Early Blood Test May Identify Survival Rates in Metastatic Prostate Cancer Cases: JAMA - Video

A blood test, performed when metastatic prostate cancer is first diagnosed, can predict which patients are likely to respond to treatment and survive the longest. It can help providers decide which patients should receive standard treatment versus who might stand to benefit from riskier, more aggressive new drug trials. The research, part of a phase 3 clinical trial funded in part by the National Cancer Institute (NCI) of the National Institutes of Health, was just published in

JAMA Network Open.

A new study found that measuring circulating tumor cells, rare cancer cells shed from tumors into the blood, is a reliable way to predict later treatment response and survival prospects. circulating tumor cells have been studied in prostate cancer before, but only in its later stages.

The research leveraged CellSearch (Menarini, Inc.), an FDA-cleared liquid biopsy technology at the Norris Comprehensive Cancer Center, to detect and measure circulating tumor cells in blood samples. Patients with more circulating tumor cells had shorter median survival lengths and a greater risk of death during the study period. Those with more circulating tumor cells also had less “progression-free survival,” which refers to the length of time when a patient’s disease is controlled by treatment without getting worse.

The research was part of a phase 3 clinical trial of the NCI-funded SWOG Cancer Research Network, a group of more than 1,300 institutions around the country that collaborate to study various cancers. Baseline blood samples from 503 patients with metastatic prostate cancer, who were participating in a new drug trial, were sent to the Keck School of Medicine team for analysis.

To analyze the blood samples, the researchers used the CellSearch platform at the Norris Comprehensive Cancer Center’s Liquid Biopsy Research Core. CellSearch uses immunomagnetic beads, antibodies attached to small magnetic particles, which bind to circulating tumor cells in the blood and pull them out to be detected and counted by specialized equipment.

Patients with five or more circulating tumor cells in their blood sample had the worst outcomes. Compared to patients with zero circulating tumor cells, they were 3.22 times as likely to die during the study period and 2.46 times as likely to have their cancer progress. They were only 0.26 times as likely to achieve a complete prostate-specific antigen (PSA) response, meaning they responded poorly to treatment.

Men with five or more circulating tumor cells had a median survival length of 27.9 months following the blood test, compared to 56.2 months for men with one to four circulating tumor cells and at least 78 months for men with zero circulating tumor cells

The bottom line: more circulating tumor cells meant that patients survived for less time, progressed much more quickly and were unlikely to respond to standard treatments.

Reference: Goldkorn A, Tangen C, Plets M, et al. Circulating Tumor Cell Count and Overall Survival in Patients With Metastatic Hormone-Sensitive Prostate Cancer. JAMA Netw Open. 2024;7(10):e2437871. doi:10.1001/jamanetworkopen.2024.37871