Cancer cases in US decline for first time
Could mark turning point; Deaths also drop; reasons unclear
WASHINGTON - The pace at which Americans are getting cancer has started to decline for the first time, marking what could be a long-awaited turning point in the battle against the disease, according to an annual report that tracks progress in the war on cancer.
Cancer deaths have also continued a decline that began in the early 1990s, meaning that for the first time both trend lines are dropping.
"It is a significant milestone," said Otis Brawley, chief medical officer at the American Cancer Society, which produces the report with the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. "It is a really big deal."
The drop in cancer incidence has been driven largely by declines in many of the leading forms of cancer - lung, prostate, and colorectal cancer in men, and breast and colorectal cancer in women.
"The take-home message is that many of the things we've been telling people to do to be healthy have finally reached the point where we can say that they are working," Brawley said.
Brawley and others cautioned, however, that part of the reduction could be due to fewer people getting screened for prostate and breast cancers. In addition, the rates at which many other types of cancer are being diagnosed are still increasing, he said, and overall far too many Americans are still getting and dying from cancer.
About 1.4 million Americans are diagnosed with cancer each year, and 560,000 die from it.
"We still have a lot to do," Brawley said. "If you look at the data it's clear that we could still do much better - much, much better."
Some specialists argue that the decrease in new cases is primarily the result of a drop in lung cancer, which is due to declines in smoking that occurred decades ago. They criticized the ongoing focus on detecting and treating cancer and called for more focus on prevention.
"The whole cancer establishment has been focused on treatment, which has not been terribly productive," said John C. Bailar III, who studies cancer trends at the National Academy of Sciences. "I think what people should conclude from this is we ought to be putting most of our resources where we know there has been progress, almost in spite of what we've done, and stop this single-minded focus on treatment."
Bailar and others argue that research should emphasize identifying the underlying causes of cancer, such as environmental exposures, to prevent cancer from occurring in the first place.
Others, while agreeing that more research is needed on both prevention and treatment, hailed the development.
"We are really seeing that the investment in cancer research is really starting to pay off," said Ellen Sigal of the Friends of Cancer Research, an advocacy group. "I think we need to do both. We need to prevent more cancer, but we still need to treat those who get cancer more effectively."
For the report, researchers analyzed data collected between 1975 and 2005 in ongoing surveys and cancer registries that federal officials use to track cancer trends. The analysis, published in today's issue of the Journal of the National Cancer Institute, found that a drop in the rate at which Americans are dying from cancer, which began in the early 1990s and has been documented in previous reports, had continued, falling about 2 percent per year for men since 2001 and 1.6 percent per year for women since 2002.
The analysis found that the overall incidence of cancer was also falling, inching down 0.8 percent per year since 1999. Notably, the drop occurred for both men and women, although it fell much more sharply for men - down 1.8 percent per year from 2001 to 2005, compared with 0.6 percent per year for women from 1998 through 2005. In previous years the incidence had fluctuated for both sexes but was generally rising or stable.
"This is really the first year that rates decreased in both women and men," said Ahmedin Jemal, the cancer society's strategic director for cancer surveillance, who led the analysis.
The fall in lung cancer in men is the result of lower smoking rates. While fewer women are smoking too, the incidence of lung cancer among them has not yet started to fall because their smoking rate declined later.
Colon cancer incidence has started falling for both men and women, probably due primarily to increased screening.
The explanation for the drop in prostate cancer diagnoses remains less clear, but it may reflect a trend toward fewer men getting screened with a test that measures a protein in the blood called prostate-specific antigen.
The drop in breast cancer could be due to a combination of factors, including fewer women taking hormones to alleviate hot flashes and other symptoms of menopause because of safety concerns, and fewer women getting mammograms.
"It's very difficult to say this is good news or bad news," Jemal said. "The fact that you have a lower detection rate is not necessarily good news. The reduction of lung and colorectal cancer is clearly good news. But it's not so clear for breast and prostate cancer."
Critics, however, noted that many forms of cancer are still on the rise, including non-Hodgkin lymphoma, kidney cancer, and melanoma.
"If you look at the overall picture, that really distorts and reduces the realization that there's been a steady increase of non-tobacco-related cancer," said Samuel Epstein, a professor emeritus at the University of Chicago.
Brawley agreed that more needs to be done in the way of prevention. But he said the new report showed that rates are falling for all groups.
"If you look at the data you can see there's something positive for black people and white people and Hispanic people. There's something positive for men. There's something positive for women. There's something positive for rich people and there's something positive for poor people," Brawley said. 