This article is from the source 'bbc' and was first published or seen on . It will not be checked again for changes.
You can find the current article at its original source at http://news.bbc.co.uk/go/rss/-/1/hi/health/7104075.stm
The article has changed 2 times. There is an RSS feed of changes available.
Previous version
1
Next version
Version 0 | Version 1 |
---|---|
Obesity 'may distort cancer test' | Obesity 'may distort cancer test' |
(2 days later) | |
Doctors must take body weight into account when reading test results for prostate cancer as obesity may distort the findings, a US study argues. | Doctors must take body weight into account when reading test results for prostate cancer as obesity may distort the findings, a US study argues. |
Obese men have more blood so the concentration of antigen, a marker for the disease, is lower, a team found. | Obese men have more blood so the concentration of antigen, a marker for the disease, is lower, a team found. |
The North Carolina study, published in the Journal of the American Medical Association, involved 14,000 patients. | The North Carolina study, published in the Journal of the American Medical Association, involved 14,000 patients. |
It may explain why obese men seem to have more aggressive cancers, as tumours may initially be missed. | It may explain why obese men seem to have more aggressive cancers, as tumours may initially be missed. |
The test for prostate-specific antigen, or PSA, is known to be notoriously unreliable. It's as if you dissolve a tablet in a cup of water versus a tub of water Dr Stephen Freedland | The test for prostate-specific antigen, or PSA, is known to be notoriously unreliable. It's as if you dissolve a tablet in a cup of water versus a tub of water Dr Stephen Freedland |
About a third of men with raised PSA levels will not have cancer, and will undergo unnecessary invasive tests. | About a third of men with raised PSA levels will not have cancer, and will undergo unnecessary invasive tests. |
Meanwhile, the test sometimes misses prostate cancer, as highlighted in this study. | Meanwhile, the test sometimes misses prostate cancer, as highlighted in this study. |
"We've known for a while that obese men tend to have lower PSA scores than normal weight men, but our study really proposes a reason why this happens, and points to a need for an adjustment in the way we interpret PSA scores to take body weight into account," said Dr Stephen Freedland, a urologist at the Duke Prostate Center. | "We've known for a while that obese men tend to have lower PSA scores than normal weight men, but our study really proposes a reason why this happens, and points to a need for an adjustment in the way we interpret PSA scores to take body weight into account," said Dr Stephen Freedland, a urologist at the Duke Prostate Center. |
"If not, we may be missing a large number of cancers each year." | "If not, we may be missing a large number of cancers each year." |
Working it out | Working it out |
At the extreme, the men in the most obese category had PSA concentrations as much as 21% lower than those of normal weight men. | At the extreme, the men in the most obese category had PSA concentrations as much as 21% lower than those of normal weight men. |
Dr Chris Hiley, of the Prostate Cancer Charity, said: "This study shows us yet another downside to obesity. An obese man's true PSA level is diluted by his increased blood volume caused by excess weight. | Dr Chris Hiley, of the Prostate Cancer Charity, said: "This study shows us yet another downside to obesity. An obese man's true PSA level is diluted by his increased blood volume caused by excess weight. |
"Doctors now need to work out how to take this into account so they can make an accurate estimate of the PSA level - important in the diagnosis and management of prostate cancer." | "Doctors now need to work out how to take this into account so they can make an accurate estimate of the PSA level - important in the diagnosis and management of prostate cancer." |
She added: "This finding could also be of wider significance in interpreting blood tests in other conditions that affect both men and women." | She added: "This finding could also be of wider significance in interpreting blood tests in other conditions that affect both men and women." |
In the UK, the disease now accounts for 13% of male cancer deaths, and is the second most common cause of cancer death in men, after lung cancer. | In the UK, the disease now accounts for 13% of male cancer deaths, and is the second most common cause of cancer death in men, after lung cancer. |
Previous version
1
Next version