Prostate Cancer Grading

If prostateThe prostate is a walnut-sized gland located between the bla... Full Definition cancerCancer is a group of diseases where cells grow abnormally an... Full Definition is suspected based on a PSA test and digital rectal exam, your doctors will want to learn more about the disease. Some doctors may recommend a prostate biopsy right away, but be sure to discuss all of your options before deciding if that is right for you. For example, there is some emerging data that MRI-guided biopsies are better at targeting aggressive cancer. And a study published in respected medical journal The Lancet, showed that MRI without a biopsyAn examination of tissue removed from the body to understand... Full Definition was more effective at finding prostate cancer than traditional methods, not to mention less invasive. With new research and new tests appearing all the time, it makes sense to take a deep breath and weigh your options. While these procedures are not yet standard, you may want to discuss them with your doctor before making a final decision.

If a biopsy is performed, your urologistA doctor who specializes in the urinary and male reproductiv... Full Definition will insert thin needles into the prostate and remove small samples of tissue. The procedure is intimidating, but your doctor will make every effort to keep you comfortable. The procedure is typically performed under a nerve block, and, if you are nervous, it’s okay to discuss the pros and cons of additional sedation with your doctor. You are also likely to receive a prophylactic antibiotic to help prevent infection, which is the biggest risk of the biopsy. There is virtually no risk (less than 1%) that this procedure will disturb or spread the cancer. The cells are simply removed and placed on slides so that a pathologistA doctor who focuses on the diagnoses of disease based on la... Full Definition can look at them under a microscope.

The pathologist will look for signs that the cells aren’t normal. The results aren’t black and white. In fact, the pathologist interprets what he or she sees and assigns a score, called a Gleason ScoreA system of grading and staging prostate cancer based on eva... Full Definition. This score tells you and your doctor a lot about your cancer.

Continued Below

1 in 7

Doctors call this process “grading” the cancer. Most pathologists in the US do not assign scores of less than 6. Cancers with a Gleason Score of 6 are considered low-grade. A Gleason Score of 7 indicates an intermediate grade and Gleason Scores of 8 to 10 are high grade cancers.

The Gleason Score is actually two scores in one. Cancer tends to be heterogeneous, which means that the cells are not consistent. Some cells might be very abnormal while others only slightly. So pathologists look at all the core samples and assign a primary grade to the most common cellular pattern they see and a secondary grade to the next most common pattern. The total Gleason Score is the sum of these two grades.

Your doctor will use this score, along with the number of core samples, percentage of cancer in each core, and other test results, to accurately gauge cancer risk level. For example, compare these two patients. Despite having the same Gleason Score (7), the second patient has more of the grade 4 pattern, as well as the higher PSA and therefore the more concerning cancer.

Patient 1
Patient 2
Gleason Score3+4 (7)4+3 (7)
Biopsy5% cancer in 1 out of 12 cores80-90% cancer in 12 out of 12 cores
Digital Rectal Exam (DRE)NormalNormal
PSA Test815

Prostate Cancer Staging

Another way doctors evaluate prostate cancer is by determining its size and how far it has spread. This is called “staging.” Early-stage tumors are small and localized, meaning they are still in the local area of the prostate. Later stages are larger, with the latest stages indicating cancers that have spread outside of the prostate, into lymph nodesSmall organs in the lymphatic system that filter lymph and p... Full Definition, into the bone or other organs.

The stage of cancer is typically determined using the biopsy in combination with some form of imaging, such as CT scans, X-rays, MRI imaging, and bone scans. In prostate cancer, the digital rectal exam is also included in the staging. Additionally, during surgery to remove the prostate, the surgeon may remove lymph nodes for testing to determine if the cancer has spread.

Cancer that is only in the prostate is staged from T1 to T4, depending on the size of the tumorA lump or swelling caused by abnormal growth of cells. Not a... Full Definition and whether or not it has spread to other tissues. Metastatic disease, which is cancer that has spread outside the prostate, is staged from N1 to M1c.


T (tumor)

T1: Tumor cannot be detected through digital rectal exam (DRE) or seen with imaging
T1a: Cancer found incidentally in resected specimen and is no more than 5% of tissue removed
T1b: Cancer found in resected specimen and is 5% or more of the tissue removed
T1c: Cancer found by needle biopsy that was done due to elevated prostate-specific antigen
T2: Tumor detected through DRE or seen with imaging and is confined within prostate
T2a: Cancer is in less than one half of only one lobe of the prostate
T2b: Cancer is in more than half of only one lobe of the prostate
T2c: Cancer is in both lobes of prostate
T3: Tumor has grown outside of the prostate, potentially into seminal vesiclesSmall glands that sit on top of the prostate that add nutrie... Full Definition
T3a: Cancer extends outside the prostate, but not into seminal vesicles
T3b: Cancer has invaded seminal vesicles
T4: Tumor has invaded tissue next to prostate other than seminal vesicles

N (node)

Nx: Regional lymph nodes cannot be assessed
N0: Cancer has not spread to regional lymph nodes
N1: Cancer has spread to regional lymph nodes

M (metastasis)

Mx: Presence of distant metastasisThe development of a secondary growth away from the primary ... Full Definition cannot be assessed
M0: Cancer has not spread to regional lymph nodes
M1: Cancer has spread beyond regional lymph nodes
M1a: Cancer has spread to non-regional lymph nodes
M1b: Cancer has spread to bone
M1c: Cancer has spread to other organs


Prostate Cancer Risk Categories

While doctors use grading and staging to evaluate prostate cancer, treatment decisions are often guided by a combined assessment of the PSA tests, the stage, rectal exam results, imaging studies and the general health and age of the patient.

Risk categories used to drive decisions:
Low Risk: Low risk, or indolent, prostate cancer is unlikely to grow in the near future. Doctors will likely discuss a treatment strategy that includes active surveillance with regular monitoring of the disease. If it begins to grow and change, treatment begins. About 30% of men decide to pursue treatment 3-5 years into active surveillance either because the disease has become higher risk or by choice.

Studies suggest that men with low risk disease who chose active surveillance do well. One study of men with localized prostate cancer compared prostatectomySurgical removal of all, or part, of the prostate., radiotherapyTreatment that uses ionizing radiation to kill cancer cells.... Full Definition, and active surveillance and found all three treatments had similar 10-year outcomes. This means the majority of patients with low risk tumors, regardless of which treatment method they chose, were alive 10 years later.

Other options include surgery to remove the prostate, which cures the disease but comes with a risk of side effects including urinary troubles and problems getting an erection. Some medical centers also offer local treatments, such as radiationHigh-energy particles that cause ionization and tissue damag... Full Definition therapy (including brachytherapyA form of radiotherapy where small radioactive implants are ... Full Definition, intensity modulated radiation therapy, and radiosurgery with the CyberKnife®), focal laser ablationThe removal of small amounts of tissue from the body using s... Full Definition, or high-intensity focused ultrasound (HIFU). These treatments also carry the risk of side effects.

Intermediate Risk: Intermediate risk prostate cancer presents doctors and patients with more of a grey area. Doctors may discuss active surveillance with patients who fall on the lower end of intermediate risk. However, most men with intermediate risk cancer need treatment, especially those at the higher end of the scale. Most men who opt for treatment for intermediate risk cancer are treated with either radiation therapy or prostatectomy.

If a man wishes for active surveillance with intermediate risk cancer some medical centers use strict criteria for recommending active surveillance. Some medical centers encourage young men with large tumors to have treatment because it is a lifesaving intervention for a disease that is likely to advance and become incurable in their lifetime.

There isn’t a lot of scientific data available about men with intermediate risk disease who choose active surveillance, so it isn’t clear if they do better, worse, or the same as men who choose treatment. One of the biggest challenges in prostate cancer care today is finding new ways to differentiate slow-growing from fast-growing disease. The search is on for better markers that will help doctors tell the difference between cancer that does not need immediate treatment and cancer that should be treated more aggressively.

High Risk / Very High Risk: High risk prostate cancer is likely to grow or spread in the near future. Urologists will typically involve medical oncologists and/or radiation oncologists on the care team because these patients have a higher risk of needing radiation and/or drugs after surgery or they are not surgical candidates and radiation or medications are best for them. These cancers are also harder to cure. One dilemma doctors face in recommending a treatment strategy for high risk prostate cancer is whether to recommend surgery or radiation.

For older men who have other health problems, surgery may be too risky, so radiation may be preferred. Also, for men with later stage disease that has already spread beyond the prostate, surgery may be more difficult and lead to higher rates of complications such as urine leakage and erectile dysfunction.

Radiation may cause a different set of side effects than surgery, such as damage to the rectumThe final section of the large intestine, which ends at the ... Full Definition that can cause pain and trouble controlling bowel movements, blood in the urine, blood in the stool, and discomfort or frequency of urination. Urinary leakage is less common and erectile dysfunction rates depend on what treatment your care team has planned.

There are few studies that have compared surgery to radiation for high risk patients. Those that have been done are outdated because technology for both surgery and radiation have improved dramatically over time.