Diagnostic accuracy of extended biopsies for the staging of microfocal prostate cancers in autopsy specimen

When prostate cancer remains undetectable: The dilemma

Since the first report on the efficacy of sextant biopsy under transrectal ultrasound guidance, there have been many modifications related to the total number of cores and the localization of biopsies to improve the prostate cancer (PCa) detection rate. The 2010 National Comprehensive Cancer Network Early PCa Detection Guidelines noted the 12-core biopsy scheme as the standard. However, this extended biopsy scheme still fails to detect 20% of high-grade PCa that can be detected by detailed pathological evaluation of radical prostatectomy; therefore, there is need for saturation biopsies. The existence of suspicions of PCa after previous negative biopsy or biopsies represents a valid indication for saturation biopsy. There has been no significant increment in morbidity or in insignificant PCa detection rates when a saturation biopsy scheme was used with an extended biopsy scheme. Along with the improvement in the PCa detection rate, accurate oncological mapping of PCa is another important consideration of saturation biopsies. The ideal number of cores and the diagnostic value of saturation biopsy after the failure of initial therapy are some of the issues that need to be addressed. Preliminary reports have shown that magnetic resonance imaging can improve the PCa detection rate, save patients from unnecessary biopsies, and decrease the need for a high number of cores; however, multiple limitations continue to exist.

Prostate cancer incidence on cystoprostatectomy specimens is directly linked to age: results from a multicentre study

OBJECTIVE

To assess the incidence and age-related histopathological characteristics of incidentally diagnosed prostate cancer from specimens obtained via radical cystoprostatectomy (RCP) for muscle-invasive bladder cancer.

PATIENTS AND METHODS

A retrospective review of the histopathological features of 2424 male patients who underwent a RCP for bladder cancer was done at eight centres between January 1996 and June 2012. No patient had preoperative suspicion of prostate cancer. Statistical analyses were performed in different age-related groups.

RESULTS

Overall, prostate cancer was diagnosed in 518 men (21.4%). Incidences varied significantly according to age (5.2% in those aged <50 years to 30.5% in those aged >75 years, P < 0.001). Most of the prostate cancers were considered as 'non-aggressive', that is to say organ-confined (≤pT2) and well-differentiated (Gleason score <7). Tumour-Node-Metastasis (TNM) stage and proportion with a Gleason score of ≥7 were significantly greater in older patients (P < 0.001). Apart from age, there were no preoperative predictive factors for 'non-aggressive' prostate-cancer status. At the end of the follow-up, only nine patients (1.7%) had biochemical recurrence of prostate cancer, and no preoperative predictive factors were identified.

CONCLUSION

The rate of incidentally diagnosed prostate cancer from RCP specimens is ≈20%, most of them being organ-confined and well-differentiated. The probability of having a 'non-aggressive' prostate cancer decreases in older men.

The contemporary concept of significant versus insignificant prostate cancer

CONTEXT

The notion of insignificant prostate cancer (Ins-PCa) has progressively emerged in the past two decades. The clinical relevance of such a definition was based on the fact that low-grade, small-volume, and organ-confined prostate cancer (PCa) may be indolent and unlikely to progress to biologic significance in the absence of treatment.

OBJECTIVE

To review the definition of Ins-PCa, its incidence, and the clinical impact of Ins-PCa on the contemporary management of PCa.

EVIDENCE ACQUISITION

A review of the literature was performed using the Medline, Scopus, and Web of Science databases with no restriction on language up to September 2010. The literature search used the following terms: insignificant, indolent, minute, microfocal, minimal, low volume, low risk, and prostate cancer.

EVIDENCE SYNTHESIS

The most commonly used criteria to define Ins-PCa are based on the pathologic assessment of the radical prostatectomy specimen: (1) Gleason score ≤ 6 without Gleason pattern 4 or 5, (2) organ-confined disease, and (3) tumour volume<0.5 cm(3). Several preoperative criteria and prognostication tools for predicting Ins-PCa have been suggested. Nomograms are best placed to estimate the risk of progression on an individualised basis, but a substantial proportion of men with a high probability of harbouring Ins-PCa are at risk for pathologic understaging and/or undergrading. Thus, there is an ongoing need for identifying novel and more accurate predictors of Ins-PCa to improve the distinction between insignificant versus significant disease and thus to promote the adequate management of PCa patients at low risk for progression.

CONCLUSIONS

The exciting challenge of obtaining the pretreatment diagnostic tools that can really distinguish insignificant from significant PCa should be one of the main objectives of urologists in the following years to decrease the risk of overtreatment of Ins-PCa.

Effect of the number of biopsy cores on prostate cancer detection and staging

Digital rectal examination, serum concentration of prostate cancer-specific antigen and transrectal ultrasound-guided biopsies are currently the main diagnostic tools to detect evidence of prostate cancer. Different prostatic biopsy strategies have been proposed in order to achieve an optimal prostate cancer detection rate and an accurate characterization of prostate cancer stage and grade. We examined the role of the number of biopsy cores on prostate cancer detection rates at initial and repeat biopsies. Moreover, we examined the relationship between the number of biopsy cores and the detection of insignificant prostate cancer. Finally, we reviewed the ability of biopsy cores in predicting prostate cancer stage and grade at radical prostatectomy. We relied on a PubMed systematic review of the contemporary English language literature using the terms ‘prostate cancer’, ‘diagnosis’, ‘transrectal ultrasound’ and ‘prostate biopsy’.