57, 95% CI 0.56-0.59). Standardisation for age, socioeconomic disadvantage or rural residence did not alter this screening gap. Around 7000 fewer women received screening than would be expected from comparable population rates. Screening gaps were largest in women over 60 and in socioeconomically advantaged areas. Women with severe or persistent mental illness had slightly higher screening rates than other mental health service users.

CONCLUSIONS

Low breast cancer screening participation rates for NSW mental health service users suggest significant risk of later detection, possibly leading to more extensive treatment and premature mortality. Focussed strategies are needed to support greater breast screening participation for NSW women who use mental health services.

Breast screening participation and degree of spread of invasive breast cancer at diagnosis in mental health service users: A population linkage study

BACKGROUND

Women living with mental health conditions may not have shared in improvements in breast cancer screening and care. No studies have directly examined the link between reduced screening participation and breast cancer spread in women using mental health (MH) services.

METHODS

Population-wide linkage of a population cancer register, BreastScreen register, and mental health service data set in women aged 50 to 74 years in New South Wales, Australia, from 2008 to 2017. Incident invasive breast cancers were identified. Predictors of degree of spread (local, regional, metastatic) at diagnosis were examined using partial proportional odds regression, adjusting for age, socioeconomic status, rurality, and patterns of screening participation.

RESULTS

A total of 29 966 incident cancers were identified and included 686 (2.4%) in women with MH service before cancer diagnoses. More than half of MH service users had regional or metastatic spread at diagnosis (adjusted odds ratio, 1.63; 95% CI, 1.41-1.89). MH service users had lower screening participation; however, advanced cancer was more common even when adjusting for screening status (adjusted odds ratio, 1.53; 95% CI, 1.32-1.77). Advanced cancer was more common in women with severe or persistent MH conditions.

CONCLUSIONS

Low screening participation rates explain only small part of the risk of more advanced breast cancer in women who use MH services. More study is needed to understand possible mechanisms contributing to more advanced breast cancer in women living with MH conditions. Health systems need strategies to ensure that women living with MH conditions enjoy population gains in breast cancer outcomes.

Screening behaviours, demographics, and stage at diagnosis in the publicly funded Ontario Breast Screening Program

PURPOSE

The Ontario Breast Screening Program (OBSP) offers free screening mammograms every 2 years, to women aged 50-74. Study objectives were to determine demographic characteristics associated with the adherence to OBSP and if women screened in the OBSP have a lower stage at diagnosis than non-screened eligible women.

METHODS

We used the Ontario cancer registry (OCR) to identify 48,927 women, aged 51-74 years, diagnosed with breast cancer between 2010 and 2017. These women were assigned as having undergone adherent screening (N = 26,108), non-adherent screening (N = 6546) or not-screened (N = 16,273) in the OBSP. We used multinomial logistic regression to investigate the demographic characteristics associated with screening behaviour, as well as the association between screening status and stage at diagnosis.

RESULTS

Among women with breast cancer, those living in rural areas (versus the largest urban areas) had a lower odds of not being screened (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.68, 0.78). Women in low-income (versus high-income) communities were more likely not to be screened (OR 1.42, 95% CI 1.33, 1.51). When stratified, the association between income and screening status only held in urban areas. Non-screened women were more likely to be diagnosed with stage II (OR 1.91, 95% CI 1.82, 2.01), III (OR 2.96, 95% CI 2.76, 3.17), or IV (OR 8.96, 95% CI 7.94, 10.12) disease compared to stage I and were less likely to be diagnosed with ductal carcinoma in situ (DCIS) (OR 0.91, 95% CI 0.84-0.98).

CONCLUSIONS

This study suggests that targeting OBSP recruitment efforts to lower income urban communities could increase screening rates. OBSP adherent women were more likely to be diagnosed with earlier stage disease, supporting the value of this initiative and those like it.

Irregular screening participation increases advanced stage breast cancer at diagnosis: A population-based study

OBJECTIVE

To evaluate the effect of irregular screening behaviour on the risk of advanced stage breast cancer at diagnosis in Flanders.

METHODS

All women aged 50-69 who were invited to the organized breast cancer screening and diagnosed with breast cancer before age 72 from 2001 to 2018 were included. All prevalent screen and interval cancers within 2 years of a prevalent screen were excluded. Screening behaviour was categorized based on the number of invitations and performed screenings. Four groups were defined: regular, irregular, only-once, and never attenders. Advanced stage cancer was defined as a stage III + breast cancer. The association between screening regularity and breast cancer stage at diagnosis was evaluated in multivariable logistic regression models, taking age of diagnosis and socio-economic status into account.

RESULTS

In total 13.5% of the 38,005 breast cancer cases were diagnosed at the advanced stage. Compared to the regular attenders, the risk of advanced stage breast cancer for the irregular attenders, women who participated only-once, and never attenders was significantly higher with OR_adjusted:1.17 (95%CI:1.06-1.29) and OR_adjusted:2.18 (95%CI:1.94-2.45), and OR_adjusted:5.95 (95%CI:5.33-6.65), respectively.

CONCLUSIONS

In our study, never attenders were nearly six times more likely to be diagnosed with advanced stage breast cancer than regular attenders, which was much higher than the estimates published thus far. An explanation for this is that the ever screened women is a heterogeneous group regarding the participation profiles which also includes irregular and only-once attenders. The benefit of regular screening should be informed to all women invited for screening.

Female breast cancer in New South Wales, Australia, by country of birth: implications for health-service delivery

BACKGROUND

NSW has a multicultural population with increasing migration from South East Asia, the Western Pacific and Eastern Mediterranean.

OBJECTIVE

To compare cancer stage, treatment (first 12 months) and survival for 12 country of birth (COB) categories recorded on the population-based NSW Cancer Registry.

DESIGN

Historic cohort study of invasive breast cancers diagnosed in 2003-2016.

PATIENTS

Data for 48,909 women (18+ ages) analysed using linked cancer registry, hospital inpatient and Medicare and pharmaceutical benefits claims data.

MEASUREMENT

Comparisons by COB using multivariate logistic regression and proportional hazards regression with follow-up of vital status to April 30th, 2020.

RESULTS

Compared with the Australia-born, women born in China, the Philippines, Vietnam and Lebanon were younger at diagnosis, whereas those from the United Kingdom, Germany, Italy and Greece were older. Women born in China, the Philippines, Vietnam, Greece and Italy lived in less advantaged areas. Adjusted analyses indicated that: (1) stage at diagnosis was less localised for women born in Germany, Greece, Italy and Lebanon; (2) a lower proportion reported comorbidity for those born in China, the Philippines and Vietnam; (3) surgery type varied, with mastectomy more likely for women born in China, the Philippines and Vietnam, and less likely for women born in Italy, Greece and Lebanon; (4) radiotherapy was more likely where breast conserving surgery was more common (Greece, Italy, and Lebanon) and the United Kingdom; and (5) systemic drug therapy was less common for women born in China and Germany. Five-year survival in NSW was high by international standards and increasing. Adjusted analyses indicate that, compared with the Australian born, survival from death from cancer at 5 years from diagnosis was higher for women born in China, the Philippines, Vietnam, Italy, the United Kingdom and Greece.

CONCLUSIONS

There is diversity by COB of stage, treatment and survival. Reasons for survival differences may include cultural factors and healthier migrant populations with lower comorbidity, and potentially, less complete death recording in Australia if some women return to their birth countries for treatment and end-of-life care. More research is needed to explore the cultural and clinical factors that health services need to accommodate.