Rare prostate cancer

About rare prostate cancers

Although prostate cancer is a common cancer in men, there are different types of prostate cancer. Some types of prostate cancer are rare. Because they are rare, there hasn’t been much research, so we don’t know much about them. Rare types of prostate cancer include:

If you are diagnosed with one of the cancers mentioned here, speak to your doctor or nurse about what that means and what treatments are suitable for you.

Like most things in our body, the prostate is made up of different types of cells. The type of cancer that develops depends on the cell it starts in.

The most common type of prostate cancer starts in some of the cells that line the prostate, called glandular epithelial (gland) cells. When we talk about common prostate cancer here, we mean this type of prostate cancer. Rarer types of cancer can also develop from gland cells, or from other types of cells in the prostate.

Some men have more than one type of prostate cancer. For example, they may have some common prostate cancer mixed with a rare prostate cancer at the same time.

Some of the rare cancers may be more aggressive than common prostate cancer. This means they may grow faster and are more likely to spread to other parts of the body.

Diagnosing rare prostate cancers

Rarer prostate cancers can be harder to diagnose. For example, some don’t cause your prostate specific antigen (PSA) level to rise. This means they’re not always picked up by a PSA test. Because of this, some rare cancers may not be diagnosed until they have already spread outside the prostate. Read more about the PSA test and other tests used to diagnose prostate cancer.

Some rare prostate cancers may only be picked up after having a biopsy to check for prostate cancer, or surgery called transurethral resection of the prostate (TURP) to treat an enlarged prostate. The tissue removed during the biopsy or TURP is looked under a microscope to see if you have common prostate cancer or a rare type of prostate cancer. Rare cancers aren’t always given a Gleason score after a biopsy. This is because they can behave differently to common prostate cancer and can’t be measured in the same way.

Because rare cancer can be aggressive and spread outside the prostate, you will probably have more tests to see if they have spread. These include:

Neuroendocrine prostate cancers

Neuroendocrine prostate cancers develop from neuroendocrine cells in the prostate. Different types of neuroendocrine prostate cancers include:

Small cell prostate cancer

Small cell prostate cancer is the most common neuroendocrine prostate cancer. Most men who have small cell prostate cancer also have common prostate cancer at the same time. And it’s most common in men who’ve had hormone therapy for normal prostate cancer. Small cell prostate cancer is aggressive and can spread quickly to other parts of the body.

Neuroendocrine cells don’t produce PSA, so a PSA test won’t help to diagnose small cell prostate cancer. And it won’t be used to monitor it.

Most small cell prostate cancers are diagnosed when they have already spread to other parts of the body (advanced prostate cancer) and are causing symptoms. This means you’ll need the following tests to diagnose small cell prostate cancer.

If you have both small cell prostate cancer and common prostate cancer, you will have a combination of treatments including chemotherapy, radiotherapy, and hormone therapy.

If you have small cell prostate cancer on its own, you probably won’t be given hormone therapy as it’s unlikely to help. But you may be offered a combination of treatments, including chemotherapy, radiotherapy and surgery.

In the UK, docetaxel (Taxotere®) is the standard chemotherapy drug for men with advanced prostate cancer that is no longer responding to hormone therapy. But if you have small cell prostate cancer you may have other types of chemotherapy, called carboplatin or cisplatin chemotherapy. You will have these together with another chemotherapy  drug, such as docetaxel or etoposide.

Your doctor or nurse will tell you what treatment options are available to you.

Large cell prostate cancer

Large cell prostate cancer is very rare. Because of this, we don’t yet know how it develops, or the best ways to treat it.

It is aggressive and can spread quickly to other parts of the body. Most men who have large cell prostate cancer also have common prostate cancer at the same time. And it’s most common in men who’ve already had hormone therapy for normal prostate cancer.

Because neuroendocrine cells don’t produce PSA, most men with large cell prostate cancer have a low PSA level. So a PSA test can’t be used to diagnose or monitor your cancer. But if you have both large cell prostate cancer and common prostate cancer at the same time, you may have higher PSA levels. More research is needed before we can know whether PSA tests can help to diagnose large cell prostate cancer mixed with common cancer.

Most large cell prostate cancers are diagnosed when they have grown large enough press against the urethra (the tube you urinate through), which can cause difficulty urinating (weeing). So large cell prostate cancer is often diagnosed when men have surgery called transurethral resection of the prostate (TURP) to treat their urinary problems. Tissue removed during surgery is looked at under the microscope to confirm you have large cell prostate cancer. You will also need scans to see if your cancer has spread.

Most men with large cell prostate cancer have chemotherapy . You may also be offered surgery and radiotherapy, depending on how much the cancer has grown and spread.

If you have both large cell prostate cancer and common prostate cancer at the same time, you may be offered hormone therapy as well as chemotherapy.

Your doctor or nurse will tell you what treatment options are available to you.

Glandular prostate cancers

Like common prostate cancer, some rare prostate cancers can develop from glandular epithelial (gland) cells in the lining of the prostate. They include:

You may hear them called adenocarcinomas. These can be mixed with common prostate cancer.

Ductal prostate cancer

You may also hear this called ductal adenocarcinoma. Ductal prostate cancer is aggressive and can spread quickly to other parts of the body. Most men who have ductal prostate cancer also have common prostate cancer at the same time. Ductal prostate cancer is usually more aggressive than common prostate cancer, and it’s more likely to come back after treatment.

Although glandular epithelial cells produce PSA, men with ductal prostate cancer often have normal PSA levels. So men are often diagnosed when the ductal prostate cancer has already spread out of the prostate.

Ductal prostate cancer usually grows close to the urethra, which is the tube you urinate (pee) through. Because of this it can cause the urethra to narrow, which can cause difficulty urinating and blood in your urine. So ductal prostate cancer is often diagnosed when men have surgery called transurethral resection of the prostate (TURP) to treat their urinary problems. Tissue removed during surgery is looked at under the microscope to confirm you have ductal prostate cancer. You will also need scans to see if your cancer has spread.

Treatment for ductal prostate cancer depends on whether your cancer has grown and spread to other parts of your body. Possible treatment options include:

Your doctor or nurse will tell you what treatment options are available to you.

Mucinous prostate cancer

You may also hear this called mucinous adenocarcinoma. This type of prostate cancer is very rare and most men who have it usually also have common prostate cancer at the same time. Like other rare cancers, there isn’t much research on mucinous prostate cancer, so we don’t yet know the best ways of diagnosing and treating them. Even though mucinous prostate cancer can spread to other parts of the body, recent research shows most mucinous prostate cancers may be slow-growing.

Like common prostate cancer, mucinous prostate cancer can cause the levels of PSA in the blood to rise. So a PSA test can be used to diagnose it. However, this rise in PSA is more likely if your cancer has spread to other parts of the body.

You will need to have a biopsy to confirm you have mucinous prostate cancer. You will also have scans to see if your cancer has spread.

Like common prostate cancer, treatment for mucinous prostate cancer will depend on whether the cancer has spread outside the prostate. Treatments can include:

Your doctor or nurse will tell you what treatment options are available to you.

Your doctor or nurse will tell you what treatment options are available to you.

How it’s diagnosed

Like common prostate cancer, mucinous prostate cancer can cause the levels of PSA in the blood to rise. So a PSA test can be used to diagnose it. However, this rise in PSA is more likely if your cancer has spread to other parts of the body.

You will need to have a biopsy to confirm you have mucinous prostate cancer. You will also have scans to see if your cancer has spread.

Signet ring cell prostate cancer

You might also hear this called signet cell prostate cancer or signet ring cell adenocarcinoma. Signet ring cell cancer can be very aggressive and spread to other parts of the body.

Like common prostate cancer, signet ring cell prostate cancer can produce high levels of PSA. This means a PSA test can be used to help diagnose signet ring cell prostate cancer. But a biopsy is needed to confirm it is a signet ring cell cancer.

If your biopsy shows that you have signet ring cell cancer, you may need further tests to check whether it started in your prostate or somewhere else. If your cancer started in another part of the body, it will affect the type of treatment you have. For example, if the cancer spread to the prostate from your stomach, you will be offered treatment for stomach cancer, not prostate cancer.

Your treatment will depend on how much the cancer has grown and whether it has spread to other parts of the body. You may be offered:

Your doctor or nurse will tell you what treatment options are available to you.

Basal cell prostate cancer

You might also hear this called adenoid cystic prostate cancer or basaloid carcinoma. Men who have basal cell prostate cancer can also have common prostate cancer at the same time. We don’t know how aggressive it is. Some studies suggest it isn’t very aggressive. But other studies suggest it might be more aggressive than common prostate cancer.

Basal cells don’t produce PSA,  and most men with basal cell prostate cancer have normal levels of PSA in their blood. This means that a PSA test probably won’t help to diagnose basal cell prostate cancer.

Basal cell cancer can grow big enough to cause the urethra (the tube you urinate through) to narrow, this can cause difficulty urinating. So basal cell prostate cancer is often diagnosed when men have surgery called transurethral resection of the prostate (TURP) to treat their urinary problems. Tissue removed during surgery is looked at under the microscope to confirm you have basal cell prostate cancer. You will also have scans to see if your cancer has spread.

Your treatment options will depend on how much the cancer has grown and whether it has spread to other parts of the body. You may be offered:

Your doctor or nurse will tell you what treatment options are available to you.

Transitional cell prostate cancer

This is also known as urothelial carcinoma. This cancer starts in the cells that line the urethra (the tube you urinate through).

Studies of men with transitional cell prostate cancer show that PSA levels can be low or high. More research is needed before we can know whether PSA tests can help to diagnose transitional cell prostate cancer.

Men with this cancer often have difficulty urinating (weeing) and find blood in their urine. This is because the cancer grows around the urethra (the tube you urinate through), causing it to narrow. So transitional cell carcinoma is often diagnosed when men have surgery called transurethral resection of the prostate (TURP) to treat their urinary problems. Tissue removed during surgery is looked at under the microscope to confirm you have transitional cell prostate cancer. You’ll also need scans to see if your cancer has spread.

If the cancer has not spread outside the prostate (localised prostate cancer), then you may be offered surgery and radiotherapy.

If the cancer has spread to areas just outside the prostate (locally advanced prostate cancer) or to more distant areas of the body such as the bones (advanced prostate cancer) then chemotherapy and radiotherapy may be an option.

In the UK, docetaxel (Taxotere®) is the standard chemotherapy drug for men with advanced prostate cancer that is no longer responding to hormone therapy. But if you have transitional cell prostate cancer you may have other types of chemotherapy, called carboplatin or cisplatin chemotherapy. If you have cisplatin chemotherapy, you will probably have it alongside another chemotherapy drug called gemcitabine.

Your doctor or nurse will tell you what treatment options are available to you.

Prostate sarcomas

Sarcomas are rare cancers that can develop anywhere in the body, including the prostate. Unlike common prostate cancer, sarcomas develop from smooth muscle cells in the prostate, called mesenchymal cells.

There are several types of prostate sarcoma. Some prostate sarcomas can be aggressive, but others are not.

Leiomyosarcoma

This is the most common type of prostate sarcoma in men (it is not the same as leiosarcoma).

Leiomyosarcoma is mostly found in men who are 40 years or older. But it can also sometimes be found in children and young men.  Most are aggressive and can spread to other parts of the body.

In most cases, men with leiomyosarcoma will have normal levels of PSA in the blood. This means that a PSA test may not help to diagnose leiomyosarcoma.

Leiomyosarcoma can grow big enough to cause the urethra (the tube you urinate through) to narrow. This can cause difficulty urinating and blood in the urine. So it is often diagnosed when men have surgery called transurethral resection of the prostate (TURP) to treat their urinary problems. Tissue removed during surgery is looked at under the microscope to confirm you have leiomyosarcoma. You’ll also need scans to see if your cancer has spread.

Treatments will depend on how much the cancer has grown and whether it has spread to other parts of the body. These can include:

Your doctor or nurse will tell you what treatment options are available to you.

Rhabdomyosarcoma

Rhabdomyosarcoma is another type of rare prostate sarcoma. It is mostly found in children, but can also be found in adult men, although this is rare. Most rhabdomyosarcomas are very aggressive and can spread to other parts of the body.

Boys and men with rhabdomyosarcoma usually have normal blood PSA levels,  so a biopsy is needed to diagnose rhabdomyosarcoma. And you’ll need scans to see if your cancer has spread.

Men or boys with this cancer will often have problems urinating (peeing) as the cancer can cause the urethra (the tube you urinate through) to narrow. So this type of prostate cancer is often diagnosed following surgery called a transurethral resection of the prostate (TURP) to treat these urinary problems. Tissue removed during surgery is looked at under the microscope.

Treatment will depend on whether the cancer has spread to other parts of the body. They may include:

Your doctor or specialist nurse will tell you what treatment options are available to you.

Other sarcomas

There are other types of sarcoma, but they are very rare. Because of this we don’t know much about them and more research is needed to find out more about whether current tests can diagnose them and what treatments work best.

Where can I get support?

Being diagnosed with any kind of prostate cancer can be frightening and overwhelming. If you are told you have a rare prostate cancer you may worry about what this means and feel frustrated that there isn’t much information available about your diagnosis and treatment.

No matter what you’re feeling or thinking, there is support available if you want it. You can speak to our Specialist Nurses, in confidence or chat with them online. Our Dealing with prostate cancer page looks at things you can do to help yourself and people who can help.

Visit our wellbeing hub for information to help support you in looking after your emotional, mental, and physical wellbeing. If you are close to someone with prostate cancer, find out more about how you can support someone with prostate cancer and where to get more information.

Questions to ask your doctor or nurse

  • What type of prostate cancer do I have?
  • Do I have a mixture of common and rare prostate cancer?
  • Is my cancer aggressive?
  • How far has my cancer spread?
  • Will I need more tests, such as an MRI, CT or bone scan?
  • What treatments are suitable for me?
  • What are the side effects of the treatments?

References

Updated: May 2022 | Due for review: May 2025

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