Clinical and pathologic features of prostate cancer detected after repeat false-negative biopsy in a screening population

Clinicopathologic differences between prostate cancers detected during initial and repeat transrectal ultrasound-guided biopsy in Korea

Purpose

The aim of this study was to investigate clinicopathologic differences between prostate cancer (PCa) detected at initial and repeat transrectal ultrasound-guided prostate biopsy in a large Korean cohort.

Materials and Methods

From 2000 through 2012, a total of 7,001 patients underwent transrectal ultrasound-guided prostate biopsy at 6 centers in Daegu and Gyeongbuk provinces. Of these 7,001 patients, the initial biopsy was positive for PCa in 2,118 patients. Repeat biopsy was performed in 374 of the 4,883 patients with an initial negative finding and a persistently elevated prostate-specific antigen (PSA) level, nodules or asymmetry by digital rectal examination (DRE), high-grade prostatic intraepithelial neoplasia, or atypical small acinar proliferation. Numbers of biopsy cores varied from 6 to 12 according to center and biopsy date.

Results

Cancer was diagnosed in 2,118 of the 7,001 patients (30.3%) at initial biopsy and in 86 of the 374 patients (23.0%) at repeat biopsy. The repeat biopsy rate was 5.3%. Mean PSA values were 68.7±289.5 ng/mL at initial biopsy and 18.0±55.4 ng/mL at repeat biopsy (p<0.001). The mean number of cancer-positive cores per biopsy was 5.5±3.5 for initial biopsy and 3.0±2.9 for repeat biopsy (p<0.001). Mean Gleason score was 7.5±1.4 at initial biopsy and 6.6±1.3 at repeat biopsy (p<0.001). For detected cancers, the low-stage rate was higher for repeat biopsy than for initial biopsy (p=0.001).

Conclusions

Cancers detected at repeat biopsy tend to have lower Gleason scores and stages than cancers detected at initial biopsy. The present study shows that repeat biopsy is needed in patients with a persistently high PSA or abnormal DRE findings.

Increased rate of positive biopsies using a combination of MR-Tomography, spectroscopy and diffusion-weighted magnetic resonance imaging prior to prostate biopsies in patients with persistent elevated prostate-specific antigen values: A retrospective analysis

Purpose:

Persistently elevated prostate-specific antigen (PSA) values following negative biopsies result in a diagnostic dilemma. In order to improve detection rates in patients with former negative biopsies and persistently elevated PSA values, magnetic resonance tomography (MRT), magnetic resonance spectroscopy (MRS), and diffusion-weighted magnetic resonance imaging (DW-MRI) were performed prior to prostate rebiopsies.

Materials and Methods:

Over a 14-month period, 67 patients (mean age of 66 years) with a history of 1-5 negative biopsies underwent endorectal magnetic resonance imaging (MRI) using T2-weighted MRT MRS and DW-MRI before an additional prostate biopsy was performed. Subsequently, 5 contrast-enhanced transrectal ultrasound-guided biopsies were performed according to a 10-core systematic scheme. Out of the 67 men, 25 patients had positive biopsies and opted for radical prostatectomy. Histological evaluation of cancer localization, PSA, diameters of primary tumors, numbers and diameters of satellite tumors, prostate volume, and staging pathology was performed. These findings were compared with MRI and MRS results.

Results:

Serum PSA levels ranged from 3.1 to 19.5 g/ml (median level of 7.96 ng/ml). After the 25 patients underwent radical prostatectomy, analysis of 20 whole-mount sections of 25 radical retropubic prostatectomy (RPE) specimens presented results agreeing with the tumor location from MRI and MRS data.

Conclusions:

The aim of image-guided diagnostics should be to provide more critical information prior to biopsy. Furthermore, the acquisition of such data is important for better risk stratification in therapeutic decisions.

Detection rate of clinically insignificant prostate cancer increases with repeat prostate biopsies

To analyze if clinically insignificant prostate cancer (CIPC) is more frequently detected with repeat prostate biopsies, we retrospectively analyzed the records of 2146 men diagnosed with prostate cancer after one or more prostate biopsies. The patients were divided into five groups according to the number of prostate biopsies obtained, e.g. group 1 had one biopsy, group 2 had two biopsies and group 3 had three biopsies. Of the 2146 patients diagnosed with prostate cancer, 1956 (91.1%), 142 (6.6%), 38 (1.8%), 9 (0.4%) and 1 (0.1%) men were in groups 1, 2, 3, 4 and 5, respectively. Groups 4 and 5 were excluded because of the small sample sizes. The remaining three groups (groups 1, 2 and 3) were statistically analyzed. There were no differences in age or prostate-specific antigen level among the three groups. CIPC was detected in 201 (10.3%), 28 (19.7%) and 9 (23.7%) patients in groups 1, 2 and 3, respectively (P<0.001). A multivariate analysis showed that the number of biopsies was an independent predictor to detect CIPC (OR=2.688 for group 2; OR=4.723 for group 3). In conclusion, patients undergoing multiple prostate biopsies are more likely to be diagnosed with CIPC than those who only undergo one biopsy. However, the risk still exists that the patient could have clinically significant prostate cancer. Therefore, when counseling patients with regard to serial repeat biopsies, the possibility of prostate cancer overdiagnosis and overtreatment must be balanced with the continued risk of clinically significant disease.

Characterization of prostate cancer detected at repeat biopsy

Background

The aim of this study was to investigate the characteristics of prostate cancer patients who were diagnosed at repeat biopsy and compare them to non-cancerous patients or patients who were diagnosed at initial biopsy.

Methods

We carried out a retrospective analysis of clinical and pathological data from 576 patients, which included data on the period of time from radical prostatectomy to biochemical failure.

Results

Cancer was diagnosed in 191 (33%) of 576 patients at initial biopsy and in 23 (18%) of 127 patients who underwent a repeat biopsy. Cut-off values of 0.80 and 0.30 for prostate specific antigen velocity (PSAV) and prostate specific antigen density (PSAD), respectively, were determined using ROC curve analysis. Based on these values, PSAV and PSAD were able to predict 94% (46 of 49) of negative repeat biopsies, indicating that these patients had undergone unnecessary repeat biopsies. Although the patients who were diagnosed at repeat biopsy had a higher rate of organ-confined tumor than those who were diagnosed at initial biopsy (73% and 44%, respectively; P = 0.041), there were no differences in the recurrence rate or the duration of biochemical failure-free survival between the two groups.

Conclusion

PSAV and PSAD may be useful indicators of the results of repeat biopsies. Although prostate cancer that was diagnosed at repeat biopsy was associated with a more favorable pathological profile, it was not associated with a better outcome after radical prostatectomy.

NMR-based metabolomics approach to target biomarkers for human prostate cancer

In the era of genomics and proteomics, metabolomics offers a unique way to probe the underlying biochemistry of malignant transformations. In the context of oncological metabolomics, the study of the global variation of metabolites involved in the development and progression of cancers, few existing techniques offer as much potential to discover biomarkers as nuclear magnetic resonance techniques. The most fundamental magnetic resonance methodologies with regard to human prostate cancer are magnetic resonance spectroscopy and magnetic resonance spectroscopic imaging. Recent in vivo explorations have examined crucial metabolites that may indicate cancerous lesions and have the potential to direct treatment; while ex vivo studies of prostatic fluids and tissues have defined novel diagnostic parameters and indicated that magnetic resonance methodologies will be paramount in future prostate cancer management.

Repeat prostate biopsy in the Prostate, Lung, Colorectal and Ovarian cancer screening trial

OBJECTIVE

To determine patterns of repeat prostate biopsy in a cohort of men undergoing prostate cancer screening who have a negative initial biopsy.

SUBJECTS AND METHODS

The Prostate, Colorectal, Lung, and Ovarian (PLCO) cancer screening trial is an ongoing study the prostate component of which consists of six annual screens with measurements of prostate-specific antigen (PSA) level and a digital rectal examination (DRE). The diagnostic follow-up of positive screening results is done by the subject's healthcare provider outside the purview of the PLCO. We analysed the experience of repeat biopsy in men in the PLCO with an initial negative biopsy. Men were divided by indication for initial biopsy into those with suspicious PSA levels and those with suspicious DRE findings.

RESULTS

The probability of having a repeat biopsy within 3 years of initial biopsy was 43% for 1736 men with suspicious PSA levels and 13% for 1025 men with suspicious DRE findings. Rates of third and fourth biopsy after a previous negative biopsy were similar to the initial repeat biopsy rate in PSA-positive men. Most men had a repeat biopsy only after having an additional round of screening. The PSA level and PSA velocity determined after initial biopsy were independent risk factors for a repeat biopsy, both in PSA-positive and DRE-positive men. High-grade prostatic intraepithelial neoplasia was a risk factor for repeat biopsy before any repeat PSA or DRE testing.

CONCLUSION

The experience of this cohort should be generally representative of patterns of care for repeat biopsy in men undergoing periodic screening. These data can provide context to the debate over optimum practices for repeat biopsy.

Are Transition Zone Biopsies Still Necessary to Improve Prostate Cancer Detection?

OBJECTIVES

The present retrospective study was designed to investigate the value of transition zone (TZ) biopsies for prostate cancer (PC) detection rate in a combined contrast enhanced color Doppler targeted (CECD) and gray-scale systematic biopsy (SB) approach.

METHODS

PSA screening participants totalling 1475 with tPSA of >1.25 ng/ml (fPSA< or =18%) were assessed. Ten SB and additionally 5 or fewer CECD were performed. The impact of TZ biopsies on the PC detection rate and the biological significance of the detected TZ-cancers were analyzed.

RESULTS

Out of 1475 biopsied patients, 395 (26.8%) were identified as PC patients; 5925 biopsy cores from these patients were analyzed. In 86 patients (21.8% of PC), we found 102 PC- positive cores in the TZ, and only in 9 of them solitary TZ-cancers without any other PC-location (2.3% of PC or 0.6% of all investigated patients). Pathologic findings after retropubic prostatectomy (RPE) revealed multifocal adenocarcinoma including involved peripheral zone (PZ) in eight of these nine patients, and solitary TZ-cancer in one patient. There was no positive correlation between prostate volume and TZ-detection rate and no patient with solitary TZ-PC after rebiopsy.

CONCLUSION

Biopsy revealed 9 solitary TZ cancers (1.8%) and RPE revealed only one of them to be truly TZ-confined cancer (0.6%). Furthermore PC-detection did not improve, even in patients with rebiopsy, and there was no correlation between detection of TZ-cancers and prostate volume. A combined use of CECD and SB to investigate participants of a PSA-screening program suggests that TZ-biopsies do not improve PC detection rate and are therefore unnecessary.

Metabolic characterization of human prostate cancer with tissue magnetic resonance spectroscopy

Diagnostic advancements for prostate cancer have so greatly increased early detections that hope abounds for improved patient outcomes. However, histopathology, which guides treatment, often subcategorizes aggressiveness insufficiently among moderately differentiated Gleason score (6 and 7) tumors (>70% of new cases). Here, we test the diagnostic capability of prostate metabolite profiles measured with intact tissue magnetic resonance spectroscopy and the sensitivity of local prostate metabolites in predicting prostate cancer status. Prostate tissue samples (n = 199) obtained from 82 prostate cancer patients after prostatectomy were analyzed with high-resolution magic angle spinning proton magnetic resonance spectroscopy, and afterwards with quantitative pathology. Metabolite profiles obtained from principal component analysis of magnetic resonance spectroscopy were correlated with pathologic quantitative findings by using linear regression analysis and evaluated against patient pathologic statuses by using ANOVA. Paired t tests show that tissue metabolite profiles can differentiate malignant from benign samples obtained from the same patient (P < 0.005) and correlate with patient serum prostate-specific antigen levels (P < 0.006). Furthermore, metabolite profiles obtained from histologically benign tissue samples of Gleason score 6 and 7 prostates can delineate a subset of less aggressive tumors (P < 0.008) and predict tumor perineural invasion within the subset (P < 0.03). These results indicate that magnetic resonance spectroscopy metabolite profiles of biopsy tissues may help direct treatment plans by assessing prostate cancer pathologic stage and aggressiveness, which at present can be histopathologically determined only after prostatectomy.