Improved Performance of Adjunctive Ultrasonography After Mammography Screening for Breast Cancer Among Chinese Females

RTKN2 knockdown alleviates the malignancy of breast cancer cells by regulating the Wnt/β-catenin pathway

RTKN2 is a new effector protein of Rho GTPase, and has been indicated to be a tumor inhibitor in colon cancer. In this article, we explored the function of RTKN2 in BC cell development. RTKN2 expression in BC tissues and BC cell lines was evaluated by RT-qPCR and Western blot assay. CCK-8, Wound-healing and Transwell assays were carried out to examine the role of RTKN2 knockdown on proliferation, the migratory ability and the invasive ability of BC cells. FCM and Western blot assay were performed to measure the function of RTKN2 silencing on BC cell apoptosis. In addition, the regulatory effect of RTKN2 on Wnt/β-catenin pathway was studied via Western blot assay. RTKN2 expression was elevated in BC tissues and BC cells. Down-regulation of RTKN2 restrained BC cell progression by suppressing cell proliferation, migratory ability, invasive ability, and inducing apoptosis. In addition, reduced of RTKN2 sharply reduced the expressing levels of Wnt3A, β-catenin, C-Myc, and Cyclin D1, suggesting that RTKN2 silencing blocked the motivation of Wnt/β-catenin pathway in BC development. The in vivo experiment also confirmed the inhibitory effect of RTKN2 on BC tumors. Our study confirmed that RTKN2 was highly expressed in BC. Moreover, RTKN2 knockdown suppressed the development of BC through affecting the Wnt/β-catenin pathway. Hence, we deduced that RTKN2 was a possible treatment target for BC.

Comparisons of clinical characteristics, prognosis, epidemiological factors, and genetic susceptibility between HER2-low and HER2-zero breast cancer among Chinese females

BACKGROUND

Traditional human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) is recommended to be divided into HER2-low and HER2-zero subtypes due to different prognosis. However, few studies investigated their differences in clinical characteristics and prognosis among Chinese HER2-negative BC and their stratified differences by hormone receptor (HR), while fewer studies investigated their differences in epidemiological factors and genetic susceptibility.

METHODS

A total of 11,911 HER2-negative BC were included to compare the clinical characteristics and prognosis between HER2-zero and HER2-low BC, and 4227 of the 11,911 HER2-negative BC were further compared to 5653 controls to investigate subtype-specific epidemiological factors and single nucleotide polymorphisms(SNPs).

RESULTS

Overall, 64.2% of HER2-negative BC were HER2-low BC, and the stratified proportions of HER2-low BC were 61.9% and 75.2% for HR-positive and HR-negative BC, respectively. Compared to HER2-zero BC, HER2-low BC among HR-positive BC showed younger age at diagnosis, later stage, poorer differentiation, and higher Ki-67, while elder age at diagnosis and lower mortality were observed for HER2-low BC among HR-negative BC (all p values <0.05). Compared to healthy controls, both HER2-low and HER2-zero BC are associated with similar epidemiological factors and SNPs. However, stronger interaction between epidemiological factors and polygenic risk scores were observed for HER2-zero BC than HER2-low BC among either HR-positive [odds ratios: 10.71 (7.55-15.17) and 8.84 (6.19-12.62) for the highest risk group compared to the lowest risk group] or HR-negative BC [7.00 (3.14-15.63) and 5.70 (3.26-9.98)].

CONCLUSIONS

HER2-low BC should deserve more attention than HER2-zero BC, especially in HR-negative BC, due to larger proportion, less clinical heterogeneity, better prognosis, and less susceptibility to risk factors.

Mammography in combination with breast ultrasonography versus mammography for breast cancer screening in women at average risk

BACKGROUND

Screening mammography can detect breast cancer at an early stage. Supporters of adding ultrasonography to the screening regimen consider it a safe and inexpensive approach to reduce false-negative rates during screening. However, those opposed to it argue that performing supplemental ultrasonography will also increase the rate of false-positive findings and can lead to unnecessary biopsies and treatments.

OBJECTIVES

To assess the comparative effectiveness and safety of mammography in combination with breast ultrasonography versus mammography alone for breast cancer screening for women at average risk of breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov up until 3 May 2021.

SELECTION CRITERIA

For efficacy and harms, we considered randomised controlled trials (RCTs) and controlled non-randomised studies enrolling at least 500 women at average risk for breast cancer between the ages of 40 and 75. We also included studies where 80% of the population met our age and breast cancer risk inclusion criteria.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and full texts, assessed risk of bias, and applied the GRADE approach. We calculated the risk ratio (RR) with 95% confidence intervals (CI) based on available event rates. We conducted a random-effects meta-analysis.

MAIN RESULTS

We included eight studies: one RCT, two prospective cohort studies, and five retrospective cohort studies, enrolling 209,207 women with a follow-up duration from one to three years. The proportion of women with dense breasts ranged from 48% to 100%. Five studies used digital mammography; one study used breast tomosynthesis; and two studies used automated breast ultrasonography (ABUS) in addition to mammography screening. One study used digital mammography alone or in combination with breast tomosynthesis and ABUS or handheld ultrasonography. Six of the eight studies evaluated the rate of cancer cases detected after one screening round, whilst two studies screened women once, twice, or more. None of the studies assessed whether mammography screening in combination with ultrasonography led to lower mortality from breast cancer or all-cause mortality. High certainty evidence from one trial showed that screening with a combination of mammography and ultrasonography detects more breast cancer than mammography alone. The J-START (Japan Strategic Anti-cancer Randomised Trial), enrolling 72,717 asymptomatic women, had a low risk of bias and found that two additional breast cancers per 1000 women were detected over two years with one additional ultrasonography than with mammography alone (5 versus 3 per 1000; RR 1.54, 95% CI 1.22 to 1.94). Low certainty evidence showed that the percentage of invasive tumours was similar, with no statistically significant difference between the two groups (69.6% (128 of 184) versus 73.5% (86 of 117); RR 0.95, 95% CI 0.82 to 1.09). However, positive lymph node status was detected less frequently in women with invasive cancer who underwent mammography screening in combination with ultrasonography than in women who underwent mammography alone (18% (23 of 128) versus 34% (29 of 86); RR 0.53, 95% CI 0.33 to 0.86; moderate certainty evidence). Further, interval carcinomas occurred less frequently in the group screened by mammography and ultrasonography compared with mammography alone (5 versus 10 in 10,000 women; RR 0.50, 95% CI 0.29 to 0.89; 72,717 participants; high certainty evidence). False-negative results were less common when ultrasonography was used in addition to mammography than with mammography alone: 9% (18 of 202) versus 23% (35 of 152; RR 0.39, 95% CI 0.23 to 0.66; moderate certainty evidence). However, the number of false-positive results and necessary biopsies were higher in the group with additional ultrasonography screening. Amongst 1000 women who do not have cancer, 37 more received a false-positive result when they participated in screening with a combination of mammography and ultrasonography than with mammography alone (RR 1.43, 95% CI 1.37 to 1.50; high certainty evidence). Compared to mammography alone, for every 1000 women participating in screening with a combination of mammography and ultrasonography, 27 more women will have a biopsy (RR 2.49, 95% CI 2.28 to 2.72; high certainty evidence). Results from cohort studies with methodological limitations confirmed these findings. A secondary analysis of the J-START provided results from 19,213 women with dense and non-dense breasts. In women with dense breasts, the combination of mammography and ultrasonography detected three more cancer cases (0 fewer to 7 more) per 1000 women screened than mammography alone (RR 1.65, 95% CI 1.0 to 2.72; 11,390 participants; high certainty evidence). A meta-analysis of three cohort studies with data from 50,327 women with dense breasts supported this finding, showing that mammography and ultrasonography combined led to statistically significantly more diagnosed cancer cases compared to mammography alone (RR 1.78, 95% CI 1.23 to 2.56; 50,327 participants; moderate certainty evidence). For women with non-dense breasts, the secondary analysis of the J-START study demonstrated that more cancer cases were detected when adding ultrasound to mammography screening compared to mammography alone (RR 1.93, 95% CI 1.01 to 3.68; 7823 participants; moderate certainty evidence), whilst two cohort studies with data from 40,636 women found no statistically significant difference between the two screening methods (RR 1.13, 95% CI 0.85 to 1.49; low certainty evidence).

AUTHORS' CONCLUSIONS

Based on one study in women at average risk of breast cancer, ultrasonography in addition to mammography leads to more screening-detected breast cancer cases. For women with dense breasts, cohort studies more in line with real-life clinical practice confirmed this finding, whilst cohort studies for women with non-dense breasts showed no statistically significant difference between the two screening interventions. However, the number of false-positive results and biopsy rates were higher in women receiving additional ultrasonography for breast cancer screening. None of the included studies analysed whether the higher number of screen-detected cancers in the intervention group resulted in a lower mortality rate compared to mammography alone. Randomised controlled trials or prospective cohort studies with a longer observation period are needed to assess the effects of the two screening interventions on morbidity and mortality.

Cost-effectiveness evaluation of risk-based breast cancer screening in Urban Hebei Province

To evaluate the implementations of Cancer Screening Program in Urban Hebei and to model the cost-effectiveness of a risk-based breast Cancer Screening Program. Women aged 40-74 years were invited to participate the Cancer Screening Program in Urban Hebei form 2016 to 2020 by completing questionnaires to collect information about breast cancer exposure. Clinical screening including ultrasound and mammography examination were performed. We developed a Markov model to estimate the lifetime costs and benefits, in terms of quality-adjusted life years (QALY), of a high-risk breast Cancer Screening Program. Nine screening strategies and no screening were included in the study. The age-specific incidence, transition probability data and lifetime treatment costs were derived and adopted from other researches. Average cost-effectiveness ratios (ACERs) were estimated as the ratios of the additional costs of the screening strategies to the QLYG compared to no screening. Incremental cost-effectiveness ratios (ICERs) were calculated based on the comparison of a lower cost strategies to the next more expensive and effective strategies after excluding dominated strategies and extendedly dominated strategies. ICERs were used to compare with a willingness-to-pay (WTP) threshold. Sensitivity analysis was explored the influence factors. A total of 84,029 women completed a risk assessment questionnaire, from which 20,655 high-risk breast cancer females were evaluated, with a high-risk rate of 24.58%. There were 13,392 high-risk females completed the screening program, with participation rate was 64.84%. Undergoing ultrasound, mammography and combined screening, the suspicious positive detection rates were 15.00%, 9.20% and 19.30%, and the positive detection rates were 2.11%, 2.76% and 3.83%, respectively. According to the results by Markov model, at the end of 45 cycle, the early diagnosis rates were 55.53%, 60.68% and 62.47% underwent the annual screening by ultrasound, mammography and combined, the proportion of advanced cancer were 17.20%, 15.85% and 15.36%, respectively. Different screening method and interval yield varied. In the exploration of various scenarios, annual ultrasound screening is the most cost-effective strategy with the ICER of ¥116,176.15/QALY. Sensitivity analyses demonstrated that the results are robust. Although it was not cost effective, combined ultrasound and mammography screening was an effective strategy for higher positive detection rate of breast cancer. High-risk population-based breast cancer screening by ultrasound annually was the most cost-effective strategy in Urban Hebei Province.

Assessment of the Benefits and Cost-Effectiveness of Population-Based Breast Cancer Screening in Urban China: A Model-Based Analysis

BACKGROUND

To decrease the burden of breast cancer (BC), the Chinese government recently introduced biennial mammography screening for women aged 45-70 years. In this study, we assess the effectiveness and cost-effectiveness of implementing this programme in urban China using a micro-simulation model.

METHODS

The 'Simulation Model on radiation Risk and breast cancer Screening' (SiMRiSc) was applied, with parameters updated based on available data for the Chinese population. The base scenario was biennial mammography screening for women aged 45-70 years, and this was compared to a reference population with no screening. Seven alternative scenarios were then simulated by varying the screening intervals and participant ages. This analysis was conducted from a societal perspective. The discounted incremental cost-effectiveness ratio (ICER) was compared to a threshold of triple the gross domestic product (GDP) per life years gained (LYG), which was 30 785 USD/LYG. Univariate sensitivity analyses were conducted to evaluate model robustness. In addition, a budget impact analysis was performed by comparing biennial screening with no screening at a time horizon of 10 years.

RESULTS

Compared with no screening, the base scenario was cost-effective in urban China, giving a discounted average cost-effectiveness ratio (ACER) of 17 309 USD/LYG. The model was most sensitive to the cost of mammography per screen, followed by mean size of self-detected tumours, mammographic breast density and the cumulative lifetime risk of BC. The efficient frontier showed that at a threshold of 30 785 USD/LYG, the base scenario was the optimal scenario with a discounted ICER of 25 261 USD/LYG. Over 10 years, screening would incur a net cost of almost 38.1 million USD for a city with 1 million citizens.

CONCLUSION

Compared to no screening, biennial mammography screening for women aged from 45-70 is cost-effective in urban China.

Breast cancer screening and early diagnosis in Chinese women

Breast cancer is the most common malignant tumor in Chinese women, and its incidence is increasing. Regular screening is an effective method for early tumor detection and improving patient prognosis. In this review, we analyze the epidemiological changes and risk factors associated with breast cancer in China and describe the establishment of a screening strategy suitable for Chinese women. Chinese patients with breast cancer tend to be younger than Western patients and to have denser breasts. Therefore, the age of initial screening in Chinese women should be earlier, and the importance of screening with a combination of ultrasound and mammography is stressed. Moreover, Chinese patients with breast cancers have several ancestry-specific genetic features, and aiding in the determination of genetic screening strategies for identifying high-risk populations. On the basis of current studies, we summarize the development of risk-stratified breast cancer screening guidelines for Chinese women and describe the significant improvement in the prognosis of patients with breast cancer in China.

Evaluation of Adjunctive Ultrasonography for Breast Cancer Detection Among Women Aged 40-49 Years With Varying Breast Density Undergoing Screening Mammography: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Mammography has limited accuracy in breast cancer screening. Ultrasonography, when used in conjunction with mammography screening, is helpful to detect early-stage and invasive cancers for asymptomatic women with dense and nondense breasts.

OBJECTIVE

To evaluate the performance of adjunctive ultrasonography with mammography for breast cancer screening, according to differences in breast density.

DESIGN, SETTING, AND PARTICIPANTS

This study is a secondary analysis of the Japan Strategic Anti-cancer Randomized Trial. Between July 2007 and March 2011, asymptomatic women aged 40 to 49 years were enrolled in Japan. The present study used data from cases enrolled from the screening center in Miyagi prefecture during 2007 to 2020. Participants were randomly assigned in a 1:1 ratio to undergo either mammography with ultrasonography (intervention group) or mammography alone (control group). Data analysis was performed from February to March 2020.

EXPOSURES

Ultrasonography adjunctive to mammography for breast cancer screening regardless of breast density.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity, recall rates, biopsy rates, and characteristics of screen-detected cancers and interval breast cancers were evaluated between study groups and for each modality according to breast density.

RESULTS

A total of 76 119 women were enrolled, and data for 19 213 women (mean [SD] age, 44.5 [2.8] years) from the Miyagi prefecture were analyzed; 9705 were randomized to the intervention group and 9508 were randomized to the control group. A total of 11 390 women (59.3%) had heterogeneously or extremely dense breasts. Among the overall group, 130 cancers were found. Sensitivity was significantly higher in the intervention group than the control group (93.2% [95% CI, 87.4%-99.0%] vs 66.7% [95% CI, 54.4%-78.9%]; P < .001). Similar trends were observed in women with dense breasts (sensitivity in intervention vs control groups, 93.2% [95% CI, 85.7%-100.0%] vs 70.6% [95% CI, 55.3%-85.9%]; P < .001) and nondense breasts (sensitivity in intervention vs control groups, 93.1% [95% CI, 83.9%-102.3%] vs 60.9% [95% CI, 40.9%-80.8%]; P < .001). The rate of interval cancers per 1000 screenings was lower in the intervention group compared with the control group (0.5 cancers [95% CI, 0.1-1.0 cancers] vs 2.0 cancers [95% CI, 1.1-2.9 cancers]; P = .004). Within the intervention group, the rate of invasive cancers detected by ultrasonography alone was significantly higher than that for mammography alone in both dense (82.4% [95% CI, 56.6%-96.2%] vs 41.7% [95% CI, 15.2%-72.3%]; P = .02) and nondense (85.7% [95% CI, 42.1%-99.6%] vs 25.0% [95% CI, 5.5%-57.2%]; P = .02) breasts. However, sensitivity of mammography or ultrasonography alone did not exceed 80% across all breast densities in the 2 groups. Compared with the control group, specificity was significantly lower in the intervention group (91.8% [95% CI, 91.2%-92.3%] vs 86.8% [95% CI, 86.2%-87.5%]; P < .001). Recall rates (13.8% [95% CI, 13.1%-14.5%] vs 8.6% [95% CI, 8.0%-9.1%]; P < .001) and biopsy rates (5.5% [95% CI, 5.1%-6.0%] vs 2.1% [95% CI, 1.8%-2.4%]; P < .001) were significantly higher in the intervention group than the control group.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a randomized clinical trial, screening mammography alone demonstrated low sensitivity, whereas adjunctive ultrasonography was associated with increased sensitivity. These findings suggest that adjunctive ultrasonography has the potential to improve detection of early-stage and invasive cancers across both dense and nondense breasts. Supplemental ultrasonography should be considered as an appropriate imaging modality for breast cancer screening in asymptomatic women aged 40 to 49 years regardless of breast density.

TRIAL REGISTRATION

NIPH Clinical Trial Identifier: UMIN000000757.

The Distinct Performances of Ultrasound, Mammograms, and MRI in Detecting Breast Cancer in Patients With Germline Pathogenic Variants in Cancer Predisposition Genes

A proportion of up to 10% of breast cancer resulted from hereditary germline pathogenic variants (GPVs) in cancer predisposition genes (CPGs), which been demonstrated distinct clinical features and imaging manifestations. However, the performance of imaging modalities for breast cancer surveillance in CPG mutation-carriers is still unclear, especially in Asian women. A population of 3002 breast cancer patients who received germline genetic testing of CPGs was enrolled from three hospitals in China. In total, 343 (11.6%) patients were found to harbor GPVs in CPGs, including 137 (4.6%) in BRCA1 and 135 (4.6%) in BRCA2. We compared the performances of ultrasound, mammograms, MRI, and the combining strategies in CPG mutation carriers and non-carriers. As a result, the ultrasound showed a higher detection rate compared with mammograms regardless of the mutation status. However, its detection rate was lower in CPG mutation carriers than in non-carriers (93.2% vs 98.0%, P=2.1×10^-4), especially in the BRCA1 mutation carriers (90.9% vs 98.0%, P=2.0×10^-4). MRI presented the highest sensitivity (98.5%) and the lowest underestimation rate (14.5%) in CPG mutation carriers among ultrasound, mammograms, and their combination. Supplemental ultrasound or mammograms would add no significant value to MRI for detecting breast cancer (P>0.05). In multivariate logistic regression analysis, the family or personal cancer history could not replace the mutation status as the impact factor for the false-negative result and underestimation. In summary, clinicians and radiologists should be aware of the atypical imaging presentation of breast cancer in patients with GPVs in CPGs.

Detection rate is not higher for women with BBD history in breast cancer screening

BACKGROUND

To investigate whether women with benign breast disease (BBD) history have higher breast cancer detection rate in screening.

METHODS

We reviewed data for 33 001 female participants in Multi-modality Independent Screening Trial (MIST). Corresponding data for 6823 breast cancer patients were retrieved from the Tianjin Breast Cancer Cases Cohort (TBCCC) and analyzed for comparison.

RESULTS

The breast cancer detection rate was 2.83‰ among women with BBD history and 3.28‰ in women without. Moreover, the proportion of carcinoma in situ (CIS) was also lower in women with BBD history than women without (7.69 versus 20.31%). In contrast, analysis of TBCCC data revealed a higher proportion of CIS in patients with BBD history (5.05%) than patients without (3.26%). Our data showed that a larger proportion of women with BBD history had undergone previous breast examinations. Additionally, among participants diagnosed with both breast cancer and BBD in MIST, we found a lower proportion of CIS in women with BBD history (11.76%) compared to women without (32.14%).

CONCLUSIONS

Women with BBD history were not found to have higher detection rate in breast cancer screening. Women with BBD history were more likely to be proactive in seeking breast examinations and to have breast cancer be diagnosed in clinic.

Is Ultrasound an Accurate Alternative for Mammography in Breast Cancer Screening in an Asian Population? A Meta-Analysis

In Asian countries, ultrasound has been proposed as a possible alternative for mammography in breast cancer screening because of its superiority in dense breasts, accessibility and low costs. This research aimed to meta-analyze the evidence for the diagnostic performance of ultrasound compared to mammography for breast cancer screening in Asian women. PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched for studies that concurrently compared mammography and ultrasound in 2000-2019. Data extraction and risk of bias were performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) statement. The primary outcome was the sensitivity and specificity. Bivariate random models were used to generate pooled estimates of diagnostic parameters and 95% confidence intervals (95% CI). In total, 4424 studies were identified of which six studies met the inclusion criteria with a sample size of 124,425 women. The pooled mean prevalence of the included studies was 3.7‱ (range: 1.2-5.7‱). The pooled sensitivity of mammography was significantly higher than that of ultrasound (0.81 [95% CI 0.71-0.88] versus 0.65 [95% CI 0.58-0.72], p = 0.03), but no significant differences were found in specificity (0.98 [95% CI: 0.94-1.00] versus 0.99 [95% CI: 0.97-1.00], p = 0.65). In conclusion, based on the currently available data on sensitivity alone, there is no indication that ultrasound can replace mammography in breast cancer screening in Asian women.

Performance of ultrasonography screening for breast cancer: a systematic review and meta-analysis

Background

To investigate the performance of primary ultrasound (P-US) screening for breast cancer, and that of supplemental ultrasound (S-US) screening for breast cancer after negative mammography (MAM).

Methods

Electronic databases (PubMed, Scopus, Web of Science, and Embase) were systematically searched to identify relevant studies published between January 2003 and May 2018. Only high-quality or fair-quality studies reporting any of the following performance values for P-US or S-US screening were included: sensitivity, specificity, cancer detected rate (CDR), recall rate (RR), biopsy rate (BR), proportion of invasive cancers among screening-detected cancers (ProIC), and proportion of node-negative cancers among screening-detected invasive cancers (ProNNIC).

Results

Twenty-three studies were included, including 12 studies in which S-US screening was used after negative MAM and 11 joint screening studies in which both primary MAM (P-MAM) and P-US were used. Meta-analyses revealed that S-US screening could detect 96% [95% confidential intervals (CIs): 82 to 99%] of occult breast cancers missed by MAM and identify 93% (95% CIs: 89 to 96%) of healthy women, with a CDR of 3.0/1000 (95% CIs: 1.8/1000 to 4.6/1000), RR of 8.8% (95% CIs: 5.0 to 13.4%), BR of 3.9% (95% CIs: 2.7 to 5.4%), ProIC of 73.9% (95% CIs: 49.0 to 93.7%), and ProNNIC of 70.9% (95% CIs: 46.0 to 91.6%). Compared with P-MAM screening, P-US screening led to the recall of significantly more women with positive screening results [1.5% (95% CIs:0.6 to 2.3%), P = 0.001] and detected significantly more invasive cancers [16.3% (95% CIs: 10.6 to 22.1%), P < 0.001]. However, there were no significant differences for other performance measures between the two screening methods, including sensitivity, specificity, CDR, BR, and ProNNIC.

Conclusions

Current evidence suggests that S-US screening could detect occult breast cancers missed by MAM. P-US screening has shown to be comparable to P-MAM screening in women with dense breasts in terms of sensitivity, specificity, cancer detection rate, and biopsy rate, but with higher recall rates and higher detection rates for invasive cancers.

Interpretation of breast cancer screening guideline for Chinese women

Breast cancer is the most common malignant tumor in Chinese women. Early screening is the best way to improve the rates of early diagnosis and survival of breast cancer patients. The peak onset age for breast cancer in Chinese women is considerably younger than those in European and American women. It is imperative to develop breast cancer screening guideline that is suitable for Chinese women. By summarizing the current evidence on breast cancer screening in Chinese women, and referring to the latest guidelines and consensus on breast cancer screening in Europe, the United States, and East Asia, the China Anti-Cancer Association and National Clinical Research Center for Cancer (Tianjin Medical University Cancer Institute and Hospital) have formulated population-based guideline for breast cancer screening in Chinese women. The guideline provides recommendations on breast cancer screening for Chinese women at average or high risk of breast cancer according to the following three aspects: age of screening, screening methods, and screening interval. This article provides more detailed information to support the recommendations in this guideline and to provide more direction for current breast cancer screening practices in China.