London, May 6 (IANS) A component found in broccoli may hold a key in the fight against breast cancer, a new study has said.

A research team from University of Michigan has found that sulforaphane targets and kills cancer stem cells as well as prevents new tumours from growing.

Current chemotherapy does not work against cancer stem cells. The researchers believe eliminating the cancer stem cells is the key to controlling cancer.

"Sulforaphane has been studied previously for its effects on cancer, but this study shows that its benefit is in inhibiting the breast cancer stem cells," Duxin Sun, the author of the study, was quoted as saying by telegraph.co.uk.

"This new insight suggests the potential of sulforaphane or broccoli extract to prevent or treat cancer by targeting the critical cancer stem cells," Sun said.

During the study, researchers took mice with breast cancer and injected varying concentrations of sulforaphane from the broccoli extract. They then used several established methods to assess the number of cancer stem cells in the tumours.

These measures showed a marked decrease in the cancer stem cell population after treatment with sulforaphane, with little effect on the normal cells.

The findings revealed cancer cells from mice treated with sulforaphane were unable to generate new tumours. The researchers then tested sulforaphane on human breast cancer cell cultures in the lab, finding similar decreases in the cancer stem cells.

They are currently developing a method to extract and preserve sulforaphane. The tests involved higher concentrations of sulforaphane than are available by simply eating broccoli.