And aspirin's possible side effects -- notably the higher risk of bleeding episodes -- need to be taken into account when considering its use, they added.
"Expert committees that develop clinical guidelines will consider the totality of evidence about aspirin's risks and benefits when guidelines for aspirin use are next updated," said lead researcher Eric Jacobs, the society's strategic director of pharmacoepidemiology.
Jacobs said, until there are new guidelines, he doesn't recommend taking aspirin for cancer prevention.
"Although recent evidence about aspirin use and cancer is encouraging, it is still premature to recommend people start taking aspirin specifically to prevent cancer," he said.
Even low-dose aspirin can substantially increase the risk of serious gastrointestinal bleeding, Jacobs pointed out.