Timothy J. Key, D.Phil., and his colleagues from the Endogenous Hormones and Breast Cancer Collaborative Group at the University of Oxford analyzed data from nine previous prospective studies on sex hormone levels in 663 women who developed breast cancer and 1765 women who did not develop breast cancer. None of the women were taking hormone replacement therapy at the time of analysis.

Key and his coworkers found that women with the highest levels of sex hormones had roughly twice the risk of breast cancer compared with women with the lowest levels of sex hormones. The authors conclude that endogenous levels of sex hormones are associated with breast cancer risk. Their results appear in the April 17 issue of the Journal of the National Cancer Institute.

Also in the April 17 JNCI:

• Fusion Protein May be Potential Therapy for Brain Cancer: An animal study has shown that a recombinant toxic protein can cause regression in a type of brain tumor called glioblastoma. Daniel A. Vallera, Ph.D., of the University of Minnesota Cancer Center and his coworkers synthesized a diphtheria toxin recombinant fusion protein (DTAT) and found that DTAT caused regression of glioblastoma tumors which had been injected into mice. DTAT had little or no toxic effect on the kidney, liver, heart, lung, and spleen. The authors conclude that DTAT may have potential as a therapy for glioblastomas.

• Increased Activity of Signaling Pathway May be Associated Ovarian Cancer: Reproductive hormones are associated with risk for epithelial ovarian cancer. To determine the role of such hormones in activating signaling pathways t
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