Serum Testosterone-Measuring Assay Predicts Response to Castration in mHSPC

By Zachary Bessette - Last Updated: December 7, 2022

High testosterone levels measured by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay may predict response to castration for patients with metastatic hormone-sensitive prostate cancer (mHSPC), according to a new study published in Clinica Chimica Acta.

Prior research has shown that testosterone levels are linked with progression-free survival (PFS) in patients with mHSPC. However, this association has primarily been investigated by inaccurate immunoassays.

Researchers from the Netherlands examined whether castrate testosterone levels determined by LC-MS/MS can be an independent risk factor for treatment response in mHSPC. A total of 106 patients treated with luteinizing hormone-releasing hormone agonists from March 2018 to August 2021 were included in the analysis.

In a separate analysis involving 67 of the patients, results from a commonly applied immunoassay were compared with results from LC-MS/MS.

Researchers reported that median PFS was shorter for high testosterone levels (>0.231 nmol/L; 18.4 vs 42.6 months; hazard ratio, 1.7; P=.018). Additionally, they found that low testosterone levels and a prostate-specific antigen response below 4 ng/mL were associated with the longest median PFS (46.2 months) compared with any other combination.

In the separate analysis, testosterone levels below the median remained associated with longer PFS in LC-MS/MS results, but immunoassay results did not show a similar difference.

Study authors wrote that these results indicate “high castration testosterone levels measured by LC-MS/MS is an independent response predictor for mHSPC patients.”