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.
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.
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.
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.
Research funding: None declared.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
Informed consent: Not applicable.
Ethical approval: Prior to the start of our study, approval of the Institutional Review Board was obtained (IRBd18-145). The study is in accordance with the declaration of Helsinki.
1. Cornford, P, Bellmunt, J, Bolla, M, Briers, E, De Santis, M, Gross, T, et al.. EAU-ESTRO-SIOG guidelines on prostate cancer. Part II: treatment of relapsing, metastatic, and castration-resistant prostate cancer. Eur Urol 2017;71:630–42. https://doi.org/10.1016/j.eururo.2016.08.002.Search in Google Scholar PubMed
2. EAU Guidelines. Edn. presented at the EAU annual congress. Amsterdam; 2020. ISBN 978-94-92671-07-3.Search in Google Scholar
3. Mohler, JL, Antonarakis, ES, Armstrong, AJ, D’Amico, AV, Davis, BJ, Dorff, T, et al.. Prostate cancer, version 2.2019, NCCN clinical practice guidelines in oncology. J Natl Compr Cancer Netw 2019;17:479–505. https://doi.org/10.6004/jnccn.2019.0023.Search in Google Scholar PubMed
4. Klotz, L, O’Callaghan, C, Ding, K, Toren, P, Dearnaley, D, Higano, CS, et al.. Nadir testosterone within first year of androgen-deprivation therapy (ADT) predicts for time to castration-resistant progression: a secondary analysis of the PR-7 trial of intermittent versus continuous ADT. J Clin Oncol 2015;33:1151–6. https://doi.org/10.1200/jco.2014.58.2973.Search in Google Scholar PubMed PubMed Central
5. van Winden, LJ, van Rossum, HH. Testosterone analysis in prostate cancer patients. In: Advances in clinical chemistry. Cambridge, MA: Elsevier; 2021.10.1016/bs.acc.2021.07.007Search in Google Scholar PubMed
6. Rosner, W, Auchus, RJ, Azziz, R, Sluss, PM, Raff, H. Position statement: utility, limitations, and pitfalls in measuring testosterone: an endocrine society position statement. J Clin Endocrinol Metab 2007;92:405–13. https://doi.org/10.1210/jc.2006-1864.Search in Google Scholar PubMed
7. La’ulu, SL, Kalp, KJ, Straseski, JA. How low can you go? Analytical performance of five automated testosterone immunoassays. Clin Biochem 2018;58:64–71. https://doi.org/10.1016/j.clinbiochem.2018.05.008.Search in Google Scholar PubMed
8. Taieb, J, Mathian, B, Millot, F, Patricot, MC, Mathieu, E, Queyrel, N, et al.. Testosterone measured by 10 immunoassays and by isotope-dilution gas chromatography-mass spectrometry in sera from 116 men, women, and children. Clin Chem 2003;49:1381–95. https://doi.org/10.1373/49.8.1381.Search in Google Scholar PubMed
9. Legro, RS, Schlaff, WD, Diamond, MP, Coutifaris, C, Casson, PR, Brzyski, RG, et al.. Total testosterone assays in women with polycystic ovary syndrome: precision and correlation with hirsutism. J Clin Endocrinol Metab 2010;95:5305–13. https://doi.org/10.1210/jc.2010-1123.Search in Google Scholar PubMed PubMed Central
10. Hamer, HM, Finken, MJJ, van Herwaarden, AE, du Toit, T, Swart, AC, Heijboer, AC. Falsely elevated plasma testosterone concentrations in neonates: importance of LC-MS/MS measurements. Clin Chem Lab Med 2018;56:e141–43. https://doi.org/10.1515/cclm-2017-1028.Search in Google Scholar PubMed
11. CLSI. Defining, establishing, and verifying reference intervals in the clinical laboratory. Approved guideline. 3rd edn. CLSI document EP28-A3c. Wayne, PA: Clinical and Laboratory Standards Institute; 2008.Search in Google Scholar
12. van Winden, LJ, Lanfermeijer, M, Heijboer, AC, van Tellingen, O, Bergman, AM, van der Poel, HG, et al.. Retrospective analysis of serum testosterone levels by LC-MS/MS in chemically castrated prostate cancer patients: biological variation and analytical performance specifications. Clin Chim Acta 2021;521:70–5. https://doi.org/10.1016/j.cca.2021.06.030.Search in Google Scholar PubMed
13. van Winden, LJ, van Tellingen, O, van Rossum, HH. Serum testosterone by liquid chromatography tandem mass spectrometry for routine clinical diagnostics. Methods Mol Biol 2018;1730:93–102. https://doi.org/10.1007/978-1-4939-7592-1_7.Search in Google Scholar PubMed
14. Aarsand, AK, Fernandez-Calle, P, Webster, C, Coskun, A, Gonzales-Lao, E, Diaz-Garzon, J, et al.. The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) biological variation database. Available from: https://biologicalvariation.eu/ [Accesed 14 Aug 2018].Search in Google Scholar
15. van der Sluis, TM, Bui, HN, Meuleman, EJ, Heijboer, AC, Hartman, JF, van Adrichem, N, et al.. Lower testosterone levels with luteinizing hormone-releasing hormone agonist therapy than with surgical castration: new insights attained by mass spectrometry. J Urol 2012;187:1601–6. https://doi.org/10.1016/j.juro.2011.12.063.Search in Google Scholar PubMed
16. Miyazawa, Y, Kato, H, Arai, S, Furuya, Y, Sekine, Y, Nomura, M, et al.. Clinical endocrinological evaluation of the gonadal axis (testosterone, LH and FSH) in prostate cancer patients switched from a GnRH antagonist to a LHRH agonist. Basic Clin Androl 2015;25:7. https://doi.org/10.1186/s12610-015-0023-2.Search in Google Scholar PubMed PubMed Central
17. Sayyid, RK, Evans, A, Hersey, K, Maloni, R, Hurtado-Coll, A, Kulkarni, G, et al.. A phase II, randomized, open-label study of neoadjuvant degarelix versus LHRH agonist in prostate cancer patients prior to radical prostatectomy. Clin Cancer Res 2017;23:1974–80. https://doi.org/10.1158/1078-0432.ccr-16-1790.Search in Google Scholar PubMed
18. Denver, N, Khan, S, Homer, NZM, MacLean, MR, Andrew, R. Current strategies for quantification of estrogens in clinical research. J Steroid Biochem Mol Biol 2019;192:105373. https://doi.org/10.1016/j.jsbmb.2019.04.022.Search in Google Scholar PubMed PubMed Central
19. Reinisch, M, Seiler, S, Hauzenberger, T, Kamischke, A, Schmatloch, S, Strittmatter, HJ, et al.. Efficacy of endocrine therapy for the treatment of breast cancer in men: results from the MALE phase 2 randomized clinical trial. JAMA Oncol 2021;7:565–72. https://doi.org/10.1001/jamaoncol.2020.7442.Search in Google Scholar PubMed PubMed Central
20. Krasowski, MD, Drees, D, Morris, CS, Maakestad, J, Blau, JL, Ekins, S. Cross-reactivity of steroid hormone immunoassays: clinical significance and two-dimensional molecular similarity prediction. BMC Clin Pathol 2014;14:33. https://doi.org/10.1186/1472-6890-14-33.Search in Google Scholar PubMed PubMed Central
21. Fairfax, BP, Morgan, RD, Protheroe, A, Shine, B, James, T. Abiraterone acetate: a potential source of interference in testosterone assays. Clin Chem Lab Med 2018;56:e138–40. https://doi.org/10.1515/cclm-2017-0631.Search in Google Scholar PubMed
22. van Rossum, HH, van Winden, LJ, Heijboer, AC. Reporting the analytical method is essential to assessing studies in which biomarkers are a major study objective. JAMA Oncol 2021;7:1402–3. https://doi.org/10.1001/jamaoncol.2021.2043.Search in Google Scholar PubMed
23. Apple, FS, Wu, AHB, Sandoval, Y, Sexter, A, Love, SA, Myers, G, et al.. Sex-specific 99th percentile upper reference limits for high sensitivity cardiac troponin assays derived using a universal sample bank. Clin Chem 2020;66:434–44. https://doi.org/10.1093/clinchem/hvz029.Search in Google Scholar PubMed
24. Schally, AV, Block, NL, Rick, FG. Discovery of LHRH and development of LHRH analogs for prostate cancer treatment. Prostate 2017;77:1036–54. https://doi.org/10.1002/pros.23360.Search in Google Scholar PubMed
25. Klotz, L, Boccon-Gibod, L, Shore, ND, Andreou, C, Persson, BE, Cantor, P, et al.. The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer. BJU Int 2008;102:1531–8. https://doi.org/10.1111/j.1464-410x.2008.08183.x.Search in Google Scholar
26. Hashimoto, K, Tabata, H, Shindo, T, Tanaka, T, Hashimoto, J, Inoue, R, et al.. Serum testosterone level is a useful biomarker for determining the optimal treatment for castration-resistant prostate cancer. Urol Oncol 2019;37:485–91. https://doi.org/10.1016/j.urolonc.2019.04.026.Search in Google Scholar PubMed
27. Shiota, M, Kashiwagi, E, Murakami, T, Takeuchi, A, Imada, K, Inokuchi, J, et al.. Serum testosterone level as possible predictive marker in androgen receptor axis-targeting agents and taxane chemotherapies for castration-resistant prostate cancer. Urol Oncol 2018;37:180.e19–24.10.1016/j.urolonc.2018.10.020Search in Google Scholar PubMed
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