In lab tests, the modified microbes virtually halted the spreading of pancreatic cancer in mice without harming healthy tissue, the Daily Express reported.
The bacteria, a weakened form of the Listeria bug, which causes food poisoning, and act like missiles tipped with atomic warheads.
When the bacteria infect cancer cells, they destroy them with blasts of radiation but the emissions are short-lived, so damage is largely confined to the target area.
Scientists studied the treatment using mice with a highly aggressive form of pancreatic cancer. They found the bacteria dramatically reduced the cancer's spread, or metastasis.
"We're encouraged that we've been able to achieve a 90 percent reduction in metastases in our first round of experiments," study co-author Dr Claudia Gravekamp, from the Albert Einstein College of Medicine in New York City, said.
The new research builds on previous work that suggested that Listeria may have cancer-fighting potential.
Several years ago scientists found that a weakened form of Listeria monocytogenes bacteria can infect cancer cells while leaving normal cells unharmed. Later they showed that it could be harnessed to carry an anti-cancer drug into tumour cells in laboratory cultures, but the approach was never tested in animals.
The research has been published in the journal Proceedings of the National Academy of Sciences.