Laboratory studies using mice suggest the compound, known as NOSH aspirin, could be effective against cancers of the colon, lung, breast, prostate, pancreas and blood, they said.
"The key components of this new compound are that it is very, very potent and yet it has minimal toxicity to the cells," researcher Khosrow Kashfi of The City College of New York said.
The compound was seen to shrink human colon cancer tumors implanted in mice by 85 percent "without adverse affects," he said.
A number of studies have indicated long-term low-dose (75mg a day) aspirin use can reduce the chance of developing certain cancers by up to half, but aspirin can cause serious stomach ulcers in some people, particularly the elderly.
The U.S. researchers have been working to develop a form of aspirin that does not affect the stomach lining and has much stronger anti-cancer qualities but acknowledged NOSH aspirin is still an experimental drug and clinical use in humans is "years away."
Still, other scientists say, the initial results are encouraging.
"It will be interesting to see how this particular compound progresses," Kat Arney, of Cancer Research UK, told Britain's The Daily Telegraph.