Having your advanced prostate cancer progress to becoming castrate resistant is a major moment in our life. For many of us becoming castrate resistant signals a major change, a foreshadowing of what the future holds. Becoming castrate resistant heralds our eventual decline which can only lead us to one destination, our demise.

How long it will take to reach the end remains very much an unknown. For some of us it could be less than one year and for others we can still be alive in 10 or more years. Like for anyone on the journey of life, there remain many unknowns, however when we become castrate resistant we know that we have taken an additional and significant step on the journey.

There has been s study that looked at prostate specific antigen (PSA) levels and the nadir (lowest number) after hormone therapy (ADT) and its potential to predict the progression to castrate resistance.

Researchers at the Department of Urology, Seoul National University College of Medicine and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea studied the overall survival rate, incidence of progression to the development of castrate resistant prostate cancer and interval until progression were analyzed with reference to the nadir PSA level.

They reviewed the progressive status and survival of 177 men with stage C (Cancer has already spread beyond the capsule of the prostate into local organs or tissues, but has not yet metastasized to other sites.) or stage D (Cancer has already spread, usually to distant lymph nodes, bones or other sites.) prostate cancer who had received ADT.

They used multiple regression analysis to analyze the predictive factors for progression to castrate resistant prostate cancer as well as the relative efficacy of the PSA nadir in predicting progression.

Using a median follow-up period of 39 months (range 3 to 89) and with 85.4% of patients (151) responding to treatment, of whom 77.5% (117) had progressed and become castrate resistant.

Median time until nadir PSA levels were reached after ADT was 8.1 months and median time until castrate resistance was 24.0 months.

Nadir PSA levels were less than 0.2 ng./ml. in 31% of respondents, 0.2 to 1.0 ng./ml. in 23%, 1.1 to 10 ng./ml. in 42% and greater than 10 ng./ml. in 5%.

Nadir PSA levels correlated significantly with pretreatment PSA levels, Gleason scores and progression to castrate resistance (p = 0.01, p <0.01 and p <0.001, respectively), and inversely correlated with the interval to the establishment of castrate resistance (r = -0.465, p <0.05). By univariate analysis bone metastasis, nadir PSA, PSA at 6 months after treatment and pretreatment PSA were significantly associated with progression to castrate resistance. Only the nadir PSA was calculated to be an independent factor by multivariate analysis. PSA nadir predicted progression to castrate resistance after 2 years with an accuracy of 86.2%. With the lower limit of the nadir PSA level set to 1.1 ng./ml., sensitivity was 80.3% and specificity was 83.8%, and these levels were deemed the most appropriate. Furthermore, PSA nadir after ADT was an independent prognosticator for survival, as were initial levels of hemoglobin and alkaline phosphatase. The nadir PSA level after hormone therapy may be the most accurate factor predicting the progression to castrate resistant prostate cancer and is an independent prognostic factor for survival. Furthermore, a lower limit for the nadir PSA level of 1.1 ng./ml. gives optimal sensitivity and specificity. J Urol. 2002 Sep;168(3):995-1000. . Kwak C, Jeong SJ, Park MS, Lee E, Lee SE.
PMID: 12187207

Joel T Nowak, M.A., M.S.W.