Secondary breast and bowel piggy backing on patient’s blood vessels ……. November 2016

New research, by the Institute of Cancer Research, into breast and bowel cancers that have spread to the liver shows that tumours power their growth using pre-existing blood vessels rather than developing new ones.

This explains why existing treatments which block the development of new blood vessels have so far failed to have the desired effect of slowing the growth of secondary breast cancer tumours. Funded by Breast Cancer Now, scientists have begun to look at whether secondary breast and bowel cancers occurring in the liver used pre-existing blood vessels to grow, known as vessel co-option, or grow new blood vessels, called angiogenesis.
Previously, scientists thought all cancers needed to establish new blood vessels in order to grow, and there have been several anti-angiogenesis drugs to help combat this. Using 187 samples from 92 bowel cancer patients, researchers found that 40% of secondary tumours obtained blood through existing blood vessels. For the first time, they found that tumours which mainly used vessel co-option responded poorly to combined treatment with angiogenesis and chemotherapy.

Researchers also looked into whether it was possible to block the vessel co-option process in secondary tumours occurring in the liver, and combined this approach with an anti-angiogenesis drug, to test a two-pronged approach to treatment. They found that when they “switched off” the gene that helps cancer cells move towards existing blood vessels and then treated the tumours with anti-angiogenesis drug in mice, there was significantly less tumour growth.
“It was thought for a long time that cancers that have spread to the liver must generate new blood vessels to thrive – but now we’ve show that they can piggy back on pre-existing vessels instead. We now need to undertake more research to understand exactly how tumours recruit pre-existing blood vessels,” Dr. Andrew Reynolds, who led the research says. He looks forward to the possibility of follow up studies and possible drug combinations that block both vessel co-option and angiogenesis that could provide hope for future treatments.

To read more at Breast Cancer Now’s website click here.