Abstract P4-01-07: A liquid biopsy test for breast cancer detection provides consistent diagnostic results in patients over six months
Authors: Benson KL , Henderson MC , Silver M , Gordon K , Borman S , Letsios E , Tran Q , Mulpuri R , Reese DE 
Published: May 2019

Abstract
Current methods of breast cancer detection are often confounded by imaging limitations, such as lesion size, benign breast tissue, and dense breasts. These limitations result in unnecessary biopsies due to false positive findings based on imaging. Despite the increased ability to detect early breast cancer, the over-use of biopsy remains an issue. There is a critical need for new approaches to breast cancer detection that improve diagnostic accuracy when clinical assessment is challenging.
Provista Diagnostics has developed Videssa® Breast - a blood-based proteomic test that measures serum protein biomarkers (SPBs) and tumor-associated autoantibodies (TAAbs). Patient biochemical data is combined with clinical data to generate a diagnostic score that correlates with either the absence or presence of breast cancer (Grades I through III). The ability of Videssa® breast to detect cancer (Invasive Breast Cancer and Ductal Carcinoma in situ) was evaluated using prospective, multi-center clinical trials. The Provista-001 study enrolled 351 women ages 25-49 and included a follow-up visit at 6 months with an additional blood draw. Eligible patients included women assessed as ACR BIRADS® 3 or 4 on imaging with no history of breast cancer or prior breast biopsy.
Serum samples from the initial visit and 6 month follow-up visit of Provista-001 were analyzed using Videssa® Breast to determine if diagnostic results for benign subjects were similar over the course of the study. Samples were analyzed for SPBs and TAAbs in order to determine whether analyte levels and diagnostic scores change over a 6-month period in patients diagnosed with a benign breast condition. Linear regression data for analytes shows overall high fidelity between the initial visit and follow-up. In addition, samples that were TAAb-positive for a given target at the initial visit tended to remain positive at follow-up. Sample background, deriving from unidentified immunological factors, can confound the analytical output when measuring TAAbs in serum. Interestingly, sample background was highly reproducible between both visits, suggesting that these values are related to inherent patient-specific factors. Overall, these data demonstrate high analytical reproducibility for in expression of independent Videssa® Breast biomarkers in patients diagnosed with a benign breast condition over the course of six months. Data for 236 women were compared between visits and demonstrated greater than 80% concordance in diagnostic status.
The ability of Videssa® breast to provide consistent diagnostic results over 6 months further supports use of the test as an adjunct to imaging for the early detection of breast cancer and provides physicians with an additional tool that can be used to inform the decision to biopsy or increase vigilance through active monitoring.
Citation Format: Benson KL, Henderson MC, Silver M, Gordon K, Borman S, Letsios E, Tran Q, Mulpuri R, Reese DE. A liquid biopsy test for breast cancer detection provides consistent diagnostic results in patients over six months [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-01-07.