Farmworkers exposed to high levels of pesticides, as well as home gardeners who use these chemicals to kill insects and fungus on their house plants, run a higher risk of brain cancer, according to a study to be released on Tuesday.

Researchers in southwestern France looked at 221 cases of brain tumours and matched those cases with 442 healthy individuals of similar age and background from the general population.

They found that all agriculture workers exposed to pesticides had a slightly elevated risk to the disease compared with healthy counterparts.

Those exposed to the highest levels of the chemicals ran more than twice the risk, and especially so with a form of cancer known as glioma, which is rapidly lethal.

A "significant increase" in cancer risk was also seen among people who treated house plants with pesticides.

The study, released online on Tuesday by the British journal Occupational and Environmental Medicine, adds to previous investigations into the link between pesticides and cancer.

The research took place in the Bordeaux wine-growing region, where 80% of all pesticides used are fungicides. The chemicals are mixed and sprayed in a mist to protect vines from fungus attack.

Meanwhile, a study suggsted that women with early-stage breast tumours can undergo a shorter course of radiation without a greater risk that their cancer will come back years later.

The results are good news for women who must quit work or travel far to receive the five-week, daily treatments usually given. "This is very disruptive to your life. If we could achieve the same outcome with less frequent visits to the radiation centre ... this would be a tremendous benefit," said Julie Gralow of the Fred Hutchinson Cancer Center in Seattle.