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Understanding Prostate Cancer

Understanding Prostate Cancer: Diagnosing, Grading and Staging

(Read time: 7 minutes) 

This article is not intended to replace professional medical care or advice. If you have any questions or need additional information, please talk with your doctor. 

A positive prostate cancer diagnosis can be a life-changing event. That’s why it’s so important to understand your treatment options. 

But with so many ways to fight prostate cancer, it can be overwhelming. That’s why we created this guide. It’s important to understand how prostate cancer is diagnosed and graded and how it can progress over time.  

Being well informed is your greatest weapon in the fight against cancer. With a diagnosis as serious as cancer, you owe it to yourself to be informed and consult with as many cancer experts as possible to get multiple perspectives on your case. 

Here is what you need to know about the risk factors for prostate cancer, as well as how it is diagnosed, graded, and staged. 

How prostate cancer is diagnosed 

The process of discovering and diagnosing prostate cancer is different for every patient. Not all men have the same indicators that would prompt their doctor to suspect a prostate cancer diagnosis. This is why it’s common for multiple tests to occur to not only rule out other common conditions of the prostate, but to also definitively diagnosis the disease and stage. 

Medical technology is constantly evolving, giving doctors an ever-growing arsenal of tools to understand the wide range of conditions the human body can experience. So, even when prostate cancer is the suspected diagnosis, there is a battery of confirmation tests that can be performed. 

These run the gamut from preliminary cancer detection screenings to prostate cancer confirmation tests to tests that determine whether the cancer has spread, according to the American Cancer Society. 

In addition to a physical exam, a digital rectal exam (DRE), and a prostate-specific antigen (PSA), a blood test may be performed by the patient’s physician. If the results of these tests indicate signs of prostate cancer, the next round of testing may begin. PSA levels are often monitored over time, and for some, over the course of several years. Changes in PSA levels may warrant further testing for cancerous cells. 

Typically, a cancer detection test will be done in conjunction with a biopsy, which surgically removes a small portion of the prostate tissue for testing. Unlike other prostate cancer screenings, a biopsy is the sole test that can accurately confirm a diagnosis, according to the American Society of Clinical Oncology (ASCO). 

What if you are at low risk for prostate cancer? 

If your doctor determines you’re at low risk, the full gamut of tests may not be necessary. For some patients who are at lower risk of prostate cancer, active surveillance may not require a biopsy, which is more invasive than the PSA blood test. In these cases, imaging tests such as MRIs and ultrasound methods may be used to detect prostate cancer, find potential spread of prostate cancer, and provide additional visuals for physicians in the event a biopsy is indicated. 

For instance, the MRI fusion method, , allows a urologist to use advanced technology to see inside the prostate gland by combining the images from a recent MRI with the images being received from a transrectal ultrasound (TRUS) procedure.. First, the MRI will indicate to the physician any areas that look abnormal. Then the areas that are suspected of being cancerous can be quickly targeted and accurately biopsied with ultrasound imaging. 

After prostate cancer has been confirmed, doctors may want to perform further image testing to see if it has spread, according to ASCO. These include additional MRIs, CT or CAT scans, and bone scans. 

How is prostate cancer graded? What is a Gleason score? 

After a positive diagnosis, a pathologist will review the biopsy under a microscope and assign two grades to each prostate cancer patient:  

  1. A primary grade for the cells that make up the largest part of the tumor, and 
  2. A secondary grade for the next largest area. 

The score for each cell group is on a scale of 1–5 as follows: 

  • Grade 1: Small, uniformed cells tightly packed together 
  • Grade 2: Varying cell sizes and shapes, loosely packed together 
  • Grade 3: Increased cell size and shape irregularity 
  • Grade 4: Large, irregular and fused cells 
  • Grade 5: Irregular, fused cells that have joined surrounding tissue cells 

These two scores are added together to provide the Gleason score. This combined score is on a scale of 2–10 (1–5 from the primary group + 1–5 from the secondary group). A healthy tissue receives a low score and abnormal tissue receives a higher score. A combined Gleason score of 6–10 indicates cancer. 

For example, if a patient had a score of 3 in the primary cell group and a score of 4 from the secondary cell group, his Gleason score would be 7 out of 10, which means that he has intermediate-grade prostate cancer. 

What are the 3 stages of prostate cancer? 

In addition to the Gleason score, a prostate cancer patient’s biopsy also provides information about the stage of prostate cancer they are experiencing. Staging is very important because it helps determine treatment options and can be an important tool for determining future prognoses. 

According to the American Cancer Society (ACS), the TNM staging system is the most common approach used to stage prostate cancer among patients in the U.S. This scale used to determine how far prostate cancer has spread within and beyond the prostate using five key pieces of information including PSA level, Gleason score, and three category, or stage, classifications.  

T-stage classifications

There are two types of T classifications, the clinical stage and the pathological stage, both of which describe the primary tumor. Needle biopsies, transrectal ultrasounds, and DREs determine the clinical stages.  

T-stage classifications are used to determine the course of treatment: 

  • T1: These tumors are not felt during a DRE. Instead, they are found when a transurethral resection of the prostate is performed to check for benign prostatic hyperplasia (BPH), a growth of the prostate that is non-cancerous. 
  • T2: These tumors can be felt during DRE. This describes cancer that is believed to be confined to the prostate gland, and whether tumors are found only in one lobe (T2a) or both lobes (T2b). 
  • T3: Describes cancer that has spread outside the prostate (T3a), or to the seminal vesicles (T3b). 
  • T4: This stage indicates that the prostate cancer tissue has sprea to surrounding tissue, and is the highest grade of T-stage classification. 

N-stage classifications

N stage classifications for prostate cancer describe the presence, or absence, of metastasis to surrounding lymph nodes. There are three levels in the N stage: 

  • N0: If the cancer cells have not spread to surrounding lymph nodes 
  • N1: If cancerous cells have spread to one or more lymph nodes in the pelvic region 
  • Nx: When lymph nodes in the area are unable to be assesse 

M-stage classifications

There are also three levels in the M stage, which declares the presence or absence of distant metastasis beyond the prostate: 

  • M0: Describes cancer that has not spread beyond the regional lymph nodes 
  • M1: Metastases have been found in distant lymph nodes as well as bones and organs 
  • Mx: When distant metastases cannot be assessed 

Once the diagnosing, grading, and staging of prostate cancer has been completed, the next step is to hone in on your treatment option. 

So what does this all mean for me? 

You’re probably wondering how much of this you’re going to remember after reading this article, and what you need to ask your doctor. Fortunately, there’s an easier way to understand your situation if you’ve been diagnosed with prostate cancer. 

The National Comprehensive Cancer Network (NCCN) developed four risk-group categories for prostate cancer, which incorporate your PSA level, prostate size, needle biopsy results, and your stage of prostate cancer:  

  • Very low risk: Prostate cancer tumors cannot be felt during a DRE and are not seen during imaging tests. PSA levels are less than 10 ng/mL with a Gleason score of 6 or less.
  • Low risk: Tumor classified as T1a, T1b, T1c, or T2a and is confined to the prostate. PSA level is less than 10 ng/mL and Gleason score is 6 or less. 
  • Intermediate risk: Has two or more of the following characteristics: T2b or T2c classification, PSA between 10 and 20 ng/mL, and a Gleason score of 7. Tumor is confined to the prostate.
  • High risk: Has two or more of the following characteristics: T3a classification, PSA higher than 20 ng/mL, and a Gleason score between 8 and 10. Tumor extends outside of the prostate.
  • Very high risk: Tumor classified as T3b or T4. The main cancerous cell group has a grade of 5, and more than four biopsy cores have Gleason scores between 8 and 10.  

Understanding the grade and stage of a tumor can aid in the decision-making process and help you arrive at a more personalized treatment plan.  

Get a diagnosis and a second opinion 

If you or a loved one you know suspects they may have prostate cancer, it’s never too early to get a diagnosis. 

In fact, early detection is one of the best tools in the fight against prostate cancer. Ask your physician for a checkup and actively discuss your concerns with them. 

If you don’t have a physician or would like to speak with a specialist, use our free Physician Finder tool to schedule an appointment today: 

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Get started by entering your ZIP Code and click submit. You will be redirected to a map view showing you the nearest doctors to your location.
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  6. Prostate Cancer Foundation. (2019). What is a Gleason Score? | Prostate Cancer Foundation. [online] Available at: https://www.pcf.org/about-prostate-cancer/diagnosis-staging-prostate-cancer/gleason-score-isup-grade/ [Accessed 23 Aug. 2019].
  7. Cancer.org. (2019). Prostate Cancer Stages. [online] Available at: http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-staging [Accessed 23 Aug. 2019].
  8. UCSF Medical Center. (2019). Patient’s Guide to Prostate Cancer: Formal Diagnosis, Grading and Staging. [online] Available at: https://www.ucsfhealth.org/education/patients_guide_to_prostate_cancer/formal_diagnosis_grading_and_staging/ [Accessed 23 Aug. 2019].
  9. Nccn.org. (2019). [online] Available at: https://www.nccn.org/about/news/ebulletin/ebulletindetail.aspx?ebulletinid=666 [Accessed 23 Aug. 2019].
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