A sampling of noteworthy presentations at the annual meeting of the American Association for the Advancement of Science, taking place in the District this weekend.
'CSI Effect' Vexes Real Sleuths
The honeymoon is over between real-life crime scene investigators and the stars that play them in the immensely popular television show "CSI." Forensic scientists are now complaining about something they call the "CSI Effect," which is, according to Max Houck of West Virginia University, "the perception of near infallibility of forensic science after watching a few episodes of CSI."
The show has had its positive effects, Houck conceded, speaking at the annual meeting. Enrollment in forensic science programs has skyrocketed, for example. At his university, four students out of a student body of 25,000 graduated as majors in forensic science in 1999. Today, 400 students are in the program -- the vast majority of them women -- making it the single-largest major on campus and a novel nexus for women in science.
On the downside, jurors and relatives of crime victims have developed unrealistic expectations of the field, expressing disappointment that their cases did not trigger fancy detective work that in many cases is not necessary and expecting test results within 30 minutes instead of the 30 days or more that is often needed, said Patricia McFeeley, a University of New Mexico forensic pathologist.
Prosecutors, too, have been bitten by the bug, demanding more tests than ever -- in some cases more than are needed -- adding to the already enormous backlog at the nation's forensic laboratories.
Finally, there is the little problem that criminals, too, apparently watch the show. Many try tricks they have seen on TV, such as not licking envelopes to avoid leaving a DNA trail, Houck said. Although law enforcement remains in the lead with a number of technical tricks the average criminal hasn't seen on the tube, he said, some experts have stopped cooperating with television shows depicting their craft.
-- Rick Weiss
Early Mammograms Questioned
A computer model devised by researchers at the Dana-Farber Cancer Institute suggests that annual mammograms for women in their forties have a very small impact on reducing cancer mortality rates and come at a high financial cost, the scientists announced yesterday.
The findings, certain to reignite the controversy over the value of mammograms in younger women, could serve as a tool for policymakers and individual patients deciding when and how often to administer the breast screens.
The model calculates that shifting to a mammogram every two years has a small impact on mortality rates and could save billions of dollars.
Beginning mammograms at age 40 rather than age 50 reduces "overall risk of death by 5 percent because the incidence of cancer in the younger women is very low," the team found. Annual screening begun at age 40 reduces mortality rates for that age group by 34 percent, but "if women underwent mammograms every two years beginning at 40 and then annually starting at 50, it would still achieve a 33 percent mortality reduction, and save nearly $5,000 per case found," according to a presentation at the meeting yesterday.
When yearly mammograms began at 50, the model found a 37 percent reduction in mortality.
Although a large body of evidence indicates mammograms in women older than 50 are effective in sharply reducing breast cancer deaths, "there is still considerable controversy over whether there is benefit for younger women," said lead researcher Sandra Lee. Mammograms given between ages 40 and 49 are less successful in identifying cancers and can produce false positive results that can lead to unnecessary biopsies, anxiety and expense, the report found.
However, women with a family history of breast cancer or risk factors such as smoking should consider earlier and more frequent exams, experts say. The team hopes to have a consumer-friendly program for computing a woman's breast cancer mortality risk on the Internet within two years.
