Review ArticleTumors of the Anterior Prostate: Implications for Diagnosis and Treatment
Section snippets
Prostate Anatomy
Our current understanding of prostate anatomy is largely based on the seminal work of McNeal. He demonstrated that the human prostate is a composite organ, made up of a nonglandular region, the anterior fibromuscular stroma (AFMS), and 3 distinct glandular zones: (1) the peripheral zone (PZ), (2) the central zone, and (3) the transition zone (TZ; Fig. 1).2
Location and Relevance
The majority of prostate tumors are located posteriorly in the PZ.4, 5 In the remaining cases, tumors are located anteriorly, in the anterior horn of the PZ, the AFMS, or the anterior portion of the TZ. These regions are usually nonpalpable on digital rectal examination (Fig. 2).
In a series of 224 men who underwent radical prostatectomy (RP), 71% of the nonpalpable tumors in the apex of the prostate were located anteriorly.6 Likewise, among 259 patients who underwent RP with exclusively
Prostate Biopsy Schemes
Until the 1980s, transperineal biopsy performed under digital guidance was the predominant method of prostate cancer diagnosis. Introduction of serum prostate-specific antigen (PSA) testing in the 1990s mandated a prostate biopsy in men with an elevated value despite a normal digital rectal examination, using a systematic sampling scheme.11 Initially, biopsies in this era were taken according to the Stamey protocol,12 in which samples were obtained in the midparasagittal plane at the base, mid,
Anterior Prostate Sampling
When using the traditional sextant scheme, anterior tumors are more difficult to detect than posterior tumors. In a series of 547 RP specimens, carcinoma was located predominantly anterior to the urethra in 21% of the specimens.17 In this series, patients who had anterior tumors were significantly more likely to require >1 set of sextant biopsies to diagnose malignancy compared with those with posterior tumors. Wright and Ellis18 showed early on that anterior apical prostate biopsies enhanced
Implications for Active Surveillance
Tumors of the anterior prostate present a special challenge to the management of patients on active surveillance (AS). Duffield et al23 endeavored to characterize disease progression in patients in whom AS failed. Of 470 men on AS, 48 (10%) had progressed and underwent RP, within an average time of 29.5 months after diagnosis. Analysis of the prostatectomy specimens in this subset of men determined that 27% were clinically insignificant according to the Epstein criteria. However, among this
Multiparametric Magnetic Resonance Imaging of the Prostate—the Gold Standard
mpMRI (T1- and T2-weighted imaging, diffusion-weighted imaging with apparent diffusion coefficient mapping, and dynamic contrast enhancement) is the preferred study for imaging prostate cancer and to aid in targeted biopsy of suspicious lesions. Targeted biopsy, via various techniques, has been demonstrated to be an efficient and effective method to detect clinically significant prostate cancer.25, 26, 27, 28, 29 Importantly, mpMRI performs best for the detection of clinically significant
Implications for Radical Prostatectomy
The prostatic apex poses a special challenge at RP because of its variable morphology, presence of the dorsal venous complex, and lack of a true capsule.37 These anatomic issues contribute to the higher positive surgical margin rate regularly seen in this region of the prostate at RP. Godoy et al38 found an overall 9.8% positive margin rate among 1308 consecutive RP specimen, with 25.8% of these occurring at the apex or anteriorly. Positive margins in these locations also translated to worse
Conclusion
Anterior prostate cancer remains an undervalued entity despite its frequent occurrence. Anterior apical cores should be integrated into standard biopsy templates at initial biopsy. Men with a prior negative biopsy in whom there is high clinical suspicion should undergo mpMRI with subsequent targeted biopsy. For men who elect AS or require definitive treatment, knowledge of APC can provide meaningful information, which may alter management.
References (40)
- et al.
Anterior distribution of stage T1c nonpalpable tumors in radical prostatectomy specimens
Urology
(2002) - et al.
Random systematic versus directed ultrasound guided transrectal core biopsies of the prostate
J Urol
(1989) Making the most of six systematic sextant biopsies
Urology
(1995)Repeat prostate biopsy—when, where and how
Urol Oncol
(2009)- et al.
Improved prostate cancer detection with anterior apical prostate biopsies
Urol Oncol
(2006) - et al.
Saturation technique does not improve cancer detection as an initial prostate biopsy strategy
J Urol
(2006) - et al.
Importance of additional “extreme” anterior apical needle biopsies in the initial detection of prostate cancer
J Urol
(2010) - et al.
Radical prostatectomy findings in patients in whom active surveillance of prostate cancer fails
J Urol
(2009) - et al.
Biopsy criteria for determining appropriateness for active surveillance in the modern era
Urology
(2014) - et al.
Improving detection of clinically significant prostate cancer: magnetic resonance imaging/transrectal ultrasound fusion guided prostate biopsy
J Urol
(2014)
Combined multiparametric MRI and targeted biopsies improve anterior prostate cancer detection, staging, and grading
Urology
Dynamic contrast-enhanced-magnetic resonance imaging evaluation of intraprostatic prostate cancer: correlation with radical prostatectomy specimens
Urology
Negative predictive value of multiparametric MRI for prostate cancer detection: outcome of 5-year follow-up in men with negative findings on initial MRI studies
Eur J Radiol
Effect of targeted biopsy guided by elastic image fusion of MRI with 3D-TRUS on diagnosis of anterior prostate cancer
Urol Oncol
High diagnostic ability of multiparametric magnetic resonance imaging to detect anterior prostate cancer missed by transrectal 12-core biopsy
J Urol
Magnetic resonance imaging guided prostate biopsy in men with repeat negative biopsies and increased prostate specific antigen
J Urol
Practical surgical anatomy for radical prostatectomy
Urol Clin North Am
Predictors of unfavorable disease after radical prostatectomy in patients at low risk by D'Amico criteria: role of multiparametric magnetic resonance imaging
J Urol
Cancer statistics, 2014
CA Cancer J Clin
The zonal anatomy of the prostate
Prostate
Cited by (14)
Image-Guided Targeted Prostate Biopsies
2021, Techniques in Vascular and Interventional RadiologyCitation Excerpt :TRUS offers the ability to acquire imaging in real time but is limited by poor spatial resolution and low sensitivity for prostate cancer, as lesions can often appear isoechoic on TRUS imaging, making them difficult to distinguish from background tissue. TRUS biopsies tend to miss anterior clinically significant prostate cancer which can represent up to 41% of prostate cancers.11,12 This has led to a joint recommendation from the AUA and SAR that any man with a prior negative biopsy, elevated PSA, and MRI Prostate Imaging Reporting and Data System (PI-RADS) of 3-5 undergo an image guided prostate biopsy.13
The Theory of Endobiogeny: Volume 3: Advanced Concepts for the Treatment of Complex Clinical Conditions
2019, The Theory of Endobiogeny: Volume 3: Advanced Concepts for the Treatment of Complex Clinical ConditionsWhy and Where do We Miss Significant Prostate Cancer with Multi-parametric Magnetic Resonance Imaging followed by Magnetic Resonance-guided and Transrectal Ultrasound-guided Biopsy in Biopsy-naïve Men?
2017, European UrologyCitation Excerpt :Anterior tumor involvement was seen in 41% of the patients, which is consistent with the literature [18]. Lesions localized in the apical region were difficult to detect with both modalities, which is also concordant with the literature [18–21]. sPCa is associated with increased age, PSA level, and a small prostate volume [22].
Transurethral Resection of the Prostate Biopsy of Suspected Anterior Prostate Cancers Identified by Multiparametric Magnetic Resonance Imaging: A Pilot Study of a Novel Technique
2016, UrologyCitation Excerpt :High-quality controlled studies for an accessible and reproducible biopsy technique are greatly needed, and these studies will be important in establishing the eventual standard mpMRI anterior lesion biopsy technique. APCs are located in the anterior horns of the peripheral zone, anterior portion of the transitional zone, or anterior fibromuscular stroma5,23 These locations are distant from the posterior prostate surface, which is the location most readily sampled by TRUS-guided biopsy. For these reasons, APCs are more difficult to detect with standard TRUS-guided biopsy.
Transrectal Ultrasound in Prostate Cancer: Current Utilization, Integration with mpMRI, HIFU and Other Emerging Applications
2022, Cancer Management and Research
Financial Disclosure: The authors declare that they have no relevant financial interests.