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Elwood V. Jensen, born 1920 in Fargo, North Dakota,[1] is the Distinguished University Professor, George and Elizabeth Wile Chair in Cancer Research at the University of Cincinnati College of Medicine's Vontz Center for Molecular Studies and the Charles B. Huggins Distinguished Service Professor Emeritus in the Ben May Institute for Cancer Research at the University of Chicago. In 2004 he received the Albert Lasker Award for Basic Medical Research for his research on estrogen receptors.

Dr. Jensen's studies on estrogenic hormones completely revolutionized the understanding of how steroid hormones work, and in doing so he made a major contribution to the treatment of breast cancer. According to the Lasker Foundation, his work has transformed the treatment of breast cancer patients, and saves or prolongs more than 100,000 lives annually.

His discovery that two-thirds of breast tumors have "receptors" specifically for estrogen, which causes cancer cells to proliferate, has made it possible to target this group of women for hormone therapy. The remaining "receptor negative" patients are now spared from a treatment that will not help them, and can start earlier on alternative therapies that will.

Dr. Jensen's landmark discovery of hormone receptors-which earned him the honor of being the "father" of the now burgeoning nuclear receptor field-has had a major impact on the treatment of breast cancer, and estrogen receptor analysis of breast cancers for therapy selection is now standard clinical practice.

During the 1950s, when Dr. Jensen was doing his work in Chicago, investigators had been focusing on estrogen's influence on the enzymes involved in biosynthesis. Dr. Jensen, however, took a different approach. As he puts it, it was like the early European mountaineers who decided to climb the Matterhorn (which he himself once did) by what at the time appeared to be the most formidable face-only to discover that it was the better way to go.

Instead of asking what the hormone does to tissue, Dr. Jensen decided to learn what happens to the hormone itself. That approach took him to the scientific summit.

But first he had a problem to overcome. He had to invent a way to measure hormones with greater accuracy than had been possible before. This he achieved by "labeling" the hormone estradiol with the radioactive isotope tritium, which can be detected in cells in amounts as unimaginably small as one-trillionth of a gram.

Dr. Jensen was about to open up to molecular science an exciting new area of study.

Using his new tritium labeling technique, Dr. Jensen discovered that a third of all cancer patients had receptors that bound with estrogen, which in turn triggered cancer cell proliferation. Since only a third of breast tumors carry estrogen receptors, a biopsy can now determine which women have them and are therefore candidates for anti-estrogen therapy. Patients who do not have the receptors are therefore spared from a treatment that will not help them. Instead, the receptor-negative patients, whose tumors are not dependent on estrogen, can now receive the more aggressive chemotherapy and/or radiation treatments sooner, before the cancer spreads.

Dr. Jensen also was able to purify the receptor protein and prepare specific antibodies to it, the first time this had ever been done for any steroid hormone receptor. This work provided physicians with a reliable tool for measuring the amount of receptor in tumors, enabling them to better decide in which direction treatment should proceed.

In the 1970s, a time when many clinicians did not consider anti-estrogen compounds to be very effective against breast cancer, Dr. Jensen and his Chicago colleague Craig Jordan, PhD, also showed that the anti-estrogen compound tamoxifen worked well in many women with large amounts of estrogen receptor. The clinical results from simply taking a pill saved patients from undergoing the more aggressive anti-hormone approach-removal of the ovaries and the adrenal glands-which has long been known to stop tumor growth in one of three patients.

Dr. Jensen and his colleagues Sohaib Khan, PhD, of UC's Department of Cell Biology, Neurology and Anatomy, and Tom Burris, PhD, of the Eli Lilly Company, are currently studying Dr. Jensen's latest finding-that the estrogen receptor has in fact two binding sites for tamoxifen-and determining its significance in the treatment of breast cancer.

Jensen was born in Springfield, Ohio, in the United States, received his bachelor's degree from Wittenberg University in 1940 and PhD in organic chemistry from the University of Chicago in 1944. From 1947 Jensen studied steroid hormones at Chicago, where he isolated estrogen receptors and discovered their importance in breast cancer. Jensen currently lives in Cincinnati, Ohio and is a member of the Department of Cancer and Cell Biology of the College of Medicine at the University of Cincinnati. In October 2009 a Cancer Symposium honoring Dr. Jensen's contributions will be held in Cincinnati.

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