@misc{snaterse_van dessel_taylor_visser_arlt_lolkema_hofland_2020, 
  title={Validation of multiplex steroid hormone measurements in prostate cancer using plasma for multimodality biomarker studies}, 
  DOI={10.1101/2020.08.05.20164202}, 
  abstractNote={<jats:p>Background
Steroid hormones are essential signaling molecules in prostate cancer (PC). However, many studies focusing on liquid biomarkers fail to take hormonal status of these patients into account. Because steroid measurements are sensitive to bias caused by matrix effects, thus assessing potential matrix effects is an important step in combining ctDNA analysis with hormone status. 

Methods
We investigated the accuracy of multi-steroid hormone profiling in mechanically-separated plasma tubes (MSP) and in CellSave Preservative plasma tubes (CS), that are typically used to obtain ctDNA. We performed multiplex steroid profiling in samples obtained from ten healthy controls and ten castration-resistant prostate cancer patients

Results
Steroid measurements were comparable between the MSP and serum tubes. A small but consistent decrease of 11 - 18% compared to serum was observed in CS tubes, which was considered to be within the acceptable margin. The minimally residual testosterone levels of castrate patients could be sensitively quantified in both CS and MSP samples. 

Conclusions
We validated the use of MSP and CS tubes for multi-steroid profiling by LC-MS/MS. The optimised use of these samples used in clinical trials will allow us to gain further insight into the steroid metabolism in PC patients.</jats:p>}, 
  publisher={Cold Spring Harbor Laboratory}, 
  author={Snaterse, Gido and van Dessel, Lisanne F. and Taylor, Angela E and Visser, Jenny A and Arlt, Wiebke and Lolkema, Martijn P. and Hofland, Johannes}, 
  year={2020}, 
  month={Aug}
  }