Clinicopathological characteristics and long-term prognosis of screening detected non-palpable breast cancer by ultrasound in hospital-based Chinese population (2001-2014)

Abstract

Purpose: The mainstay modality of breast cancer screening in China is the hospital-based opportunistic screening among asymptomatic self-referred women. There is little data about the ultrasound (US) detected non-palpable breast cancer (NPBC) in Chinese population. Methods: We analyzed 699 consecutive NPBC from 1.8-2.3 million asymptomatic women from 2001 to 2014, including 572 US-detected NPBC from 3,786 US-positive women and 127 mammography (MG) detected NPBC from 788 MG-positive women. The clinicopathological features, disease-free survival (DFS) and overall survival (OS) were compared between the US- and MG-detected NPBC. Prognostic factors of NPBC were identified. Results: Compared to MG, US could detect more invasive NPBC (83.6% vs 54.3%, p < 0.001), lymph node positive NPBC (19.1% vs 10.2%, p = 0.018), lower grade (24.8% vs 16.5%, p < 0.001), multifocal (19.2% vs 6.3%, p < 0.001), PR positive (71.4% vs 66.9%, p = 0.041), Her2 negative (74.3% vs 54.3%, p < 0.001), Ki67 high (defined as > 14%, 46.3% vs 37.0%, p = 0.031) cancers and more NPBC who received chemotherapy (40.7% vs 21.3%, p < 0.001). There was no significant difference in 10-year DFS and OS between US-detected vs MG-detected NPBC, DCIS and invasive NPBC. For all NPBC and the US-detected NPBC, the common DFS-predictors included pT, pN, p53 and bilateral cancers. Conclusion: US could detect more invasive, node-positive, multifocal NPBC in hospital-based asymptomatic Chinese female, who could achieve comparable 10-year DFS and OS as MG-detected NPBC. US would not delay early detection of NPBC with improved cost-effectiveness, thus could serve as the feasible initial imaging modality in hospital-based opportunistic screening among Chinese women.