Abstract P1-02-02: Is ultrasound screening justified for non-palpable breast cancer in asymptomatic Chinese women: A real-world study based on long-term survival of consecutive cohort (2001-2017)
Authors: Yao R , Pan B , Xu Y , Zhou Y , Zhu Q , Zhang J , Wu H , Mao F , Lin Y , Shen S , Sun Q 
Published: May 2019

Background: Ultrasound (US) is an effective initial screening test for breast cancer both in Caucasian and Chinese women [PMID: 26712110, 26715161, and 25668012]. The real-world modality of breast cancer screening in the China is hospital-based screening among asymptomatic self-referred women. In our previous study, we showed that US and mammography (MG) detected non-palpable breast cancer (NPBC) had similar long-term survival and that US detected more invasive NPBC with positive lymph node [2016 SABCS P5-02-05, PMID: 27689334]. This study was to investigate whether these findings would be still true with more NPBC cases included and longer follow-up in the consecutive hospital cohort.

Methods: From 2001 to 2017, 5,264 asymptomatic women with positive (BI-RADS 4 and 5) initial screening US underwent biopsies in PUMC Hospital, and 914 US-NPBC in 883 women were diagnosed. Meanwhile, women without dense breasts (defined as BI-RADS category C and D) also received screening MG after physical examination and US. There were 1,159 patients with positive (BI-RADS 4 and 5) MG and normal US (BI-RADS 1, 2 and 3) underwent MG-guided biopsies and 216 MG-NPBC were diagnosed in 214 women. The clinicopathological characteristics and 10-year disease-free survival (DFS) and overall survival (OS) were reviewed and compared between the US-NPBC and MG-NPBC. Prognostic factors of NPBC were identified by univariate and multivariate Cox analysis.

Result: Compared to MG, US could detect more invasive (81.2% vs 48.6%, p&lt;0.001), lymph node positive (18.3% vs 10.2%, p&lt;0.001), stage II+III (21.7% vs 12.5%, p&lt;0.001) and low grade cancer (p=0.001).Between invasive US-NPBC and MG-NPBC, no significant difference was identified for lymph node status, TNM stage or subtype.US-NPBC received more breast conserving surgery (32.6% vs 24.1%, p&lt;0.001) and chemotherapy (37.5% vs 23.6%, p&lt;0.001). There was no significant difference in DFS or OS between US- vs MG-NPBC among ductal carcinoma in situ (DCIS), invasive and all NPBC. For the US-NPBC, the DFS factors included TNM stage and Hormone receptor status whereas OS-predictors were pN and subtype.

Table 1.Kaplan-Meier estimates of DFS and OS between US-NPBC and MG-NPBC§Patients (No.) 10-year DFS (%)P value10-year OS (%)P valueAllUS-NPBC (914)92.40.57098.20.143 MG-NPBC (216)94.7 100.0 DCISUS-NPBC (172)97.70.170100.0- MG-NBPC (111)95.3 100.0 InvasiveUS-NPBC (742)91.20.45897.90.251 MG-NPBC (105)94.4 100.0 § Kaplan-Meier survival curves between each two subgroups would be displayed in the poster.

Conclusion: Overall, US could detect more invasive NPBC patients with positive lymph node and advanced stage compared to MG, and screen invasive NPBC at similar TNM stage and subtype distribution as MG. US-NPBC patients received more breast conserving surgery and chemotherapy, and could achieve comparable 10-year DFS and OS as MG-detected NPBC. Hence US is justified in the real-world as the initial imaging modality in hospital-based screening Chinese women.

Citation Format: Yao R, Pan B, Xu Y, Zhou Y, Zhu Q, Zhang J, Wu H, Mao F, Lin Y, Shen S, Sun Q. Is ultrasound screening justified for non-palpable breast cancer in asymptomatic Chinese women: A real-world study based on long-term survival of consecutive cohort (2001-2017) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-02-02.