It would soon be possible to keep cancer at bay by killing off precancerous cells every few months, just like dentists scrape away plaque to prevent tooth decay.
Researchers have identified drugs that could accomplish the same in mice.
Until now, attempts at the "chemoprevention" of tumors have not been particularly successful, as the drugs are used to treat people who don't yet have cancer, only the mildest side effects are acceptable.
Thus, the drugs usually only inhibit the growth of precancerous cells, rather than killing them off, reports New Scientist.
Now, Xiangwei Wu, a molecular biologist at the MD Anderson Cancer Center in Houston, Texas, and his colleagues have found two compounds that kill precancerous polyps in mice.
One of these compounds is known to kill cancer cells, the other makes precancerous cells susceptible to the first compound.
When injected together, they killed up to 90 per cent of polyps and left normal cells unaffected.
The same mixture also killed human intestinal polyps in the lab.
If the drugs also kill polyps in people, they could be taken less frequently than drugs that merely inhibit growth, limiting side effects.
While a 90 per cent success rate would be poor for chemotherapy, only a tiny fraction of precancerous cells ultimately become malignant.
Thus, Wu said that just reducing their numbers could slash the risk of cancer.
The study has been published in Nature.