Mammography screening is associated with more favourable breast cancer tumour characteristics and better overall survival: case-only analysis of 3739 Asian breast cancer patients

BACKGROUND

Early detection of breast cancer (BC) through mammography screening (MAM) is known to reduce mortality. We examined the differential effect that mammography has on BC characteristics and overall survival and the sociodemographic determinants of MAM utilization in a multi-ethnic Asian population.

METHODS

This study included 3739 BC patients from the Singapore Breast Cancer Cohort (2010-2018). Self-reported sociodemographic characteristics were collected using a structured questionnaire. Clinical data were obtained through medical records. Patients were classified as screeners (last screening mammogram ≤ 2 years before diagnosis), non-screeners (aware but did not attend or last screen > 2years), and those unaware of MAM. Associations between MAM behaviour (MB) and sociodemographic factors and MB and tumour characteristics were examined using multinomial regression. Ten-year overall survival was modelled using Cox regression.

RESULTS

Patients unaware of screening were more likely diagnosed with late stage (OR_{stage III vs stage I (Ref)} [95% CI]: 4.94 [3.45-7.07], p < 0.001), high grade (OR_{poorly vs well-differentiated (reference)}: 1.53 [1.06-2.20], p = 0.022), nodal-positive, large size (OR_{>5cm vs ≤2cm (reference)}: 5.06 [3.10-8.25], p < 0.001), and HER2-positive tumours (OR_{HER2-negative vs HER2-positive (reference)}: 0.72 [0.53-0.97], p = 0.028). Similar trends were observed between screeners and non-screeners with smaller effect sizes. Overall survival was significantly shorter than screeners in the both groups (HR_{non-screeners}: 1.89 [1.22-2.94], p = 0.005; HR_unaware: 2.90 [1.69-4.98], p < 0.001). Non-screeners and those unaware were less health conscious, older, of Malay ethnicity, less highly educated, of lower socioeconomic status, more frequently ever smokers, and less physically active. Among screeners, there were more reported personal histories of benign breast surgeries or gynaecological conditions and positive family history of breast cancer.

CONCLUSIONS

Mammography attendance is associated with more favourable BC characteristics and overall survival. Disparities in the utility of MAM services suggest that different strategies may be needed to improve MAM uptake.

Barriers to breast cancer screening in Singapore: A literature review

INTRODUCTION

Breast cancer is a leading cause of cancer death among women, and its age-standardised incidence rate is one of the highest in Asia. We aimed to review studies on barriers to breast cancer screening to inform future policies in Singapore.

METHOD

This was a literature review of both quantitative and qualitative studies published between 2012 and 2020 using PubMed, Google Scholar and Cochrane databases, which analysed the perceptions and behaviours of women towards breast cancer screening in Singapore.

RESULTS

Through a thematic analysis based on the Health Belief Model, significant themes associated with low breast cancer screening uptake in Singapore were identified. The themes are: (1) high perceived barriers versus benefits, including fear of the breast cancer screening procedure and its possible outcomes, (2) personal challenges that impede screening attendance and paying for screening and treatment, and (3) low perceived susceptibility to breast cancer.

CONCLUSION

Perceived costs/barriers vs benefits of screening appear to be the most common barriers to breast cancer screening in Singapore. Based on the barriers identified, increasing convenience to get screened, reducing mammogram and treatment costs, and improving engagement with support groups are recommended to improve the screening uptake rate in Singapore.

Trends in health screening participation and lifestyle behaviours after participation in a free, access-enhanced screening intervention in a low-income Singaporean rental-flat community

Our objective was to evaluate the impact of an access-enhanced health screening intervention on screening adherence in a rental-flat community. In Singapore, public rental flats provide heavily subsidised rentals for the needy who cannot afford to own their own homes; with a majority of Singaporeans (≥85%) staying in owner-occupied public housing. We observed trends in health screening adherence and health behaviours among residents of a multi-ethnic public rental-flat community in Singapore from 2013 to 2017, after participation in a free, access-enhanced multi-modality screening programme in 2011. Residents staying in neighbouring owner-occupied housing who participated in the same screening programme served as a basis of comparison. A total of 478 rental-flat residents and 505 owner-occupied flat residents participated. In the rental-flat community, hypertension screening rates improved from 18.3% (24/131) in 2013, to 61.2% (52/85) in 2015 and 44.2% (34/77) in 2017 (p < .001). For diabetes, rates improved from 26.2% (43/164) → 47.0% (54/115) → 49.5% (45/91; p < .001). For dyslipidaemia screening, rates improved from 18.2% (31/170) → 39.6% (38/96) → 47.5% (38/80; p < .001). In the owner-occupied community (n = 505), screening rates largely remained stagnant (hypertension: 52.2% → 75.0% → 54.5%, p = .059; diabetes: 66.0% → 56.5% → 66.7%, p = .434; dyslipidaemia: 53.1% → 50.0% → 57.1%, p = .818). In the rental-flat community, unhealthy behaviours increased from 2013 to 2017, with higher proportions of overweight (30.4% → 24.8% → 52.1%, p < .001), higher smoking (11.7% → 36.9% → 32.5%, p < .001) and higher drinking rates (1.4% → 0.7% → 8.1%, p < .001). This shift was also reflected in the owner-occupied community, with higher percentages of overweight and higher drinking rates (p < .001).