Word: tumors
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Though scientists do not know how breast cancer begins, they do have some ideas about how it progresses. The female hormone estrogen, which is produced in the ovaries and causes a young girl's breasts to develop, also plays an unmistakable role in promoting the growth of tumor cells. Why do childlessness, late menopause, early onset of menstruation and delayed childbearing all increase the risk of breast cancer? One likely explanation is that all involve a prolonged, uninterrupted presence of high levels of estrogen in the bloodstream. Doctors have also noticed that women whose ovaries were removed before...
Consider these facts. By the time a breast tumor is large enough to be felt as a lump, it is generally more than 1 cm (0.4 in.) in diameter and contains several billion cancer cells, some of which may have broken loose, circulated through the bloodstream and begun to infiltrate other organs. A mammogram can detect pinpoint tumors that are less than 0.5 cm (0.2 in.) across, often well before the process of metastasis has started. This is not to say that a manual exam by a doctor or the woman herself is a waste of time. Such exams...
...that is not incentive enough, early detection through mammography can sometimes bring another bonus: surgery that spares the breast. A small, early tumor can often be removed with a lumpectomy procedure rather than a mastectomy...
...Burkhardt of Covington, La., the unthinkable slowly became the inevitable. Twenty years ago, an aunt was stricken with the disease. Her mother died from it a decade later. In 1986 Maria's younger sister Jo Ann began fighting for her life. Next her older sister Rose developed an aggressive tumor. Maria consulted a doctor and was told she was "a ticking time bomb." Ominously, her tissues were judged too dense for mammograms to scan reliably...
Generally, diseases such as those studied inthe Hanover project go though a long promotionstage of 20 years or more, says Mathews-Roth,before the tumor erupts in full force in the body.Any test to measure a drug's effect on skincancer, she contends, whould require monitoringthe patient though both the promotion andinitiation stages, many more years thanGreenberg's study...