New research has shown post-surgery radiotherapy can help those suffering with breast cancer to avoid a recurrence of the disease.
The treatment benefited those with dense breast tissue the most after having lumps removed, a study of 335 patients showed.
Twenty-two per cent of women who had not undergone radiotherapy suffered a relapse over a 10-year time span - but the rate more than halved - to 10% - when sufferers did receive the treatment.
Although breast tissue density was of "minimal" significance when radiotherapy was given, the difference was marked when those with high density breast tissue did not receive the treatment.
Of those, 40% suffered a relapse within 10 years. But none of the women with low density breast tissue developed further complications after not receiving radiotherapy.
Dr Steven Narod, of the Women's College Research Institute in Toronto, said: "The composition of the breast tissue surrounding the breast cancer is important in predicting whether or not a breast cancer will return after surgery."
In the report, the authors said it was crucial to establish the cases in which radiotherapy would help.
"The findings indicate that women with low breast density, who have a low chance of recurrence after surgery, may not need radiation but that women with high breast density could significantly benefit from the additional therapy," they said.
Copyright © Press Association 2009
<http://www.womensresearch.ca/news/index.php> (Women's College Research Institute)