Purpose: Tumor-associated vasculature is distinguished its convolutedness, leakiness, and chaotic architecture, which facilitates the creation of a treatment resistant tumor microenvironment. Measurable differences in these attributes might help stratify patients by potential benefit of systemic therapy. In this work, we present a new category of radiomic quantitative tumor-associated vasculature (QuanTAV) biomarkers and investigate their ability to predict outcomes across multiple cancers, imaging modalities, and treatment regimens. Experimental Design: We isolated tumor vasculature and extracted mathematical measurements of twistedness and organization using routine pre-treatment radiology (computed tomography or contrast-enhanced MRI) from 558 patients total, who received one of four therapeutic intervention strategies for breast (n=371) or non-small cell lung cancer (NSCLC, n=187). QuanTAV response scores and risk scores/groups were derived and then assessed for response and survival prediction for each therapy. Results:Classifiers of QuanTAV measurements significantly (p<.05) predicted response in held out testing cohorts alone (AUCs=0.63-0.71). Similarly, QuanTAV risk scores were prognostic of recurrence-free survival in treatment cohorts for breast cancer chemotherapy-only (p=0.0022, HR=1.25, 95% CI 1.08-1.44, C-index=.66) and NSCLC chemoradiation+surgery (p=0.039, HR=1.28, 95% CI 1.01-1.62, C-index=0.66) cohorts. QuanTAV high/low risk groups were independently prognostic among all treatments, including chemotherapy-only NSCLC patients (p=0.034, HR=2.29, 95% CI 1.07-4.94, C-index=0.62). Conclusions: Across domains, we observed an association of vascular morphology on CT and MRI – as captured by metrics of vessel curvature, torsion, and organizational heterogeneity – and treatment outcome. Our findings suggest the potential of shape and structure of the tumor-associated vasculature as biomarkers for multiple cancers and treatments.