The key to detecting, treating and saving women from dying of breast cancer may lie in early changes in cells that line the inner surfaces of organs, American scientists said on Wednesday.

More than 90 percent of all cancers begin in these epithelial cells. The disease develops when the cells undergo genetic changes, divide uncontrollably and spread to surrounding tissue.

Until now scientists believed that a regulatory system in the body, called senescence, was a barrier to cell growth. But researchers at the University of California, San Francisco have discovered that epithelial cells in the breast can bypass senescence, which could be one of the earliest signs of cancer.

"What we've discovered is that in tissue culture these human mammary epithelial cells spontaneously go past senescence. That in and of itself is an amazing finding because for all these years senescence, as classically described, was an insurmountable barrier to further growth," Dr Thea Tlsty, a molecular pathologist, said in a telephone interview.

The ramifications of the research are incredible because once the cells bypass the barrier they keep proliferating, undergo chromosomal changes and become very unstable which is what causes the mutations that fuel cancer.

IDENTIFYING CANCER EARLY ON

Tlsty and her colleagues not only discovered what was happening but also identified molecular markers that show it has occurred, which could be used to identify breast and other cancers at their earliest and most treatable stage.

"It gives us a way of identifying those cells that have gone beyond senescence and are in this vulnerable stage," Tlsty explained.

The scientists are in the process of seeing if the cells they observed in the laboratory samples react the same way in the human body.

If they do scientists may be able to identify very early pre-cancerous changes up to a decade before they would have resulted in a breast lump or showed up on a mammogram.

For millions of women the findings could mean the difference between early treatment and losing a breast, undergoing debilitating chemotherapy and radiation treatments or death.

"It would give us a handle (on early breast cancer cells) for the first time. We would know where they are. We would know their characteristics and that would give us the ammunition to go after them," according to Tlsty.

"I can foresee the day when you would actually introduce something into the ductal tree (in the breast) and it simply removes all of these aberrant cells and leaves the normal ones there," she added.

The scientists were trying to find out why most cancers begin in epithelial cells when they made their discovery. Their research is published in the science journal Nature.

"Figuring out why mutations occur -- never mind what they actually are -- could provide a new means for intercepting the disease before it gets started," said Tlsty.

(From ChinaDaily)