Stages of prostate cancer

Diagnosis and detection

Early detection makes a difference in treatment outcomes and long-term health. Prostate cancer screening is typically the first step, to find prostate cancer before symptoms appear. The most common screening tools are the digital rectal exam and the prostate-specific antigen (PSA) blood test.

Early detection not only increases the chances of successful treatment but also allows for a wider range of treatment options tailored to your specific situation.

Screening Methods

Prostate cancer screening aims to identify cancer at an early stage, often before any symptoms develop.

The two main screening methods are the digital rectal exam and the PSA blood test. During a digital rectal exam, a healthcare professional examines the prostate gland through the rectum to check for lumps or irregularities. The PSA blood test measures the level of prostate-specific antigen in your blood – higher levels can be a sign of prostate cancer, but they could be other conditions like an enlarged prostate or infection.

How prostate cancer stages are determined

Prostate cancer staging describes how far the cancer has spread in the body. Stage is determined by a combination of test results, imaging tests and prostate biopsy results. The commonly used system for this is the TNM staging system(Tumour, Node, Metastasis).

Tumour (T)

This refers to the size and location of the tumour in the prostate gland or beyond:

• T1: The tumour is too small to be felt during a digital rectal exam or seen on imaging scans.
• T2: The tumour is confined entirely within the prostate.
  • T2a: It is in half or less of one lobe of the prostate gland.
  • T2b: It is in more than half of one lobe.
  • T2c: It is found in both lobes but hasn’t spread beyond the prostate.
• T3: The cancer has broken through the outer capsule of the prostate:
  • T3a: Spread through the outer capsule.
  • T3b: Spread into the seminal vesicles.
• T4: The cancer has invaded nearby organs, such as the bladder or rectum.

Node (N)

Node staging determines whether cancer cells have spread to nearby lymph nodes:

• N0: No cancer is found in the nearby lymph nodes.
• N1: Cancer found in one or more local lymph nodes.

Metastasis (M)

Metastasis describes whether cancer has spread to other parts of the body::

• M0: The cancer has not spread to other areas.
• M1: The cancer has spread beyond the prostate to distant lymph nodes, bones, or other parts of the body (called metastatic prostate cancer).
  • M1a: Spread to distant lymph nodes.
  • M1b: Spread to the bones.
  • M1c: Spread to other organs, such as the liver or lungs.

Localised, locally advanced and advanced prostate cancer

Prostate cancer falls into one of three categories based on its stage:

1. Localised (early): Cancer is contained entirely within the prostate (T1 or T2).
2. Locally advanced: Cancer has spread outside the prostate capsule but not to distant parts of the body (T3 or T4 with M0).
3. Advanced (metastatic): Cancer has spread to other areas, such as bones or organs (M1).

Understanding the clinical stage helps doctors recommend tailored treatment options.

https://www.cancerresearchuk.org/about-cancer/prostate-cancer/stages/tnm-staging

Diagnostic tools

Your doctor will use a combination of diagnostic tools to confirm the diagnosis and determine the cancer’s stage. These tools include imaging tests, biopsy samples, and lab tests.

Imaging tests, such as MRI or transrectal ultrasound, provide detailed pictures of the prostate and surrounding tissues, helping to pinpoint the location and size of any tumours. A prostate biopsy involves taking small samples of prostate tissue to look for cancer cells under a microscope.

Together, these diagnostic tools give the information needed to accurately stage the cancer and plan the most effective treatment.

Imaging tests

Imaging tests play a crucial role in the diagnosis and staging of prostate cancer. Techniques like transrectal ultrasound, MRI, and CT scans allow doctors to visualize the prostate gland and nearby tissues, helping to assess the size and extent of the tumor. These tests are also used to check if the cancer has spread to other parts of the body, such as lymph nodes or bones, which is especially important for identifying metastatic prostate cancer. The TNM staging system, developed by the American Joint Committee on Cancer, uses information from imaging tests to classify the cancer based on tumor size (T), involvement of nearby lymph nodes (N), and spread to distant parts of the body (M). In addition to imaging, the Gleason score and grade group—determined from biopsy samples—help assess how aggressive the prostate cancer cells are. Risk groups, such as those defined by the Cambridge Prognostic Group, further guide treatment decisions by combining stage, grade, and other factors. By using these advanced diagnostic tools and staging systems, your healthcare team can recommend the best treatment options for your individual situation, whether that means active surveillance, surgery, or other therapies, always considering your overall health and personal preferences.

Prostate cancer grading (Gleason Score and Grade Groups)

While staging describes the tumour’s spread, the grading system for prostate cancer evaluates how abnormal the prostate cells look under a microscope in biopsy samples. This helps predict how aggressive the cancer is and how quickly it might grow.

How the Gleason Score works

The Gleason score is based on the patterns of cancer cells in your prostate biopsy samples. These patterns range from 1 (normal-looking cells) to 5 (very abnormal, aggressive cells). Most prostate cancers involve two Grades (patterns), which are added together to give a Gleason score.

For example:

• Gleason score 3+4=7 means Grade 3 is more common, and Grade 4 is present.
• Gleason score 4+3=7 a greater weight on aggressive Grade 4 cells.

Grade Groups

Doctors simplify the Gleason score into Grade Groups for easier understanding:

• Grade Group 1 (Gleason 6): The cancer is slow-growing and less likely to spread.
• Grade Group 2 (Gleason 3+4=7): Slightly faster but generally still manageable.
• Grade Group 3 (Gleason 4+3=7): A higher proportion of aggressive cancer cells.
• Grade Group 4 (Gleason 8): Indicates more aggressive behaviour.
• Grade Group 5 (Gleason 9–10): Cancer is fast-growing and highly aggressive.

https://www.cancerresearchuk.org/about-cancer/prostate-cancer/stages/grades

How stage and grade affect treatment choices

The stage and grade of your prostate cancer shape your treatment plan. They are considered alongside other factors like age, general health and personal preferences.

Treatment by stage

Localised Prostate Cancer (Stage I or II)

• Treatment options: Active surveillance, surgery to remove the prostate (prostatectomy) or radiotherapy.

Locally Advanced Prostate Cancer (Stage III)

• Treatment options: Surgery or radiotherapy combined with hormone therapy to reduce testosterone that encourages cancer growth.

Advanced Prostate Cancer (Stage IV)

• Treatment options: Hormone therapy, potentially combined with chemotherapy or newer targeted drugs.

Individualised care

Your treatment plan isn’t solely based on staging and grading. Personal factors like age, overall fitness, and your willingness to manage potential side effects also shape decisions.