Sub-castrate testosterone nadir and clinical outcomes in intermediate or high-risk localized prostate cancer.

Related Articles

Sub-castrate testosterone nadir and clinical outcomes in intermediate or high-risk localized prostate cancer.

Int J Radiat Oncol Biol Phys. 2018 Dec 10;:

Authors: Bryant AK, McKay RR, Kader AK, Parsons JK, Einck JP, Kane CJ, Mundt AJ, Murphy JD, Rose BS

Abstract
PURPOSE: It is unclear if additional serum testosterone suppression below the castrate threshold of 50 ng/dL improves clinical outcomes in patients with localized prostate cancer (PCa) undergoing definitive therapy.
METHODS: We examined the association of sub-castrate testosterone nadir with PSA response and long-term clinical outcomes in 764 US veterans with intermediate- or high-risk localized PCa treated with ADT and definitive radiotherapy from 2000-2015. Patients were categorized into testosterone nadir groups based on the minimum testosterone measurement during continuous gonadotropic-releasing hormone agonist therapy (<20 ng/dL vs. 20-49 ng/dL). Outcomes included PSA response (3-month post-radiotherapy PSA and 2-year PSA nadir; multivariable linear regression) and long-term clinical outcomes (biochemical recurrence, metastasis, and PCa-specific mortality; Fine-Gray competing risk regression).
RESULTS: A testosterone nadir of 20-49 ng/dL was associated with higher 3-month post-radiotherapy PSA compared to <20 ng/dL (ß = 0.16, 95% CI 0.06-0.26, p=0.001) and higher 2-year PSA nadir (ß = 0.12, 95% CI 0.04-0.21, p=0.005). Compared to the <20 ng/dL group, the 20-49 ng/dL group showed higher 10-year biochemical recurrence rates (28.1% vs. 18.3%) and metastasis rates (12.9% vs. 7.8%) persisting on multivariable analyses (biochemical recurrence: subdistribution hazard ratio [SDHR] 1.62 for 20-49 ng/dL, 95% CI 1.07-2.45, p=0.02; metastasis: SDHR 2.19, 95% CI 1.21-3.94, p=0.009). There was a trend toward inferior PCa-specific mortality for the 20-49 ng/dL group (SDHR 1.95, 95% CI 0.90-4.22, p=0.09).
CONCLUSIONS: Additional serum testosterone suppression below 50 ng/dL was associated with improved PSA responses and lower rates of biochemical recurrence and metastasis in this cohort of localized PCa patients.

PMID: 30543857 [PubMed - as supplied by publisher]

from PubMed via alexandrossfakianakis on Inoreader https://ift.tt/2QAE7KL