Prostate-specific antigen decline pattern in advanced prostate cancer receiving androgen deprivation therapy and relationship with prostate-specific antigen progression

INTRODUCTION

The aim of this study is to evaluate prostate-specific antigen decline pattern including prostate-specific antigen kinetics following androgen deprivation therapy on prostate-specific antigen progression in the patients with advanced prostate cancer.

MATERIALS AND METHODS

Ninety-seven advanced prostate cancer patients receiving maximum androgen deprivation therapy were enrolled in case-control study. Baseline prostate-specific antigen, Gleason Score, bone metastase, nadir prostate-specific antigen, time to nadir prostate-specific antigen, declining slope to nadir prostate-specific antigen, estimated baseline prostate-specific antigen half-time, current prostate-specific antigen, post-nadir prostate-specific antigen time, estimated prostate-specific antigen, estimated decline of baseline prostate-specific antigen as quantitative, and ratio were recorded and calculated.

RESULTS

The ratio of prostate-specific antigen progression was significantly lower at the patients who had slower declining slope to prostate-specific antigen, longer time to nadir prostate-specific antigen, and lower estimated decline ratio of baseline prostate-specific antigen (p: .016, p: .020, and p: .026, respectively).

CONCLUSIONS

The shorter time to nadir prostate-specific antigen following androgen deprivation therapy, faster declining slope to nadir prostate-specific antigen and higher estimated decline ratio of baseline prostate-specific antigen are associated with higher risk of disease progression in patients with hormone-sensitive prostate cancer.

Clinical experience with limited lymph node dissection for prostate cancer in Korea: single center comparison of 247 open and 354 robot-assisted laparoscopic radical prostatectomy series

PURPOSE

There are limited data on the role of limited pelvic lymph node dissection (PLND) in patients with prostate cancer in Korea. The objective of this study was to demonstrate our clinical experience with limited PLND and the difference in its yield between open retropubic radical prostatectomy (RRP) and robot-assisted laparoscopic radical prostatectomy (RALP) for prostate cancer patients in Korea.

MATERIALS AND METHODS

We retrospectively analyzed 601 consecutive patients undergoing radical prostatectomy and bilateral limited PLND by either RRP (n=247) or RALP (n=354) in Asan Medical Center. All patients were divided into three groups according to the D'Amico's risk stratification method. Clinicopathologic data, including the yield of lymph nodes, were thoroughly reviewed and compared among the three risk groups or between the RRP and RALP subjects.

RESULTS

The mean patient age was 64.9 years and the mean preoperative prostate-specific antigen was 9.8 ng/ml. The median number of removed lymph nodes per patient was 5 (range, 0 to 20). The numbers of patients of each risk group were 167, 199, and 238, and the numbers of patients with tumor-positive lymph nodes were 1 (0.6%), 4 (2.0%), and 17 (7.1%) in the low-, intermediate-, and high-risk groups, respectively. In the high-risk group, the lymph node-positive ratio was higher in RRP (14.9%) than in RALP subjects (2.4%).

CONCLUSIONS

We speculate that limited PLND may help in prostate cancer staging in intermediate- and high-risk prostate cancer groups. RRP is a more effective surgical modality for PLND than is RALP, especially in high-risk prostate cancer groups.

Prostate-specific antigen nadir and time to prostate-specific antigen nadir following maximal androgen blockade independently predict prognosis in patients with metastatic prostate cancer

Purpose

To evaluate the influence of prostate-specific antigen (PSA) kinetics following maximal androgen blockade (MAB) on disease progression and cancer-specific survival in patients with metastatic, hormone-sensitive prostate cancer.

Materials and Methods

One hundred thirty-one patients with metastatic, hormone-sensitive prostate cancer treated with MAB at our institution were included in this study. Patients' characteristics, PSA at MAB initiation, PSA nadir, time to PSA nadir (TTN), and PSA decline were analyzed by using univariate and multivariate analysis.

Results

At a median follow-up of 30 months, 97 patients (74.0%) showed disease progression and 65 patients (49.6%) died. Fifty-nine patients (45.0%) died from prostate cancer. In the univariate analysis, PSA at MAB initiation, PSA nadir, TTN, and PSA decline were significant predictors of progression-free survival. Also, PSA nadir, TTN, and PSA decline were significant predictors of cancer-specific survival. In the multivariate analysis, higher PSA nadir (≥0.2 ng/ml) and shorter TTN (<8 months) were independent predictors of shorter progression-free and cancer-specific survival. In the combined analysis of PSA nadir and TTN, patients with higher PSA nadir and shorter TTN had the worst progression-free survival (hazard ratio [HR], 14.098; p<0.001) and cancer-specific survival (HR, 14.050; p<0.001) compared with those with lower PSA nadir and longer TTN.

Conclusions

Our results suggest that higher PSA nadir level and shorter TTN following MAB are associated with higher risk of disease progression and poorer survival in patients with metastatic, hormone-sensitive prostate cancer. Furthermore, these two variables have a synergistic effect on the outcome.

Clinical significance of free-to-total prostate-specific antigen (PSA) ratio in advanced prostate cancer patients with PSA less than 0.1 ng/ml after hormone treatment

PURPOSE

We analyzed the pattern of change in the free-to-total prostate-specific antigen (f/t PSA) ratio and the progression to castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer who received hormone treatment and whose PSA nadir was below 0.1 ng/ml.

MATERIALS AND METHODS

We retrospectively analyzed the medical records of 52 patients with advanced prostate cancer. All patients were treated with maximum androgen blockade (gonadotrophin-releasing hormone agonist and anti-androgen agents). The patients were divided into two groups: those with a nadir f/t PSA ratio above 60% and those with a nadir f/t PSA ratio of 60% or below. Age, initial PSA, clinical stage, lymph node metastasis, bone metastasis, and follow-up data, including PSA, free PSA, and f/t PSA ratio, were collected. The Mann-Whitney U-test, Fisher exact test, chi-square test, Kaplan-Meier survival analysis, and log rank test were used.

RESULTS

There were 24 patients in the group with a nadir f/t PSA ratio above 60% and 28 patients in the group with a nadir f/t PSA ratio of 60% or below. After hormone therapy, the median f/t PSA ratio in each group increased from 37% and 34% at 3 months to 75% and 60% at 6 months, respectively. At 9 months, however, the f/t PSA ratio increased to 80% in the group with a nadir f/t PSA ratio above 60%, whereas it decreased to 31% in the group with a nadir f/t PSA ratio of 60% or below. From 9 to 15 months, the f/t PSA ratio showed a tendency to decrease (75 to 37% and 27 to 20%, respectively). The progression to CRPC was significantly different between the two groups (10 vs. 24).

CONCLUSIONS

Progression to CRPC was significantly higher in the group with a lower f/t PSA ratio. Additionally, the pattern of change in the f/t PSA ratio was significantly different after 9 months. Collectively, the f/t PSA ratio can be used as an additional marker for prognosis of hormone treatment.

Efficacy of alternative antiandrogen therapy for prostate cancer that relapsed after initial maximum androgen blockade

PURPOSE

We evaluated the effectiveness of second-line maximum androgen blockade (MAB) with an alternative antiandrogen in patients who relapsed after initial MAB.

MATERIALS AND METHODS

We retrospectively analyzed 47 patients with prostate cancer who relapsed after initial MAB, including surgical or medical castration combined with antiandrogens, from January 1998 to December 2009. When the serum prostate-specific antigen (PSA) level was increased on three consecutive occasions, we discontinued the antiandrogen and then administered an alternative antiandrogen. Seven patients were assessed for antiandrogen withdrawal syndrome (AWS). The effect of the second-line MAB was evaluated by the serum PSA level, and response was subdivided into ≥50% and <50% PSA reductions from the baseline PSA at the start of second-line MAB.

RESULTS

PSA reduction was observed in 32 patients (68.1%). Among them, 23 (48.9%) achieved ≥50% PSA reductions with a mean response duration of 13.4±5.4 months. Nine (19.2%) patients reached <50% PSA reductions with a mean response duration of 12.2±6.2 months. The time to nadir PSA level after first-line MAB in the ≥50% PSA reduction group, <50% PSA reduction group, and PSA elevation group was 15.6±12.9 months, 11.8±6.0 months, and 8±6.5 months, respectively. That is to say, it was significantly longer in the responder groups (p=0.038).

CONCLUSIONS

Second-line MAB using an alternative antiandrogen is an effective treatment option before cytotoxic chemotherapy in patients who relapse after initial MAB.