Cancer Detection : DNA Study Brings ' New Era '

[mickmyrna]

Scientists have revealed a major leap forward in cancer detection after finding dozens of common genetic changes that can increase the risk of the disease.

Tests on 250,000 patients found 83 inherited variations in the DNA code that could either raise or lower the chances of developing breast, ovarian or prostate cancer.

Together the cancers affect almost 100,000 people a year in the UK. More than 26,000 of them die.

The findings will allow doctors to identify women with a near 100% chance of developing breast cancer, and men with a one in two risk of prostate cancer.

Scientists have hailed the research as the dawn of a new era in cancer diagnosis and treatment.

Professor Ros Eeles from The Institute of Cancer Research said: "These results are the single biggest leap forward in finding the genetic causes of prostate cancer yet made.

"They allow us, for the first time, to identify men who have a very high risk of developing prostate cancer during their lifetime through inheritance of genetic variants.

"If we can show from further studies that such men benefit from regular screening we could have a big impact on the number of men dying from the disease."

This is the largest study of its kind, involving around 1,000 scientists around the world. They analysed DNA for tiny changes that could change the way genes work, altering cancer risk as a result.

In the near future patients could be asked to spit into a tube by their GP who could then run a £30 test on their DNA in the surgery.

They would then have an individual risk profile for some of the most common cancers.

The most immediate practical use of the research could be in women who carry the inherited breast cancer gene BRCA1. On average they face a 70% risk of developing breast cancer in their lifetime.

But the new genetic variants can give women much more detail on their risk. If they also inherit several of the newly identified high risk changes to their DNA their chances of developing the disease are raised to between 90 and 100%.

But if they inherit the protective DNA changes, their risk drops to below 30%.

Scientists say it could help women with the BRCA gene decide whether to have a preventative mastectomy. Sharon Osborne had her breasts removed last year because she carried the gene.

Professor Montse Garcia-Closas, another of the researchers, said the study was a "huge step" in understanding the causes of breast cancer.

"These findings will help us to predict who is at increased risk of developing the disease and who could benefit most from prevention strategies, such as lifestyle changes and chemo-prevention, and early-detection strategies, such as regular screening," she said.

Around 57% of cancer risk is set by genetic factors, with lifestyle making up the rest.

Scientists believe there could be thousands of genetic variations that affect cancer risk. Patients with lung and colorectal cancers are to be tested as part of a study starting this summer

The study was funded by Cancer Research UK and the Wellcome Trust. The results are published in a series of papers in journals including Nature Genetics, PLOS Genetics, and the American Journal of Human Genetics.

[Arthur Little]

Yes ... saw that last night on News At Ten!
... FASCINATING!

[Terpe]

Like Arthur, I also found this fascinating. Exciting too in a way. Especially when considering prostate cancer in UK where every hour one man dies from it.
We all know us men are not good at seeking help from the GP and this procedure, being so simple, could help tremendously.
I also heard an interview on BBC local radio yesterday that explained new and highly accurate non-invasive treatments for prostate cancer.

Many advancements being made these days.

[Doc Alan]

We’ve known for many years that the 200 + different types of cancer – a purposeless proliferation of cells – have genetic mutations. These may be spontaneous, increasing in numbers with age, and some are known to be inherited with increased risk of various cancers.


• This latest research identifies more DNA markers which could increase risk of breast, prostate, or ovarian cancer. The research scientists think this could lead in a few years to a more extensive DNA screening test than currently available.


• The cost ( in financial terms ) isn’t known. For a struggling UK National Health Service, let alone the majority of Filipinos who can never afford a doctor, it's a significant consideration.



• It’s not, in fact, the only consideration. Currently available tests, such as for “ breast cancer genes “ ( BRCA1 and 2 ) on selected people with a family history of this cancer, ONLY indicate risk. They’re NOT a diagnosis. Would someone be prepared for the consequences if they knew they had these genes ? Removal of breasts, ovaries, and large bowel to avoid the increased chances of cancer in all these sites ? Less drastic - but not 100% guaranteed - forms of prevention, such as drugs ?


• For people actually diagnosed with breast cancer in the UK, chances of cure - or at least long term survival - are steadily improving ( survival is only half as good in Philippines ). There is already effective screening – although it’s been criticised for over-diagnosis/treatment of patients who might never die from this cancer.



• Prostate cancer does kill too many men – but by FAR the majority with this diagnosis survive ( and die later of other causes ). There is no good screening test for this cancer ( “ PSA “ is unreliable ). Many prostate cancers are “ low grade “ , requiring minimal or no treatment – but the diagnosis, once made, has many implications. Not all men would wish to know whether or not they are at increased risk ( but don’t actually have ) this cancer.


• There is also no good screening test for ovarian cancer, which has a bad outlook overall. But as with EVERY other cancer type, there is a range of ovarian cancers ( with good to bad outlooks ). Not every woman would wish to know she is at increased risk of this cancer.



• Even if such DNA screening tests become available, and affordable, in the future - whether for cancer, Alzheimer’s disease, diabetes or heart disease – not everyone would want them. They don’t provide a diagnosis, just a future degree of risk. At the very least, counselling and informed consent would be needed. Insurance companies - and others - might wish to know the results.


• Cancer is increasing in frequency – the most significant risk factor being increasing age. But at least 2 / 5 cancers result from lifestyle “ choices “. Risks could be reduced by not smoking, improving diet, avoiding obesity, keeping active, and avoiding excessive sun exposure. Occupation, education/awareness, and screening for early cancers ( breast, bowel, cervix ) are other factors. A DNA test to prove NO risk of ANY cancer is highly unlikely.



• Two cancers, both of which are much commoner in the Philippines, can be reduced in frequency - if not completely prevented - by vaccines available now in both countries. These are HPV vaccines ( cervical cancer ) and hepatitis B vaccine ( liver cancer ).


• All this we already know. The genetic research is interesting, helps the scientists with their research grants, and keeps medical journalists busy. But the implications of population testing for conditions which people MIGHT get in the future need to be balanced against applying what we know and can afford NOW – whether in UK, Philippines, or elsewhere in the world.