Mother dies of cancer and baby in remission as scientists prove tumours can be caught in the womb
By David Derbyshire
Pregnant women can transmit cancer to their unborn babies, British scientists have proved for the first time.
In an 'extremely rare' case that challenges conventional wisdom about human biology, a mother with leukaemia passed the blood disease to her daughter.
Normally a child's immune system would recognise and destroy any invasive cancer cells.
Although doctors know of 30 past cases of mothers and babies sharing the same cancer - usually leukaemia or the skin cancer melanoma - they have never before shown that the child's disease definitely originated in the mother.
Professor Mel Greaves, who led the study at the Institute of Cancer Research in Sutton, Surrey, said the risks to unborn babies were extemely low.
'It appears that in this and, we presume, other cases of mother to offspring cancer, the maternal cancer cells did cross the placenta into the developing foetus and succeeded in implanting because they were invisible to the immune system,' he said.
'We are pleased to have resolved this longstanding puzzle.
'But we stress that such mother to offspring transfer of cancer is exceedingly rare and the chances of any pregnant woman with cancer passing it on to her child are remote.'
The study investigated a case in Japan in which a 28-year-old was diagnosed with leukaemia shortly after she gave birth.
Eleven months later, her daughter-was also diagnosed with the disease. The child is now in remission since starting treatment about a year and a half ago.
Genetic tests on the child's blood cells showed that she had the cancer cells at birth and that they came from her mother, the journal Proceedings of the National Academy of Sciences reports.
Closer investigation revealed that the daughter's leukaemia cells were missing a vital piece of DNA that would have flagged them up as 'intruders' to her immune system.
Without this, her system was unable to target and destroy th cancer cells and she went on to develop the disease.
The researchers say the same mutation could allow melanoma cancer cells to pass from mother to baby.
However, they believe it is unlikely that other cancers could be passed on this way.
Professor Peter Johnson, of Cancer Research UK, said: 'This is an extremely unusual case, but this study is particularly revealing because it suggests that the cancer cells could only cause a problem in the baby by evading their immune system.
'This is really important research as it adds to the evidence that cancers need to evade the immune system before they can grow, giving hope that by alerting a patient's immune system to a cancer we can develop new types of treatment.
'Women needing cancer treatment-around the time of having a baby who are worried about this research should speak to the specialists looking after them for advice.'
Dr David Grant, scientific director at charity Leukaemia Research, added: 'The important message from this fascinating piece of research is that leukaemia cells can be destroyed by the immune system.
He added: 'Harnessing the power of the immune system to first cure and then protect patients from leukaemia is one of our priority areas of research.'
Cancer in pregnancy is rare, with only one in 1,000 pregnant women thought to be affected by the disease.
The outcome for mother and child depends on the type of cancer and the stage at which it is discovered.
Source : http://www.dailymail.co.uk/
Friday, October 16, 2009
Posted by Anast at 9:43 PM