Time to next systemic therapy after stereotactic body radiation therapy for oligoprogressive metastatic castrate-resistant prostate cancer.

• DOI: 10.1200/jco.2024.42.4_suppl.62
• Publication Date: 2024-01-29T21:06:41Z
• Authors: Corbin J. Eule; Nellowe Candelario; Tyler P. Robin
• Keywords: Systemic therapy; Stereotactic radiation therapy

62 Background: Patients with castrate-resistant prostate cancer (CRPC) progressive disease are generally require a change/escalation in systemic therapy. For patients limited ( ≤3) sites of (oligoprogression), metastasis-directed therapy stereotactic body radiation (SBRT) may allow longer interval before next line therapy, but there is data describing this approach. Methods: This retrospective study oligoprogressive metastatic CRPC (omCRPC) treated SBRT at single center between 2011-2022. The primary endpoint was time to (TTNST) after SBRT. Secondary endpoints included overall survival (OS) and TTNST stratified by presence untreated non-progressing metastases. Results: Thirty-two omCRPC received 38 had median age 72.5 years (range 50.6-84.3) PSA 6.85 ng/mL 0.39-922.0) majority an ECOG 1-2 (29 patients, 90.6%) metastases detected on conventional CT and/or bone scans (26 81.3%). most commonly utilized regimen 3000 cGy 5 fractions (18 metastases, 47.4%) (Table). Sixteen were all known disease, whereas 16 least one metastasis the Of 32 23 (65.7%) only, 3 (9.4%) lymph node (LN) 6 (18.8%) other (pelvic tumor, n=2; pelvic tumor + LN, n =1; LN bone, n=1; dura liver, n=1). 1.0 prior androgen receptor signaling inhibitors predominantly 81.3%) chemotherapy naïve. Following SBRT, 10.1 months OS 41.3 months. 0 versus ≥1 metastasis, 11.3 8.7 months, respectively (HR 0.67, 95% CI 0.33-1.36, logrank p=0.24). There no grade ≥3 toxicities due Conclusions: In cohort, delayed for delay initiation well selected including those [Table: see text]