2008年职称英语考试阅读判断习题(十三)

13次大中小

Beyond the Pap

Scientists have known for some time that virtually all cases of cervical cancer are triggered by a family of viruses called human papillomavirus, or HPV. Most women who become ineffected with HPV are able to shake off the virus and suffer no apparent long-term consequences to their health. But a few women develop a persistent infection that can, for reasons that are not entirely clear, eventually lead to cancerous changes in the cervix.

Now researchers at the Digene Corp of Beltsville, Maryland, have developed a test that detects an active HPV infection by looking for its genetic byproducts in the vagina. The HPV test was better than the standard Pap test at finding cervical cancer at any stage, according to two studies published this month in the Journal of the American Medical Association. So far, so good. Unfortunately, the test's false-positive rate—how often it indicated that there was a problem when none existed was almost twice as high as that for the Pap smear. In these cases, a biopsy of the woman’s cervix showed no sign of disease.

And that’s the crux of the problem. How many women should undergo what is, when it comes right down to it, unnecessary treatment to find a few more cases of cervical cancer? Shouldn’t health officials focus instead on making sure that more women undergo regular Pap-smear examinations? After all, Pap smears, though far from perfect, have helped dramatically lower the death toll from cervical cancer taking it from the No. 1 cause of death due to cancer in American women to the 10th.

Complicating matters is the fact that HPV is a very common infection. In some parts of the U.S. as many as half of all women under age 35 have an active case. Yet 99 out of 100 women who are HPV-positive will never get cervical cancer, estimates Dr. Joanna Cain, vice president of the American College of Obstetricians and Gynecologists. “If those 99 women live their lives as if they’re going to develop cancer”, she says, “we’re not necessarily doing them any good.”

At present, the HPV test is approved in the U. S. only to help resolve ambiguous results from a Pap-Smear test. Many gynecologists believe that HPV will eventually replace the pap. But they’re not willing to abandon it without a lot more detailed information and neither should you.

练习

1. The cause of cervical cancer was discovered by American scientists some time ago.