Prostate cancer develops when cells in the prostate start multiplying uncontrollably. This can happen if the genetic information (DNA) in the cells has changed (mutated). The body’s immune system usually keeps these cells in check. Cancer develops if too many mutated cells multiply and a tumor grows.
The diagnosis “prostate cancer” usually comes as a shock to men and those close to them. The good news is that prostate cancer is one of the types of cancer with the best chances of recovery. This is because it often grows very slowly so it is generally possible to treat it effectively.
Prostate cancer normally doesn’t cause any symptoms until it has reached a more advanced stage. It may then cause problems such as an increased urge to urinate (pee) or a weaker flow of urine. In most cases, though, problems urinating aren’t caused by cancer, but by a benign enlarged prostate. This is very common in men over the age of 50.
In rare cases, blood in urine or semen can also be a sign of prostate cancer. If the cancer is at a very advanced stage, it may also spread to other parts of the body (like the bones) through the lymphatic system or blood vessels. This can lead to symptoms such as bone pain.
Causes and risk factors
The exact causes of prostate cancer aren’t known. But some factors are known to increase the risk. These are the main risk factors:
- Age: The risk of prostate cancer increases with age.
- Ethnicity: Black men are somewhat more likely to develop prostate cancer.
- Close relatives: Men who have a father or brother who developed prostate cancer are at a somewhat higher risk themselves. If your father and several brothers have (had) prostate cancer, your risk is even higher.
- High doses of vitamin E: Dietary supplements that have a lot of vitamin E in them have been proven to increase the risk of prostate cancer if taken over many years.
Certain types of food, such as red meat or tomatoes, are often associated with cancer – some are thought to cause cancer and some are believed to prevent it. But research has not proven that men can lower their risk of developing prostate cancer by eating a specific diet.
The number of men who are diagnosed with prostate cancer has increased quite a lot in recent years, but is going down a bit now. One reason for the increase was the fact that men tend to live longer nowadays: The risk of developing prostate cancer increases with age, and is very rare in men younger than 50.
The second reason has to do with more men going for prostate cancer screening. Screening has led to more frequent detection of smaller cancer growths which wouldn’t have been found otherwise. This is because many smaller growths don’t cause any symptoms during a man’s lifetime. So screening increases the number of cancer diagnoses.
The following tables show how likely it is that a man of a certain age will be diagnosed with prostate cancer within the next ten years and how likely it is that he will die of it. The numbers are averages: A man’s individual risk will also depend on whether he has risk factors and – if so – which risk factors.
|Current age||Number of men who will be diagnosed with prostate cancer in the next ten years|
|45||4 out of 1,000|
|55||25 out of 1,000|
|65||59 out of 1,000|
|75||59 in 1,000|
Source: RKI 2015
|Current age||Number of men who will die of prostate cancer in the next ten years|
|45||Fewer than 1 out of 1,000|
|55||2 out of 1,000|
|65||7 out of 1,000|
|75||19 out of 1,000|
Source: RKI 2015
Whether and how prostate cancer continues to grow will vary from person to person. Most men who are diagnosed with prostate cancer have a good chance of recovery. This is because prostate cancer often only grows in the prostate (localized) and hasn’t spread to other parts of the body (metastasis). More than 90% of men who are diagnosed with prostate cancer are still alive five years later. If you only consider men who are diagnosed with localized prostate cancer, this figure even increases to 99%.
In recent decades, several studies have shown that many men have small cancer growths in their prostate that don’t cause any symptoms. In those studies, the men’s prostates were examined after they had died of something else. In other words, they died with prostate cancer, but they didn’t die of it. Also known as latent prostate cancer, these growths are quite common in men over 50: It's estimated that 30 to 70% of men in this age group have latent prostate cancer.
But there are also more aggressive forms of prostate cancer that grow fast and can shorten your life. When prostate cancer is diagnosed, it’s not easy to predict how it will continue to develop. Tissue samples and other tests can be used to see whether a tumor is more likely to be aggressive (a high-risk tumor) or grow very slowly (a low-risk tumor). The most suitable treatment options will depend on the results of these tests, together with other factors such as the age of the man.
If it’s thought that a man might have prostate cancer, the doctor will first ask about the symptoms to get a rough idea of the problem and figure out what might be causing it (anamnesis). After that, one or more of the following examinations may be done:
- Palpation (feeling): Here the doctor gently inserts a finger into the anus to feel the size, hardness and surface of the prostate. This test is also known as a digital rectal exam (from the Latin word digitus, meaning “finger”). Although some men find it uncomfortable, it's usually not painful.
- PSA test: The PSA test is a blood test that looks for a certain protein known as “prostate-specific antigen.” This protein is produced inside the prostate. Small amounts of it enter the bloodstream. Having high levels of PSA might – but doesn’t necessarily – mean that someone has prostate cancer. Other things can lead to an increase in PSA levels too.
- Transrectal ultrasound (TRUS): Ultrasound is used to check the size and shape of the prostate gland. This involves gently inserting an ultrasound device about as wide as a finger into the rectum (the end part of the bowel).
- Tissue sample (biopsy): The only way to find out whether there actually is cancerous tissue in the prostate is by taking a tissue sample. Ten to twelve tissue samples are usually taken to be examined under a microscope, where they can be checked for cancer. The most commonly used approach is called fine needle aspiration. Like TRUS, this involves gently inserting an ultrasound device into the rectum. There is a fine needle inside the device. The needle is pushed through the wall of the rectum and into the prostate, where it is used to remove samples of tissue. The ultrasound helps guide the needle to the right place. This procedure is done using local anesthetic, or – in some rare cases – brief general anesthetic.
Based on the tissue samples, doctors can estimate how “aggressive” the tumor is. This means how much the tissue has changed, how likely it is that the cancer will grow, and how fast it will spread to other parts of the body. Something called the Gleason grading system is used to calculate a score that shows how aggressive the tumor is. If someone has prostate cancer, the score is between 6 and 10 – where 6 isn’t aggressive, and scores between 8 and 10 are very aggressive.
Three of the described diagnostic procedures are also offered as screening tests for the early detection of prostate cancer: palpation (feeling), the PSA test and transrectal ultrasound (TRUS).
People sometimes think that screening can stop cancer from developing. But none of the screening examinations currently on offer can do so. The aim is rather to detect prostate cancer as early as possible to improve the chances of successful treatment.
In Germany, the costs of palpation to screen for prostate cancer are covered by statutory health insurers: All men aged 45 and over are entitled to this examination once a year. But it doesn’t have any proven benefits. For instance, there is no proof that men are less likely to die of prostate cancer if they have this examination regularly.
Transrectal ultrasound isn’t suitable for the detection of prostate cancer. Statutory health insurers in Germany will only cover the costs of an ultrasound examination if someone has symptoms that suggest they might have a medical problem affecting their prostate, such as a benign enlarged prostate.
The benefits of PSA tests in prostate cancer screening have been studied in large studies. The results show that, together with possible advantages, there are also some serious disadvantages such as overdiagnosis. Before deciding whether to have a PSA test, it is worth carefully considering the pros and cons.
The possible treatment options for prostate cancer will depend on various factors. These include:
- how much the cells have changed (how aggressive the tumor is)
- how much the tumor has grown or spread (the stage of prostate cancer)
- the man’s PSA levels
- individual factors such as the man’s age, how healthy he is otherwise, and how important the pros and cons are to him.
Men who have high-risk prostate cancer will usually have their prostate surgically removed or treatment with radiotherapy. Radiotherapy can be done in two ways: from outside of the body (external radiotherapy) or from inside the body (internal radiotherapy, or brachytherapy).
The most common side effects of radiotherapy or removing the prostate gland are accidental leakage of urine (urinary incontinence) and erection problems (impotence). External radiotherapy is especially likely to cause diarrhea, and in some cases inflammations in the bowel which may result in blood in the stool and cramps.
If the tumor is small, only inside the prostate, and not aggressive (low-risk prostate cancer), the following treatments are also possible:
- Active surveillance: Here the prostate cancer is simply monitored, and not treated, at first. This strategy is based on the fact that low-risk prostate cancer usually grows very slowly or doesn't grow at all. It is often found that the cancer has still not advanced even years after it was diagnosed. Instead of having treatment, the prostate is checked regularly. Treatment attempting to get rid of the cancer (curative treatment) is only started if the tumor starts growing. The advantage of this approach is that the side effects of surgery or radiotherapy can be avoided as long as the cancer does not grow. One possible disadvantage: If the cancer does progress, that is sometimes discovered too late. It may have already spread to other parts of the body by then (metastasis). Knowing that you have cancer in your body can be distressing too.
- Watchful waiting: This strategy also starts by only monitoring the prostate cancer at first. But if the tumor starts growing, only the symptoms are treated, not the tumor itself (this is known as “palliative” care). This approach is mainly considered in older men, who may also have other medical problems. The risks and stress of surgery or radiotherapy could outweigh the possible benefits of this treatment.
There is no “right” or “wrong” treatment decision for men who have low-risk prostate cancer. The strategy that one man chooses will mainly depend on his personal preferences and values. Some will feel it is more important to avoid side effects like impotence or incontinence as much as possible. Others will want to be very sure that the cancer has been removed, so they are willing to accept the risks associated with treatment.
For more advanced stages of prostate cancer, there are several kinds of hormonal treatments and chemotherapies that aim to slow the growth.
When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.
More information (in German) about prostate cancer, such as criteria for assessing the aggressiveness of a tumor, and treatment options can be found on the Cancer Information Service (Krebsinformationsdienst) website of the German Cancer Research Center.
Deutsche Gesellschaft für Urologie (DGU). Interdisziplinäre Leitlinie der Qualität S3 zur Früherkennung, Diagnose und Therapie der verschiedenen Stadien des Prostatakarzinoms. AWMF-Register-Nr.: 043/022OL. December 2016. (Leitlinienprogramm Onkologie).
Klein EA, Thompson IM, Jr., Tangen CM, Crowley JJ, Lucia MS, Goodman PJ et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). Jama 2011; 306(14): 1549-1556.
Pron G. Prostate-Specific Antigen (PSA)-Based Population Screening for Prostate Cancer: An Evidence-Based Analysis. Ont Health Technol Assess Ser 2015; 15(10): 1-64.
Robert Koch-Institut (RKI). Bericht zum Krebsgeschehen in Deutschland 2016. Berlin: Ruksal Druck; 2016.
Robert Koch-Institut (RKI), Gesellschaft der epidemiologischen Krebsregister in Deutschland e.V. (GEKID). Krebs in Deutschland 2011/2012. Berlin: RKI; 2015.
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