e12004 Background: Personalized Rx for patients (PTs) can improve response. Although archival tissue is available in all PTs, FTT testing of molecular, immunohistochemical, and/or chemosensitivity characteristics may be more optimal for TP than tissues obtained before previous Rx and/or new mets, and archival tissue is inadequate for cell culture information. This study was performed to determine the availability of FTT in a multi-site cancer center. Methods: Pts seen over 22 months were evaluated. PT clinical characteristics were evaluated to determine the prevalence of mets by site, and feasibility of biopsy (bx) for FTT by site. A bx algorithm for FTT was developed and quantified. Results: 26,794 successive PTs were evaluated. BrCa was present in 2043 (7.6%). Median age was 61 (range 27 to 98). Mets were present in only 174 (8.5% of BrCa) who had 256 sites involved (1.47 site per PT). 68% of PTs had multiple sites involved. Of PTs with multiple sites, 96 (81%) had 2, 16 (14%) had 3, and 6 (5%) had 4 sites involved. Single site was the pattern in only 9% of liver, 7% of lung, 32% of bone, 0% of adrenal 6% of skin, but 71% of brain mets. The most frequent sites of mets were bone (50%), lung (31%), liver (26%), brain (10%), skin or soft tissue (11%), lymph node (6%), and effusion/ascites (3.4%). In order to theoretically obtain FTT for development of a personalized TP based on an algorithm preferring in order local bx > para/thoracentesis, > non-osseous needle bx > video-assisted tissue bx > osseous bx, 18% of PTs would have had a local bx, 3% para/thoracentesis, 23% liver bx, 19% lung bx, 17% bone bx, and 12% would not have had a bx because of brain-only mets. Conclusions: Most BrCa PTs in oncology practices have only locoregional disease. Most PTs with mets have multiple sites. FTT acquisition would be feasible for 88% of PTs with mets for personalized TP, and in most the bx would be simple and non-invasive. However, tissue culture tests would necessitate a more invasive video-assisted bx in 42% of PTs. Physicians should consider additional bx to personalize TP when appropriate for improving outcomes. [Table: see text]