History of Cancer Treatments: Hormone therapy

Another 19th century discovery laid the groundwork for an important modern method to treat and prevent breast cancer. Thomas Beatson graduated from the University of Edinburgh in 1874 and developed an interest in the relation of the ovaries to milk formation in the breasts. In 1878 he discovered that the breasts of rabbits stopped producing milk after he removed the ovaries. He described his results to the Edinburgh Medico-Chirurgical Society in 1896: “This fact seemed to me of great interest, for it pointed to one organ holding control over the secretion of another and separate organ.”

Because the breast was “held in control” by the ovaries, Beatson decided to test removal of the ovaries (called oophorectomy) in advanced breast cancer. He found that oophorectomy often resulted in improvement for breast cancer patients. He also suspected that “the ovaries may be the exciting cause of carcinoma” of the breast. He had discovered the stimulating effect of the female ovarian hormone (estrogen) on breast cancer, even before the hormone itself was discovered. His work provided a foundation for the modern use of hormone therapy, such as tamoxifen and the aromatase inhibitors, to treat or prevent breast cancer.

A half century after Beatson’s discovery, Charles Huggins, a urologist at the University of Chicago, reported dramatic regression of metastatic prostate cancer after the testicles were removed. Later, drugs that blocked male hormones were found to be effective treatment for prostate cancer.

New classes of drugs (such as aromatase inhibitors, LHRH [luteinizing hormone-releasing hormone] analogs and inhibitors, and others) have greatly changed the way prostate and breast cancers are treated. Research to better understand how hormones influence cancer growth has guided progress in developing many new drugs for cancer treatment. It’s also helping researchers look at new ways to use drugs to reduce the risk of developing breast and prostate cancer.