[Breast cancer screening in urban Beijing, 2014-2019]

Objective: To analyze the current status of breast cancer screening among females in Urban Beijing Cancer Screening Program, 2014-2019. Methods: Based on an on-going cancer screening program launched by the National Urban Cancer Screening Program, women residences aged 40 to 69 were recruited from 80 streets in six districts of Beijing (Dongcheng, Xicheng, Chaoyang, Haidian, Fengtai and Shijingshan District) using cluster sampling method. General demographic information and potential risk factors, results of clinical examination and follow-up outcomes of the target population (diagnosed breast cancer or not) were collected using epidemiological questionnaire, risk evaluation, clinical examination using ultrasound and (or) joint screening with mammography and follow-up, respectively. Proportion of high-risk cases evaluated by the questionnaire, recall rate, proportion of cases with BI-RADS grade 3 and BI-RADS grade 4/5, proportion of the cases with stage 0 or I, incidence rate and cumulative incidence rate were calculated. Cox proportional hazard regression model was used to estimate the hazard ratio (HR) and 95% confidence interval (95%CI) among females who experienced different screening scenario. Results: A total of 53 916 women with the age of (57.2±7.3) completed high-risk assessment were included into analysis. The proportion of overweigh and obesity were 40.90% (22 053 cases) and 15.34% (8 270 cases), respectively. A total of 17 535 cases (32.52%) were evaluated as positive case detected by the questionnaire. The clinical recall rate was 47.64% (8 353 cases) among the high-risk females. The positive rate detected by ultrasound or mammography alone was 1.84% and 4.00%, while the suspicious positive detection rates were 14.50% and 17.83%, respectively. The positive rate and suspicious positive rate detected by joint screening using ultrasound and mammography were 5.44% and 27.74% respectively. In total, 252 cases were diagnosed with breast cancer after an average of 2.68 years follow-up. The incidence rate and cumulative incidence rate of breast cancer were 174.34/100 000 person years and 470/100 000, respectively. The early detection rate was 68.6% among the residences who received clinical examination. Compared with the negative residence evaluated by the questionnaire, the positive cases has a 55% higher risk of diagnosed with breast cancer (HR=1.55, 95%CI:1.20-2.00); Cases that recognized by baseline ultrasound and mammography joint screening as BI-RADS 4/5 and BI-RADS 3 have higher risk of diagnosed with breast cancer than that of with the results of BI-RADS 1-2, with the HR of 12.60 (95%CI:6.49-24.47) and 1.89 (0.93-3.83), respectively. Conclusion: Females with high risk of breast cancer in Beijing have a better recall rate of receiving the clinical screening examination. Joint using ultrasonography and mammography in breast cancer screening can improve the positive detection rate among high risk females.