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The Prostate Gland

Anatomy
 

The prostate is a relatively small chestnut-sized organ, which only exists in the male and is to be found right underneath the bladder at the beginning of the urethra. At its front lies the pubic bone and at its backside the rectum. The prostate encircles the urethra and can put some pressure on it should it get enlarged. The prostate is a gland and consists of billions of small tubes that produce the fluid in semen. If you look closely, the prostate is even made up of a couple of glands, all contained within a capsule. Except for connective tissue, to give it strength, the capsule also consists of a number of muscle fibers, that may play a role in ejaculation.

Underneath the prostate, downstream, the sphincter, i.e. the closing mechanism, of the bladder is found. Two small tubes take care of a constant supply of sperm cells from the testicles, that are mixed with prostatic fluid to form semen. A small supply of ready made semen is kept in store in the seminal vesicles, located behind the bladder. Right next to the prostate a number of tiny nerve fibers conduct signals to and from the penis and regulate erections.

In normal circumstances, the prostate measures about 15 cc; during life it might grow up to 100 cc or more.


Functions
 

The prostate is a gland: so the prostatic tissue produces something, namely the fluid in semen. Semen is for the most part made up of seminal fluid and for a small part of sperm cells. That is the reason why, after vasectomy for sterilization, when the seminal ducts are cut close to the testicles, there is still a 'normal' amount of semen produced at ejaculation. After a vasectomy, semen does not look any different than before because the volume of the total amount of sperm cells is small. When ejaculation takes place, the seminal vesicles contract, so that an amount of semen is injected into the urethra to leave the body when it is ejected from the penis.

A small sphincter (valve) is created (evoluted, as you will) between bladder and prostate around the urethra to prevent the semen going 'the wrong way' (into the bladder). Its sole purpose is to act during ejaculation and it has no function in closing the bladder to prevent leakage of urine, although it does make it difficult to void urine during ejaculation (and for some men during all of erection).

The prostate is a typical male organ without a female equivalent (this statement may sound strange, but a female thing as a nipple has its male counterpart). At birth, the prostate is already there, but very small. The male sex-hormone (testosterone) will induce further growth of the prostate during puberty. In a number of men, the prostate will continue to grow during the years. If testosterone is not available in the body, for example after castration (as was common with eunuchs in a harem in Turkey once) the prostate will not grow, or, if castration is done at a later age, will shrink.


Diseases, Signs and Symptoms
 

In general, three thing can happen to a prostate: infection, enlargement, cancer.


Prostatitis (prostatic infection). 
In prostatitis there is an infection (with bacteria) of the glandular tissue of the prostate. This is almost always preceded by a cystitis. There are always bacteria present in urethra and bladder, since it is a nicely warm and moist place to be while via the urine a lot of nourishment is provided. Usually only 'known' gut-bacteria are hanging around, and these are quite harmless: they are useful bacteria, that help in digesting the food in the intestines. These bacteria happen to get into the urethra and bladder all the time, but are washed away with the urine at regular intervals before their number get too much increased (bacteria are like rabbits). The bladder is used to this constant invasion of friendly bacteria and can handle it all.

In certain circumstances (low urine production because of sweating, low resistance during a period of flue, unusually aggressive bacteria) the number of bacteria can, however, increase and an infection of bladder or prostate may result. Often the bladder will get itself cured by flushing out urine and bacteria, but the prostate is less fortunate. Firstly, urine does flow past the prostate, but not through it, so it does not really clean the glandular tissue of the prostate with its many tubes and corners.

Secondly, for some reason the resistance against bacteria in the prostate is not as high as could be; the fact that the bacteria involved are not absolute 'strangers' to the defense system of our body - they are 'known' gut bacteria - may be a possible explanation for this. As long as these bacteria are not too aggressive and do not cause too many problems, they are more or less left alone by our defense. Things are usually very much different in case of prostatic infections with 'strange bacteria' or venereal disease; this usually results in high fever and general sickness.

Usually, prostatitis is a rather mild disease, and a lot of men do not really notice their infection. A prostatitis may cause pain, which can be located low in the abdomen, around the anus, in the groin, in the back. It is mostly a low grade pain, which could be gone for a few days and then rise again.

There can also be some irritation when passing urine: visiting the toilet more often, difficulty is postponing that visit, a burning feeling during voiding. The symptoms are caused by the prostate lying close to the bladder and irritating it. Additionally, often bacteria are 'seeded' form the prostate 'stronghold' to bladder of urethra, causing extra irritation. In some cases, bacteria can go upstream into the vas deferens, causing groin pain or an infection of the epididymis. 
Because of the infection, the prostate may get swollen, causing a less forceful passing of urine.

When the prostate is cured (by itself, or after antibiotics), usually some scar-tissue will remain, which will not cause any problems, but will enhance the chances on 'new' infections. A prostatitis does not cause cancer of the prostate. Although usually no special cause for prostatitis can be found, some conditions may give a higher chance for its develop ment: an enlarged prostate (BPH), or prostatic cysts. In prostatic cysts small spaces filled with prostatic fluid may be found in the prostate, in which bacteria, once they are inside the cyst, can survive despite adequate treatment with antibiotics.

 

Prostatodynia ('prostatic pain').
In some cases the prostate may be too sensitive, even painful, without an infection present: there are regular vague pains in the lower abdomen, groin or around the anus, which may be worse just before ejaculation, or just after, or have nothing to do with it. Just like a sensitive stomach can cause pains during periods of high tension at work or at home ('acid burning'), the region of the prostate (i.e. prostate, bladder, urethra, testicle) can get irritated during stress, and cause pain. Usually, at examination nothing wrong can be found with bladder or prostate, although prostatodynia is probably more often seen in men, who have had a prostatitis.

Prostate enlargement, BPH (Benign Prostatic Hyperplasia).


In a number of men, the prostate can get enlarged during the years. Why this happens only in a great number, but not in all men, is unknown. Although the male sex-hormone testosterone is necessary for a normal development and growth of the prostate (without testosterone no enlargement), a very high testosterone production (the testosterone level may be very different in different men) does not automatically lead to BPH.

Also, an enlarged prostate does not always produce symptoms. Some men have a very large prostate, but have no difficulty passing urine, while others can not pass urine at all, but have only a slightly enlarged prostate.


When BPH does give trouble, it usually starts off with a loss of strength of the urinary flow. It takes longer for the bladder to empty. This is caused by the enlarged prostate (which is wrapped around the urethra) constricting the urethra, diminishing the passage of urine and causing a diminished flow. The flow will diminish over a period of many years, so it often goes unnoticed. Moreover, a lot of men think that a diminished flow comes naturally with age. In time, the enlarged prostate will start irritating the bladder, causing some men to go to the toilet more often, while even at night they have to get up several times to pass urine. Fortunately, the bladder, which acts as an engine for the urinary flow, is capable of enhancing its strength during the years.

This is often visible as large muscle bundles at cystoscopy. Unfortunately, this gathering of strength of the bladder can not go on forever: at a certain point the bladder is at the top of its strength and it will fail the competition with the ever growing, ever more constricting prostate. From this moment on the bladder will not be able to empty itself completely. If the prostate keeps on growing, ever more urine will stay behind once the patient thinks his bladder is empty; this is such a slow process, that it will generally not be noticed. Until, often after a party (alcohol has a negative effect on muscle strength as a whole, and bladder strength in particular), the patient is unable to pass urine altogether.

Of course, it does not have to come this far. Sometimes, the prostate just stops growing any further. Often, the prostate may stop growing for several years and thereafter start growing again. In a number of cases, the symptoms will cause the patient to go to his doctor: a weak flow of urine, trouble starting voiding, dribbling after passing urine, going to the toilet more often. In other cases, complications will be the reason to visit the doctor: inability to pass urine, cystitis, prostatitis or bladder stones (because of the amount of urine that stays behind in the bladder). Prostatic cancer fortunately does not belong to the list.


Nowadays, most men arrive at the doctors office in time. If treatment is postponed for too long, then either therapy gets more difficult or even impossible (when the bladder is distended beyond repair). Elsewhere on the Urology Page you will find a questionnaire, helping you to make up your mind whether it is necessary to consult a doctor for your voiding problems or not. If you have problems passing urine, but the answer provided by the questionnaire still leaves you in doubt, you are advised to consult you doctor. Possible further examinations are: digital rectal examination (your doctor feeling the prostate with his/her finger in the rectum), taking blood samples, cystoscopy, transrectal ultra sound.
 

Prostate Cancer. 


All men will get prostatic cancer, unless they are castrated at an early age and hence do not produce any male sex-hormone (testosterone). It has been shown that almost all males of ninety-or-older have cancer cells present in their prostate; fortunately, prostate cancer is slow-growing, so most of them will never have any trouble with their cancer. At a younger age, the slow rate of growth is of lesser benefit, making early treatment probably necessary to prevent spreading of cancer cells to other parts of the body. However, in some cases of prostate cancer the cancer cells will remain dormant ('sleeping') and will never cause any symptoms. When prostate cancer is found in a man, it is, unfortunately, not predictable at present whether in his case the cancer will ever be 'active' or remain dormant forever.

It is unknown how prostate cancer develops, although testosterone is necessary for its existence. Prostate cancer is not caused by prostatitis or a benign enlargement of the prostate. Usually the cancer cells are found at a different location than the 'benign enlargement' cells. BPH is usually found directly around the urethra, while prostate cancer will generally develop at the outskirts of the prostatic gland. This feature, fortunately, makes it easier to detect the cancer from the rectum. Of course, it is possible for a man to have BPH and prostate cancer, a rather common combination, causing the patient to visit his doctor because of problems passing urine (because of BPH), and (because the doctor will do a digital rectal examination) leading to a diagnosis of prostate cancer.

In the beginning, prostate cancer will cause no or little signs that it is there. Since the swelling, i.e. the cancer usually develops at the outskirts of the prostate, it will only cause a diminished stream late in its course. Also, prostate cancer hardly ever causes pain by itself; pain will usually arise only when it is spread to other parts of the body. The cancer cells spread via the lymphnodes or by way of the bloodstream, or both.

When it spreads via the lymphnodes, the nodes near to the prostate get enlarged and form the starting point for further spreading of the cancer cells throughout the body; the lymphnodes serve as a last defense against the spreading, but only last for a very short period of time. If the cancer spreads directly via the bloodstream, but also when it does through the lymphnodes, the disease usually has a preference for the bones. If these cells start growing they can cause pain because the abnormal tissue pushes the normal bony tissue aside.

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Examinations
 

The prostate and its function can be investigated in different ways. Not all possible investigations are, of course, necessary. As a rule, the urologist will make a choice to be able to eliminate or confirm possible causes of the patients problems. It is a mistake to think that the latest invention in diagnostic tools will always be the best available. In certain cases additional information can be gathered from a 'new' test, but this is not always so; a CT-scan can be very useful to get an impression of the extent of spreading of prostate cancer, but it can prove to be difficult to visualize the prostate itself, while this it often easier with transrectal ultrasound. A few possible examinations will be discussed here; there are more, but that would be impossible on this Page.


Several examinations exist into the presence of prostate cancer and possible spread of the disease: digital rectal examination (your doctor feeling the prostate with his/her finger in the rectum), taking blood samples ( PSA), transrectal or transperineal ultrasound, MRI of the prostate, and PET and bone scans.

Blood:
Is there an infection in the body (for example in the kidney, bladder or prostate)??To find this out, the sedimentation rate can be measured and the number of white blood cells (leukocytes). 
Is there a high amount of PSA (Prostate Specific Antigen) in the blood? PSA is a substance made by the prostate and can be released into the bloodstream in higher-than-normal amounts when there is something wrong with the prostate; The prostate may be enlarged, infected or may contain cancer. Further analysis is then necessary to find out what is wrong. In normal circumstances, PSA should not exceed 4.

 

Urine: 
Is there an infection of the bladder present? It is often impossible to find out where the infection is located (kidneys, bladder, prostate). Usually, in prostatitis the white blood cell count in the urine is not all that high, although a concurrent cystitis can cause higher numbers. 
Are red blood cells present in the urine? This could happen in cases of infection, but can also be a sign of cancer of kidneys, bladder or prostate.

 

Semen. 
In some cases it may be necessary to examine a semen sample for the presence of white blood cells or bacteria in order to check for a possible prostatitis. 
By way of ultrasound (too high to hear and painless) the prostate can be analysed. Because the prostate is located behind the pubic bone far from the abdominal skin, it can be difficult to visualize from the front. So the ultrasound is performed using a small stick, probing the rectum. The stick is usually only slightly thicker than the doctors finger, so the examination ought not to be painful. Calcifications inside the prostate ( a sign of an 'old' prostatitis) are readily visible, while the size of the organ can be measured accurately. Normally, the prostate shows as a regular dark-grey ellipse on screen; lighter spots may signify infection, darker ones may point to cancer. The size, shape and extend of the prostate cancer can usually be estimated quite accurately.

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Cystoscopy means looking into the urethra and bladder using a small tube, which can be made of metal (rigid) or plastics (flexible). This is perhaps the most important examination of the bladder, since even very small bladder tumors or stones can be found, while the urethra and prostate can be inspected in one go. The size of the prostate can be judged, especially whether it is obstructing the urethra or not. One does also get an impression of the quality of the bladder muscles.


A CT-scan can be used to 'cut the body into thin slices' with the use of X-ray. For better visibility, a contrasting substance is often injected into a vein just before the examination. CT-scanning is important to find out whether prostate cancer has spread to the nearby lymphnodes. Although it is a quite sensitive examination, in some cases a small operation is still necessary to take a closer look and take tissue samples for microscopic examination.


A bone-scan or PET scan  is also used to find out whether prostate cancer has spread to other parts of the body or not. A radioactive substance is injected into the bloodstream, which can glue itself to prostate cancer cells in the bones, if they are there. With a special type of camera, the event can be filmed, producing an image of possible distant spreading of the tumour. 

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Biopsy Sometimes it may be necessary to take tissue samples (biopsy) from the prostate for further microscopic examination, for example in case of suspicion of cancer on digital rectal examination, When PSA is high or when the ultrasound of the prostate is abnormal. The biopsy is usually taken via the rectum or perineum, either under guidance of  by way of the ultrasound probe. Using a very thin needle several small pieces of prostate are removed. Nowadays, this is usually done with a  sprin,g-loaded probe resulting in a fast and painless procedure. A general anaesthetic may be required.Afterwards a few drops of blood may be lost in the stools or the urine, but the bleeding usually stops within minutes. Often, a short course of antibiotics is given to prevent infection.

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It is impossible to present all possible therapeutic options for all diseases of the prostate. More frequent forms of treatment will be mentioned.


Prostatitis.


As mentioned above, it can be very difficult to treat prostatitis definitively. Usually it will be necessary to use antibiotics for a long period of time, while care must be taken to drink as much as needed to provide adequate flushing of bladder and urethra. It can take several months before the prostate is fully recove red, so that the drinking/flushing part of therapy is very important to keep everything as clean as possible during recovery; unfortunately, it often happens that the drinking part of therapy gets forgotten once the patient feels better, resulting in a relapse of the prostatitis. Sometimes, the prostate has been infected for so long that it will never fully recover and will remain susceptible to new infections; some men will keep having pain and discomfort now and then for the rest of their life. In some cases dietary measures may help alleviating the discomfort (no gaseous drinks, no chilly, not too much alcohol), while often a warm bath will help relieve the pain. Drinking and flushing the bladder and urethra will always be necessary. Look also under prostatodynia.

Of course, if a cause of the prostatitis can be found, like prostatic cysts, it should be treated; fortunately, usually no serious prostatic problems can be found.


Benign prostatic enlargement, BPH
While in the past an operation was the only solution, nowadays different treatments exist to choose from: 


Medication.

Some medication seems to have been specially designed for the prostate and can either cause shrinking of the prostate or give it more room to expand.
A number of small muscle fibers can be found in the outer layers of the prostate. Certain medicines, the  alpha-blockers (tamsulosin or alfusosin) are able to relax these muscle fibers, giving room to the prostatic tissue inside; thus, the prostate can expand outwards, which relieves the constricted urethra inside the prostate somewhat, causing a better stream. If the prostate continues to grow, however, the newly created space will get occupied with more prostatic tissue and the voiding problems will return.


Testosterone

(the male sex-hormone, produced in the testicles) triggers the prostate to grow. Certain medicines, the so-called 5-alpha-reductase inhibitors, can render the testosterone, that gets into the prostatic tissue, inactive, causing a diminishing growth or even shrinking of the prostate. This shrinking of the prostate is a slow process and it will often take a couple of years for the prostate to get so much smaller as to be able to stop the medication. In some cases, for example when passing urine has become impossible, this is too slow. It is unclear what will happen when the medication, after successful use, is discontinued; will the prostate start growing again at its usual rate, or will it make up for lost size and grow more rapidly?


Sometimes, both types of medication can be combined, one causing rapid improvement in symptoms, while the other will give benefit in the long run, causing shrinking of the prostate. 

Operations on the prostate via the urethra.

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In the last couple of years, many new possibilities have come to light. Not all of these modern technologies have proven to be as effective, while a great many of them are still quite experimental and side-effects and/or complications have not been fully investigated.

 

A variation of the TURP is the VLAP or HoLEP (Visual Laser Ablation of the Prostate or green light laser ). The way the operation is performed is about the same as in a TURP, but the tissue is not scraped away, but more or less vanishes because of the very hot LASER-light. An advantage of the VLAP is that the operation is usually less bloody than a TURP, while it can also be performed in patients who are not in such a good physical condition. The HoLEP is used for larger prostates to avoid an open operation. The disadvantage is that the LASER does not seem to work in some patients, while some prostates are simply not cut out to be LASERed. Additionally, some patients will complain of a serious urge to go to the toilet (irritation) which may last for several weeks. 


Open operations on the prostate.
This is the operation which carries the biggest amount of experience. Nowadays, the open prostatectomy is usually done in cases when a TURP would take too much time, i.e. in large prostates. An incision is made into the skin of the lower abdomen. When the prostate is reached, it is opened and the extra tissue is removed. As in a TURP, not the whole prostate is removed, and the 'skin' is left behind. It is a much done, safe procedure, which will cause some blood loss. Sometimes, blood transfusions are necessary. Because the wall of the prostate has been opened, a catheter will remain in place for about a week to allow the wall, that has been sown together of course, to get watertight again. After this operation, as in the TURP and, to a lesser extend, the VLAP, the semen will flow into the bladder during ejaculation.

 

Other options.

These include more minimally invasive procedures including the following:

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Urolift - a procedure performed under local or general anaesthetic as a day case where prostate tissue is not removed and using a cystoscope “ tacs” help move the prostate lobes apart. This procedure is not suitable for all prostates but does reduce the risk of retrograde ejaculation.

 

Rezum - a procedure performed under local or general anaesthetic as a day case where prostate tissue is not removed but is vaporised using hot water This procedure is not suitable for all prostates but does reduce the risk of retrograde ejaculation.


Do nothing. In some cases of enlarged prostate, it is not bothering its owner. When there is (still) an equilibrium between the bladder, getting stronger, and the prostate, getting tighter, is it a good option to wait and see what happens. A lot of men start urinating at a slower pace once they get older and they will probably never get into real trouble because of this. In these cases it is quite safe to wait, although frequent controls will be necessary - in some cases the patient notices no change while his bladder does get into trouble.

 

Prostate cancer. 

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Before treatment two questions need to be answered: 'has the cancer spread to other parts of the body?' and 'what is the physical condition of the patient?'. 
Spreading. When the prostate cancer has spread, then small lumps of cancer tissue can be found outside the prostate: they can be detected by PET-scanning in the lymph nodes or by bone-scanning in the bones. In case of spreading of cancer treating the prostate only is useless, because then the lumps of cancer elsewhere in the body are left out. Apart from this, once the cancer has spread, it can not be cured completely anymore.

 

The prostate can be completely removed, so that the cancer inside is removed with it. Contrary to an 'open prostatectomy' in case of a benign enlargement of the prostate (when only part of the prostate is removed) this 'radical prostatectomy' is a major operation, for which a pretty good state of health is necessary and the whole of the prostate is removed. This is usually performed  laparoscopically or robotically .

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Less invasive procedures include HIFU ( high intensity focused ultrasound) , which can be used in selected circumstances for less aggressive tumours.


In some cases, however, the growth of the cancer (and its satellites) is very slow, so that, especially in the elderly, problems are not to be expected. In those cases, waiting might be the best option. If there are already cancer-related problems, like pain in the bones because of spreading, or in younger men, or if the growth rate is high, anti-hormonal treatment may be an option. Just like the benign prostatic tissue, prostate cancer growth is stimulated by testosterone, the male sex hormone, made in the testicles. If the testosterone production can be diminis hed, or even obliterated, every bit of prostatic tissue, wherever it is, will lose its stimulant to grow and will shrink. Two ways are open to reach this goal: an operation to remove the tissue of the testicle (castration) or medication that inhibits testosterone production by the testicles ( a socalled chemical castration); both have the same result. An unavoidable complication of both is the loss of potency and libido. Unfortunately, after a while the cancer will become insensitive to this treatment and start growing again; then additional medication will be needed. 

Physical condition.
If no spreading of the cancer has occurred and the cancer is confined to the prostate, there is a possibility to cure the cancer.

The prostate can be completely removed, so that the cancer inside is removed with it. Contrary to an 'open prostatectomy' in case of a benign enlargement of the prostate (when only part of the prostate is removed) this 'radical prostatectomy' is a major operation, for which a pretty good state of health is necessary. Because prostate cancer is mostly found in the elderly, who might suffer from other diseases, it often happens that the physical condition of the patient prohibits such an operation. Apart from this, these operations may lead to impotence or incontinence, although this does not happen as often as it used to. 

External irradiation of the prostate may be considered an alternative, which can also provide a cure for prostate cancer. This is, however, in a sense an invisible treatment, since the effect of treatment is not as instant as an operation. Radiation therapy is not without its complications, although techniques have improved over the years. The healthy tissue surrounding the prostate will also be irradiated; the bladder might get 'scarred' and subsequently shrink. Radiation therapy may also lead to impotence, because the nerves controlling potency lie just beside the prostate and can be damaged. Also the rectum, lying right behind the prostate, may be damaged, causing a chronic inflammation and irritation. Although irradiation of the prostate clearly has its disadvantages, it is an accepted cure for prostate cancer, which is generally undergone without too much side-effects.

In a special type of radiation therapy small needles are inserted into the prostate under general anaesthesia and small pellets made of radioactive material left behind. In this way a high dose of radiation is administered for a prolonged time to the cancer tissue without much harm to the surroun ding healthy tissues, thus causing less side-effects. This technique is rather new and its effects in the long run largely unknown. At the moment it seems that the cancer can be adequately treated, although not all cancer cells will be killed; the surviving cells are presumably damaged to such an extend, that they will not cause any harm in the future. This type of treatment is usually only offered on an experimental base and has not yet been generally accepted.


In the case of prostate cancer, 'to do nothing' may be an appropriate form of treatment. In some case, even if the cancer has not spread, the treatment can be worse than the disease. Especially in the elderly, when the cancer has been found accidentally, it is often improbable to expect the cancer to do much harm in the short lifetime left; treating the cancer will then cause damage without the benefit of an extended or better life.

At younger ages, treatment of prostate cancer may not always be considered the only therapy. It was shown that in some men prostate cancer can be found, but it will never lead to any problems like spreading, pain, etcetera. Unfortunately, in most cases it has proven to be very difficult, if not impossible to separate the men with 'active' cancer from the ones with the 'sleeping' variety. Still, in some cases it is decided to wait and see. Sometimes, when the tissue that is removed during an operation for a benign prostatic enlargement is examined, cancer cell are found in small numbers (less than 5 percent). In most of these cases the remaining cancer cells will be either absent or will never be active, so treatment is unnecessary. These patient should, however, be followed up for several years to be able to start treatment if and when the cancer should turn active after all. 


Further Reading

The Inner Body - The Prostate Gland


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