WEDNESDAY, Jan. 19, 2005 (HealthDayNews) -- Cancer has displaced heart disease as the leading killer of Americans under the age of 85, according to the American Cancer Society's latest projections released Wednesday.
Even though the mortality rates are higher relative to heart disease, according to the latest report, the mortality from many types of cancer is actually declining.
Cancer now accounts for about 23 percent of all deaths among Americans regardless of age, the annual report found.
In addition, the report projects that there will be 1,372,910 new cases of cancer in the United States this year, and 570,280 deaths.
Heart disease still remains the leading killer for all Americans regardless of age. In 2002, more than 690,000 people died from heart disease compared to more than 550,00 deaths from all cancers, according to federal statistics.
For the cancer outlook, however, there is both encouraging and discouraging news.
Americans are surviving longer than ever after a diagnosis of cancer. Lung cancer rates for men continue to decline, and have dropped for the first time for women. Rates of colorectal cancer for men and women are down, and so are cervical cancer rates.
But rates of cancers linked to too much weight are increasing, reflecting the obesity epidemic wracking America.
About one-third of new cancer cases this year will be due to tobacco use and one-third to poor nutrition, physical inactivity or overweight and obesity.
The report also provides an update of recent cancer trends. From 1993 to 2001, overall cancer death rates declined 1.5 percent per year for men; for women, the annual decline was 0.8 percent from 1992 to 2001.
Overall, people are surviving longer after having had cancer. Since the late 1970s, the five-year survival rate for men has grown from 43 percent to 64 percent and, for women from 57 percent to 64 percent.
Lung cancer remains the leading cancer killer, accounting for 31 percent of cancer deaths in men and 27 percent of deaths in women. In men, lung cancer is followed by prostate cancer, then colorectal cancer as the top killers. For women, breast cancer ranks second for mortality, followed by colorectal cancer.
"The order of the top three have not changed since the late 1980s when the number of deaths from lung cancer overtook those of breast cancer in women and prostate overtook colon and rectal cancer in men," Elizabeth Ward, director of surveillance research at the American Cancer Society's department of epidemiology and surveillance research, told a news conference Wednesday.
For women, the most commonly diagnosed cancer is breast cancer, followed by lung and bronchus cancers and then colorectal cancer. For men, the most commonly diagnosed cancers are lung cancer, prostate and colorectal cancer, in that order.
From 1998 to 2001, lung cancer continued to decrease in men and, for the first time, also in women.
"Decreasing incidence rates of lung cancer and several other cancers reflect substantial progress against tobacco smoking, which began to decline in men in the '70s," Ward said.
It's too early to tell whether the reported decline in women is actually a decline or merely a stabilization, but it probably does signal that the lung cancer epidemic in women has peaked, she added.
The incidences of colorectal cancer among men and women and cervical cancer have also declined, probably as a result of stepped-up screening efforts, the report said.
Conversely, rates of prostate, breast and thyroid cancer and melanoma are on the rise. Increases in thyroid cancer may be due to improvement in diagnoses or an increase in exposure to medical radiation, such as X-rays. At the same time, breast cancer mortality has declined, although it's not clear if this is due to improved detection or improved treatment, the report stated.
Obese men run a 50 percent greater risk of developing cancer overall, particularly cancer of the liver, pancreas, stomach and esophagus. Obese women face a 70 percent greater cancer risk, particularly cancer of the uterus, kidney, cervix and pancreas.
Cancers linked to infectious diseases, many of which are preventable, were also highlighted in the report.
The cancer society estimated that worldwide, 17 percent of new cancers will be attributable to infection, including 26 percent of cancers in economically developing countries (1.5 million cases) and 7.2 percent (360,000 cases) in developed countries.
Liver cancer can be caused by the hepatitis B and C viruses; cervical cancer by human papillomavirus; stomach cancer by Helicobacter pylori bacterium; and Kaposi's Sarcoma and lymphoma by HIV, the virus that causes AIDS. There are ways to prevent or screen for most of these diseases: a vaccine for hepatitis B; good screening tests for cervical cancer; and behavioral changes that can prevent contracting diseases, the report said.
Ward emphasized two challenges for the future.
"We need to encourage cessation among people who continue to smoke, and we need to maintain efforts to decrease initiation of smoking among young people," she said. "We also need to reverse the epidemic of overweight and obesity that's overtaken our society both in children and adults."
The report will be published in the January/February issue of CA: A Cancer Journal for Clinicians.
For more on cancer, visit the American Cancer Society.