A daily dose of aspirin may be effective at blocking breast tumour growth, Indian-origin researchers have claimed.
Dr Sushanta Banerjee, research director of the Cancer Research Unit at the Kansas City Veterans Affairs Medical Center, and his team found that aspirin may be able to ensure that conditions around cancer stem cells are not conducive for reproduction.
"In cancer, when you treat the patient, initially the tumour will hopefully shrink. The problem comes 5 or 10 years down the road when the disease relapses," said Banerjee.
Cancer has stem cells, or residual cells. These cells have already survived chemotherapy or other cancer treatment and they go dormant until conditions in the body are more favourable for them to again reproduce.
"When they reappear they can be very aggressive, nasty tumours," 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 milligrammes 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 per cent 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," said Banerjee.
"Basically, they couldn't grow or reproduce. So there are two parts here. 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," he said.
Experts, however, suggest patients 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.
Other researchers in the study included Samdipto Sarkar, Dr Snigdha Banerjee, Dr Amlan Das, Archana De, and Dr Gargi Maity.
