Prostate cancer has four basic stages which are
- Stage 1: the cancer is very small and completely inside the prostate gland which feels normal when a rectal examination is done
- Stage 2: the cancer is still inside the prostate gland, but is larger and a lump or hard area can be felt when a rectal examination is done
- Stage 3: the cancer has broken through the covering of the prostate and may have grown into the neck of the bladder or the seminal vesicle
- Stage 4: the cancer has spread to another part of the body
How prostate cancer tends to spread
Prostate cancer tends to spread to the bones rather than any other organs.
Sometimes these stages are called A - D (with A being Stage 1), particularly if you are being treated in North America where the system is called the Dukes'-Jewett Staging System.
With prostate cancer, it is sometimes possible for there to be metastases (cancer spread) present even when the prostate tumour is still very small. So even if the tumour appears to be very small, but the bone scan shows that there is cancer in the bones, then the prostate cancer is Stage 4.
TNM stages of prostate cancer
For their records, doctors use a slightly more complicated staging system called the TNM system. This is used all over the world. It separately assesses the tumour (T), lymph nodes (N) and secondary cancer or metastases (M).
This is the T (tumour) staging:
- T1 The tumour is too small to be seen on scans or felt during examination of the prostate. (It has been discovered by needle biopsy.
- T2 The tumour is completely inside the prostate gland
- T3 The tumour has broken through the capsule (covering) of the prostate gland
- T4 The tumour has spread into other body organs (secondary prostate cancer) nearby such as the rectum (back passage) or bladder
Lymph nodes are described as being 'positive' if they contain cancer cells. If a lymph node has cancer cells inside it, it is usually bigger than normal. The more it is affected by the cancer, the bigger it will be.
This is the N (lymph node) staging
- N0 No cancer cells found in any lymph nodes
- N1 One positive lymph node smaller than 2cm in greatest dimension
- N2 One positive lymph node that is between 2 and 5cm or multiple positive lymph nodes less than 5cm
- N3 Any positive lymph node that is bigger than 5 cm
This is the staging for metastases (cancer spread)
- M0 No distant metastasis
- M1 Distant metastasis
So, a cancer described as T2 N0 M0 would be
- a cancer that is entirely within the prostate
- with no cancer spread to lymph nodes
- or outside the pelvis
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