Predictors of prostate cancer on repeat prostatic biopsy in men with serum total prostate-specific antigen between 4.1 and 10 ng/mL

Utility of percent free prostate-specific antigen in repeat prostate biopsy

OBJECTIVES

To assess the utility of the percent free prostate-specific antigen (%fPSA) for the prediction of prostate cancer in men undergoing repeat biopsy.

METHODS

A retrospective review was performed of 1037 patients in an institutional review board-approved repeat prostate biopsy database. A total of 617 patients who underwent 683 biopsies had all their data available for analysis. The patients were categorized as having undergone 1 repeat biopsy or >1 repeat biopsy.

RESULTS

The overall cancer detection rate was 27% and 22% in men who underwent 1 and >1 repeat biopsy, respectively. The area under the receiver operating characteristic curve for the %fPSA was 0.65 for men who underwent 1 repeat biopsy. Multivariate analysis demonstrated that a positive family history, decreasing %fPSA, and presence of high-grade intraepithelial neoplasia and/or atypical small acinar proliferation predicted for cancer. The univariate odds ratio for every 5% decrease in the %fPSA was 1.5 (95% confidence interval 1.2-1.7). The performance of %fPSA was further improved in men who underwent >1 repeat biopsy, with an area under the curve of 0.72. In men who underwent >1 repeat biopsy, multivariate analysis showed that a decreasing %fPSA, >20 cores removed, and high-grade intraepithelial neoplasia predicted for cancer. The univariate odds ratio for every 5% decrease in the %fPSA was 1.8 (95% confidence interval 1.4-2.3). A %fPSA cutoff of 10% achieved 90% and 91% specificity in the 1 repeat biopsy and >1 repeat biopsy groups, respectively.

CONCLUSIONS

%fPSA is useful in predicting for prostate cancer in the repeat biopsy population, particularly for those who have undergone multiple repeat biopsies. A persistently low %fPSA should prompt additional investigation in these men.

[The significance of rebiopsy in the diagnosis of prostate cancer]

OBJECTIVE

The objective of this study was to evaluate whether rebiopsy of the prostate leads to a significant increase in the detection rate of prostate cancer compared with performing a single biopsy.

METHODS

Data from 406 patients were evaluated retrospectively. The patients had undergone ultrasound-guided transrectal biopsy of the prostate between January 2004 and August 2005. Besides demographic data, the patient information was reviewed with regard to the number of biopsy samples taken per patient, histological results, and the occurrence of complications during or after the examination. If prostate cancer was detected, data acquisition included the number of positive biopsy samples taken per examination as well as the subsequent therapy and the TNM classification of the tumor. After a follow-up time between 24 and 42 months, all patients with a histologically negative first biopsy were reevaluated regarding rebiopsy. We evaluated the follow-up time (in months) and the histological results. If prostate cancer was detected, we assessed the number of positive biopsy cores as well as the subsequent therapy and the TNM classification.

RESULTS

In 37.7% of all patients (n=153), prostate cancer was detected in the first biopsy. In 56.9% of these (n=87), a high-grade carcinoma with a Gleason score >or=7 was diagnosed. In 108 patients, a second biopsy was performed. The mean time between the first biopsy and rebiopsy was 21.7 months (range 1.3-41.2 months). With the second biopsy, prostate cancer was detected in 29 cases (26.9%), of which 51.7% (n=15) showed a high-grade carcinoma. There was no significant difference between the first biopsy and the second biopsy concerning either the detection rate of carcinomas related to the total number of transrectal multibiopsies or the detection of high-grade carcinomas related to the number of detected carcinomas. Provided that values beyond the second standard deviation were excluded from analysis, prostate-specific antigen (PSA) values at the time of rebiopsy were significant elevated compared with PSA values at the time of first biopsy. More than two-thirds of all patients with a histologically positive result in the second biopsy revealed a PSA velocity >or=0.6 ng/ml/year. Furthermore, there was no significance between the number of histologically positive samples per multibiopsy when prostate cancer was diagnosed in the first biopsy compared with the number of positive samples in the second biopsy. Complications after biopsy were noted in 19 patients. In three cases, hospitalization was necessary.

CONCLUSION

As a result of performing a rebiopsy, the detection rate of prostate cancer increased significantly compared with the detection rate after a single biopsy. Thus, the number of patients who could receive therapy was also increased. Due to the relatively low complication rate of prostate multibiopsy, this examination can be widely indicated. There was not a higher detection rate of high-grade prostate cancer in the second biopsy compared with performing only a single biopsy. The indication for a second biopsy as well as the determination of the time interval between the first and second biopsy should consider the current PSA value and PSA dynamics. Therapeutic consequences should also be taken into consideration. In the event of a PSA velocity >0.6 ng/ml/year, a rebiopsy should definitely be performed.

Phase I-II trial of weekly bicalutamide in men with elevated prostate-specific antigen and negative prostate biopsies

BACKGROUND

Men with elevated prostate-specific antigen (PSA) and negative prostate biopsies are at risk for prostate cancer. The antiandrogen bicalutamide has a prolonged half-life, thus potentially allowing an intermittent administration to retain activity while reducing toxicity. We conducted a phase I-II trial of weekly bicalutamide in men with PSA >4 ng/mL and negative biopsies.

METHODS

Eighty subjects were nonrandomly assigned to a three-arm trial to either bicalutamide 50 mg/wk (n = 26) or 100 mg/wk (n = 28) or no treatment (n = 26) for 6 months. Blood samples were obtained at 0, 3, and 6 months, and prostate biopsies were repeated after 6 months. The outcome measures were 6-month changes of tissue Ki-67 (primary end point), high-grade prostatic intraepithelial neoplasia (HG-PIN), proliferative inflammatory atrophy, circulating PSA, and sex hormones.

RESULTS

Ki-67 expression was higher in HG-PIN than in normal tissue (10% versus 3%; P < 0.01) but was not modulated by bicalutamide in normal luminal cells. A trend toward an improvement of HG-PIN status was found in treated subjects (26% improved, 60% had no change, 15% worsened) as compared with the no-treatment arm (4% improved, 83% had no change, 13% worsened; P = 0.07). Proliferative inflammatory atrophy prevalence was not reduced by bicalutamide. Bicalutamide reduced PSA by 50% in both arms and raised testosterone and estradiol levels. Asymptomatic breast swelling was noted in 40% of the treated cases.

CONCLUSIONS

A weekly administration of bicalutamide seems to be reasonably safe and shows an encouraging signal of activity on HG-PIN prevalence, supporting further studies of this schedule in men at high risk despite the negative primary end-point findings on Ki-67.

Assessment of serum level of prostate-specific antigen adjusted for the transition zone volume in early detection of prostate cancer

OBJECTIVE

To determine the clinical usefulness of prostate-specific antigen (PSA) density in the transition zone (PSADTZ) for increasing the specificity in early detection of prostate cancer (PCa) and reducing unnecessary biopsies in males with PSA between 4.0 and 10 ng/mL.

MATERIALS AND METHODS

This cross-sectional study obtained PSADTZ measurements in 68 patients with PSA between 4.0 and 10 ng/mL. All patients underwent transrectal ultrasonography (TRUS) with biopsies. PSADTZ was estimated by dividing the PSA value by the volume of the transition zone (TZ) obtained. We compared performance measurements for these parameters with those from the PSA itself, PSA density (PSAD) and free PSA/total PSA ratio (F/T PSA). The ability of the method in increasing PSA specificity was demonstrated and compared in univariate and multivariate analyses, and by Receiver Operating Characteristic Curves (ROC).

RESULTS

Of the 68 patients under study, 17 (25%) were diagnosed with PCa. The TZ volume (p = 0.001) and PSADTZ (p = 0.001) variables presented means that exhibited statistically significant differences. When compared with the area under the curve (AUC), ROC curves obtained by this method revealed that PSADTZ was the strongest predictor for PCa when considering the cut-off point provided by the curve; that is, 0.35 ng/mL/cc. When PSADTZ was employed, the detection failure would be close to 20%, and less than 45% of cases would undergo unnecessary biopsies. On the other hand, when F/T PSA was used, the loss would reach almost 40%; however less than 30% would undergo unnecessary biopsies. Nevertheless, PSADTZ had the only AUC presenting p < 0.05 in significance when compared with 50%, and was consequently discriminative.

CONCLUSIONS

PSADTZ increased PSA specificity in early detection of PCa in males with PSA between 4.0 and 10 ng/mL. However, it was shown to have lower predictive value and lower accuracy than the percentage of free PSA since it presents a higher negative predictive value than all other parameters assessed, and it can be considered clinically useful for reducing unnecessary indications for biopsy.

Prostate cancer screening

Prostate cancer is the leading noncutaneous cancer in men of the Western world. Because of its prevalence and ability to cause morbidity and mortality,prostate cancer screening continues to be an important area of focus in health care. This article covers the sensitivity and specificity of prostate-specific antigen and current techniques used to improve the test's validity, the importance of detecting clinically important cancers with screening, as well as the downward stage migration, decreased disease-specific mortality, and decreased metastases rate seen inpatients screened and treated for prostate cancer.

Screening for prostate cancer: current recommendations

Recent studies have questioned the efficacy of PSA as a marker for the early detection of prostate cancer, but techniques are being investigated to improve the sensitivity and specificity of screening. It is hoped that new methods can differentiate between lethal and nonlethal cancers, thereby avoiding lead-time bias. Even with the current limitations of PSA, the combination of stage migration seen with screening, the recent Scandinavian study showing decrease of disease progression following surgical extirpation, and the known mortality in patients presenting with advanced disease help support PSA screening for prostate cancer. It is hoped that prospective, randomized, long-term screening studies, such as the PLCO and ERSCP trials, will show improved survival using the admittedly imperfect PSA marker in prostate cancer screening.

Screening for Prostate Cancer

Prostate cancer is a highly prevalent disease in the Western world. In the United States alone, prostate cancer affects approximately 230,000 men and causes the death of 30,000 American men annually. Several theoretical health care measures may be implemented to decrease the morbidity and mortality of any disease. These measures include prevention, screening, improved curative treatment, and the transformation of an acute lethal disease to a chronic, tolerable one. This summary focuses on the screening aspects of prostate cancer.