High baseline circulating tumor cell (CTC) counts are strongly associated with inferior progression-free and overall survival in patients with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC), according to real-world data presented at the virtual 2021 Genitourinary Cancers Symposium. Investigators believe their study is the first to demonstrate this association.
“Identifying patients who have poor prognosis can help with counseling and enrollment in clinical trials to help improve outcomes,” lead author Umang Swami, MD, of the University of Utah in Salt Lake City, Utah, told Renal & Urology News.
The study included 99 patients with newly diagnosed mHSPC initiating androgen deprivation therapy (ADT). On multivariate analyses, CTC counts of 5 or more at ADT initiation were significantly associated with approximately 7.4-fold and 24.9-fold increased risks for progression and death, respectively, compared with a CTC count of 0, the investigators reported.
High CTC counts were associated with poor progression-free and overall survival even in a subgroup of patients receiving intensified ADT.
After further validation, CTC counts may provide a simple way to risk stratify patients, Dr Swami said.
He noted that recently published results from the SWOG S1216 study — a phase 3 randomized trial comparing ADT plus the novel hormonal therapy orteronel and ADT plus bicalutamide in men with newly diagnosed mHSPC — demonstrated that baseline CTC count was highly prognostic of 7-month PSA (a surrogate for poor OS) and 2-year PFS, after adjusting for disease volume.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Swami U, McFarland TR, Haaland B, et al. Association of circulating tumor cells (CTC) with survival outcomes in patients (pts) with metastatic hormone sensitive prostate cancer (mHSPC) in a real-world cohort. Presented at the virtual 2021 Genitourinary Cancers Symposium, February 11 to 13. Abstract 59.
Goldkorn A, Tangen C, Plets M, et al. Baseline circulating tumor cell count as a prognostic marker of PSA response and disease progression in metastatic castrate-sensitive prostate cancer (SWOG S1216). Published online January 26, 2021. Clin Cancer Res. doi:10.1158/1078-0432.CCR-20-3587