Does size matter? The significance of prostate size on pathologic and functional outcomes in patients undergoing robotic prostatectomy

[Laparoscopic radical resection of large (223 g) solitary fibrous tumor of the prostate: a case report]

A 67-year-old male patient was referred to our hospital by the community health service center for "sudden dysuria for half a day". The diagnosis of solitary fibrous tumor of the prostate was established after transrectal prostate biopsy. After excluding contraindications, laparoscopic radical prostatectomy with bladder neck urethrostomy was performed. The operation was completed in 3 h and 15 min with an intraoperative blood loss of about 100 mL. Postoperative examination of the resected tumor revealed a large spherical tumor mass measuring about 11 cm×7.5 cm×6 cm with a net weight of 223 g. Postoperative pathology suggested solitary fibrous tumor of the prostate (medium-risk type). The abdominal drainage tube was removed 5 days after the operation and the catheter was removed 1 week after operation. The patient had good urine control at night without incontinence but with occasional urine leakage during daytime, and the overall therapeutic effect was satisfactory. Postoperative follow-up found good urine control of the patient without signs of tumor recurrence or metastasis. Laparoscopic radical prostatectomy often is difficult for large prostate tumors with a weight exceeding 200 g, and requires the surgeon to have rich experience in laparoscopic surgery with good understanding of prostate anatomy and close cooperation of the operation team to achieve satisfactory oncology control and functional protection of the urinary system.

The influence of prostate volume on pathological outcomes after radical prostatectomy: A single-center retrospective study

Currently, the association between prostate volume (PV) or prostate weight with pathological outcomes in patients with prostate cancer (PCa) is not well understood. This study aimed to explore whether PV can predict the adverse pathological outcomes of PCa patients after radical prostatectomy (RP). A total of 1063 men with confirmed localized PCa who underwent RP at the First Affiliated Hospital of Zhejiang University from January 2014 to April 2019 were retrospectively analyzed. Patients were assigned into small, medium and large groups based on the PV. The analysis of variance, χ2 test or Student t test was performed to compare differences among groups. Univariate and multivariate analyses were performed to identify significant predictors of pathological outcomes upgrading. Among the 1063 cases, approximately 35.0% had an upgrade of postoperative pathology. Compared with the small prostate group, more patients in the large prostate group achieved a Gleason score (GS) 6 and International Society of Urological Pathology (ISUP) grade 1 of postoperative pathological findings, clinical cT1c and cT2a stages and pathological pT2a and pT2b stages; the incidence of positive surgical margins and extraprostatic extension was relatively low (all P < .001). In multiple logistic regression, PV served as a significant predictor of any Gleason score upgrading (GSU) (odds ratio [OR] 0.988, 95% confidence interval [CI] 0.978-0.998), major GSU (OR 0.980, 95% CI 0.965-0.995) and any ISUP grade group upgrading (GGU) (OR 0.989, 95% CI 0.979-0.999). This study shows that PV can predict adverse pathological outcomes in PCa patients after radical prostatectomy. Pca patients with smaller prostate volume tend to have the high-grade disease at postoperative pathology as well as pathological outcome upgrading.

How accurately can multiparametric magnetic resonance imaging measure the tumour volume of a prostate cancer? Results of a systematic review

The tumour volume of a cancer within the prostate gland is commonly measured with multiparametric MRI. The measurement has a role in many clinical scenarios including focal therapy, but the accuracy of it has never been systematically reviewed. We included articles if they compared tumour volume measurements obtained by mpMRI with a reference volume measurement obtained after radical prostatectomy. Correlation and concordance statistics were summarised. A simple accuracy score was derived by dividing the given mean or median mpMRI volume by the histopathological reference volume. Factors affecting the accuracy were noted. Scores for potential bias and quality were calculated for each article. A total of 18 articles describing 1438 patients were identified. Nine articles gave Pearson's correlation scores, with a median value of 0.75 but the range was wide (0.42-0.97). A total of 11 articles reported mean values for volume while 9 reported median values. For all 18 articles, the mean or median values for MRI volumes were lower than the corresponding reference values suggesting consistent underestimation. For articles reporting mean and median values for volume, the median accuracy scores were 0.83 and 0.80, respectively. The accuracy was higher for tumours of greater volume, higher grade and when an endorectal coil was used. Accuracy did not seem to improve over time, with a 3 Tesla magnet or by applying a shrinkage factor to the reference measurement. Most studies showed evidence of at least moderate bias, and their quality was highly variable, but neither of these appeared to affect accuracy.

The association between prostate weight and positive surgical margins in prostate cancer: A meta-analysis

There have been some conflicting claims whether larger prostate weight (PW) reduces the risk of positive surgical margins (PSMs). This study aims to examine the associations between PW and PSMs. PubMed, Web of Science and Cochrane library were systematically retrieved. Relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were synthesised utilising random-effect models. Ultimately, 22 cohort studies met criteria were enrolled in this meta-analysis, of which 18 studies reporting the RR of the highest VS lowest category of PW yielded the combined RR of PSMs of 0.61 (95% CI 0.50-0.74). Subgroup analysis showed that geographic region and surgical modalities were considered as potential confounders of influence of PW on PSMs. The nonlinear dose-response relationship demonstrated that PSM risk decreased by 1% (RR = 0.99, 95% CI, 0.98-0.99) for every one gram increment in PW. This study suggests PW has a negative association with risk of PSMs, and having a appropriate PW is very important.

A systematic review of the accuracy of the digital rectal examination as a method of measuring prostate gland volume

Objective:

There are many important clinical scenarios in which estimates of the volume of the prostate gland can have an influence on clinical decisions. The digital rectal examination is the simplest and most readily available method for measuring it. It is commonly performed numerous times every day by practising urologists and radiation oncologists. The prostate gland volume is the most studied parameter arising from it. Although reported in many heterogeneous studies, the accuracy of the digital rectal examination in measuring the volume has never been reviewed. Our aim was to conduct the world’s first systematic review.

Methods:

Articles from the literature were included if they compared the digital rectal examination with more accurate measures including fluid displacement after radical prostatectomy and transrectal ultrasound measurements.

Results:

Nineteen articles describing 7891 patients were reviewed and summarised. Wide variations were noted but most studies provided correlation coefficients that lay between 0.3 and 0.7. For those studies that did not involve special training in volume estimation or were not conducted by a urologist with a special interest in the correlation, the coefficients were below 0.6. For eight studies that analysed the estimated volume as a categorical variable, concordance was described using a variety of statistical tests but was generally high.

Conclusions:

The reported correlations were weak to moderate strength indicating that the digital rectal examination may not be accurate enough when quantitative measurements are required. However, enlargement of the prostate was detectable with high levels of concordance, indicating that the digital rectal examination is effective for that purpose.

Level of evidence:

Not applicable for this multicentre audit.

How Accurately Can Prostate Gland Imaging Measure the Prostate Gland Volume? Results of a Systematic Review

AIM

The measurement of the volume of the prostate gland can have an influence on many clinical decisions. Various imaging methods have been used to measure it. Our aim was to conduct the first systematic review of their accuracy.

METHODS

The literature describing the accuracy of imaging methods for measuring the prostate gland volume was systematically reviewed. Articles were included if they compared volume measurements obtained by medical imaging with a reference volume measurement obtained after removal of the gland by radical prostatectomy. Correlation and concordance statistics were summarised.

RESULTS

28 articles describing 7768 patients were identified. The imaging methods were ultrasound, computed tomography, and magnetic resonance imaging (US, CT, and MRI). Wide variations were noted but most articles about US and CT provided correlation coefficients that lay between 0.70 and 0.90, while those describing MRI seemed slightly more accurate at 0.80-0.96. When concordance was reported, it was similar; over- and underestimation of the prostate were variably reported. Most studies showed evidence of at least moderate bias and the quality of the studies was highly variable.

DISCUSSION

The reported correlations were moderate to high in strength indicating that imaging is sufficiently accurate when quantitative measurements of prostate gland volume are required. MRI was slightly more accurate than the other methods.