RB1 and neoplasm: For instance, while data on clinician-assessed performance status (eg, Eastern Cooperative Oncology Group score) were not available, our model included the validated VA Frailty Index, which estimates outcomes highly correlated with performance status.21,22 Symptom burden, tumor genomics (eg, TP53, RB1, PTEN), and pharmacogenomic factors (eg, SLCO1B3) were not available.23 Chemotherapy dosing data were also lacking, though FIRSTANA showed no OS difference between cabazitaxel doses of 25 and 20 mg/m2.