WHAT EXACTLY is the prostate-specific antigen (PSA) blood test for the prostate?
Prostate-specific antigen (PSA) is a protein produced by the cells of the prostate gland. The PSA test is a simple blood test, which can be done in most laboratories. Because PSA is produced by the body and can be used to detect disease, it is sometimes called a tumour marker. It is normal for men to have low levels of PSA in their blood; however, an elevated level of PSA in the blood stream does not necessarily indicate a cancer of the prostate.
An elevated PSA is simply a warning signal that further tests need to be done as benign (not cancerous) conditions can also increase PSA levels.
As men age, both benign prostate conditions and prostate cancer become more frequent. The most common benign prostate conditions are prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH: enlargement of the prostate).
There is no evidence that prostatitis or BPH causes cancer, but it is possible for a man to have one or both of these conditions and to develop prostate cancer as well.
PSA levels alone do not give doctors enough information to distinguish between benign prostate conditions and cancer. However, the doctor will take the result of the PSA test into account when deciding whether to check further for signs of prostate cancer.
DOES A vasectomy work immediately and how effective is it in the long term?
A vasectomy does not work immediately and it is important that some form of contraception is used until it is confirmed that there are no sperm in the ejaculate. Immediately after a vasectomy, active sperm remain in the semen for a period. It may take 15 to 20 ejaculations and several weeks before your semen is free of sperm.
After your vasectomy you should be given full details about semen analysis and after you have provided the samples you will be informed when it is safe to dispense with other forms of contraception.
You can only dispense with other forms of contraception when you have two semen specimens showing no sperm.
Vasectomy is virtually 100 per cent effective but there are occasional failures where the vasa rejoin.
This happens in 0.1 per cent of cases in the first three months and in 0.02 per cent of cases in the first three years after the operation. By comparison, the failure rate for latex condoms is 12 per cent or more; for diaphragms, it's 18 per cent.
I HAD acne as a teenager and, now in my 40s, I have bad scarring on my cheeks. A friend told me that this could be cleared by laser. Is this true?
Acne scarring affects 30 per cent of people who have had moderate or severe acne.
Acne scarring can be divided into early and late scarring. The type you describe, late scars, never completely disappear.
However, it can be improved with some techniques. There are different types of scars that one gets in acne, and there are treatments for each type of scar. Most people have a mixture of scars and so need a mixture of treatments.
Laser resurfacing, where the top layers of the skin are vaporised, can be helpful. A similar technique, though less high tech, is dermabrasion.
Both of these work by smoothing out irregularities in the skin's surface, like sanding a rough piece of wood. One new type of resurfacing laser avoids that "raw skin" look by breaking the laser beam up into many smaller beams, a bit like a camera breaks up a picture in pixels. Other types of scars can be helped by surgery, such as cutting out larger scars, or grafting very small (ice pick) scars. If you are going to have treatment for your acne scarring, it is also important that you have realistic expectations of what can be done.
Most studies show that if there is an improvement, that it is never very marked and no treatment is ever going to give you back a perfect complexion.
Obviously, the best treatment for acne scarring is to try to prevent it by seeking treatment for acne early with a doctor or dermatologist when you're a teenager or young adult before the scarring occurs.
This column was edited by Thomas Lynch, consultant urological surgeon, St James's Hospital, Dublin, with contributions from Dr Nap Keeling, consultant gastroenterologist, and Dr Patrick Ormond, consultant dermatologist and dermatological surgeon
" As men age, both benign prostate conditions and prostate cancer become more frequent
" The best treatment for acne scarring is to try to prevent it by seeking treatment for acne early with a doctor or dermatologist when you're a teenager or young adult before the scarring occurs