Lung Cancer Deaths Solely Responsible for the “Cancer Epidemic”

Birmingham, AL - The “cancer epidemic” of the past 50 years actually consisted of one disease - cancer of the lung due to cigarette smoking, according to two UAB (University of Alabama at Birmingham) scientists in the Jan. 1 issue of the Journal of Clinical Oncology.

“When lung cancer is excluded, mortality from all other forms of cancer combined declined continuously from 1950 to 1998, dropping 25 percent during this period,” says Dr. Brad Rodu, lead author of the study. Rodu, an oral pathologist, wrote the paper with Dr. Philip Cole, an epidemiologist. The two experts attributed the decline in mortality primarily to advances in cancer treatment as well as to screening programs and early diagnosis. The analysis is good news for cancer patients and a vindication of cancer research and policy, Rodu says. “One of the most intractable of human illnesses is clearly in retreat.”
According to the authors, the trends in cancer mortality (excluding lung cancer) are illustrated clearly by the fact that there are 86,000 fewer deaths each year than there would have been in 1950.  Even more impressive, there are 30,000 fewer deaths now than there would have been as recently as 1990.

For a half-century, lung cancer (90 percent of which results from cigarette smoking) has clouded the many successes in the cancer field, Rodu says. If all other cancer deaths caused by cigarettes were excluded, the drop in other cancer mortality would total 31 percent. The impact of smoking is also seen in cancers of the oral cavity, pharynx, esophagus, pancreas, urinary bladder, and kidney.
Americans have enjoyed a longer average life span since 1950, resulting mainly from decreasing rates of death from cardiovascular and other diseases.  The overall cancer mortality rate began its decline only after 1990, as Cole and Rodu pointed out in a landmark 1996 study published in the journal Cancer. “Thus, for four decades cancer seemingly ran counter to the general pattern of declining mortality,” the current article states.

The widespread emphasis on grouping lung cancer in with overall cancer mortality rates brought important social consequences, the authors write. The perception that little progress was being made against the disease caused the federal government to launch the war on cancer in 1971. “With mortality rates still spiraling upward, the war was being criticized as ineffectual and pessimism persisted well into the 1990s,” the article states.

In reality, the war on cancer accelerated progress, Rodu and Cole say. The decline of cancer other than lung cancer was 0.4 percent a year from 1950 to 1990, and more than doubled that to 0.9 percent annually from 1990 to 1996.  The rate of decline in mortality again more than doubled from 1996 to 1998 to 2.2 percent a year. “Prospects for continuing mortality reductions are excellent as medical progress continues, as gains become more widely available, and as all smoking-related cancers continue their inevitable decline.”
 
Rodu and Cole’s article deflates the myth that the war on cancer was ineffectual. It also blames the focus on all-cancer mortality for the widespread perception of a cancer epidemic caused by environmental pollution. “There is no denying the existence of environmental problems, but the present data show that they produced no striking increase in cancer mortality,” it states. “In reality, the so-called cancer epidemic consisted of one disease, cancer of the lung, and was due to one lifestyle factor, cigarette smoking.”

Cole, a widely published epidemiologist, retired from the UAB faculty a year ago.  Rodu is a professor of pathology and a senior scientist with the UAB Comprehensive Cancer Center.