FOLLOW-UP AFTER RADICAL PROSTATECTOMY OR RADIATION THERAPY FOR PROSTATE CANCER

Cost-effectiveness analysis comparing degarelix with leuprolide in hormonal therapy for patients with locally advanced prostate cancer

Degarelix, approved in the USA in 2008, is a gonadotropin-releasing hormone antagonist, representing one of the latest additions to androgen deprivation therapy (ADT). ADT is used as first-line therapy for locally advanced or metastatic prostate cancer with the aim to reduce testosterone to castrate levels. Like other gonadotropin-releasing hormone-antagonists, degarelix treatment results in rapid decrease in luteinizing hormone, follicle-stimulating hormone and testosterone levels without the associated risk of flare. Using one registration trial for degarelix with leuprolide as the active control, a cost-effectiveness analysis with a Markov model and a 20-year time horizon found the incremental cost-effectiveness ratio for degarelix to be US$245/quality-adjusted life years. Degarelix provides a cost-effective treatment for ADT among patients with locally advanced prostate cancer.

Therapy of recurrent disease after radical prostatectomy in 2007

Recurrence rates of 20-40% after prostatectomy are described. This review will discuss curative treatment options for salvage after primary therapy. Relevant information was identified through searches of published studies, abstracts from scientific meetings, and review articles. Clinical experience in salvage therapy is limited. Conformal radiotherapy to the prostatic bed for PSA relapse and biopsy proven local recurrences after prostatectomy remains the only potentially curative therapy. It can provide durable biochemical control in a range from 17 to 78%. Salvage radiotherapy is well tolerated. Some prognostic factors exist which can help to select the right patient for this treatment. Patients have to be treated early for PSA relapse. Conformal radiotherapy to the prostatic bed for PSA relapse and biopsy proven local recurrences after prostatectomy is a good documented curative therapy. In a patient with a high probability of local recurrence early radiotherapy for PSA relapse is suggested.

Usefulness of the nadir value of serum prostate-specific antigen measured by an ultrasensitive assay as a predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer

INTRODUCTION

The objective of this study was to determine whether the nadir value of serum prostate-specific antigen (PSA) measured by an ultrasensitive assay could be a useful predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer.

MATERIALS AND METHODS

This study included 127 patients who underwent radical prostatectomy for clinically localized prostate cancer without neoadjuvant hormonal therapy and were pathologically diagnosed as negative for lymph node metastasis. The serum PSA value was measured using an ultrasensitive PSA assay system (Roche Diagnostics, Mannheim, Germany), and the findings were analyzed with respect to several clinicopathological factors. In this series, biochemical recurrence was defined as PSA persistently >0.2 ng/ml.

RESULTS

Based on the nadir PSA value, we divided 127 patients into three groups as follows: group A (n=99):<or=0.01 ng/ml; group B (n=16): 0.01-0.05 ng/ml, and group C (n=12): >or=0.05 ng/ml. The nadir PSA value was significantly associated with preoperative PSA value, but not other conventional clinicopathological prognostic parameters. During the observation period (median 31 months, range 6-75 months), biochemical recurrence occurred in 16 patients, that is, 1 in group A (6.3%), 4 in group B (25.0%), and 11 in group C (91.7%). Multivariate analysis using the Cox proportional hazards regression model indicated that the nadir PSA value was an independent predictor for biochemical recurrence after radical prostatectomy.

CONCLUSION

These findings suggest that the nadir serum PSA value measured by an ultrasensitive assay could be a useful predictor of biochemical recurrence after radical prostatectomy for clinically localized prostate cancer, and that careful follow-up should be considered in cases demonstrating a nadir PSA value>0.01 ng/ml because of the significantly higher probability of biochemical recurrence in such cases.

Time and PSA threshold model prognosticates long-term overall and disease-specific survival in prostate cancer patients as early as 3 months after external beam radiation therapy

The specific aim of this analysis was to evaluate the capability of a time and prostate-specific antigen (PSA) threshold model to prognosticate overall survival (OS) and disease-specific survival (DSS) based on early PSA kinetics after radiotherapy for prostate cancer by retrospective review of outcomes in 918 patients. Crossing below analyzed PSA thresholds at specific defined time points reduced disease-specific death hazard ratios to relative to the cohort above threshold. The time and PSA threshold model demonstrates the ability to prognosticate OS and DSS as early as 3 months post-radiotherapy for prostate cancer.

Early prostate-specific antigen (PSA) kinetics following prostate carcinoma radiotherapy

BACKGROUND

The goal of the current study was to analyze the prognostic value of early prostate-specific antigen (PSA) kinetics, with PSA assessed as reaching or failing to reach discrete threshold values at fixed time points during follow-up after external-beam radiotherapy (EBRT) for prostate carcinoma.

METHODS

The authors conducted a retrospective review of PSA follow-up for 839 patients treated between May 1987 and December 2000 at the Cleveland Clinic Foundation (Cleveland, OH). They also assessed the impact on bRFS of PSA levels lower than defined threshold values at given time points during follow-up.

RESULTS

During a median follow-up of 74 months (range, 24-189 months), 540 patients (64.4%) maintained bRFS, whereas 299 patients (35.6%) did not maintain bRFS. The median nadir among patients with sustained bRFS was 0.4 ng/mL, with a median time to nadir of 28.9 months. Patients who did not maintain bRFS reached a median nadir of 1.3 ng/mL at a median of 15 months (P < 0.0001 for both nadir level and time to nadir). Reaching PSA thresholds of 3.0, 2.0, 1.0, 0.5, and 0.2 ng/mL at any time during follow-up was correlated with improved bRFS (P < 0.0001, each threshold). Patients whose PSA levels crossed the appropriate thresholds within 3 and 6 months of follow-up, irrespective of the time or level of eventual nadir, exhibited significantly improved bRFS when compared with patients whose PSA levels reached those thresholds at any time during follow-up and patients whose PSA levels never reached those thresholds (all thresholds: P < 0.0001).

CONCLUSIONS

Despite previous conclusions that early PSA assessment may lack prognostic value, the data obtained in the current study suggest that the kinetics of early PSA decline is predictive of long-term bRFS when assessed using a time-and-PSA threshold model. After EBRT for prostate carcinoma, PSA levels below various discrete PSA thresholds were indicative of statistically meaningful long-term outcome differences between experimental arms as early as 90 days after radiotherapy. If the time-and-PSA threshold model is shown to be predictive of prostate carcinoma mortality as well, then it may allow the scientific community to evaluate promising treatment concepts and technologies at a highly accelerated pace.

Combination of low-dose flutamide and finasteride for PSA-only recurrent prostate cancer after primary therapy

OBJECTIVES

To evaluate the efficacy and tolerability of combined finasteride and low-dose flutamide for prostate-specific antigen (PSA)-only recurrence after definitive therapy and to determine the predictors of recurrence-free survival.

METHODS

Seventy-one men with biochemical recurrence after primary therapy for prostate cancer were prospectively enrolled from 1996 to 1998. Forty-two patients had undergone radical retropubic prostatectomy and 29 had undergone external beam radiotherapy. Radionuclide bone scans and computed tomography of the abdomen and pelvis showed no metastasis. The initial treatment with finasteride (5 mg twice daily) and flutamide (125 mg twice daily) was continued unless participants were unable to tolerate the agents or experienced PSA progression.

RESULTS

At a mean of 44.4 months (range 12 to 92) of follow-up, 54 (76%) of 71 patients were available for measurement of disease status and response to therapy. Three patients had died of unrelated causes; 5 men withdrew from the study because of side effects and 1 patient for protocol violation. Eight patients were lost to follow-up. Twenty-seven patients (38%) continued receiving therapy with no evidence of PSA progression (PSA level less than 0.4 ng/mL), 6 patients maintained a more than 50% reduction in their baseline PSA level at the time of analysis, and 21 (29%) had PSA progression (ie, elevated PSA level on three consecutive tests more than 4 weeks apart). Major side effects were breast tenderness (90%), gynecomastia (72%), gastrointestinal disturbances (22%), fatigue (10%), and decreased libido (4%). The side effects were mild and well tolerated by most patients.

CONCLUSIONS

The combination of finasteride and flutamide showed a moderate efficacy in patients with PSA-only recurrence after definitive therapy. The efficacy appears to be greater in patients who can achieve a PSA nadir of 0.1 ng/mL or less after the start of treatment.

Follow-up surveillance strategies for genitourinary malignancies

BACKGROUND

Genitourinary cancers account for more than 20% of all malignancies in the United States. These cancers do not usually yield rapid mortality, thereby necessitating longer-term surveillance strategies.

METHODS

A review and analysis of relevant studies were performed. Follow-up strategies are proposed to reflect effective methods to detect recurrent prostate, bladder, renal, and testicular cancers. Cost analysis was performed using Medicare reimbursement rates.

RESULTS

For genitourinary tumors, follow-up tests can be planned rationally based on detection rates and patterns. Tumor grade and stage drive follow-up strategies, along with therapeutic implications of detecting a recurrence. Symptomatic recurrences often obviate the need for radiographic tests and can minimize costs. Stage- specific plans for these four urologic malignancies are outlined specifically.

CONCLUSIONS

Not all surveillance approaches have been critically tested for follow-up of genitourinary tumors, but ample data are available to propose sound medical and economic strategies.

The prostate: diagnostic evaluation of metastatic disease

One of the single most important considerations in clinical management of the patient with prostate cancer is whether or not metastatic disease is present. The identification of metastatic disease in a patient with newly diagnosed prostate cancer represents an absolute contraindication to definitive local therapies such as radial prostatectomy or radiation therapy. Similarly, the identification of metastatic disease in a patient with disease recurrence after definitive local therapy represents an absolute contraindication to salvage radiotherapy or cryosurgery. Patients with metastatic disease do not benefit from definitive therapy, and the cost and morbidity associated with such treatment should therefore be avoided in these patients. Because of the significance of metastatic disease to clinical management, it is important for the diagnostic radiologist to be aware of important considerations in the metastatic work-up of patients with newly diagnosed prostate cancer and patients with suspected cancer recurrence after definitive local therapy.

Brachytherapy for clinically localized prostate cancer: results at 7- and 8-year follow-up

In recent years, there has been a resurgence of interest in interstitial radiation as a cost-effective and efficient method of treating organ-confined prostate cancer. We describe our 7- and 8-year results with transperineal Iodine-125 and Palladium-103 implantation. A total of 551 consecutive patients were treated. Of these, 320/551 (58%) received implant alone (Group I), and 231/551 (42%)--considered higher risk patients--were also treated with a modest dose (45 Gy) of external beam irradiation (Group II). The median follow-up for Group I was 55 months, and for Group II, 60 months. At 7 years, the actuarial freedom from biochemical failure (prostate-specific antigen (PSA) < or = 1.0 ng/mL) was 80% in Group I patients, and, at 8 years, 65% in Group II patients. Morbidity was minimal if patients had not undergone prior transurethral prostate resections. The results indicate that interstitial radiation is a valid treatment for clinically localized prostate cancer.

Defining the ideal tumor marker for prostate cancer

The ideal tumor marker would function well for detection, screening, staging, prognosis, follow-up, and performance characteristics. Prostate-specific antigen is a remarkably good tool in this respect; however, the translation into improved patient outcomes is still uncertain.

Use of serum concentration techniques to enhance early detection of recurrent prostate cancer after radical prostatectomy

OBJECTIVES

We evaluated the clinical applicability of serum concentration techniques to enhance the detection of prostate-specific antigen (PSA) in men with recurrent prostate cancer after radical prostatectomy.

METHODS

We concentrated blood serum by lyophilization and ultrafiltration from female patients who had undergone cystoprostatectomy, "cured" patients who had undergone radical prostatectomy, patients without prostate cancer, and patients with prostate cancer treated with radiation or hormonal therapy. The primary study group consisted of 31 patients with recurrent disease after radical prostatectomy whose initial postoperative PSA fell to undetectable levels (less than 0.07 ng/mL) that later turned positive (0.07 ng/mL or more) by the Tosoh AIA 600 immunoassay run in the ultrasensitive mode. All serum samples of less than 0.07 ng/mL were concentrated by lyophilization or ultrafiltration.

RESULTS

Serum concentrated by lyophilization and filtration detected PSA recurrence significantly earlier than did unconcentrated serum in 29 of 31 patients (94%) and in 28 of 31 patients (90%), respectively. The mean advantage for the 29 patients was 362 days; for the 28 patients it was 383 days. The mean native PSA was 0.04 ng/mL (range 0.00 to 0.06) at the time of earliest detection by concentration techniques. Serum from female patients who had undergone cystoprostatectomy and "cured" patients who had undergone radical prostatectomy failed to concentrate, giving a test specificity of 100%.

CONCLUSIONS

Serum concentration is a specific and sensitive technique that provides a significant lead time of an additional 12 months in detecting cancer recurrence after radical prostatectomy when compared with nonconcentrated serum. Because the Tosoh assay, when run in the ultrasensitive mode, gave an additional lead time of 9 months at a residual cancer detection limit of 0.07 ng/mL, the combination of the Tosoh assay and serum concentration allows detection of a failed radical prostatectomy about 2 years earlier than does the Hybritech Tandem-R assay, which has a residual cancer detection limit of 0.2 ng/mL.