Background: Safety net hospitals (SNH) care for a substantial proportion of medically vulnerable populations (MVP). Addressing health disparities at a hospital level through partnerships with cancer centers is a potential strategy to improve outcomes of MVPs. We thus compared outcomes for metastatic prostate (mPCa), kidney (mKCa), and urothelial cancer (mUCC) among National Cancer Institute centers (NCI), NCI affiliated SNH (NCI-SNH), and non-affiliated SNH using the Texas Cancer Registry (TCR). Methods: The TCR has 98% case ascertainment of all cancers diagnosed in Texas. The TCR can identify each facility where a patient was diagnosed and treated, allowing detailed hospital level comparisons of outcomes. The TCR was queried from 2004-2017 for mPCa, mKCa, and mUCC. Publicly available data identified Texas NCIs. The top quartile of Disproportionate Share Hospital Index values identified SNH. SNH with established relationships to NCI were designated NCI-SNH and remainder were SNH. Non-SNH were hospitals not affiliated with NCI nor SNH. MVPs were defined as age > 75, non-US natives, non-whites, and uninsured or Medicaid patients. Cox multivariable regression was used to assess overall mortality (OM). Results: Of the 1,048,464 patients in TCR, MVPs accounted for 44.7% of cases. The SNHs and NCI-SNHs accounted for 53.1% of all MVP cancer care statewide. MVPs were the majority of cases within NCI-SNH compared to other SNH or NCI (80% vs 45% vs 37.1%, p<0.01). TCR identified 20,503 metastatic genitourinary (GU) cancers. For mPCa, rates of hormone therapy were similar between NCI-SNH (76.7%) and NCI (76.2%), but greater than SNH (51.5%) or non-SNH (49.7%) (p<0.01). Receipt of chemotherapy or immunotherapy was greater at NCI-SNH compared to other SNH or non-SNH for both mKCa (36.1% vs 31.1% vs 27.1%, p<0.01) and mUCC (44.0% vs 36.7% vs 33.2%, p<0.01). On multivariable cox analysis, equivalent OM between NCI and NCI-SNH for any metastatic GU cancer (Table). OM was worse at other SNH and non-SNH compared to NCI (Table). Conclusions: Medically vulnerable patients made up almost half of cancer care in Texas and majority were cared for at SNH. NCI-SNHs had equivalent OM to NCI and superior OM compared to other SNH. Future initiatives to improve cancer care should focus on strengthening existing relationships between NCI and SNH, and examine mechanisms to centralize care of MVPs to these facilities.

*Reference group.

**Model adjusts for age, sex, race, nativity, insurance, region, systemic therapy, radiation.