No reason for immediate repeat sextant biopsy after negative initial sextant biopsy in men with PSA level of 4.0 ng/mL or greater (ERSPC, Rotterdam)

New Biopsy Techniques and Imaging Features of Transrectal Ultrasound for Targeting PI-RADS 4 and 5 Lesions

PURPOSE

To introduce new biopsy techniques and imaging features of transrectal ultrasound (TRUS) for targeting Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 lesions Methods: TRUS-guided targeted and/or systematic biopsies were performed in 432 men with PI-RADS 4 and 5 lesions following magnetic resonance imaging examination. A TRUS operator who was familiar with the new techniques and imaging features performed lesion detection. Overall and significant cancer detection rates (CDRs) were compared among the men with PI-RADS 4 and 5 lesions. The CDRs in the peripheral and transition zones were compared. Additionally, we assessed whether targeted or systematic biopsies contributed to cancer detection. The standard reference was a biopsy examination.

RESULTS

The overall CDRs in the men with PI-RADS 4 and 5 lesions were 49.5% (139/281) and 74.8% (113/151) (p < 0.0001); significant CDRs were 33.1% (93/281) and 58.3% (88/151) (p < 0.0001); and CDRs in the peripheral and transition zones were 53.6% (187/349) and 78.3% (65/83) (p < 0.0001), respectively. Of the 139 men with clinically significant cancer PI-RADS 4 lesions, 107 (77.0%) were diagnosed by targeted biopsy, 5 (3.6%) by systematic biopsy, and 27 (19.4%) by both. Of the 113 men with clinically significant cancer PI-RADS 5 lesions, 97 (85.8%) were diagnosed by targeted biopsy, 3 (2.7%) by systematic biopsy, and 13 (11.5%) by both.

CONCLUSIONS

Most PI-RADS 4 and 5 lesions can be targeted with TRUS if the new techniques and imaging features are applied.

Management of men with a suspicion of prostate cancer after negative initial prostate biopsy results

INTRODUCTION

For men with elevated prostate-specific antigen (PSA), appropriate management after negative prostate biopsy remains controversial. After determining PSA kinetics, subsequent follow-up was considered.

PATIENTS AND METHODS

A total of 115 cases with negative repeat biopsy were followed by evaluating PSA kinetics and ratio of percent free PSA (F/T) and by performing second repeat biopsy.

RESULTS

Eighteen cancer cases were diagnosed. Shorter PSA doubling times and faster velocities were found in cancer cases compared with cases without cancer. We observed a clear decrease in F/T among cancer cases.

CONCLUSIONS

To avoid unnecessary repeat biopsies, cases with a suspicion of cancer after negative biopsy can be divided into two groups: one that requires additional biopsies and one with an average change in PSA of <1 ng/ml/year and no change in F/T, which is recommended for surveillance as stable disease without biopsy over a specified time period.

Prostate cancer diagnosis among men with isolated high-grade intraepithelial neoplasia enrolled onto a 3-year prospective phase III clinical trial of oral toremifene

PURPOSE

Prostate cancer (PCa) prevention remains an appealing strategy for the reduction of overtreatment and secondary adverse effects. We evaluated the efficacy of toremifene citrate 20 mg in PCa prevention among men with isolated high-grade prostatic intraepithelial neoplasia (HGPIN) on biopsy.

PATIENTS AND METHODS

One thousand five hundred ninety men with HGPIN, or HGPIN and atypia, and no PCa on prostate biopsy were randomly assigned 1:1 to receive toremifene citrate 20 mg or placebo in a 3-year phase III, double-blind, multicenter trial. Men underwent annual biopsy until cancer detection or study end. Efficacy analysis was performed in 1,467 men who underwent at least one on-study biopsy. Baseline risk factors were evaluated to determine influence on cancer detection.

RESULTS

Cancer was detected in 34.7% and 32.3% of men in the placebo and treatment groups, respectively, with no observed difference (P = .39, log-rank test) in PCa-free survival. The 3-year Kaplan-Meier PCa-free survival estimate was 54.9% (99% CI, 43.3% to 66.5%) in the placebo group and 59.5% (99% CI, 48.1% to 70.9%) in the treatment group. Exploration of baseline risk factors demonstrated no subset in which a risk reduction was observed. In the placebo group, 17.9%, 12.9%, and 13.6% of men at risk at the beginning of years 1, 2, and 3, respectively, were diagnosed with PCa.

CONCLUSION

Although toremifene 20 mg did not lower the PCa detection rate, men with isolated HGPIN have a high likelihood of eventual PCa diagnosis, demonstrating they are ideal candidates for inclusion in chemoprevention trials and require surveillance by periodic prostate biopsy.

Long-term follow-up of men with isolated high-grade prostatic intra-epithelial neoplasia followed by serial delayed interval biopsy

OBJECTIVES

To analyze the outcomes of serial delayed interval biopsy (DIBx) in men with isolated high-grade prostatic intraepithelial neoplasia (HGPIN). The natural history of isolated HGPIN is poorly defined. Since January 2000, we have monitored men with isolated HGPIN using DIBx every 3 years, regardless of the change in prostate-specific antigen (PSA) level.

METHODS

The institutional biopsy records from 1996 onward were reviewed to identify the men with isolated HGPIN found on 12-core needle biopsy specimens who had undergone a minimum of 1 DIBx in our follow-up strategy. Patient age, biopsy and prostatectomy pathologic outcomes, and longitudinal PSA measurements were recorded.

RESULTS

A total of 112 men had undergone a first DIBx and 47 had undergone a second DIBx at the last follow-up examination at a mean of 34.4 and 66.2 months after the HGPIN diagnosis, respectively. Prostate cancer was found in 25 (22.3%) of 112 men and 11 (23.4%) of 47 men at DIBx-1 and DIBx-2, respectively. The PSA velocity was not predictive of cancer during short-term follow-up. Of the men diagnosed with cancer, 63.6% had a Gleason score of ≥7, and 9 (81.8%) of 11 men had clinically significant disease (Gleason score of ≥7 and/or >5% cancer volume) at surgery. All cancers were organ confined at and surgery.

CONCLUSIONS

Men with isolated HGPIN have a continued risk of developing prostate cancer during long-term follow-up, regardless of the changes in the serum PSA level. Collectively, the relatively high likelihood of organ confinement and clinically significant cancer suggest empiric DIBx every 2-3 years could be a valuable tool in the follow-up of men with isolated HGPIN found by extended core biopsy.

Prostate cancer detection at rebiopsy after an initial benign diagnosis: results using sextant extended prostate biopsy

INTRODUCTION

Sextant prostate biopsy remains the standard technique for the detection of prostate cancer. It is well known that after a diagnosis of small acinar proliferation (ASAP) or high grade prostate intraepithelial neoplasia (HGPIN), the possibility of finding cancer is approximately 40% and 30%, respectively.

OBJECTIVE

We aim to analyze follow-up biopsies on patients who initially received a benign diagnosis after exclusion of HGPIN and ASAP.

METHODS

From July 2000 to December 2003, 1177 patients were submitted to sextant extended prostate biopsy in our hospital. The mean patient age was 65.5 years old, and the median number of fragments collected at biopsy was 13. HGPIN and ASAP were excluded from our study. We only considered patients who had a diagnosis of benign at the first biopsy and were subjected to rebiopsies up until May 2005 because of a maintained suspicion of cancer.

RESULTS

Cancer was initially detected in 524 patients (44.5%), and the diagnosis was benign in 415 (35.3%). Rebiopsy was indicated for 76 of the latter patients (18.3%) because of a persistent suspicion of cancer. Eight cases of adenocarcinoma (10.5%) were detected, six (75%) at the first rebiopsy. Six patients were submitted to radical prostatectomy, and all tumors were considered clinically significant.

CONCLUSION

Our data indicate that in extended prostate biopsy, the first biopsy detects more cancer, and the first, second, and third rebiopsies after an initial benign diagnosis succeed in finding cancer in 7.9% (6/55), 5.9% (1/15) and 20% (1/4) of patients, respectively.

Discrete Fourier analysis of ultrasound RF time series for detection of prostate cancer

In this paper, we demonstrate that a set of six features extracted from the discrete Fourier transform of ultrasound Radio-Frequency (RF) time series can be used to detect prostate cancer with high sensitivity and specificity. Ultrasound RF time series refer to a series of echoes received from one spatial location of tissue while the imaging probe and the tissue are fixed in position. Our previous investigations have shown that at least one feature, fractal dimension, of these signals demonstrates strong correlation with the tissue microstructure. In the current paper, six new features that represent the frequency spectrum of the RF time series have been used, in conjunction with a neural network classification approach, to detect prostate cancer in regions of tissue as small as 0.03 cm2. Based on pathology results used as gold standard, we have acquired mean accuracy of 91%, mean sensitivity of 92% and mean specificity of 90% on seven human prostates.

Prostate cancer testing following a negative prostate biopsy: over testing the elderly

BACKGROUND

Screening elderly men for prostate cancer is not recommended because definitive treatments are unlikely to extend life expectancy.

OBJECTIVE

Describe clinical outcomes after a negative prostate biopsy in a population-based cohort of men ages 65 and older.

DESIGN

Retrospective cohort study.

PARTICIPANTS

9,410 Medicare-eligible men who underwent a prostate biopsy in Los Angeles or New Mexico in 1992.

MEASUREMENTS

We used Medicare and SEER databases to identify a cohort with an initial negative biopsy (n = 7,119) and to ascertain survival, subsequent PSA testing, prostate biopsies, and prostate cancer detection and treatment through 1997.

RESULTS

The overall 5-year survival was 79.4% (95% CI 78.4-80.3), but only 74.6% (72.4-76.7) for men ages 75-79 at the time of the initial negative biopsy and 55.0% (51.9-57.9) for men ages 80+. During a median 4.5 years follow-up, a cumulative 75.0% (73.9-76.1) of the cohort underwent PSA testing. Among men ages 75-79 and 80+, the cumulative proportions that underwent PSA testing were 75.4% (73.0-77.8) and 74.3% (71.1-77.5), respectively. Additionally, 29.1% (26.7-31.6) of men ages 75-79 and 20.1% (17.6-23.1) of men ages 80+ underwent repeat prostate biopsy, and 10.9% (9.4-12.7) and 8.3% (6.6-10.4), respectively, were diagnosed with cancer. Among men ages 75+ with localized cancers, approximately 34% received definitive treatment.

CONCLUSIONS

High proportions of men ages 75+ underwent PSA testing and repeat prostate biopsies after an initial negative prostate biopsy. Given the known harms and uncertain benefits for finding and treating localized cancer in elderly men, most continued PSA testing after a negative biopsy is potentially inappropriate.

Computer-aided diagnosis of prostate cancer with emphasis on ultrasound-based approaches: a review

This paper reviews the state of the art in computer-aided diagnosis of prostate cancer and focuses, in particular, on ultrasound-based techniques for detection of cancer in prostate tissue. The current standard procedure for diagnosis of prostate cancer, i.e., ultrasound-guided biopsy followed by histopathological analysis of tissue samples, is invasive and produces a high rate of false negatives resulting in the need for repeated trials. It is against these backdrops that the search for new methods to diagnose prostate cancer continues. Image-based approaches (such as MRI, ultrasound and elastography) represent a major research trend for diagnosis of prostate cancer. Due to the integration of ultrasound imaging in the current clinical procedure for detection of prostate cancer, we specifically provide a more detailed review of methodologies that use ultrasound RF-spectrum parameters, B-scan texture features and Doppler measures for prostate tissue characterization. We present current and future directions of research aimed at computer-aided detection of prostate cancer and conclude that ultrasound is likely to play an important role in the field.

Obtaining fresh prostate cancer tissue for research: a novel biopsy needle and sampling technique for radical prostatectomy specimens

BACKGROUND

Fresh or fresh-frozen tissue samples are preferred for molecular profiling as formalin fixation degrades intracellular nucleic acids. Radical prostatectomy (RP) specimens are a valuable source of prostate cancer tissue, but the reliance on whole-organ pathological processing for prognostication limits sampling opportunities. Few studies have addressed specific harvesting techniques using prostatectomy specimens.

MATERIALS AND METHODS

Ex vivo biopsies were performed on 23 consecutive fresh RP specimens using a purpose-designed needle. A standard sextant approach was used with an additional lateral biopsy on each side. Cores from each lobe were snap-frozen together and sections assessed by a pathologist blinded to the RP and pre-operative biopsy pathology. Comparison with pre-operative biopsies was performed using the t-test and chi(2) statistical tests. Eleven randomly selected RP specimens were further evaluated for the effects of needle tracks and margin perforation.

RESULTS

Cancer was detected in 19 of 23 specimens, giving a sensitivity of 83.6%. The average tumor involvement was 28.3% per section compared with 15.6% for pre-operative biopsies (P < 0.02). There was no statistically significant difference between the groups for either Gleason sum score concordance or tumor location concordance. In 3 of 11 cases, needle margin perforation was identified; in none of the cases did it compromise pathological assessment, although in one case a deeper block resection was required.

CONCLUSIONS

Ex vivo biopsy is a useful technique for retrieving fresh tissue whilst preserving organ morphology in RP specimens. The purpose-designed needle and harvesting technique provide good yields of cancer tissue from a high proportion of sampled prostatectomy specimens.

4-YEAR PROSTATE SPECIFIC ANTIGEN PROGRESSION AND DIAGNOSIS OF PROSTATE CANCER IN THE EUROPEAN RANDOMIZED STUDY OF SCREENING FOR PROSTATE CANCER, SECTION ROTTERDAM

PURPOSE

The European Randomized Study of Screening for Prostate Cancer investigates the impact of screening on prostate cancer mortality and contributes to a better understanding of available screening tests. The present study evaluates the predictive value of a prostate specific antigen (PSA) increase to PSA 3.0 ng/ml or greater in a 4-year period in men who present with low PSA values (less than 3.0 ng/ml) at first screen.

MATERIALS AND METHODS

A total of 42,376 men were randomized to screening vs control in Rotterdam. Of 6,467 men 5,771 had PSA values of less than 3.0 ng/ml, did not undergo biopsy at baseline and were rescreened after 4 years with PSA 3.0 ng/ml or greater as biopsy indication. PSA progression in a 4-year interscreening interval is evaluated by determining the positive predictive values, detection rates and parameters of aggressiveness of round 2 cancers.

RESULTS

PSA progression to more than 3.0 ng/ml occurred in 0.9%, 9.3% and 48.6% of men who presented with PSA values less than 1.0, 1 to 1.9 and 2 to 2.9 ng/ml, respectively, in round 1. Their respective positive predictive values amounted to 19.0%, 23.8% and 27.9%. Cancer detection rates increased with increasing PSA values in round 1. The distribution of low, moderate and high risk cancers depends on round 2 but not on round 1 PSA ranges.

CONCLUSIONS

PSA progression to the (arbitrary) cutoff value of 3.0 ng/ml and the diagnosis of prostate cancer in round 2 screening with a 4-year interval depends strongly on PSA values at the time of the 1st screen. These observations will be helpful to design future screening procedures. With levels less than 2.0 ng/ml PSA progression to levels of 3.0 ng/ml or greater is rare as it was seen only in 4.8% of all men.