Sometimes you can know too much. The aim of screening healthy people for cancer is to discover tumors when they are small and tr

admin2015-02-12  34

问题     Sometimes you can know too much. The aim of screening healthy people for cancer is to discover tumors when they are small and treatable. It sounds laudable and often it is. But it sometimes leads to unnecessary treatment. The body has a battery of mechanisms for stopping small tumors from becoming large ones. Treating those that would have been suppressed anyway does no good and can often be harmful.
    Take lung cancer. A report in this week’s Journal of the American Medical Association, by Peter Bach of the Memorial Sloan-Kettering Cancer Centre in New York and his colleagues, suggests that, despite much fanfare around the use of computed tomography(CT)to detect tumors in the lungs well before they cause symptoms, the test may not reduce the risk of dying from the disease at all—indeed, it may make things worse.
    The story begins last year, when Claudia Henschke of Cornell University and her colleagues made headlines with a report that patients whose lung cancer had been diagnosed early by CT screening had excellent long-term survival prospects. Her research suggested that 88% of patients could expect to be alive ten years after their diagnosis. Dr. Bach found similar results in a separate study. In his case, 94% of patients diagnosed with early-stage lung cancer were alive four years later.
    Survival data alone, though, fail to answer a basic question: "compared with what?" People are bound to live longer after their diagnosis if that diagnosis is made earlier. Early diagnosis is of little value unless it results in a better prognosis.
    Dr. Bach, therefore, interrogated his data more thoroughly. He used statistical models based on results from studies of lung cancer that did not involve CT screening, to try to predict what would have happened to the individuals in his own study if they had not been part of that study The results were not encouraging.
    Screening did, indeed, detect more tumors. Over the course of five years, 144 cases of lung cancer were picked up in a population of 3,200, compared with a predicted number of 44. Despite these early diagnoses, though, there was no reduction in the number of people who went on to develop advanced cancer, nor a significant drop in the number who died of the disease(38, compared with a prediction of 39). Considering that early diagnosis prompted a tenfold increase in surgery aimed at removing the cancer(the predicted number of surgical interventions was 11; the actual number was 109), and that such surgery is unsafe—5% of patients die and another 20-40% suffer serious complications—the whole process seems to make things worse.
On which of the following would the author least probably agree?

选项 A、The final word on CT screening for lung cancer will still have to wait.
B、Bach compared screened people’s data with what would have happened to be unscreened.
C、Early screening, to some extent, may not reduce the death rate from the disease.
D、We shouldn’t resort to surgery when screening detects our tumors.

答案D

解析 属信息推断题。虽然作者在文中表达了CT筛查弊大于利,但是确切的结论尚未得出,仍需要大量的实验去证明,故选项A符合文意。在第五段,作者描述了巴赫所做的实验,选项B与其相符合。选项C在文中最后一段第三句有表述,故C项符合文意。虽然作者在最后表示切除肿瘤的手术并不安全,但我们不应该绝对否定切除肿瘤手术,故选项D符合题意,为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/Ys74777K
0

最新回复(0)