Smoking cigarettes does not increase the chances a woman will be diagnosed with advanced or aggressive breast cancer, according to a new study.

Researchers said they were testing a theory that since smoking is associated with more cancers in other parts of the body -- including the lungs, esophagus and bladder -- the same would apply to breast cancer.

"That doesn't appear to be the case," said Dr. Matthew Abramowitz of the Fox Chase Cancer Center. "There is no good news about smoking, but since about 10 percent of our patients are smokers, this research provides us with some relief. The question that remains is will smoking affect their survival?"

The results come from an analysis of 35 years of data for more than 6,000 patients.