The headlines have been hot in early October with the news of a significant decline in cancer death rates. The American Cancer Society released a report detailing an overall decline in cancer death rates of 2.1% from 2002 through 2004, compared to the 1.1% decline seen between 1993 and 2002. These rates include all types of cancer in both men and women, from all races. The decreases were greater in men (2.6% per year) compared to women (1.8% per year). Declines were seen in the top three cancer killers in men (lung, prostate, and colorectal cancer) and two of the top three killers in women (breast and colorectal cancers).
What can we take from these headlines? Is getting that mammogram still important? Will putting out that cigarette really help me? Let's delve deeper into this headline and explore what the causes for this decline may be, and how it affects us.
For starters, you may be wondering why we are talking about numbers from 2004 in 2007. Well, here's how it works. All medical facilities report information about new cancer cases and deaths to a state based cancer registry. The state registries collect, manage, and analyze this data, sharing it with the National Program of Cancer Registries (NPCR, which is run by the Centers for Disease Control, or CDC). The NPCR, along with the National Cancer Institute's SEER program, collect and analyze data for the entire US population. As you can imagine, this is a time- consuming process, and so the reported data is typically from 3 to 4 years prior.
Thus, we're talking about 2004 data because that is the most recent information that we have available. Let's look at some of the specifics:
Despite remaining the second-leading cause of cancer death for both men and women, colon cancer deaths are dropping more rapidly than any other cancer: a 5% drop in men and 4.5% drop in women. That can likely be attributed to two things, early detection and better treatments. Higher rates of colon cancer screening with colonoscopy have led to earlier detection, leading to a greater number of people being cured of the disease. In 1996, physicians had only one type of chemotherapy available to treat colon cancer. Now there are six, leading to longer survival for even those with advanced disease.
There's more good news for colon cancer. The number of people being diagnosed with it is declining as well; down by 2.5% a year. What's the reason? Screening! Screening with colonoscopy and sigmoidoscopy allows pre-cancerous polyps to be detected and removed before they become cancer. More folks are getting screening for colon cancer, but the number being screened is still only 50% of the population. Imagine how the rates would decline if everyone underwent screening for colon cancer.
On the surface, the news looks good, as rates for new breast cancer cases dropped by 3.4% a year from 2001-2004. Researchers are attributing the largest portion of this decline to the decrease in hormone replacement therapy use seen in 2002 and 2003. But the news isn't all good. Unfortunately, from 2000 through 2003, the number of women getting mammograms declined by a little over 3%. This may mean the decrease is in part because we are not finding the cancers in those women who are not being screened. Larger problems such as insurance coverage and access to care may also play a role in this decline in screening.
Lung cancer death rates account for the big difference in male and female cancer mortality. In men, the death rates have steadily declined by about 2% a year, but in women, the death rate is still increasing, although less rapidly than in the past. On the plus side, the actual number of lung cancer cases in women leveled off between 1998 and 2004 (following a long period of increases). Researchers attribute this to the fact that smoking became more common among US women after World War II (years after men took up the habit), and women have been quitting at a slower pace compared to men. This led to an earlier spike in lung cancer in men and a slower decline in women. While we have been hearing more about people who have never smoked being diagnosed with lung cancer, smoking is still by far the leading cause- and a preventable one.
Surveys by the CDC in 2004 and 2005 found smoking rates in US adults had remained constant at about 21%, after an eight-year decline. They also reported that 42.5% of smokers had stopped smoking for at least one day in the past year in an attempt to quit. Even more alarming, there has been no decline in smoking among US adolescents from 2002-2005. Unfortunately, smoking remains the most preventable cause of cancer incidence and death.
The number of prostate cancer cases stabilized from 1995 to 2004, after declining from 1992 through 1995. Increases in the number of cases of multiple myeloma, as well as cancers of the kidney, liver, and esophagus were seen in men between 1975 and 2004. In women, increases were seen in cases of melanoma, non-Hodgkin's lymphoma, leukemia, kidney, and bladder cancer between 1975 and 2004. In both men and women, thyroid cancer rates nearly tripled from 1995 through 2004. There is still a lot of work to do in the areas of prevention, early detection and treatment for many types of cancer.
As always, group statistics have little to do with what happens to an individual. As active participants in our own health, we must do what we can to decrease our own risk. This means it is very important to adopt a healthy lifestyle, including quitting smoking, keeping alcohol consumption to a minimum, exercising regularly, maintaining a healthy weight, and eating a well-balanced diet. In addition, we have to participate in appropriate cancer screenings, such as mammograms and Pap tests for women, PSA levels for men, colon cancer screening, and periodic visits to a physician for preventive healthcare for both sexes. Sounds like quite a bit of work, but it's our life and we should be responsible for taking care of it.