As with erectile dysfunction (ED) in general, when it occurs in association with cancer or other serious illnesses there is usually a mixture of physical and psychological causes.

The two types of cancer most likely to be associated with ED are prostate cancer and cancer of the lower bowel (rectum). It is more common for the treatments for these cancers to cause erectile dysfunction rather than the cancer itself.

Prostate cancer
The prostate gland is located underneath the bladder and it produces a fluid that is part of semen. Running through the middle of the prostate is the urine channel from the bladder. This means prostate disease, which is often benign, can disturb bladder behaviour.

Prostate cancer is one of the most common cancers in men and its frequency is increasing. Partly this is because men are living longer, and prostate cancer has always been more common in older men.

There are many types of prostate cancer treatment. The type used depends largely on the stage of the disease.

Radical prostatectomy
Radical prostatectomy is an operation to remove the prostate gland by surgery. However, this carries a fairly high risk of disturbing the nerves that go to the penis and therefore can cause erectile dysfunction.

It’s difficult to gauge the percentage of men who suffer ED after the operation because the range of results published in medical literature varies.

The risk of developing erectile dysfunction is reduced when nerve-sparing procedures can be used. The type of protectomy performed depends on the extent and severity of the prostate cancer. If appropriate the surgeon may be able to spare the nerve bundles to the penis as they pass alongside the prostate.

ED treatments are potentially effective in men who have had a radical prostatectomy - although they may not all be equally so. Oral therapy (ie tablets) seems to be less effective in men who have had non-nerve sparing surgery. Trial and error might be required to find the most suitable treatment for an individual.

Transurethral resection of prostate (TURP)
This is commonly used to treat men with benign prosthatic enlargement. It is only used to treat cancer in men with poor health and very advanced disease. Such a treatment can also be associated with ED.

Bowel cancer
Cancer of the bowel is another common cancer. If diagnosed early, it can have a very good outcome.

The bowel is very long. It is usually possible to remove the section that contains the cancer, and then join the ends of the bowel back together again. This avoids the need for a ‘bag’, or ‘stoma’, on the tummy wall.

Surgery to remove a tumour in the lower part of the bowel may damage the nerves responsible for erections. However, as with prostate cancer,treatments for EDmay work and the most effective one has to be chosen on an individual basis.

General issues
Although there are hundreds of different cancers, and there have been great leaps forward in treating many of them, for most people the ‘Big C’ is nearly always viewed with alarm.

During the initial period of anxiety, there may well be very little desire for sex. Some find the intimacy of sex a comfort during this difficult time, although this doesn’t necessarily mean it will be easy to resume a sexual relationship.

Relationship issues
Any serious illness can cause anxiety and uncertainty in a relationship. As far as sex is concerned, there could be a fear that:

  * sex could cause physical injuries
  * sex could cause the illness to break out again
  * the cancer could be contagious or sexually transmitted.

These kinds of worries are usually completely without foundation, but they can make a sexual relationship come to a standstill. It’s vital for couples in this situation to talk to each other, and to a doctor, about their concerns.

Usually, it will be enough just to be reassured that all is well, but sometimes the couple will benefit from being referred to a doctor or therapist specialising in psychosexual medicine.

If you have concerns about undertaking sexual intercourse then consult your doctor.

Support
There are many excellent support organisations for people with cancer (see links). The GP and nurses in primary care and the staff of the palliative care team are all there to help, too.