How reliable are blood tests for prostate cancer? Ask the GP Dr Martin Scurr


Concerned about my frequent toilet visits, a GP gave me a PSA blood test. This was normal for my age of 73 (1.4), but examination revealed a small, hard lump and an MRI diagnosed prostate cancer. How reliable are PSA tests?

David Fisher, Nottinghamshire.

Prostate cancer is the most common cancer in men, with one in eight diagnosed. There have been calls for middle-aged men to be screened for the disease, primarily using the prostate-specific antigen (PSA) blood test, which you had.

PSA is a protein made by the prostate, the walnut-sized gland located below the bladder, and the amount that ends up in the blood can give doctors an idea of ??how healthy it is. This test is far from perfect, however, as PSA levels can be elevated by a range of factors, including exercise, sexual activity, an enlarged prostate, constipation and infection – as well as cancer.

Prostate cancer is the most common cancer in men - one in eight is diagnosed. [File image]

Prostate cancer is the most common cancer in men, with one in eight diagnosed. [File image]

As you have discovered, it is also possible to have a false negative result – where the test suggests there is no cancer when there is. Therefore, physical examination is vital.

In your case, the cancer was discovered because you had urinary symptoms that your doctor rightly wanted to investigate further.

However, a DRE (digital rectal exam) can only detect tumors at the front and back of the prostate — and 25 percent of tumors occur elsewhere in the gland.

In terms of screening, the most reliable option is magnetic resonance imaging (MRI), as it allows you to see inside the gland. But one problem is the limited availability on the NHS.

Separately, researchers are looking at tests to detect cancer DNA fragments in the bloodstream. My advice if you have symptoms or are 50 or older and decide to have your PSA levels tested, see your GP.

There have been calls for middle-aged men to be screened for the disease, primarily using the prostate-specific antigen (PSA) blood test. [File image]

There have been calls for middle-aged men to be screened for the disease, primarily using the prostate-specific antigen (PSA) blood test. [File image]

There have been calls for middle-aged men to be screened for the disease, primarily using the prostate-specific antigen (PSA) blood test. [File image]

The best policy is to screen only those at higher risk: this includes men with a first-degree relative (i.e., a father or brother) who has been diagnosed with prostate cancer under the age of 65, and black men (who, for understandable reasons, have a higher risk).

I hope your cancer is confined to the prostate, as is the case in at least 78 percent of patients at the time of diagnosis.

If this is the case, the likely treatment is surgery to remove the gland. I wish you a speedy and smooth recovery.

Is a daily calcium supplement a good idea after being diagnosed with osteopenia?

Liz Landau, South London.

This is a good question, as there is a lot of confusion about the term osteopenia (as opposed to osteoporosis), and even more about whether calcium supplements are advisable.

Osteopenia refers to the loss of bone mineral – primarily calcium – that we should all expect as the years go by. It is a normal part of the aging process and is caused by the body reabsorbing calcium rather than staying in the bones where it keeps them strong.

There is much confusion about the term osteopenia (as opposed to osteoporosis), and even more about whether calcium supplements are advisable, writes Dr. Martin Scurr.

There is much confusion about the term osteopenia (as opposed to osteoporosis), and even more about whether calcium supplements are advisable, writes Dr. Martin Scurr.

There is much confusion about the term osteopenia (as opposed to osteoporosis), and even more about whether calcium supplements are advisable, writes Dr. Martin Scurr.

It’s not a medical diagnosis as such, but rather a warning that your bone density is declining. This can progress to osteoporosis, where bone mineral density becomes lower than expected for someone your age, increasing the risk of fractures.

Risk factors include being female (due to the drop in estrogen during menopause), as well as age, body size, family history, and medications such as glucocorticoids. A diet deficient in calcium and vitamin D is another factor.

A daily calcium supplement can help, especially if taken along with a vitamin D supplement, as it promotes calcium absorption. The suggestion is 1,000 mg of calcium and 600 IU of vitamin D.

There is strong evidence that these supplements reduce bone turnover by one-fifth – a powerful mechanism for limiting progression from osteopenia to osteoporosis.

However, studies have shown that long-term use of calcium supplements may increase the risk of heart disease in some people. It is therefore a decision that must be made after consultation with your doctor.

Eating a diet rich in calcium-containing foods — milk, cheese, and leafy green vegetables — doesn’t have this negative effect, so should be a priority for you in the meantime.

In my opinion…Patients should be prioritized over pay

Every time I go grocery shopping I wonder if I read the prices right. They seem to be increasing weekly.

The cost of living is more expensive than it used to be; there can be no doubt about that. So on the one hand I understand why junior doctors want to raise their wages – the basis of their continued union action.

A doctor starting his basic training will earn around £29,384 - not particularly well paid. However, unlike other jobs, the opportunities for advancement and pay rise are guaranteed. [File image]

A doctor starting his basic training will earn around £29,384 - not particularly well paid. However, unlike other jobs, the opportunities for advancement and pay rise are guaranteed. [File image]

A doctor starting his basic training will earn around £29,384 – not particularly well paid. However, unlike other jobs, the opportunities for advancement and pay rise are guaranteed. [File image]

A doctor starting his basic training will earn around £29,384 – not particularly well paid. However, unlike other jobs, the opportunities for advancement and pay rise are guaranteed. While I accept that their salaries have not risen in line with inflation, I am concerned that people in medical training are willing to go on strike day after day, resulting in 196,000 canceled patient appointments to date.

Recommended reading for anyone aspiring to become a doctor has always been the work of William Osler, who became a professor of medicine at the University of Oxford. One of his mottos was ‘Do the right thing and do it first’. Indeed.

Write to Dr. Scurr

Write to dr. Scurr at Good Health, Daily Mail, 9 Derry Street, London W8 5HY or email: [email protected] — add contact details. Dr. Scurr cannot respond to personal correspondence. Answers should be taken in a general context. In case of health problems, consult your own doctor.