The presence of prostate cancer on saturation biopsy can be accurately predicted

Tumor-Associated Release of Prostatic Cells into the Blood after Transrectal Ultrasound-Guided Biopsy in Patients with Histologically Confirmed Prostate Cancer

BACKGROUND

Transrectal ultrasound-guided prostate biopsy (TRUS) is a standard procedure for prostate cancer diagnosis. Because prostate cancer is a multifocal disease in many patients, multiple sampling (n ≥ 10) is required, which may bear the risk of systemic spread of cancer cells.

DESIGN

Using the standardized CellSearch® system that allows for the detection of single epithelial cell adhesion molecule-positive circulating tumor cells (CTCs) in blood, we investigated whether prostate biopsy is associated with release of prostatic tumor cells into the circulation. Peripheral blood was obtained before and within 30 min after performing prostate biopsy from 115 men with increased serum prostate-specific antigen.

RESULTS

The number of CTCs significantly increased after biopsy in men with histologically confirmed prostate cancer (odds ratio, 7.8; 95% CI, 4.8–12.8), whereas no biopsy-related changes could be detected in men without confirmed prostate cancer. Multivariable analysis showed that biopsy-related increase of CTCs was significantly correlated with a worse progression-free survival (hazard ratio, 12.4; 95% CI, 3.2–48.6) within the median follow-up of 41 months.

CONCLUSIONS

Prostate biopsies may lead to a tumor-associated release of CTCs into the blood circulation. Larger confirmatory trials with longer follow-up periods are required before any change in clinical practice can be recommended.

Atypical small acinar proliferation and two or more cores of high-grade intraepithelial neoplasia on a previous prostate biopsy are significant predictors of cancer during a transperineal template-guided saturation biopsy aimed at sampling one core for each 1 mL of prostate volume

Objective

The objective of this study was to evaluate whether high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical small acinar proliferation (ASAP) predict prostate cancer (PCa) during repeat transperineal template saturation biopsy with a high number of cores per prostate volume in patients with persistent clinical suspicion of PCa who underwent at least one previous negative transrectal ultrasound (TRUS)-guided biopsy.

Methods

We retrospectively evaluated 135 consecutive patients with persistent clinical suspicion of PCa, despite a set of negative TRUS-guided biopsies and increasing prostate-specific antigen levels; abnormal findings on digital rectal examination, TRUS, or magnetic resonance imaging; previous biopsy showing HGPIN; and previous biopsy showing atypical glands. Transperineal template saturation biopsy (TTSB) was performed at 5mm intervals to sample one core for each 1 mL of prostate volume.

Results

The median rate of biopsy cores per prostate volume was 1.00 (range: 0.75–1.39). The PCa detection rates in patients who were diagnosed with HGPIN, or had two or more cores of HGPIN or ASAP, were 53% (9/17), 89% (8/9), and 83% (10/12), respectively. Two or more HGPIN cores and ASAP were positive predictors of PCa on TTSB. The high-grade cancer rates (Gleason score [GS] ≥7) in patients with ASAP and two or more cores of HGPIN were 20% and 80%, respectively. The cancer detection rate represented by a GS score ≥8 in patients with ASAP or two or more cores of HGPIN at a previous TRUS-guided biopsy was 5.5% (1/18).

Conclusion

ASAP or two or more cores of HGPIN at a previous TRUS-guided biopsy strongly indicated the presence of PCa on TTSB.

Predictors of prostate cancer in ultrasound-guided transperineal saturation biopsy in Turkish men with multiple prior negative biopsies

BACKGROUND

Transperineal prostate biopsy (STPB) is associated with an improved cancer detection rate and an increase in anterior and apical prostate cancers compared to standard transrectal biopsy.

PATIENTS AND METHODS

A total of 48 men with at least two sets of prior prostate biopsies underwent transrectal ultrasound-guided STPB. Prostate rebiopsy indications were serum prostate-specific antigen (PSA) levels greater than 2.5 ng/mL and/or abnormal digital rectal examination and/or presence of high-grade prostatic intraepithelial neoplasia (HGPIN; ≥2 cores) or atypical small acinar proliferation (ASAP) at previous biopsies. The procedure was performed at dorsal lithotomy position under general anesthesia using a perineal 0.5 cm brachytherapy template attached to the transrectal ultrasound probe. Specimens from each zone were sent separately for pathological examination.

RESULTS

Mean PSA level at STPB was 15.9 ng/mL (range 4.03 to 59.57). An average of 54.5 cores was obtained. Prostate adenocarcinoma was detected in 15 of 48 (31%) patients. Mean percentage of malignant cores was 11.9%. Multivariate logistic regression analysis revealed that age and presence of ASAP or HGPIN at previous biopsies were independent predictors of prostate cancer (p<0.05). No major complications, including sepsis and severe urinary or rectal bleeding, were observed in any of the patients. Five patients (10%) developed acute urinary retention after the procedure requiring urethral catheterization.

CONCLUSIONS

Considerable number of patients with negative multiple biopsies were diagnosed with prostate cancer. STPB is a well-tolerated procedure with minimal morbidity, which can be considered for the diagnosis of prostate cancer in patients with previous negative biopsies.

A direct comparison of the diagnostic accuracy of three prostate cancer nomograms designed to predict the likelihood of a positive initial transrectal biopsy

BACKGROUND

Several tools have been developed to predict the outcome of prostate biopsies performed to diagnosis prostate cancer (PCa). However, few studies have focused on the comparative accuracy of these predictive tools. We aim to establish the predictive accuracy of three commonly used nomograms by comparing their prostate biopsy outcome predictions with actual pathological results.

METHODS

From January 2008 to December 2010, 708 consecutive patients with an elevated serum PSA level and/or abnormal DRE were referred to our institution. All data were collected prospectively. All patients underwent a TRUS 12-core biopsy. Probability of a positive biopsy was predicted using three online risk calculation nomograms. The discriminative ability of the nomograms was assessed via AUC and the most accurate model was calibrated and compared to actual biopsy results.

RESULTS

Of 667 patients fulfilling all three nomograms criteria, 384 (57.5%) had PCa and 283 (42.5%) did not. AUC for the PCPT-CRC, SWOP-PRI, and Montreal nomograms was 0.68 (95% CI, 0.63-0.72), 0.72 (95% CI, 0.68-0.76), and 0.79 (95% CI, 0.76-0.82), respectively. A comparison of the three models' performance showed that the Montreal model provided the greatest predictive accuracy (P = 0.03).

CONCLUSIONS

External validation of three commonly used nomograms designed to predict the likelihood of a positive prostate biopsy reveals the Montreal model was more accurate than either the PCPT-CRC or SWOP-PRI models. The Montreal nomogram achieves a diagnostic accuracy of 79% and is superior to PSA alone though we await further research to define the probability (of cancer) threshold above which a prostate biopsy would be advised.

Imaging prostate cancer lymph node metastases with a multimodality contrast agent

BACKGROUND

Methods to detect lymph node (LN) metastases in prostate cancer (PCa) are limited. Pelvic LN dissection is commonly performed during prostatectomy, but often followed by morbid complications. More refined methods for detecting LN invasion are needed.

METHODS

We developed a dual-labeled targeting agent having a near-infrared (NIR) fluorophore for intraoperative guidance, and a conventional radiotracer for detection of LN metastasis. Nu/Nu mice were orthotopically implanted with DsRed-expressing human PCa (PC3) cells. Antibody (Ab) specific for epithelial cell adhesion molecule was conjugated to DOTA, IRDye 800CW, and radiolabeled with (64) Cu. Dual-labeled Ab was administered intravenously at 10-12 weeks post-implantation, and positron emission tomography/computed tomography (PET/CT) and fluorescence imaging were performed within 18-24 hr.

RESULTS

Metastasis to lumbar LNs was detected by DsRed fluorescence imaging, as well as pathology, in 75% of mice having pathology-confirmed primary prostate tumors. These metastases were also detected by NIR fluorescence imaging. In some cases, metastases to sciatic, medial, renal, and axillary nodes were also detected. For all LNs examined, no significant differences were found between the percentages of metastases detected by NIR imaging (63%) and µPET/CT (64%) (P = 0.93), or between those detected by DsRed imaging (25%) and pathological examination (19%) (P = 0.12).

CONCLUSION

This study demonstrates that a multimodality contrast agent is useful for early detection of metastatic disease, and has applications for intraoperative PCa treatment. Further agent optimization is necessary to enhance specificity, and provide validation for prostate and other LN metastasizing epithelial cancers.

The optimal rebiopsy prostatic scheme depends on patient clinical characteristics: results of a recursive partitioning analysis based on a 24-core systematic scheme

BACKGROUND

The most beneficial number and the location of prostate biopsies remain matters of debate, especially after an initial negative biopsy.

OBJECTIVE

To identify the optimal combination of sampling sites (number and location) to detect prostate cancer (PCa) in patients previously submitted to an initial negative prostatic biopsy.

DESIGN, SETTING, AND PARTICIPANTS

A transrectal ultrasound-guided systematic 24-core prostate biopsy (24PBx) was performed prospectively in 340 consecutive patients after a first negative biopsy (at least 12 cores).

MEASUREMENTS

We relied on a classification and regression tree analysis to identify three clinically different subgroups of patients at dissimilar risk of harboring PCa at second biopsy. Subsequently, we set the cancer-positive rate of the 24PBx at 100% and calculated PCa detection rates for 255 possible combinations of sampling sites. We selected the optimal biopsy scheme (defined as the combination of sampling sites that detected 95% of all the cancers with the minimal number of biopsy cores) for each patient subgroup.

RESULTS AND LIMITATIONS

After an initial negative biopsy, cancer was detected at rebiopsy in 95 men (27.9%). At a given number of cores, the cancer detection rates varied significantly according to the different combination of sites considered. Three different PCa risk groups were identified: (1) previous report of atypical small acinar proliferation of the prostate (ASAP), (2) no previous ASAP and ratio of free prostate-specific antigen (fPSA) to total PSA (%fPSA) ≤10%, and (3) no previous ASAP and %fPSA >10%. For patients with previous ASAP or patients with no previous ASAP and %fPSA ≤10%, two schemes with different combinations of 14 cores were most favorable. The optimal sampling in patients with no previous ASAP and %fPSA >10% was a scheme with a combination of 20 cores.

CONCLUSIONS

Both the number and the location of biopsy cores taken affect cancer detection rates in a repeated biopsy setting. We developed an internally validated flowchart to identify the most advantageous set of sampling sites according to patient characteristics.

Prostate cancer detection after a negative prostate biopsy: lessons learnt in the Cleveland Clinic experience

Urologists are often faced with the dilemma of managing patients with a negative initial prostate biopsy in whom clinical or pathological risk for prostate cancer still exists. Such real-life challenging scenarios might raise questions such as: Who should undergo further biopsies? What are the optimal predictors for prostate cancer on subsequent biopsies? What is the optimal biopsy protocol that should be used? When to stop the biopsy cascade? The last decade has witnessed numerous studies that have analyzed factors conferring a significant risk for cancer discovered on repeat biopsies. We and others have developed predictive models to aid decision-making regarding pursuing further biopsies. For decades, high-grade prostatic intraepithelial neoplasia has been considered a strong risk indicator for subsequent cancer. However, it has been recently shown that only through segmentation of this heterogeneous population does the real risk profile emerge. Biopsy templates underwent modification regarding the number and location of cores with emergence of the transrectal or brachytherapy grid transperineal saturation biopsy. However, the best biopsy protocol remains controversial. We have refined the initial biopsy template to a 14 core initial biopsy template that optimizes cancer detection, and have shown that transrectal saturation biopsy significantly improves cancer detection for repeat biopsy. Another concern is the overdiagnosis of clinically insignificant cancer on repeat biopsies, so we explored ways to limit this, and to deal with its ramifications. Through carrying out a Medline literature search, we critically evaluated pertinent articles together with emphasis of our own journey in this arena to assist in the decision-making process for repeat biopsy population.

Comparison of real-time sonoelastography with T2-weighted endorectal magnetic resonance imaging for prostate cancer detection

OBJECTIVES

The purpose of this study was to compare the value of real-time sonoelastography with T2-weighted endorectal magnetic resonance imaging (MRI) for prostate cancer detection.

METHODS

Thirty-three patients with an elevated prostate-specific antigen level were investigated with real-time sonoelastography and T2-weighted endorectal MRI for prostate cancer diagnosis before systematic prostate biopsy. Real-time sonoelastography was performed to assess prostate tissue elasticity, and hard areas were considered suspicious for prostate cancer. Low-signal intensity nodules on T2-weighted endorectal MRI were considered suspicious for prostate cancer. Imaging findings were assigned to 6 areas of the peripheral zone (sextants), and their cancer detection rates were compared.

RESULTS

Overall, prostate cancer was detected in 13 of 33 patients (39.4%). Both real-time sonoelastography and T2-weighted endorectal MRI detected 11 cancer-positive patients (84.6%). Real-time sonoelastography showed 27 suspicious lesions in 198 sextants, and 15 (55.6%) were cancer positive. T2-weighted endorectal MRI showed 31 suspicious lesions in 198 sextants, and 13 (40.6%) were cancer positive. These findings resulted in sensitivity rates and negative predictive values per patient of 84.6% and 86.7%, respectively, for sonoelastography and 84.6% and 83.3% for MRI. The per-sextant analysis showed sensitivity rates and negative predictive values of 57.7% and 93.6% for sonoelastography and 50.0% and 92.2% for MRI.

CONCLUSIONS

Real-time sonoelastography showed comparable results as T2-weighted endorectal MRI for prostate cancer detection.

Are we able to correctly identify prostate cancer patients who could be adequately treated by focal therapy?

INTRODUCTION AND OBJECTIVE

Because of the improvements on detection of early stage prostate cancer over the last decade, focal therapy for localized prostate cancer (PC) has been proposed for patients with low-risk disease. Such treatment would allow the control of cancer, thereby diminishing side effects, such as urinary incontinence and sexual dysfunction, which have an enormous impact on quality of life. The critical issue is whether it is possible to preoperatively predict clinically significant unifocal or unilateral prostate cancer with sufficient accuracy. Our aim is to determine whether there is any preoperative feature that can help select the ideal patient for focal therapy.

MATERIAL AND METHODS

A total of 599 patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy followed by radical prostatectomy to treat PC were examined in our laboratory between 2001 and 2009. We established very restricted criteria to select patients with very-low-risk disease for whom focal therapy would be suitable (only 1 biopsy core positive, tumor no larger than 80% of a single core, no perineural invasion, PSA serum level < 10 ng/ml, Gleason score < 7 and clinical stage T1c, T2a-b). We defined 2 groups of patients who would be either adequately treated or not treated by focal therapy. The primary endpoint was the evaluation of preoperative features in order to identify which parameters should be considered when choosing good candidates for focal therapy.

RESULTS

Fifty-six out of 599 patients met our criteria. The mean age was 59 years, and the mean number of biopsy cores was 14.4. Forty-seven (83.9%) were staged T1c, and 9 (16.1%) were staged T2a-b. Forty-four (78.6%) patients could be considered to have been adequately treated by focal therapy, and 12 (21.4%) could not. There was no statistical difference between the 2 groups considering age, clinical stage, PSA levels, Gleason score, and tumor volume in the biopsy. All 12 patients who could be considered inadequately treated had a bilateral, significant secondary tumor, 58.3% had Gleason ≥ 7, and 25% were staged pT3.

CONCLUSION

Although focal therapy might be a good option for patients with localized prostate cancer, we are so far unable to select which of them would benefit from it based on preoperative data, even using very restricted criteria, and a considerable proportion of men would still be left undertreated.