Anti-cancer drugs in clinical trials for some types of leukaemia could prove effective in treating the most common type of breast cancer, Australian researchers have claimed.
The researchers at the Walter and Eliza Hall Institute have been investigating in their study that a drug known as BH3-mimetics, when combined with another breast cancer drug called tamoxifen, effectively treats some types of breast cancers, according to 'The Age' report today.
Known as aggressive oestrogen receptor-positive, or ER-positive, they represent about 70 per cent of breast cancers, according to the report.
Geoff Lindeman, the joint head of Walter and Eliza Hall's breast cancer laboratory, said that in animal trials the drug combination had either deferred tumour growth or led to tumour disappearance.
"For breast cancer it looks as though you need to have the two working together," he said adding "The drug by itself does not appear effective, but certainly with the conventional breast cancer drug tamoxifen it changes things significantly.
"The researchers had implanted tumour samples taken from breast cancer patients in mice whose immune system was unable to reject the tissue. The mice were then treated with the drug combination. This meant the responses that we saw were in real human breast cancers," he said.
"We're all very excited by this."
Lindeman said the findings also had potential implications for other types of tumour-based cancers.
The common thread between these breast cancer types and some types of leukaemia is the molecule BCL-2.
This molecule, which is expressed in up to 85 per cent of ER-positive breast cancers, serves as a kind of lifeline for cancer tumours.
"BCL-2 can make tumours more resistant to chemotherapy," Lindeman said.
He said "So in a sense we have turned this lifeline into an Achilles' heel because we're able to switch off the survival pathways of this specific molecule."
Lindeman said this made cancer cells less likely to survive treatment, when combined with the breast cancer drug tamoxifen.
