CT Scans and Lung Cancer
Small or slow-growing nodules (小结节) discovered on a lung scan are unlikely to develop into tumors over the next two years, researchers reported on Wednesday.
The findings reported in the New England Journal of Medicine, could help doctors decide when to do more aggressive testing for lung cancer. They could also help patients avoid unnecessarily aggressive and potentially harmful testing when lesions (损伤) found.
Lung cancer, the biggest cancer killer in the United States and globally, is often not diagnosed until it has spread. It kills 159,000 people a year in the United States alone.
The work is part of a larger effort to develop guidelines to help doctors decide what to do when such growths, often discovered by accident, appear in a scan.
High-tech (高技术的) X-rays called CT scans can detect tumors-but they see all sorts of other blobs (模糊的一团 ) that are not tumors, and often the only way to tell the difference is to take a biopsy (活检), a dangerous procedure.
At the moment, routine lung cancer screening is considered impractical because of its high cost and because too many healthy people are called back for further testing.
Good guideline could help make lung cancer screening practical, Dr. Rob van Kiaveren of the Erasmus Medical Center in Rotterdam, the Netherlands, who led the new study, said in a telephone interview.
The team looked at7,557 people at high risk for lung cancer because they were current and former smokers. All received multidetector (多层螺旋) CT scans that measured the size of any suspicious-looking modules.
Volunteers who had nodules over 9.7 mm in width, or had growth of 4.6 mm that grew fast enough to more than double in volume every 400 days, were sent for further testing. Of the 196 people who fell into that category, 70 were found to have lung cancer，10 additional cases were found years later.
But of the 7, 361 who tested negative during screening only 20 lung cancer cases later developed.
In a second round of screening done one year after the first, 1.8 percent were sent to the doctor because they had a nodule that was large or fast-growing. More than half turned out to have lung cancer.
The result means that if the screening test says you don't have lung cancer, you probably don't,the researcher said. "The chances of finding lung cancer one and two years after a negative first-round test were l in l,000 and 3 in l,000 respectively, " they concluded.
36. The new study indicates that in case of small or slow-growing lung nodules_________.
A. you cannot be too careful
B. cancer is just matter of time
C. a biopsy is unnecessary
D. more aggressive testing is a must
37. Which is probably NOT true of lung cancer?
A. Smokers are usually considered to be at high risk for it.
B. It is the leading cause of cancer deaths around the world.
C. 159,000 new cases of it are diagnosed in the US each year.
D. It often goes unnoticed until it has spread.
38. According to the passage, good guidelines for lung cancer screening ________.
A. are a little bit too costly
B. do not exist yet
C. are being implemented
D. have been developed
39. All the following statements are true EXCEPT________.
A. a relatively small number of the volunteers had large or fast-growing nodules
B. almost all those with large or fast-growing nodules were found to have lung cancer
C. all the volunteers were at high risk for lung cancer
D. most of the volunteers tested negative during screening
40. In the eyes of the researchers the percentages given in the last paragraph ________.
A. are somewhat inaccurate
B. are pretty small
C. are rather high
D. are quite unbelievable
36．C[解析]本题是细节题。根据第一段的叙述我们知道肺部扫描发现的小的生长缓慢的结节在其后的两年里不会发展成肿瘤。因此活检或是进一步的检查是不需要的。
37．C [解析]本题是细节题。选项A、B、D在文中第三和第八段中都提到过，而选项C所讲的159，000人被确诊肺癌不符合第二段中提到的159，000人死于肺癌的事实。
38．D [解析]本题是细节题。根据文章第四段我们知道专家们正在发展完善对医生的指导方针。
39．B [解析]本题是细节题。根据文章第十一段我们知道A项正确、B项错误；由第八段知C项正确；由第十段知D项正确。
40．B[解析]本题是理解题。根据最后一段，我们知道这个患病比率在专家那里是忽略不计的，如果检查表明你没有患肺癌，你就可能不会得。