Illustration of prostate biopsy with needles targeting specific locations.

Decoding Prostate Biopsy Results: Why Location Matters

Rhea Morgan in Health & Wellness December 2025 • 5 min read.

"Understanding Discordance in Positive Cores for Better Prostate Cancer Management"

Prostate cancer is a leading health concern for men worldwide, ranking as the second most common cancer in males. Early and accurate detection is critical, and transrectal ultrasonography (TRUS) guided prostate biopsy has become a standard diagnostic tool. This procedure not only confirms the presence of cancer but also provides essential information about its location and extent.

The detailed information gleaned from a prostate biopsy plays a pivotal role in determining the most appropriate treatment strategy. Factors such as active surveillance, radical prostatectomy, and hormone therapy are all considered based on the biopsy's findings. During a radical prostatectomy, surgeons rely on biopsy data to decide how closely or widely to dissect, and whether to attempt to preserve the neurovascular bundle, which is vital for maintaining erectile function and continence.

However, TRUS-Bx isn't foolproof. Sampling limitations can lead to inaccuracies, with some cancers going undetected. This is particularly concerning when surgeons aim to preserve the neurovascular bundle, as undetected cancer in these areas can result in positive surgical margins (PSM), indicating that cancer cells remain after surgery. Recent research has focused on comparing the location of positive cores in biopsies with the location of PSMs to improve surgical outcomes.

Positive Surgical Margins and Discordance: Unpacking the Data

Illustration of prostate biopsy with needles targeting specific locations.

A recent study investigated the correlation between positive cores found during a prostate biopsy and the location of positive surgical margins (PSM) following radical prostatectomy. The study retrospectively analyzed data from patients diagnosed with prostate cancer via standard 12-core TRUS-Bx who subsequently underwent radical prostatectomy and were found to have PSMs. After excluding cases with fewer than 12 biopsy cores or incomplete location data, 46 patients with PSMs were included in the analysis.

The location of PSMs within the pathology specimens was meticulously recorded at six different sites: the apex, base, and lateral aspects on both sides of the prostate. Discordance between the biopsy results and PSM location was defined as instances where no positive cores were identified in the biopsy at the same location as the PSM.

Most Common PSM Locations: The most frequent sites for PSMs were the right apex (n=21) and left apex (n=15).
Multiple PSMs: Multiple PSMs were reported in 21 specimens (45.7%).
Concordance vs. Discordance: In 32 specimens (69.6%), one or more concordant positive biopsy cores were identified. However, 14 specimens (28%) showed no concordant biopsy cores at the PSM location.
Discordance Rate: When analyzed by location, the right apex PSM had the highest rate of discordance (38%).
Patient Characteristics: The discordant group had significantly lower prostate volume and a lower number of positive cores in the biopsy compared to the concordant group.

The study revealed that a significant portion of PSMs (28%) occurred in locations where the tumor was not detected during the initial biopsy. This finding underscores the limitations of TRUS-Bx and highlights the potential for undetected cancer to compromise surgical outcomes. The apex of the prostate, particularly on the right side, exhibited the highest rate of discordance, suggesting that this area may be more prone to sampling errors or harbor undetected tumors.

Key Takeaways for Patients and Future Directions

This study emphasizes that a notable fraction of PSMs occur in areas where tumors were not initially detected by biopsy, with the apex region showing the highest discordance. This highlights the need for surgeons to exercise caution during dissection, especially in the apex, even when biopsy results are negative. Further research is needed to refine biopsy techniques, enhance imaging modalities, and develop more precise surgical strategies to minimize the risk of PSMs and improve outcomes for men undergoing radical prostatectomy for prostate cancer.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.4111/kju.2015.56.10.710, Alternate LINK

Title: Discordance Between Location Of Positive Cores In Biopsy And Location Of Positive Surgical Margin Following Radical Prostatectomy

Subject: General Medicine

Journal: Korean Journal of Urology

Publisher: The Korean Urological Association

Authors: Ji Won Kim, Hyoung Keun Park, Hyeong Gon Kim, Dong Yeub Ham, Sung Hyun Paick, Yong Soo Lho, Woo Suk Choi

Published: 2015-01-01

Everything You Need To Know

What is the role of prostate biopsy in prostate cancer diagnosis and treatment?

Prostate cancer is a leading health concern for men worldwide. Early and accurate detection is critical for effective management. The standard diagnostic tool, transrectal ultrasonography (TRUS)-guided prostate biopsy, confirms cancer presence, providing information on location and extent. This data is pivotal in determining treatment strategies, including active surveillance, radical prostatectomy, and hormone therapy. Understanding these factors is key for informed patient care.

What is radical prostatectomy and how does biopsy data influence it?

A radical prostatectomy is a surgical procedure where the entire prostate gland is removed. Biopsy data guides surgeons in deciding the extent of dissection and whether to preserve the neurovascular bundle. The goal is to remove the cancer while preserving critical functions like erectile function and continence. The location of Positive Surgical Margins (PSMs) after surgery indicates where cancer cells remain, potentially impacting treatment success.

What are Positive Surgical Margins (PSMs) and what is discordance?

Positive Surgical Margins (PSMs) refer to the presence of cancer cells at the edge of the tissue removed during a radical prostatectomy. The study found that PSMs frequently occurred in the right and left apex of the prostate. Discordance between biopsy results and PSM location means that cancer was found in the surgical specimen at a location where it was not identified in the initial biopsy. This can lead to recurrence.

What does discordance mean and why is it significant?

Discordance signifies a discrepancy between the prostate biopsy findings and the actual cancer location after surgery. The apex region showed the highest discordance rate. Sampling limitations during Transrectal Ultrasonography (TRUS)-guided prostate biopsy can lead to cancer being missed, particularly in areas where the neurovascular bundle is located. This directly impacts treatment outcomes. The study showed that 28% of cases had discordance. Further research is needed to refine biopsy techniques and enhance imaging modalities.

What are the main conclusions regarding biopsy accuracy and surgical outcomes?

The study's key takeaway is that a significant portion of Positive Surgical Margins (PSMs) occur in areas where tumors were not detected by biopsy, particularly in the apex region. This underscores the need for surgeons to be cautious during dissection, even when biopsy results are negative. It calls for enhanced biopsy techniques, advanced imaging, and refined surgical strategies to reduce the risk of PSMs and improve outcomes for patients undergoing radical prostatectomy for prostate cancer.