Association of time to prostate-specific antigen nadir and logarithm of prostate-specific antigen velocity after progression in metastatic prostate cancer with prior primary androgen deprivation therapy

We investigated the association of time to prostate-specific antigen nadir （TTPN） and logarithm of prostate-specific antigen velocity after progression Log（PSAVAP） in metastatic prostate cancer with prior primary androgen deprivation therapy （ADT）. All metastatic prostate cancer patients treated with primary ADT from 2000 to 2009 were reviewed. Patients who developed disease progression were included in the subsequent analyses. Patients were categorized into three groups according to their TTPN： TTPN of 〈3 months, 3-17 months, and 〉17 months. We compared the Log（PSAVAP） between the different TTPN groups using Mann-Whitney U-test and Kruskal-Wallis test. Further multiple linear regression analyses on Log（PSAVAP） were performed to adjust for other potential confounding factors. Among 419 patients who were treated with primary ADT, 306 patients developed disease progression with a median follow-up of 28 months, Longer TTPN was associated with lower Log（PSAVAP） （P = 0.008） within all subgroup analyses （TTPN of 〈3 vs 3-17 months, P = 0.020; TTPN of 3-17 vs 〉17 months, P = 0.009; and TTPN of 〈3 vs 〉17 months, P = 0.001）. Upon multiple linear regression analyses, baseline PSA （regression coefficient 0.001, P = 0.045）, PSA nadir （regression coefficient 0.002, P = 0.040）, and TTPN （regression coefficient -0.030, P = 0.001） were the three factors that were significantly associated with Log（PSAVAP）. In conclusion, a longer TTPN was associated with lower Log（PSAVAP） in metastatic prostate cancer patients following primary ADT. TTPN cut-offs at 3 months and 17 months appeared to have prognostic significance in predicting Log（PSAVAP）. TTPN may serve as a good prognostic indicator in deciding the treatment strategy in patients with disease progression.

PSA time to nadir as a prognostic factor of first-line docetaxel treatment in castration-resistant prostate cancer： evidence from patients in Northwestern China

Docetaxel-based chemotherapy remains the first-line treatment for patients with metastatic castration-resistant prostate cancer （mCRPC） in China; however, the prognostic factors associated with effects in these patients are still controversial. In this study, we retrospectively reviewed the data from 71 eligible Chinese patients who received docetaxel chemotherapy from 2009 to 2016 in our hospital and experienced a reduction of prostate-specific antigen （PSA） level 〉50% during the treatment and investigated the potential role of time to nadir （TTN） of PSA. TTN was defined as the time from start of chemotherapy to the nadir of PSA level during the treatment. Multivariable Cox regression models and Kaplan-Meier analysis were used to predict overall survival （OS）. In these patients, the median of TTN was 17 weeks. Patients with TTN ≥17 weeks had a longer response time to chemotherapy compared to TTN 〈17 weeks （42.83 vs 21.50 weeks, P 〈 0.001）. The time to PSA progression in patients with TTN ：〉17 weeks was 11.44 weeks compared to 5.63 weeks when TTN was 〈17 weeks. We found several factors to be associated with OS, including TTN （hazard ratio [HR]. 3.937, 95% confidence interval [CI]： 1.502-10.309, P = 0.005）, PSA level at the diagnosis of cancer （HR： 4,337, 95% CI： 1.616-11.645, P= 0.004）, duration of initial androgen deprivation therapy （HR： 2.982, 95% CI： 1.104-8.045, P= 0.031）, neutrophil-to-lymphocyte ratio （HR： 3.963, 95% CI： 1.380-11.384, P = 0.011）, and total PSA response （Class 1 [〈0 response] compared to Class 2 [0-50% response], HR： 3.978, 95% CI： 1.278-12.387, P = 0.017）. In conclusion, TTN of PSA remains an important prognostic marker in predicting therapeutic outcome in Chinese population who receive chemotherapy for mCRPC and have 〉50% PSA remission.