单选题 The American Cancer Society, which has long been a staunch defender of most cancer screening, is now saying that the benefits of detecting many cancers, especially breast and prostate, have been overstated. It is quietly working on a message, to put on its Web site early next year, to emphasize that screening for breast and prostate cancers and certain other cancers can come with a real risk of over treating many small cancers while missing cancers that are deadly. The cancer society"s decision to reconsider its message about the risks as well as potential benefits of screening was spurred in part by an analysis published Wednesday in The Journal of the American Medical Association, Dr. Otis Brawley, chief medical officer of the cancer society, said. In it, researchers report a 40 percent increase in breast cancer diagnoses and a near doubling of early stage cancers, but just a 10 percent decline in cancers that have spread beyond the breast to the lymph nodes or elsewhere in the body. With prostate cancer, the situation is similar, the researchers report. If breast and prostate cancer screening really fulfilled their promise, the researchers note, cancers that once were found late, when they were often incurable, would now be found early, when they could be cured. A large increase in early cancers would be balanced by a corresponding decline in late-stage cancers. That is what happened with screening for colon and cervical cancers. But not with breast and prostate cancers. Still, the researchers and others say, they do not think all screening will—or should—go away. Instead, they say that when people make a decision about being screened, they should understand what is known about the risks and benefits. For now, those risks are not emphasized in the cancer society"s mammogram message which states that a mammogram is" one of the best things a woman can do to protect her health. " The new analysis finds that prostate cancer screening and breast cancer screening are not so different. Both have a problem that runs counter to everything people have been told about cancer; They are finding cancers that do not need to be found because they would never spread and kill or even be noticed if left alone. That has led to a huge increase in cancer diagnoses because, without screening, those innocuous cancers would go undetected. At the same time, both screening tests are not making much of a dent in the number of cancers that are deadly. That may be because many lethal breast cancers grow so fast they spring up between mammograms. And the deadly prostate ones have already spread at the time of cancer screening. The dilemma for breast and prostate screening is that it is not usually clear which tumors need aggressive treatment and which can be left alone. " The issue here is, as we look at cancer medicine over the last 35 or 40 years, we have always worked to treat cancer or to find cancer early, " Dr. Brawley said. " And we never sat back and actually thought. Are we treating the cancers that need to be treated?"

单选题 The first two paragraphs of the passage show the American Cancer Society______.

单选题 The author turns to the statistics and follow-up reasoning, the purpose of which is to tell the reader______.

单选题 As suggested in Paragraphs 6 and 7, the difference between benign and deadly tumors lies in the fact that______.

单选题 When hearing Dr. Brawley saying "The issue here is... And we never sat back and actually thought. Are we...?" , one may be left with an impression that American cancer medicine begins to______.

单选题 When finishing reading the passage, one may conclude that in the past decades American cancer medicine has been______.