Prostatic Adenocarcinoma: Understanding Your Pathology Report

by Trevor A. Flood, MD FRCPC
March 25, 2026

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Prostatic adenocarcinoma is the most common type of prostate cancer. It is sometimes called acinar adenocarcinoma because the cancer cells form small clusters that resemble glands called acini. The cancer develops from epithelial cells that normally line the inside of the prostate gland. Prostate cancer is one of the most common cancers in men, and the risk increases with age, particularly after 50.

Is prostatic adenocarcinoma aggressive?

Prostatic adenocarcinoma varies widely in its behavior. Many tumours grow very slowly and may never cause symptoms or require treatment. Others are more aggressive and can grow and spread quickly. The information in your pathology report — particularly the Gleason grade, Grade Group, and whether the cancer has spread beyond the prostate — helps your medical team understand how your tumour is likely to behave and what treatment, if any, is needed.

What are the symptoms of prostate cancer?

Many cases of prostate cancer cause no symptoms at all and are discovered only because of a rise in a blood protein called prostate-specific antigen (PSA). PSA is produced by prostate cells, and elevated levels can indicate prostate cancer, although other conditions can also raise PSA.

Some men experience urinary symptoms such as difficulty starting urination, a weak or interrupted urine stream, or the need to urinate frequently, especially at night. These symptoms are also common with benign prostatic hyperplasia, a non-cancerous enlargement of the prostate. Less commonly, prostate cancer can cause blood in the urine or semen, erectile dysfunction, or pelvic discomfort.

In cases where the cancer has spread beyond the prostate, it most often affects the bones, which can cause bone pain or fractures. Other sites of metastasis include the lungs, liver, and lymph nodes.

How is prostatic adenocarcinoma diagnosed?

Most prostate cancers are initially suspected based on an elevated PSA blood test or an abnormal finding on a digital rectal examination (DRE), in which a doctor manually feels the prostate through the rectum. When either of these is abnormal, the next step is a core needle biopsy, in which a thin needle removes small cylinders of tissue — called cores — from different areas of the prostate. A standard biopsy usually includes 10 to 15 cores.

A pathologist examines the tissue under a microscope and determines whether cancer is present, how much cancer is there, and how aggressive it appears. This information guides treatment decisions, which may include active surveillance, radiation therapy, or surgery to remove the prostate (radical prostatectomy). If you have had surgery to remove your prostate, you may also find it helpful to read our guide to understanding your radical prostatectomy pathology report.

Gleason grade, Gleason score, and Grade Group

Your pathology report will almost always include information about the Gleason grade, Gleason score, and Grade Group. These three numbers all describe the same thing — how abnormal the cancer cells look under the microscope — but they each provide the information in a slightly different way. Together, they are the most important predictors of how your cancer will behave.

Gleason grade

The Gleason grade describes how much the cancer cells look like normal prostate gland cells. It is assigned on a scale from 3 to 5. (Grades 1 and 2 are no longer used in clinical practice.)

• Grade 3 — The cancer cells still form recognizable gland structures. This is the least aggressive appearance.
• Grade 4 — The gland structures are poorly formed, fused, or lost. This is more aggressive.
• Grade 5 — There are no gland structures at all. The cells grow in solid sheets, cords, or single files. This is the most aggressive pattern.

Because most prostate cancers contain more than one grade of cancer, pathologists assign two grades: a primary grade for the most common pattern and a secondary grade for the next most common pattern.

Gleason score

The Gleason score is calculated by adding the primary and secondary Gleason grades together. For example, if most of the cancer is grade 3 and the next most common pattern is grade 4, the Gleason score is 3+4=7. If only one grade is present throughout, both the primary and secondary grades are recorded as the same number — for example, 3+3=6. Gleason scores in practice range from 6 to 10.

The order of the numbers matters: a score of 3+4=7 means that the less aggressive pattern (grade 3) is more common, while a score of 4+3=7 means the more aggressive pattern (grade 4) is dominant. These two scores have different prognostic implications despite having the same sum.

Grade Group

The Grade Group is a simplified grading system introduced to make it easier to communicate cancer risk. It groups Gleason scores into five categories, numbered 1 to 5. Grade Group 1 represents the lowest-risk cancers; Grade Group 5 represents the most aggressive.

• Grade Group 1 — Gleason score 3+3=6. Low-risk cancer. Often suitable for active surveillance.
• Grade Group 2 — Gleason score 3+4=7. Intermediate risk with predominantly low-grade pattern.
• Grade Group 3 — Gleason score 4+3=7. Intermediate risk with predominantly higher-grade pattern.
• Grade Group 4 — Gleason score 4+4=8—high-risk cancer.
• Grade Group 5 — Gleason score 4+5=9, 5+4=9, or 5+5=10—highest risk cancer.

Intraductal carcinoma and cribriform pattern

Your pathology report may mention intraductal carcinoma of the prostate (IDC-P) or a cribriform pattern. These specific appearances are recognized by pathologists as signs of more aggressive disease, even when the overall Gleason score appears moderate.

• Intraductal carcinoma (IDC-P) — This refers to cancer cells filling and expanding the natural ducts and glands of the prostate from the inside. IDC-P is associated with high-grade disease and a higher risk of recurrence after treatment. It is often reported separately from the Gleason grading system.
• Cribriform pattern — This term describes a specific microscopic arrangement in which cancer cells form large, round clusters with holes, resembling a sieve. Cribriform Gleason grade 4 is considered more aggressive than other forms of grade 4 cancer. Its presence may influence treatment decisions.

If either of these features appears in your report, ask your doctor how it affects your treatment plan.

Understanding biopsy cores and tumour involvement

Because a biopsy takes tissue from multiple areas of the prostate, your report will provide information about how widely cancer is distributed across the cores that were taken. This helps doctors understand the extent of the disease before deciding on treatment.

Your report will typically include:

• The total number of cores taken.
• The number of cores that contain cancer (called positive cores).
• The percentage of each core that is involved in cancer.
• The total estimated percentage or millimeter length of cancer across all cores.

This information is important for treatment planning. For example, some active surveillance programs require that no single core have more than 50% cancer involvement as a condition of eligibility. A higher number of positive cores or a higher overall tumour volume suggests more extensive disease.

When cancer appears in separate, non-contiguous areas within a single core, pathologists may report tumour involvement in different ways—for example, by measuring the total combined length of cancer or by measuring the full span from one end of the cancer to the other. Both approaches are valid and may reflect the true extent of the disease differently.

Tumour volume after surgery

If your prostate was removed surgically (radical prostatectomy), the pathology report will include an estimate of the percentage of the prostate replaced by cancer, sometimes called tumour volume or tumour quantification. Larger-volume tumours are associated with a higher risk of recurrence. For a complete explanation of findings reported after prostatectomy, see our radical prostatectomy report guide.

Extraprostatic extension

Extraprostatic extension means that cancer cells have grown through the outer edge of the prostate and into the surrounding fatty tissue. The prostate gland lacks a true capsule, as many other organs do, but it has a well-defined outer boundary. When cancer cells are found beyond that boundary, it is called extraprostatic extension. This finding is associated with a higher risk of cancer recurrence and is used to assign a higher pathologic tumour stage (pT3a).

Seminal vesicle invasion

The seminal vesicles are two small glandular structures located just behind and above the prostate. They contribute fluid to semen. When cancer cells spread directly from the prostate into the seminal vesicles, it is called seminal vesicle invasion. This is considered a sign of more advanced local disease (pT3b) and is associated with a higher risk of recurrence after treatment.

Bladder neck invasion

The bladder neck is the area where the base of the bladder connects to the prostate. If cancer cells have grown from the prostate into the muscular wall of the bladder neck, this is reported as bladder neck invasion. It is also considered locally advanced disease (pT4) and is associated with a higher risk of recurrence.

Perineural invasion

Perineural invasion means that cancer cells are growing along the outside of a nerve. Nerves run throughout the prostate and into surrounding tissue, and cancer cells can travel along them like a highway, reaching areas beyond the main tumour mass. When perineural invasion is found, it raises the concern that cancer may have already spread slightly beyond where it appears on imaging. Its presence is taken into account in staging and treatment planning and is associated with a higher risk of disease recurrence.

Intraneural invasion — cancer cells growing inside a nerve — is a related but less common finding that carries similar significance.

Lymphovascular invasion

Lymphovascular invasion means that cancer cells have entered a blood vessel or lymphatic channel within the prostate tissue. Lymphatic channels carry fluid to nearby lymph nodes, and blood vessels circulate throughout the body. When cancer cells enter these channels, they have a route for spreading to distant organs or lymph nodes. Lymphovascular invasion increases the concern for systemic spread and is considered when determining prognosis and the need for additional treatment.

Surgical margins

Margins are assessed only when the entire prostate is surgically removed (radical prostatectomy). They refer to the edges of the tissue that was cut during surgery. A pathologist examines these edges to determine whether cancer cells are present at or near the cut surface.

• Negative margin (clear margin) — No cancer cells are present at the cut edge. This suggests the surgeon was able to remove all visible cancer.
• Positive margin — Cancer cells are present at the cut edge, meaning some cancer cells may remain in the body at the site of surgery. A positive margin increases the risk of cancer coming back locally and may lead your doctor to recommend additional treatment such as radiation therapy.

Reports often specify where a positive margin is located — for example, at the apex (tip) of the prostate, the bladder neck, or along the back surface (posterior margin). The extent of the positive margin (focal vs. extensive) may also be noted.

Lymph nodes

Lymph nodes are small immune organs located throughout the body. During surgery for prostate cancer, the lymph nodes near the prostate (pelvic lymph nodes) are sometimes removed and examined to check for cancer spread. This is called a lymph node dissection.

Your report will indicate whether any lymph nodes were sent for examination and whether cancer was found. A result of N0 means no cancer was found in the lymph nodes. A result of N1 means cancer cells were found in one or more lymph nodes, which is considered metastatic disease and influences both staging and treatment planning. If no lymph nodes were removed, the nodal stage will be listed as NX.

When cancer is present in a lymph node, the report may also mention the size of the cancer deposit and whether the cancer has broken through the lymph node’s outer wall into the surrounding tissue — a finding called extranodal extension.

Biomarker and molecular testing

Some pathology reports — especially for advanced or recurrent prostate cancer — include results from molecular or genetic tests. These tests look for specific changes in the DNA of cancer cells that may affect how the cancer behaves or how it responds to treatment. Not all patients will have these tests; they are most commonly ordered when the cancer is high-grade, has spread, or has stopped responding to standard hormone therapy.

Common findings you may see reported include:

• BRCA1 and BRCA2 mutations — These genes normally help cells repair damaged DNA. When they are mutated, cancer cells cannot repair DNA effectively. BRCA mutations in prostate cancer are associated with more aggressive disease and may predict a response to a class of drugs called PARP inhibitors. BRCA mutations can also be inherited, meaning family members may benefit from genetic counselling.
• PTEN loss — PTEN is a gene that normally acts as a brake on cell growth. Loss of PTEN function can lead to faster tumour growth. PTEN loss is detected by immunohistochemistry (IHC) and is associated with more aggressive tumours.
• ATM mutation — ATM is another DNA repair gene. Mutations in ATM can increase the risk of aggressive prostate cancer and may also predict sensitivity to certain DNA-damaging treatments.
• PALB2 mutation — PALB2 works alongside BRCA2 in DNA repair. Mutations may be associated with aggressive disease and potential responsiveness to PARP inhibitors.
• Androgen receptor (AR) variants — The androgen receptor is the protein that allows prostate cancer cells to respond to male hormones (androgens) like testosterone. In some men with advanced or treatment-resistant cancer, changes in the AR gene — particularly a variant called AR-V7 — can make cancer resistant to standard hormone-blocking drugs. Testing for AR variants helps guide the choice of systemic therapy.
• TMPRSS2-ERG fusion — This genetic rearrangement, found in approximately 40–50% of prostate cancers, occurs when two genes fuse in a way that drives cancer growth. Its presence can help confirm a diagnosis of prostatic adenocarcinoma and is the subject of ongoing research into its prognostic significance.
• Mismatch repair (MMR) and microsatellite instability (MSI) — A small subset of prostate cancers have defects in their DNA mismatch repair system. Tumours with this finding (called MMR-deficient or MSI-high) may respond to immunotherapy drugs called checkpoint inhibitors, which are not typically used for prostate cancer.

A full explanation of these and other biomarker tests used in prostate cancer is available in our Biomarkers and Molecular Testing section.

Pathologic stage (pTNM)

The pathologic stage describes the extent of the cancer based on what the pathologist finds in the tissue removed during surgery. It uses the internationally recognized TNM staging system, which evaluates three things: the primary tumour (T), lymph node involvement (N), and distant metastasis (M). Higher numbers indicate more advanced disease.

Note that pathologic staging applies only to surgical specimens. Biopsies are not staged in the same way.

Tumour stage (pT)

• pT2 — The cancer is confined entirely within the prostate gland.
• pT3a — Cancer has grown beyond the prostate into the surrounding tissue (extraprostatic extension), or into the bladder neck.
• pT3b — Cancer has spread into one or both seminal vesicles.
• pT4 — Cancer has invaded nearby structures such as the rectum, the pelvic floor muscles, or the external urinary sphincter (beyond the bladder neck).

Nodal stage (pN)

• pN0 — No cancer found in any lymph nodes examined.
• pN1 — Cancer found in one or more regional lymph nodes.
• pNX — No lymph nodes were removed or examined.

What is active surveillance?

Active surveillance is a management approach used for men with low-risk or very-low-risk prostate cancer — typically Grade Group 1 (Gleason 3+3=6). Because these cancers grow very slowly and are unlikely to cause harm in the near term, it is often reasonable to monitor them closely rather than treat them immediately. This avoids the side effects of surgery or radiation in patients who may not need treatment for many years, if ever.

Active surveillance typically involves:

• Regular PSA blood tests (often every 3–6 months).
• Periodic digital rectal examinations.
• Repeat prostate biopsies (usually every 1–3 years) to check whether the cancer has changed.
• Prostate MRI at regular intervals in some programs.

If a repeat biopsy shows that the cancer has increased in grade or volume, or if PSA rises significantly, treatment will typically be recommended at that point.

Prognosis

The prognosis for prostatic adenocarcinoma depends on several factors working together. No single finding tells the complete picture — your doctor will consider all of the following when discussing your outlook and options:

• Grade Group — The most important predictor of how the cancer will behave. Grade Group 1 cancers have an excellent prognosis; Grade Group 4–5 cancers carry a higher risk of recurrence and spread.
• Pathologic stage — Whether the cancer is confined to the prostate (pT2) or has spread locally (pT3–pT4) or to lymph nodes (pN1) significantly affects the likelihood of cure with surgery or radiation.
• Surgical margin status — A positive margin after prostatectomy is associated with a higher risk of biochemical recurrence (a rising PSA after surgery).
• Perineural invasion and lymphovascular invasion — Both are associated with a higher risk of advanced disease and recurrence.
• PSA level — The pre-treatment PSA level and how quickly it changes after treatment are important indicators of disease activity.
• Tumour volume — Higher tumour volume in biopsy cores or in the surgical specimen is associated with greater disease burden.
• Molecular features — Mutations in BRCA2, PTEN loss, and high Ki-67 expression are associated with more aggressive behaviour.

Overall, the majority of men diagnosed with prostate cancer — particularly those with localized disease — have an excellent long-term prognosis with appropriate treatment. Your treatment team will use all of the information in your pathology report to develop a management plan tailored to your individual situation.

Questions to ask your doctor

Your pathology report contains a lot of information, and it can be difficult to know what to ask. The following questions may help guide your next conversation with your doctor or specialist.

• What is my Grade Group, and what does it mean for my risk level?
• Is my cancer confined to the prostate, or has it spread to nearby tissue or lymph nodes?
• What is my pathologic stage (pT and pN)?
• Does my report mention perineural invasion, lymphovascular invasion, intraductal carcinoma, or a cribriform pattern — and how does that affect my treatment options?
• Are my surgical margins positive or negative? (If you had surgery)
• Am I a candidate for active surveillance, or is treatment recommended?
• Has any molecular or biomarker testing been done or recommended, such as BRCA testing?
• Should my family members be referred for genetic counselling, given my results?
• What is my PSA level now, and how will it be monitored going forward?
• What are my treatment options, and what are the risks and benefits of each?
• How often will I need follow-up appointments and tests?