Daily aspirin could block growth of breast cancer

A study led by an Indian-origin researcher has found a daily dose of aspirin is effective at blocking breast tumour growth in laboratory tests.

Aspirin is used worldwide as a 'blood thinner' and to relieve inflammation, pain and fever.

The trick is to ensure conditions around cancer stem cells are not conducive for reproduction, something aspirin seems able to do, said Sushanta Banerjee, professor at the University of Kansas Medical Centre in the US.

"We could give aspirin after chemotherapy to prevent relapse and keep the pressure on, which we saw was effective in both the laboratory and the mouse model, and we could use it preventatively," Banerjee noted.

Experts suggest patients to consult with a doctor before starting a daily aspirin regimen. The drug is known to thin the blood and increase the risk of gastrointestinal bleeding.

"Of course there is a risk, but you have to weigh that against the risks of cancer," Banerjee said.

To test his theory that aspirin could alter the molecular signature in breast cancer cells enough that they would not spread, Banerjee used both incubated cells and mouse models.

For the cell test, breast cancer cells were placed in 96 separate plates and then incubated. Just over half the cultures were exposed to differing doses of acetylsalicylic acid, commonly known as aspirin.

According to Banerjee, exposure to aspirin dramatically increased the rate of cell death in the test. For those cells that did not die off, many were left unable to grow.

The second part of his study involved studying 20 mice with aggressive tumours.

For 15 days, half the mice were given the human equivalent of 75 milligrams of aspirin per day, which is considered a low dose.

At the end of the study period, the tumours were weighed. Mice that received aspirin had tumours that were, on average, 47 percent smaller.

To show that aspirin could also prevent cancer, the researchers gave an additional group of mice aspirin for 10 days before exposing them to cancer cells.

After 15 days, those mice had significantly less cancerous growth than the control group.

"We found aspirin caused these residual cancer cells to lose their self-renewal properties," Banerjee said.

The study is to appear in the forthcoming issue of the journal Laboratory Investigation.