Like other cancers, prostate cancer can spread (metastasis) from the site of where it first started to other sites of the body. Once it spreads, the disease may still respond to the treatment, but typically it is now no longer to be cured. Bones, liver, and lungs are the most common sites for prostate cancer metastasis. How do you know that it has spread? And how fast this metastasis?
Since the early detection of the disease is very crucial for the prognosis and outlook of patients (because the disease is much more difficult to treat once it spreads (at advanced stages), it’s very important to diagnose the disease as early as possible.
In the U.S, the number of men diagnosed with the disease at later stages decreases drastically due to the implementation of PSA (prostate specific antigen) screening test .
The PSA test is also recommended in other countries (such as UK and Canada). However whether this test is necessary for all men is debatable.
For those who eventually don’t have prostate cancer in their life, the choice to take the test may put them at high risk of getting over-diagnosis, making anxiety more likely.
Therefore, some experts agree that the screening prostate cancer test is more recommended for those who have some /many risk factors of the disease. For more advice, consult more with your GP!
How prostate cancer is diagnosed?
There are several procedures and tests that need to be performed by doctors before making diagnosis. These may include :
PSA screening test
Prostate specific antigen is a kind of protein produced by prostate cells (both for normal and abnormal cells). The elevated level of PSA may signal the existence of abnormal growth, which could be a benign tumor (non-cancerous) and cancerous tumor.
However there are also patients with prostate cancer who don’t have significant elevated levels of PSA.
At first, the specialist may need to do it manually (by putting a gloved finger into the rectum) to find any signs (such as hard prostate or lumpy) that point to the abnormal condition of prostate gland.
Then if necessary, the specialist may need to perform an ultrasound scan. This is purposed to examine the gland of prostate. Before taking the test, your specialist asks you to get a bowel movement so thus your rectum is empty.
This test uses an appropriate sound wave to create more detailed picture of your prostate gland.
If there is a lump /hardening of prostate gland, you may need to take a biopsy test, a procedure to take a sample of tissue /cells (a biopsy) which then will be closely analyzed and examined under a special microscope to determine whether or not these cells are cancerous cells.
There are several options to take a biopsy. But in many cases, specialists take it through the rectum of patient. Sometimes, it’s removed from the skin behind testicles.
If the result of your biopsy doesn’t point to the existence of cancerous cells, but your specialist still believe that there may be a small cancer of prostate – you may be suggested to take another special biopsy test called ‘transperineal template biopsy’. This additional test is more accurate to find small prostate cancer cells that may be missed by your previous biopsy.
IVU or IVP – Intravenous urogram
It is less common to be used in diagnosing prostate cancer. But it may bes suggested if you have difficulties associated with urination or symptoms of a blockage /problem associated with the kidneys.
See also how cancer of prostate affects the male urinary system in this section!
How quickly and fast does prostate cancer spread?
The answer is usually dependent on the following variables :
The level of PSA (prostate specific antigen) in the blood of patient when the diagnosis of his cancer was made. Low level of PSA may point to less quickly of cancer to spread than high level of PSA. However this is not always proportional – there are also a few patients with low PSA have an aggressive prostate cancer.
But in general, patients with higher level of PSA are more likely to have cancer that grows and spreads more quickly.
The Gleason score, also called as the grade of the cancer, can give more accurate result in predicting how quickly prostate cancer spreads.
The score consists of 1 (the lowest grade) to 5 (the highest grade). But there are also some doctors who give the range of Gleason score from 1 to 10. In essence, higher score points more quickly metastasis, while cancer with lower score is likely to grow and spread more slowly.
The Gleason score is also important for the outlook of patients. It’s usually taken into account to determine the treatment plan.
For instance, doctor may recommend ‘active monitoring’ (only watching & waiting) for an older man with early stage of prostate cancer and 2-6 of Gleason score (this range is categorized low grade). In such case, the cancer is more likely to grow slowly and there is also a little chance for it to spread. As a result, there may be no any significant problem that can be caused by the cancer.
But for patients with 8-10 Gleason score and also have advanced stage of cancer, active treatments are usually necessary to kill the cancer and eliminate the risk of metastasis.
How do you know if prostate cancer has spread?
Cancer that has spread is more likely to generate more complications than when it is still at its early stage. So it’s important to know its symptoms when it has become advanced.
For instance, if it has spread to the bones – you may experience bone pain. The growth of cancerous tumor at advanced stage may also block the small tubes that carry urine to the bladder from the kidneys. It may also become severe enough to lead to a drastic weight loss.
However, the diagnosis of whether or not it has spread is not enough from the complications or symptoms that are present.
After making diagnosis of the disease, doctors need to perform several further tests to get to know the stage of cancer – whether it is still completely in the prostate or has spread (if so, how far it has spread). The process of staging is very crucial, because it can affect your treatment plan.
The following are some further tests to determine the stage of the disease and how far the cancer has spread:
X-ray test is one of the most common choices for imaging test. In general, it is purposed to examine the overall health of patient. It is also often used before performing certain surgery.
Since bone is the most common site of prostate cancer metastasis, performing bone scanning test is often the first priority after you are diagnosed with cancer of prostate – particularly true if you also have high level of PSA and higher Gleason score!
The result of bone scanning can be used to find hot spots of the bones – these spots usually signal the most active bone cells in repairing the damaged bone. However, having some hot spots doesn’t mean that the cancer has definitely spread to the bone, because they also can form due to arthritis or old fractures. But doctors can analyze the pattern of these hot spots to determine whether they occur due to cancer or other health conditions.
If necessary, doctor may need to perform X-ray test on these hot spots to help diagnose the existence of cancer in the bones.
CT & MRI scans
These tests are used to detect the existence of abnormal cells in the nearby lymph nodes. You may also need to take these tests before going to have radiotherapy (in curing & killing the prostate cancer) and before certain surgery (such as surgery to remove prostate if required).
Abdomen ultrasound test
This test uses the energy of sound waves to produce a more detailed picture of certain sites inside the body. With the result of this abdominal ultrasound test, doctor can analyze how well the bladder and kidneys works.
Stage I, II, III, and IV of prostate cancer
In general, prostate cancer are grouped into 4 major stages. The following are some explanations about these stages :
Stage I – the earliest stage! For this category, the cancer is still very small and doesn’t spread (completely inside the gland of prostate). Overall it is the most treatable stage, but also the most difficult stage to diagnose (during rectal examination, the existence of cancer at stage 1 is often missed).
Stage II! The cells of cancerous tumor still don’t spread, but the tumor looks larger in size. Typically, doctor can feel hard area or a lump during a rectal examination – in other words, stage II is relatively easier to be detected than stage I.
Stage III! The cancer cells have broken through covering of the gland of prostate. It may also have spread and grown in the small tubes that carry semen. This stage is usually also considered into ‘locally-advanced-disease’.
Stage IV! It is the most advanced stage. The cancer now has spread and grown in the nearby sites /organs (particularly such as rectum and bladder). Once it spreads, it can go far away from the original site – as a result, lymph nodes or other distinct sites /organs of the body (particularly such as bones, lungs, and liver) can be affected by the cancer.
Another staging system to classify how prostate cancer progresses is TNM-system.
‘T’ consists of T1 to T4, which used to describe the size and characteristic of tumor.
‘N’ variable consists of Nx, N0, and N1, which points the stage of cancer that spread to the lymph nodes.
And for ‘M’ (it consists of M0 and M1), it describes of when the cancer hasn’t spread (M0) and has spread (M1).
From the picture above, we can see that the cancer is still completely inside the prostate at T1 to T2. Then at T3, the cancerous tumor begins to broke and spread to the covering (capsule) of the prostate gland (this phase is categorized into ‘T3a’) – and then it may also spread into two glands at the base of male bladder (if so, this phase is classified into the next phase of T3 called ‘T3b’).
And for T4, the cancerous tumor has spread into nearby sites (these may include nearby muscles, bladder, rectum, and pelvic cavity).
Where does prostate cancer usually spread?
Once it spreads to the nearby sites, there is a chance for the cancerous cells to spread to other distinct organs.
As mentioned before, bone is the most common distinct site that often affected by this cancer ! After bones – lungs and liver are other common distinct organs of its metastasis.