They took advantage of a tissue bank from the Mayo Clinic Benign Breast Disease Cohort, which includes several thousand women who, between 1967 and 1991, had a benign breast biopsy. Of this group, 235 women had atypical hyperplasia and tissue available for the study. Cancer follow-up information was available for all of these women. Hartmann and her co-workers determined the amount of COX-2 in these samples by staining immunohistochemistry methods. Forty-one of the 235 women with atypia developed breast cancer over roughly a 15- to 20-year period.
The research team found a significantly higher level of COX-2 in atypias of those women who went on to develop breast cancer than they did in control subjects. "Intense COX-2 expression," Hartmann said, "is associated with a significantly greater likelihood of a subsequent breast cancer in women with atypia. Specifically, for women with strong staining, their risk of breast cancer at 20 years was 31 percent, versus 14 percent for those with negative or weak staining."
She noted that increased COX-2 expression has also been seen in an early form of breast cancer called ductal carcinoma in situ, or DCIS. Hartmann said that COX-2 represents a potential target for chemoprevention. Her team plans to expand the test group and will continue to profile women with atypia who did and who did not develop breast cancer in an attempt to identify early predictors of risk.
Reduction in the Risk of Human Breast Cancer by COX-2 Inhibitors: Abstract No. 2352
Results of a five-year study have shown for the first time a significant reduction in ri
Source:American Association for Cancer Research