Testosterone analysis in castrated prostate cancer patients: suitability of the castration cut-off and analytical accuracy of the present-day clinical immunoassays.

Autor:	van Winden LJ; Department of Laboratory Medicine, Netherlands Cancer Institute, Amsterdam, The Netherlands., Lentjes EGWM; Department of Laboratory Medicine, University Medical Center Utrecht, Utrecht, The Netherlands., Demir AY; Department of Clinical Chemistry and Haematology, Meander Medical Center, Amersfoort, The Netherlands., Huijgen HJ; Department of Laboratory Medicine, Red Cross Hospital, Beverwijk, The Netherlands., Bergman AM; Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands., van der Poel HG; Department of Urology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.; Department of Urology, Amsterdam University Medical Center, Amsterdam, The Netherlands., van Rossum HH; Department of Laboratory Medicine, Netherlands Cancer Institute, Amsterdam, The Netherlands.
Jazyk:	angličtina
Zdroj:	Clinical chemistry and laboratory medicine [Clin Chem Lab Med] 2022 Aug 02; Vol. 60 (10), pp. 1661-1668. Date of Electronic Publication: 2022 Aug 02 (Print Publication: 2022).
DOI:	10.1515/cclm-2022-0506
Abstrakt:	Objectives: Testosterone testing is relevant for evaluating castration adequacy and diagnosis of castration-resistant prostate cancer (PCa). However, the recommended testosterone cut-off of 1.7 nmol/L (50 ng/dL) to define adequate castration is based on consensus and not validated for the automated immunoassays (AIA) used in today's medical laboratories. Furthermore, appropriate population intervals have not been determined by a state-of-the-art assay. We investigated the analytical suitability of this cut-off and the accuracy of the present-day AIAs for testosterone analysis in castrated PCa patients. Methods: Leftover serum from 120 PCa patients castrated with luteinizing hormone-releasing hormone agonists was analysed for testosterone by five methods: Architect i2000 (Abbott), Access (Beckman), Cobas 6000 (Roche), Atellica (Siemens), LC-MS/MS. For all assays, the castration 95th, 97.5th and 99th percentile upper limits were determined. Furthermore, Passing-Bablok regression, mean bias and Spearman's correlation coefficients were compared to the LC-MS/MS method and total error based on biological variation. Results: All castration upper limits, ranging from 0.472 nmol/L (LC-MS/MS) to 1.25 nmol/L (Access) (95% percentile), were significantly lower than the current castration cut-off (1.7 nmol/L). Slopes of Passing-Bablok regressions comparing the AIA with the LC-MS/MS method ranged from 1.4 (Cobas and Atellica) to 3.8 (Access). The Architect showed the highest correlation with LC-MS/MS (ρ=0.58). All AIA failed to meet the desirable total error criterion. Conclusions: These results suggest that a lower general testosterone castration cut-off may be more appropriate in evaluating the adequacy of castration in PCa and that present-day AIA lack analytical accuracy to quantify testosterone levels in castrated PCa. (© 2022 Walter de Gruyter GmbH, Berlin/Boston.)
Databáze:	MEDLINE
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