Friday 19 September 2008

Sexual Function After Treatment

Introduction

Treatment for prostate cancer can affect your sexual function. This information sheet describes what may happen and why, and what is available to assist you. Not all aspects of male sexual problems are covered here - just the ones you may encounter with treatment.

When a man has trouble gaining an erection, doctors call this "erectile dysfunction" or ED. Many factors can influence normal sexual function and one of the most important is simply growing older! But others are diabetes, smoking or a history of smoking, high alcohol intake and some medications. Emotional or psychological stress can also cause a decline in sexual activity. Many men will have a combination of these influential factors, and so there is a wide variability in sexual function as men grow older.

There is a wide variability in sexual function as men grow older; however a gradual decline is normal.

Prostate cancer therapy is an additional negative influence on whatever your normal level of function is. Thus men who had frequent sexual activity before their treatment are more likely to continue this after treatment, than men who were only occasionally sexually active. Similarly those who have weak erections before treatment are likely to have weaker or no erections afterwards. The prostate cancer itself rarely has a direct effect on reducing erectile function.

But let us now look more closely at what sexual activity involves.


Normal Sexual Function

There are four parts to normal sexual function in men - sex drive (also called libido), erection, ejaculation (emission of fluid), and orgasm.


What causes sex drive?

At puberty, the brain increases production of hormones that stimulate greater production of testosterone by the testicles. Testosterone is the main hormone responsible for the development of male sex organs and sexual behaviour. When testosterone levels drop, sex drive diminishes. This occurs naturally with aging, but may also occur with illness, some commonly used medications and with hormone treatment for prostate cancer.


What happens when you have an erection?

The penis contains nerves, smooth muscle and blood vessels in three spongy chambers called sinusoids. When a man is sexually stimulated, the nerves release a substance which causes the smooth muscle to relax. This causes the spongy chambers to dilate and blood is pumped in. The penis elongates shutting off the veins so that blood doesn't leave the penis.

After ejaculation, the nerves stop releasing the smooth muscle relaxing substance, blood flow to the penis is reduced, blood flow out of it increases and the erection subsides. It follows that both nerves and healthy blood vessels are important for erections. The nerves necessary for erections are separate from those involved in the skin sensation from the penis and those involved in orgasm.

Maintaining a healthy blood flow to the penis is essential for successful erections and lifestyle factors can improve it: quitting smoking, reducing alcohol intake, eating a healthy diet, and engaging in regular exercise and physical activity - all can help improve blood flow.


What happens during ejaculation?

Sperm mature and are stored in a structure close to each testis called the epididymis and structures close to the bladder called the seminal vesicles (Figure 1). During ejaculation, semen, which contains sperm and fluid from other sources (such as the prostate and seminal vesicles), is propelled by muscular contractions along tubes into the urethra (urine tube). During ejaculation, a muscular valve at the bladder outlet closes, blocking the outflow of urine and forcing semen out of the penis.





What happens during orgasm?

Orgasm mainly happens in the brain and has little to do with the prostate. As long as normal skin sensation is intact, orgasm can occur even in the absence of an erection and ejaculation. This is the key reason why satisfactory sexual function can be restored to most men after prostate cancer treatment involving surgery or radiotherapy. The common exception here is men receiving hormone therapy, because this frequently causes loss of libido (sexual desire) as well as function.


Why are erections affected by treatment to the prostate gland?

The prostate is not particularly important for normal sexual function. It adds secretions to the ejaculate, which help the sperm to survive. However it does not control the ability to have an erection.

Nevertheless, structures which are important to erectile function lie in close proximity to the prostate and can be damaged when the prostate cancer is treated. A series of fine nerves which assist in the ability to have an erection lie in bundles against the prostatic capsule. During sexual arousal, blood fills the penis to create an erection, and small blood vessels expand in order to deliver enough blood. Prostate cancer treatment such as radiotherapy and surgery can damage both the nerves and the blood vessels.


Trans-urethral resection of the prostate gland

A trans-urethral resection of the prostate (TURP) is an operation to remove prostate tissue through the urine outflow tube (the urethra). It can improve urine flow when the tube is blocked by benign enlargement of the prostate, or by prostate cancer. Only a part of the prostate is removed and so some men call this a "re-bore".

During this operation, the constricting "valve" at the urinary bladder outlet is often opened - so that during ejaculation (because there's no barrier to keep semen from going back into the bladder), semen is propelled into the bladder rather than along the penis to the outside. This results in a "dry ejaculation". It is neither painful nor dangerous and the semen is passed out when the bladder is next emptied.


Radical prostatectomy

During this operation for cancer, the entire prostate and the seminal vesicles are removed. After a radical prostatectomy, initially the focus of attention is on the return of urinary control (continence), as the nerves and muscles controlling urination also lie close to the prostate area.

A man will normally lose the capacity to have erections immediately after the operation, however with time, there is usually some return of erections. In part, the return of erections depends on the extent to which the nerves which lie close to the prostate have been spared during surgery. This in turn depends on how far the cancer extends into this area and so is a choice that the surgeon can make only at the time of surgery. To spare the nerves and also leave cancer behind would defeat the purpose of the operation.

However if it is considered safe to do so, techniques are available to preserve these nerves. More recently some surgeons have been reconstructing the pathway by grafting nerves taken from another part of the body, into the area. Nevertheless, although the nerves are important they are not essential. After a radical prostatectomy, approximately 10% of men who did not have nerves spared have some return of erections.

You may be advised by your doctor to "give it time". After surgery your body needs time to heal. Erections may return gradually. The erection you may have 4 months after surgery is not necessarily as good as the one you will have 2 years later. Many men experience improved natural erections over time with continued improvement reported for up to 4 years postoperatively! Aids to assist with an erection after surgery may improve your long-term function and so you may want to consider these quite early - only a few weeks after your operation.

It is not necessary to achieve erection or penetration in order to achieve orgasm!

After a radical prostatectomy, the stimuli that cause an erection may need to be altered. Visual stimulation may not be as important as direct stimulation of the penis. No damage can be done through experimenting with your sexual activity. If you have a partial erection, go ahead and attempt intercourse - vaginal stimulation will encourage further and better quality erections. Continue with sexual relations even though erections may not occur. Don't wait for the time when they "just happen".

Natural erections can improve for up to 4 years after a radical prostatectomy.

Soon after surgery traditional vaginal penetration may not be easy. Some men have found that if they attempt sexual activity standing up, they can achieve a much firmer erection. Sexual activity can continue either while a man remains standing, or while he's kneeling. Lubrications, such as K-Y jelly, may also help.


Radiotherapy

After radiotherapy to the prostate, sexual function is not usually affected in the short to medium term. Several years after radiotherapy erectile function typically declines gradually. This is thought to be due to the progressive damage to the nerves and small blood vessels near the prostate that are important for erections. It is reported that brachytherapy (interstitial radiotherapy) to control prostate cancer carries a lower risk of erectile dysfunction in comparison to conformal radiotherapy delivered by external beam (see Mr PHIP no 3) or surgery.

Further research is needed on this issue. Intensity modulated radiotherapy is a newer delivery technique that may reduce damage to healthy tissues adjacent to the prostate. Remember also that aging itself has an effect on sexual function!


Hormone Treatment

Control of prostate cancer using hormone therapy usually results in the reduction of testosterone, and sex drive will be diminished for most men. However, continuation of simple physical expressions of love and concern between you and your partner can be very important in the ensuing years.


What you can do

Medications


A group of drugs available in Australia called PDE5 inhibitors (Table 1) can help men achieve an erection or better quality erection. If the medication doesn't work at the first attempt, it may be worthwhile retrying a month or so later. These are not aphrodisiacs (ie do not increase sex drive) and typically direct penile stimulation is required to stimulate an erection when using these drugs. Men on hormone therapy may be helped, but their sexual desire is usually low. These drugs are not subsidized by the Government Pharmaceutical Benefits Scheme (PBS).

Men taking nitrate medication (eg. anginine) for a heart condition must not use these medications as the risk of low blood pressure and sudden death is increased. Your doctor will advise you on your risk or may recommend you seek advice from a heart specialist. Sexual activity is indeed a form of exercise and heart attacks are more likely to occur during exercise than otherwise.




Side effects

Headaches, facial flushing, indigestion and visual disturbances (not reported with Cialis) may be experienced by a few men. There are a small number of medications that if taken at the same time may increase the risk of these side effects, eg. the antibiotic erythromycin and antifungals such as ketoconazole.


Other products and ways of taking them will be made available in the future.

Injection therapy


Direct penile injections are the most effective form of therapy to achieve erections after a radical prostatectomy. A drug is injected each time an erection is required - this occurs without any direct sexual stimulation - it is a chemical response. Caverject ImpulseTM (alprostadil) is the most freely available but, as with PDE5 inhibitors, it is not supported by the PBS scheme.

It is important to start by injecting small doses (eg 2.5 - 5 micrograms) and then gradually increase the dose until a satisfactory result is achieved. This reduces the risk of one of the uncommon side effects - a painful prolonged erection, called priapism. Any erection lasting more than 4 hours with this type of medication requires urgent medical intervention. Typically blood is drained from the penis and an "antidote" injected into the penis. Some doctors prescribe a tablet to help deflate the erection, should it last for 3 hours or more, eg. pseudoephidrine 60 - 120 mg orally.

Most doctors recommend a maximum of 3 injections per week because more frequent use may lead to scarring within the penis. The correct technique of injection therapy can be learned by most men, provided their eyesight and dexterity are reasonable.

There are injectable medications other than Caverject ImpulseTM that have been used, some in combination. As all rely on a relatively normal blood supply to the penis, injection therapy can fail if this is inadequate. Caverject ImpulseTM is in a powder form that can be stored or transported at room temperature. When required it is mixed to a solution in the syringe. Other agents usually require refrigeration to store.





Vacuum erection devices (VEDs)

An erection can be created by drawing blood into the penis by way of a vacuum pump placed over the penis. Once the erection is created, a constrictive band is placed onto the penile base close to the pubic bone to maintain the erection during sexual activity. The band should be released within 30 minutes to reduce the risk of damage to the penis itself. A VED is reusable. Education and personal experience with these devices is very helpful and most companies have video tapes which demonstrate their use. VEDs are not available on the PBS and cost between $500 and $800 each.





Penile prostheses

Devices can be placed within the penis to create a mechanical erection. Such an operation is normally not performed until 2 years after radical prostatectomy since recovery may occur naturally prior to this. During the operation, the normal spongy penile structure is destroyed to allow the device to be placed. Most of the cost of inserting these devices is covered by private health funds.





In conclusion

Most men are able to enjoy a sexual relationship following surgery and radiotherapy, since their sensation of arousal, excitement and orgasm is typically unchanged. What is often lacking is the spontaneous event of a rigid penis. A number of options for achieving an erection have been mentioned and one or more of these is often successful. You can experiment also with other forms of sexual intimacy - there may be new discoveries to be made!

Remember there is no potential for harm to your sexual partner from either the cancer or from any potential urinary leakage during a sexual encounter. Your partner, wherever possible should be included in discussions about your sexuality and treatment choices.

Check out these useful websites:
www.impotence.org www.prostatehealth.org.au www.prostatehealth.org.au

Keep in mind the larger picture. There is far more to a fulfilling relationship than an erect penis, even though the latter often becomes the focus of attention during consultations with doctors! There are many resources available to assist you to explore and develop your relationship (see below). The ultimate goal is to continue a fulfilling relationship and to be rid of a life threatening disease.

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