Cáncer de próstata

What is prostate cancer?

Prostate cancer is a cáncer which develops from cells in the prostate gland. It is the most common cancer in men in the UK. Each year, about 52,000 men are diagnosed with prostate cancer in the UK. It affects about 1 in 8 men in the UK at some point in their lives. Most cases develop in men over the age of 75 years.

Prostate cancer is often slow-growing, does not reduce life expectancy, and may not need treatment. In some cases it is more aggressive, spreads to other parts of the body and may benefit from treatment. In general, the more advanced the cancer (the more it has grown and spread), the less chance that treatment will be curative. However, treatment can often slow the progress of the cancer.

Prostate cancer is different to most other cancers because small areas of cancer within the prostate are actually very common, especially in older men. These may not grow or cause any problems for many years (if at all).

Although the exact cause is unclear, certain risk factors increase the chance that prostate cancer may develop. These include:

• Envejecimiento. Most cases occur in older men.

• Family history and genetic factors. If your father or brother had prostate cancer at a relatively early age (before the age of 60 years) then you have an increased risk. Also, if the type of cáncer de mama which is linked to a faulty gene runs in your female relatives then you are at increased risk of prostate cancer. These factors point towards a faulty gene which may occur in some men.

• Grupo étnico. Prostate cancer is more common in African-Caribbean men and less common in Asian men.

• Obesidad is a risk factor for advanced prostate cancer.

• Dieta is possibly a risk factor. As with other cancers, a diet high in fats and low in fruit and vegetables may increase the risk.

• Exposure to the metal cadmium may be a risk.

Prostate cancer is often slow-growing. There may be no symptoms at first, even for years. As the tumour grows, it may press on and irritate the urethra, or cause a partial blockage to the flow of urine. Prostate cancer symptoms may then develop and can include one or more of the following:

• Poor stream. The flow of urine is weaker, and it takes longer to empty your bladder.

• Hesitación. You may have to wait at the toilet for a while before urine starts to flow.

• Dribbling. A bit more urine may trickle out and stain your underpants soon after you finish at the toilet.

• Incontinencia urinaria.

• Frequency. You may pass urine more often than normal.

• Urgency. You may have to get to the toilet quickly.

• Poor emptying. You may have a feeling of not quite emptying your bladder.

Nota: all the above prostate cancer symptoms are common in older men. Most men who develop the above symptoms do reportado have prostate cancer but have a non-cancerous (benign) enlargement of the prostate. However, it is best to have any new symptoms checked out by a doctor.

Other symptoms such as pain at the base of the penis or passing blood occasionally occur. (These do not occur with benign prostate enlargement.)

If the cancer spreads to other parts of the body, various other symptoms can develop. The most common site for the cancer to spread is to one or more bones, especially the pelvis, lower spine and hips. Affected bones can become painful and tender. Sometimes the first symptoms to develop are from secondary tumours in bones.

Evaluación inicial

If a doctor suspects that you may have prostate cancer, he or she will usually:

• Examine the prostate. They do this by inserting a gloved finger through the back passage (anus) into the rectum to feel the back of the prostate. An enlarged-feeling gland, particularly if it is not smooth to feel, may indicate prostate cancer. However, a normal-feeling prostate gland does not rule out prostate cancer.

• Do a blood test to measure the level of prostate specific antigen (PSA). PSA is a chemical which is made by both normal and cancerous (malignant) prostate cells. Basically, the higher the level of PSA, the more likely that you have cancer of the prostate. However, a mild-to-moderately raised PSA can occur in conditions other than prostate cancer. (If you have confirmed prostate cancer, the PSA blood test is also used to monitor treatment. If treatment is working and cancer cells are killed then the level of PSA falls.)

Multi-parametric MRI

Multi-parametric magnetic resonance imaging (mp-MRI) is a relatively new scanning technique that produces a detailed image of the prostate.

It has been approved by NICE, and could prevent unnecessary biopsies for those with low-risk cancer. It is hoped the system will make it easier to identify cancers earlier and reduce the need for further treatment.

It is recommended as a first-line investigation for people with suspected clinically localised prostate cancer. You can find out more in the 'Further Reading' section, below.

Biopsia

Una biopsia is not always necessary to confirm a diagnosis of prostate cancer. Your doctor will be able to discuss the reasons for you to have a biopsy, if appropriate, with you in more detail.

A small biopsy of the prostate gland is taken by using a fine needle. This is usually done with the aid of a special ultrasound scanner. The probe of the scanner is about the size and shape of a finger. It is passed through the anus into the rectum to lie behind the prostate. This finds the exact position of the prostate. The doctor then pushes a fine needle into the back of the prostate from within the rectum to obtain the biopsy. Several samples are usually taken from different parts of the prostate.

Having a prostate biopsy can be uncomfortable. Therefore, local anestésico is used to reduce the pain as much as possible.

Sometimes prostate cancer is diagnosed from analysing the prostate tissue removed at the time of a prostatectomy operation, such as a transurethral resection of the prostate (TURP).

The severity of the disease is mainly based on three factors - the grade of the cancer cells, the stage of the cancer, and the blood PSA level.

Grade of the cancer

Samples of tissue (taken in the biopsy procedure) are looked at under the microscope to assess the cancer cells. By looking at certain features of the cells, the cancer can be graded. The common grading system used is called the Gleason Score.

A Gleason score of between 2 and 6 is a low-grade prostate cancer. It is likely to grow very slowly. A Gleason score of 7 is an intermediate grade that will grow at a moderate rate. A Gleason score of 8 to10 is a high-grade cancer that is likely to grow more quickly.

Estadificación

If you are confirmed to have prostate cancer, further tests may be advised to assess if it has spread. These tests are not advised in all cases. It depends on factors such as your age and the grade of the tumour cells. Tests which may be done include una gammagrafía ósea, a computerised tomography (CT) scan, an MRI scan, a tummy (abdominal) ultrasound scan or other tests. This assessment is called staging of the cancer. The aim of staging is to find out:

• How much the tumour has grown and whether it has grown through the wall of the prostate and into nearby structures such as the bladder wall.

• Whether the cancer has spread to local lymph nodes.

• Si el cáncer se ha extendido a otras áreas del cuerpo (metastatizado).

See the separate leaflet called Stages of Cancer for more details.

The treatment of prostate cancer is complicated. It varies tremendously between different cases. In addition, different men may choose to have different treatments compared to others with a similar type of prostate cancer.

The National Institute for Health and Care Excellence (NICE) recommend that everyone newly diagnosed with prostate cancer should be given a risk stratification. This means a measure of how high your risk is, which depends on several factors including how abnormal the prostate cancer cells are, how high your blood PSA level is and how far the cancer has spread.

The treatment options you will be offered will depend on these results and on what you and your doctor decide would be best for you.

Treatment options which may be considered include: surgery, radiotherapy, hormone treatment and, less commonly, chemotherapy. Often a combination of two or more of these treatments is used.

If a cancer is advanced then you may require treatments such as:

• Nutritional supplements.

• Painkillers.

• Other techniques to help keep you free of pain or other symptoms.

Treatment aims

Treatment may aim to cure the cancer. In particular, the earlier the stage of the cancer, the better the chance of a cure. (Doctors tend to use the word remission rather than the word cured.

Remission means there is no evidence of cancer following treatment. If you are in remission, you may be cured. However, in some cases a cancer returns months or years later. This is why doctors are sometimes reluctant to use the word cured.)

Treatment may aim to control the cancer. If a cure is not realistic, with treatment it is often possible to limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.

Treatment may aim to ease prostate cancer symptoms. Even if a cure is not possible, treatments may be used to reduce the size of a cancer, which may ease symptoms such as pain.

Treatment options for prostate cancer

• Active surveillance: in some cases it may be best not to have any active treatment but to see how the cancer develops.

• Surgery to remove the prostate.

• Radioterapia.

• Hormone treatment: two groups of medicines are available:

  • Medicines which work on the pituitary gland - for example, goserelina, leuprorelin and triptorelin. (Your pituitary gland makes a hormone which circulates in the bloodstream to stimulate the testicles to make testosterone. These medicines stop your pituitary gland from making this stimulating hormone.) Goserelin is an implant that is injected under the skin. Leuprorelin and triptorelin are given by injection.

  • Medicines which block the action of testosterone (anti-androgen medicines) - for example, flutamide y ciproterona. These medicines are tablets.

  • NICE has recommended enzalutamide, along with hormone therapy, as an option to treat hormone-sensitive prostate cancer that has metastised. Enzalutamide blocks androgen receptors, meaning that it blocks the effect of the hormone testosterone on prostate cancer cells.

• Chemotherapy:

  • If your cancer has spread to other parts of your body (metastasised) and the cancer is hormone-sensitive, the current options are hormone treatment as above, with or without steroid treatment, or a type of chemotherapy called docetaxel with steroid treatment.

Apalutamide plus androgen deprivation therapy (ADT)
NICE has recommended that an anti-androgen treatment called apalutamide can be offered in combination with anti-androgen medicines if:

• You have hormone-sensitive prostate cancer that has metastasised and a form of chemotherapy called docetaxel isn't suitable; or

• You have hormone-sensitive prostate cancer which is at high risk of metastasising even though you are taking anti-androgen medicine.

Other treatments for prostate cancer

Cryotherapy (also known as cryosurgery) is an alternative treatment for men with early stage prostate cancer and recurrent prostate cancer. It is not yet available in all hospitals in the UK. It involves placing a number of metal probes through the skin and into the affected area of the prostate gland. The probes contain liquid nitrogen, which freezes and destroys the cancer cells.

High-intensity focused ultrasound (HIFU) treatment may be offered to some men, again with early prostate cancer. As this is still a relatively new procedure, it is not yet available in all hospitals in the UK. HIFU involves inserting a probe into the rectum. It is then pushed through the wall of the bowel into the prostate.

The probe produces a high-energy beam of ultrasound which then heats and destroys the cancer. The probe is surrounded by a cooling balloon to protect the normal prostate tissue from damage.

The possible complications of prostate cancer include:

• Urinary obstruction, which may lead to lesión renal aguda o enfermedad renal crónica.

• Sexual dysfunction, eg, disfunción eréctil.

• Spread of prostate cancer (metastases) may cause bone pain, fractures, or compression of the spinal.

• Complications of hormonal treatments may include hot flushes, or breast enlargement (gynaecomastia).

The outlook for prostate cancer is very variable. Some prostate cancers are slow-growing and do not affect life expectancy. On the other hand, some have already spread to other parts of the body when they are diagnosed. The response to treatment is also variable.

The treatment of cancer is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general. The specialist who knows your case can give more accurate information about your particular outlook and how well your type and stage of cancer are likely to respond to treatment.

Screening for prostate cancer is controversial. A routine blood test which shows a high PSA puede indicate that you have prostate cancer. However, there are other causes of a high PSA. Also, many prostate cancers are slow-growing and do not cause problems, particularly in older men.

Some experts believe that if all men were screened then there may be many men found with a raised PSA level. Many men may then be investigated and treated unnecessarily with all the possible risks and side-effects of the investigations and treatment. Put simply, some people believe that screening for all men may do more harm than good.

Currently there is no national screening programme in the UK. However, you can decide for yourself if you would like a PSA test. It is best to discuss the pros and cons of the test with your GP. See the separate leaflet called Prostate Specific Antigen (PSA) Test for more information.