Background: The prognosis of metastatic cancer is in general poor. This can be affected by several factors including age, histology, treatment choices & SoM etc. Methods: This retrospective study leverages ConcertAI’s deeply curated Patient360 datasets for 8 solid cancers to assess the impact of SoM on the outcomes of patients. For the purpose of this analysis, we focused on the most common SoM (bone, brain, lung & liver). Patients had either a Single SoM (SSM) or Multiple SoM (MSM) and we focused this analysis on patients with SSM. The overall survival (OS) & progression free survival (PFS) from the date of metastasis as well as the time to metastasis (TTM) from initial diagnosis were determined for each cohort. We also computed a consolidated OS & PFS for all patients with MSM. Results: 140K patients were included in this study of which 60K patients had a SoM. The distribution of SoM is dependent on the primary cancer type. For example, in breast & prostate cancer, bone metastasis accounts for 50-80 % of the metastatic cohort whereas it is only 8-21% in lung & melanoma. As expected, the overall values of OS/PFS were primarily governed by the primary cancer type (Table), but this analysis provides further interesting insights: 1. Within a cohort, there were significant differences in the prognosis of patients based on the SoM . Brain & liver had a poorer prognosis compared to the other SoM across most cohorts. 2. The relative prognosis for some SoM were dependant on the primary cancer type. For example, there was a very significant difference between the OS/PFS values in the breast cancer cohort when comparing brain vs bone as SoM. However, in the lung cancer cohort, this difference was less pronounced, and the trend was flipped. 3. For some cohorts the SSM for certain sites had a worse prognosis than the MSM. In breast cancer the OS of the brain & liver SoM was worse than the MSM. 4. The TTM is also dependent on the primary cancer and there is a correlation between the average TTM and the OS of the cohort. Conclusions: The patterns of cancer metastasis and the absolute and relative prognosis for a particular SoM is dependent on the primary cancer type. Such insights from a large real-world data study can impact clinical decisions regarding the aggressiveness of treatment based on the primary cancer type as well as the metastatic site.