Breast-cancer mortality in screened versus unscreened women: Long-term results from a population-based study in Queensland, Australia

Effect of screening mammography on the risk of breast cancer deaths and of all-cause deaths: a systematic review with meta-analysis of cohort studies

OBJECTIVES

Observational cohort studies are used to evaluate the effectiveness of screening mammography in women offered screening. Because screening mammography has no effect on causes of death other than breast cancer (BC), cohort studies should show reductions in the risk of BC death substantially greater than possible reductions in the risk of all-cause death. We assessed the risk of BC deaths and of all-cause (or of nonBC) deaths associated with screening mammography attendance reported in cohort studies.

STUDY DESIGN AND SETTING

Cohort studies published from 2002 to 2022 on women invited to screening mammography were searched in PubMed, Web of Sciences, Scopus, and in review articles. Random effect meta-analyses were performed using relative risks (RRs) of death between women who attended screening compared to women who did not attend screening.

RESULTS

Eighteen cohort studies were identified, nine that reported RRs of BC deaths only, five that reported RRs of all-cause deaths only, and four that reported RRs for both BC deaths and all-cause deaths. The latter four cohort studies reported 12-76 times more all-cause deaths than BC deaths. The random-effect summary of RR for BC mortality in screening attendees vs nonattendees was 0.55 (95% CI: 0.50-0.60) in 13 cohort studies. The summary of RR for all-cause mortality was 0.54 (0.50-0.58) in 10 cohort studies. In the four cohort studies that evaluated both outcomes, the summary of RRs were 0.63 (0.43-0.83) for BC mortality and of 0.54 (0.44-0.64) for all-cause mortality.

CONCLUSION

The similar relative reductions in breast- and all-cause (or nonBC) mortality indicates that screening mammography attendance is an indicator of characteristics associated with a lower risk of dying from any cause, including from BC, which observational studies have falsely interpreted as a screening effect.

Radar localization of breast and axillary lesions with SCOUT: a prospective single institution pilot study

BACKGROUND

Wire-guided localization has been the mainstay of localization techniques for non-palpable breast and axillary lesions prior to excision. Evidence is still growing for relatively newer localization technologies. This study evaluated the efficacy of the wireless localization technology, SCOUT®, for both breast and axillary surgery.

METHODS

Data were extracted from a prospective database (2021-2023) of consecutive patients undergoing wide local excision, excisional biopsy, targeted axillary dissection, or axillary lymph node dissection with SCOUT at a high-volume tertiary centre. Rates of successful reflector placement, intraoperative lesion localization, and reflector retrieval were evaluated. A survey of surgeon-reported ease of lesion localization and reflector retrieval was also evaluated.

CLINICAL TRIAL REGISTRATION

ACTRN386751.

RESULTS

One-hundred-ninety-five reflectors were deployed in 172 patients. Median interval between deployment and surgery was 3 days (range 1-20) and mean distance from reflector to lesion was 3.2 mm (standard deviation, SD 3.1). Rate of successful localization and reflector retrieval was 100% for both breast and axillary procedures. Mean operating time was 65.8 min (SD 33). None of the reflectors migrated. No reflector deployment or localization-related complications occurred. Ninety-eight percent of surgeons were satisfied with ease of localization for the first half of cases.

CONCLUSION

SCOUT is an accurate and reliable method to localize and excise both breast and axillary lesions, and it may overcome some of the limitations of wire-guided localization.

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.

Severity and risk factors of interval breast cancer in Queensland, Australia: a population-based study

BACKGROUND

Interval breast cancers (BC) are those diagnosed within 24 months of a negative mammogram. This study estimates the odds of being diagnosed with high-severity BC among screen-detected, interval, and other symptom-detected BC (no screening history within 2 years); and explores factors associated with being diagnosed with interval BC.

METHODS

Telephone interviews and self-administered questionnaires were conducted among women (n = 3,326) diagnosed with BC in 2010-2013 in Queensland. Respondents were categorised into screen-detected, interval, and other symptom-detected BCs. Data were analysed using logistic regressions with multiple imputation.

RESULTS

Compared with screen-detected BC, interval BC had higher odds of late-stage (OR = 3.50, 2.9-4.3), high-grade (OR = 2.36, 1.9-2.9) and triple-negative cancers (OR = 2.55, 1.9-3.5). Compared with other symptom-detected BC, interval BC had lower odds of late stage (OR = 0.75, 0.6-0.9), but higher odds of triple-negative cancers (OR = 1.68, 1.2-2.3). Among women who had a negative mammogram (n = 2,145), 69.8% were diagnosed at their next mammogram, while 30.2% were diagnosed with an interval cancer. Those with an interval cancer were more likely to have healthy weight (OR = 1.37, 1.1-1.7), received hormone replacement therapy (2-10 years: OR = 1.33, 1.0-1.7; > 10 years: OR = 1.55, 1.1-2.2), conducted monthly breast self-examinations (BSE) (OR = 1.66, 1.2-2.3) and had previous mammogram in a public facility (OR = 1.52, 1.2-2.0).

CONCLUSION

These results highlight the benefits of screening even among those with an interval cancer. Women-conducted BSE were more likely to have interval BC which may reflect their increased ability to notice symptoms between screening intervals.

Nano-Based Theranostic Platforms for Breast Cancer: A Review of Latest Advancements

Breast cancer (BC) is a highly metastatic multifactorial disease with various histological and molecular subtypes. Due to recent advancements, the mortality rate in BC has improved over the past five decades. Detection and treatment of many cancers are now possible due to the application of nanomedicine in clinical practice. Nanomedicine products such as Doxil^® and Abraxane^® have already been extensively used for BC adjuvant therapy with favorable clinical outcomes. However, these products were designed initially for generic anticancer purposes and not specifically for BC treatment. With a better understanding of the molecular biology of BC, several novel and promising nanotherapeutic strategies and devices have been developed in recent years. In this context, multi-functionalized nanostructures are becoming potential carriers for enhanced chemotherapy in BC patients. To design these nanostructures, a wide range of materials, such as proteins, lipids, polymers, and hybrid materials, can be used and tailored for specific purposes against BC. Selective targeting of BC cells results in the activation of programmed cell death in BC cells and can be considered a promising strategy for managing triple-negative BC. Currently, conventional BC screening methods such as mammography, digital breast tomosynthesis (DBT), ultrasonography, and magnetic resonance imaging (MRI) are either costly or expose the user to hazardous radiation that could harm them. Therefore, there is a need for such analytical techniques for detecting BC that are highly selective and sensitive, have a very low detection limit, are durable, biocompatible, and reproducible. In detecting BC biomarkers, nanostructures are used alone or in conjunction with numerous molecules. This review intends to highlight the recent advances in nanomedicine in BC treatment and diagnosis, emphasizing the targeting of BC cells that overexpress receptors of epidermal growth factors. Researchers may gain insight from these strategies to design and develop more tailored nanomedicine for BC to achieve further improvements in cancer specificity, antitumorigenic effects, anti-metastasis effects, and drug resistance reversal effects.