Good News on Cancer Both Incidence and Mortality Rates Are on the Decline

The tide is shifting when it comes to cancer deaths, a new study claims.

The report, prepared by the nation’s leading cancer organizations, shows that cancer death rates decreased on average 2.1{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year from 2002 through 2004, nearly twice the annual decrease of 1.1{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year from 1993 through 2002.

The findings are detailed in the Annual Report to the Nation on the Status of Cancer, 1975-2004, published online (www.interscience.wiley.com/cancer/report2007) and in the Nov. 15, 2007 issue of Cancer.

Among the general population, the report shows that long-term declines in cancer death rates continued through 2004 for both sexes, and, despite overall higher death rates for men, the declines from 2002 through 2004 were 2.6{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year among men and 1.8{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year among women.

Death rates decreased for the majority of the top 15 cancers in men and women. Important declines were noted for the three leading causes of cancer deaths in men: lung, prostate, and colorectal cancers. In women, deaths rates from colorectal cancer and breast cancer decreased, while the rate of increase for lung cancer deaths slowed substantially.

“The significant decline in cancer death rates demonstrates important progress in the fight against cancer that has been achieved through effective tobacco control, screening, early detection, and appropriate treatment,” said Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention (CDC). “As a nation, we must commit to continuing and enhancing these important public-health efforts.”

Dr. John Seffrin, CEO of the American Cancer Society (ACS), said shifts in the way health care is administered in the U.S. could bolster the positive trends.

“The evidence is unmistakable: we are truly turning the tide in the cancer battle,” Seffrin said. “The gains could be even greater if everyone in the U.S. had access to essential health care, including primary care and prevention services.”

Incidence Down, Too

Meanwhile, a midpoint assessment of the American Cancer Society’s goal to cut cancer incidence by 25{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} by 2015 finds overall cancer incidence rates were 8{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} lower in 2004 than they were in 1992.

Despite those gains, the authors of the report say the rate of reduction over the first half of the challenge period was only about half the size necessary to reach the challenge goal, and that new understandings of preventable factors and new efforts are needed, particularly in the areas of tobacco control and obesity, to increase progress.

In 1998, the volunteer board of directors of the American Cancer Society set an ambitious challenge goal for the U.S. to reduce cancer incidence rates by 25{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} between 1992 and 2015. The midpoint report shows that incidence rates have been dropping 0.6{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year since 1992, the year cancer incidence peaked in the U.S. The greatest declines have occurred among men and among those age 65 years and older. Although decreasing trends were similar by race, incidence rates continue to be higher among African-Americans than among whites.

The report finds that, while declining trends have been observed for some cancer sites, others have remained constant or increased over the 12-year period. Drops in incidence were seen for cancers of the prostate, lung (in men), colorectum, ovary, oral cavity, stomach, and cervix. Meanwhile, a marked decline for invasive breast cancer in women began in 1999, while incidence rates for lung cancer in women have stabilized in recent years.

However, for several sites, no appreciable downturn has been seen, including multiple myeloma, non-Hodgkin lymphoma, leukemia, and cancers of the corpus uteri, bladder, pancreas, and brain. Cancer incidence rates have increased for melanoma and cancers of the kidney, liver, thyroid, and esophagus.

The authors say historical declines in the use of tobacco and recent declines in the use of certain hormone therapies have contributed to incidence reductions in several cancer sites and will likely result in steeper declines in the decade to come. However, they note, these favorable changes are somewhat offset by the increasing prevalence of obesity, which contributes to higher risk for many types of cancers.

“If we want to increase the progress we’re seeing, we will need not only new understandings of the factors that can lower the risk of getting cancer, but also stronger efforts to act on what we already know about cancer prevention,” said Dr. Tim Byers of the University of Colorado School of Medicine, a member of the ACS Incidence and Mortality Committee and co-author of the report. “In particular, we need to continue to reduce tobacco use and start reversing the epidemic of obesity.”

The Cancer report also notes the decline in cancer incidence rates across both sexes and all races. It adds that the falling incidence rates for breast cancer between 2001 through 2004 could be partly explained by the declining use of hormone replacement therapy as well as the recently reported decline in use of screening mammography.

The report also noted that lung cancer incidence rates in women stabilized from 1998 through 2004 after long-term increases, and in men the rate declined 1.8{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year from 1991 through 2004. Colorectal cancer incidence rates decreased by more than 2{06cf2b9696b159f874511d23dbc893eb1ac83014175ed30550cfff22781411e5} per year for men and women, likely due to prevention through the removal of pre-cancerous polyps.

“We now have an infrastructure in this country for obtaining high-quality information about new cases of cancer, and we can now describe the successes in cancer interventions and treatment as well as uncover populations with varying risks and outcomes,” said Dr. Holly Howe, executive director of the North American Association of Central Cancer Registries (NAACCR). “Without this surveillance, we would be ill-equipped to address the challenges we face in further reducing the cancer burden.”

The report’s authors say that earlier detection of disease through screening, improved prognosis through more effective treatment, tobacco control, and reduction in inequalities in cancer care all point to the success of the nation’s dedication and focus on reducing the burden of cancer in the U.S.

The study was conducted by scientists at the CDC, ACS, NCI, which is part of the National Institutes of Health, and NAACCR, in collaboration with scientists from the Indian Health Service and the Mayo Clinic College of Medicine.

Keeping Momentum

Dr. LaSalle Leffall Jr., chair of the President’s Cancer Panel, noted recently that, while 2007 brought the announcement of the steepest decline in cancer deaths ever recorded in the U.S., there’s much more work to be done.

“This milestone reflects the wisdom of our national investments in cancer research and care and is one of the most encouraging signs of progress since the war on cancer was declared in 1971,” Leffall said. “Yet, this year alone, more than a half-million more Americans will lose their battle with cancer. Tragically, nearly two-thirds of these deaths could have been prevented through changes in lifestyle.”

The panel, like the American Cancer Society and the researchers behind the Cancer report, point to obesity and tobacco as serious problems — and obvious opportunities for widespread lifestyle improvements.

“Despite irrefutable evidence that modifiable behaviors are linked to numerous types of cancer, and the implementation of a multitude of programs to combat risk-promoting behaviors, many millions of Americans continue to practice unhealthy lifestyles,” Leffall said. “Although efforts have been made to halt alarming obesity trends by promoting healthier eating and physical activity, the number of organizations, institutions, and individuals that have made a commitment to healthy living still is too small.”

The panel also said preventive services, including programs promoting nutrition and physical activity, need to become an integral and reimbursable component of primary care, and called on national legislators to bolster public health programs and more strictly regulate tobacco sales and marketing, particularly to young people.

“Research has shown that adopting a healthy lifestyle is an effective defense against cancer,” Leffall said. “Public and private organizations must coordinate efforts to educate the American public about the relationship between healthy behaviors and disease prevention.”

If that happens, perhaps the good news will be even better a decade from now — and beyond.