If women in their 40s have regular mammograms to detect breast cancer, the screenings will save lives, says a team headed by Dr. Charles R. Smart, a noted Utah cancer specialist.

The finding, published in the April 1 edition of the journal Cancer, refutes a 1992 recommendation by the National Cancer Institute that women of that age group don't need mammograms.A huge uproar greeted the NCI's reversal of its long-standing recommendation that women in their 40s should get mammograms to detect breast cancer. Many experts disputed the change, and the American Cancer Society refused to go along with it.

Late last year, NCI director Dr. Samuel Broder stepped down from his post. Insiders said two issues that undermined his position with NCI were controversies over NCI's handling of an unrelated scandal about a researcher falsifying data, and the change in direction regarding mammography.

New research by a team headed by Smart, a Salt Lake physician and the former director of NCI's Early Detection Branch, reaffirms the earlier stance: Women in their 40s should get mammograms.

That mammography saves the lives of older women has never been disputed. The latest paper shows that it also saves women in their 40s.

Remarkably, this analysis uses statistics from the same eight studies that the NCI relied upon when issuing its controversial 1992 revision.

Even when a debatable Canadian study is included in the statistics, mammography shows a 14 per-cent benefit.

But when the Canadian study is excluded, the results are especially impressive, showing a 23 percent reduction in deaths from breast cancer among women who had mam-mo-grams compared to those who did not.

The main difference between the NCI findings in 1992 and Smart's new analysis is that Smart's team used a longer follow-up period. Deaths that occurred after seven years are included in the new statistics.

In the original studies, some women in the 40-49 age group who were screened by mammography had medical procedures as a result. For example, a cancerous tumor would be removed, or a woman might have a mastectomy.

Tumors weren't as likely to be detected in women of the same age in control groups who didn't have mammograms, so they were not as likely to have the medical procedures.

Yet seven years later, when the NCI compared the groups, mortality was about the same. The NCI concluded that mammograms didn't benefit women in their 40s.

When Smart's experts carried out a longer-term follow-up, they did find differences in survival. Enough years had passed for women in the control group to begin dying from cancers that were not detected earlier, while women who had mammograms in their 40s were more likely to survive.

"Younger women with positive lymph nodes (cancer in lymph nodes) lived longer than older women, and the reason for this was they didn't have as many lymph nodes involved," Smart said.

"We have now anywhere from eight to 18 years follow-up," he said. And the findings support the value of mammography.

Armed with that, the National Cancer Institute is likely to return to its earlier recommendation that women in their 40s should have mammograms.

Another important fact is that for the first time, "there has been a reduction in breast cancer mortality in the United States, of 5.5 percent," Smart said.

"This has been present for several years in women under 50, but only recently been reported for women over 50."

Mammography contributed to the drop in breast cancer deaths, he said.

Other members of the reanalysis team were R. Edward Hendrick and James H. Rutledge III, both of the University of Colorado, Denver, and Robert A. Smith of the American Cancer Society in Atlanta.