When Elizabeth Edwards told the world last week that the cancer that had attacked her body two years ago had returned and then added, with some conviction, that she and her husband planned to go forward with his presidential campaign, the news was greeted with a mixture of admiration and doubt.
Should someone with cancer and two small children be making plans for an enterprise likely to demand significant investments of time and energy over the next two years? What was she thinking? Katie Couric asked on national television.
Edwards' answer reflected the most public manifestation of a significant if subtle turning point in the long war on cancer. A cancer diagnosis is no longer necessarily the death sentence it long was. Growing numbers of Americans are living longer as they fight the disease and, in the last two years, the number of cancer cases has actually declined.
While the death rate from cancer is high -- accounting for at least 20 percent of deaths in the United States -- about 40 percent of the million Americans who are diagnosed with cancer each year get early treatment and live for many years after the diagnosis. Many are fully cured.
Still, the war on cancer is far from won.
The gains made have been hard-fought in a long and expensive battle with a disease that continues to be more feared than any. While the mortality rates from heart disease, stroke and pneumonia have been cut by half since 1950, the advances in the war on cancer have been minimal, despite a largely successful anti-smoking campaign and billions spent on new drugs and aggressive treatment regimes.
The more we learn about cancer, the more complicated the fight becomes. Earlier this year, two respected studies produced sharply differing conclusions about how some forms of lung cancer should be treated.
Cancer's challenge is so difficult because it takes so many forms. It is not one disease but more than 100 diseases, all with common factors. While only a small fraction of cancers are believed to be inherited, all cancers develop because something in a cell's genes has gone wrong; determining just what is a difficult challenge for each variation.
Still, researchers are optimistic because so much has been learned about the genetic roots of cancer. And hardly a week passes without the introduction of new drugs and new treatment strategies. There are more than 10 million cancer survivors living among us now, more than three times the 3 million counted in 1971.
In January of this year, the American Cancer Society reported that the number of cancer deaths in the United States has dropped for the second year in a row. Encouraged researchers said the statistical report suggests that this may be the start of a continuing decrease.
"This second consecutive drop in the number of actual cancer deaths, much steeper than the first, shows last year's historic drop was no fluke," said John R. Seffrin, the American Cancer Society's chief executive officer. "Everyone involved in the fight against cancer should be proud of this remarkable achievement. The hard work toward preventing cancer, catching it early, and making treatment more effective is paying dramatic, lifesaving dividends. Thirteen years of continuing drops in the overall cancer death rate have now overtaken trends in aging and growth of the U.S. population, resulting in decreased numbers of deaths."
The American Cancer Society projects there will be 559,650 deaths from cancer in 2007; 289,550 among men and 270,100 among women. The Society also predicts there will be 1,444,920 new cases of cancer in 2007; 766,860 among men and 678,060 among women.
In Maryland alone, the cancer society predicts, there will be 10,210 cancer deaths this year, with the largest number -- 2,900 -- coming from cancer of the lung and bronchus. Colon and rectum cancers and breast cancer are a distant second and third among likely causes of cancer deaths in Maryland this year.
Nationally, among men, cancers of the prostate, lung and bronchus, and colon and rectum account for more than half (54 percent) of all newly diagnosed cancers. Prostate cancer alone accounts for nearly a third (29 percent) of cases in men. American men now face a one-in-two chance of contracting prostate cancer in their lives.
The three most commonly diagnosed types of cancer among women in 2007 are expected to be cancers of the breast, lung and bronchus, and colon and rectum, accounting for more than half (52 percent) of estimated cancer cases in women. Breast cancer alone is expected to account for more than one in four (26 percent) new cancer cases among women.
Deadly lung cancer
Lung cancer surpassed breast cancer as the leading cause of cancer death in women in 1987. Lung cancer is expected to account for 26 percent of all female cancer deaths in 2007. It is also by far the most significant cancer killer of men. About 30 percent of all cancer victims are smokers.
The continuing success of national anti-smoking campaigns is helping to reduce the lung cancer death rate among men and appears to have halted a recent rise in the lung cancer rate among women.
Non-smokers also face lung cancer dangers from the inhalation of tobacco smoke in bars, restaurants and other public places, researchers agree. Research on this danger has led to the banning of smoking in many major cities -- including Baltimore, which banned public smoking earlier this year .
The state of Maryland is also considering a public smoking ban, with possible exemptions for clubs and other special cases.
Researchers have become more and more successful in identifying other likely causes of cancer. The most dangerous carcinogens -- as these cancer triggers are called -- are radioactive chemicals like those released at Chernobyl, but the list also includes more commonplace substances like car exhausts, pesticides, industrial waste, asbestos, fiberglass wool and some processed foods.
Some dangerous combinations of behavior also can sharply raise cancer risks, researchers have discovered.
If a smoker is also a heavy drinker, for instance, the risk rises not only for lung cancer but also for other cancers. Research has indicated that such a person is far more likely to get cancer of the esophagus than somebody who drinks the same amount but smokes ten or fewer cigarettes a day.
Researchers suspect that food may be a contributing factor in 35 percent of all fatal cancers, but have had a hard time pinning down likely culprits. Eating large amounts of fatty meats, oils and dairy products appear to increase the risk of cancer in the breast, cancer stomach and colon. Intake of food that is smoked, pickled or salted also should be limited, some experts suggest.
Some foods appear to offer cancer protection. Fiber-rich foods, like whole-grain cereals and fruits, insure against bowel cancer. People who get plenty of vitamins A and C, which are abundant in vegetables like spinach, Brussels sprouts and broccoli, appear to get fewer cancers of the respiratory and digestive systems.
Skin cancer is an increased danger for anyone who chooses to tan. Residents in the southeastern and southwestern United States have a more than 10 percent chance of suffering some form of skin cancer by the age of 75.
Proving relationships between carcinogens and actual cases of cancer is sometimes difficult because the genetic susceptibility to different forms of cancer varies, depending on the widely diverse genetic makeup of individuals. Thus, someone can be a heavy smoker all of their life and live to age 90 without developing cancer.
Still, the danger of falling victim to some form of cancer grows with age. That's because each time a cell in your body divides there is a danger that a random mistake will be made when the body's basic blueprint is copied. After many decades of copying, the odds grow that a cancer-triggering defect will appear.
Cancer dangers also vary significantly among ethnic groups. The cancer death rate among African-American men is more than a third higher than for white men, while the death rate for Hispanic men is significantly lower. Researchers suspect a combination of genetic, environmental and social patterns is responsible for the differences. African-American men are, on average, less likely to be tested for cancers, like prostate, that are suceptable to early cures. The reason might be cultural or economic.
Cancer death rates might drop significantly if larger proportions of the population sought basic diagnostic tools like the PSA test for prostate cancer and mammography for breast cancer, experts agree. A steady increase in the number of people who have had their cancers diagnosed early because of screening has had a significant impact on the numbers of people who have survived their cancers for five year or more.
Researchers are hard at work developing more sophisticated diagnostic tools that they hope will do a far better job of identifying early-stage cancers by detecting traces of proteins produced by aberrant genes. Early and more accurate detection promises more cures or longer lives for cancer victims.
Drugs designed to attack specific cancer cells based on their unique genetic makeup are already significantly lengthening the life expectancy of the victims of many cancers that had previously been considered untreatable.
Doctors worry about the extraordinarily high costs of some innovative cancer drugs, tests and other treatments, and making the treatment of cancer more affordable is a growing priority for physicians who treat the disease.
Still there is growing hope that an increasingly rapid pace of research will lead to growing levels of success in lengthening the lives of cancer victims and providing absolute cure for more.
The war on cancer is far from over but the pivotal battles may already be underway.