Cancer Update
Michael J. Thun, M.D.
Vice President of Epidemiology and Surveillance Research,
American Cancer Society
Friday, Jan. 31, 2002; 3 p.m. ET

The advent of new drugs has allowed many cancer patients who would have normally faced a fatal outlook to continue to live relatively normal lives. Though still sick, many now see their diseases as a chronic disease, much like diabetes or asthma. Today, an estimated 9 million Americans are cancer survivors, up from an estimated 6 million in 1990. However, cancer is far from being a problem of the past. In the American Cancer Society's newly released Cancer Facts & Figures 2003, it is estimated that in the U.S. there will be 1,334,100 new cancer cases and 556,500 deaths from cancer this year.

Dr. Michael J. Thun, vice president of Epidemiology and Surveillance Research at the American Cancer Society, will be online Friday, Jan. 31 at 3 p.m. ET, to field questions and comments on the latest cancer information.

Submit your questions and comments either before or during the discussion.

Dr. Thun has worked for almost 25 years in epidemiology and the prevention of chronic diseases. From 1978-1980, he served as a medical officer with the state epidemiologist of New Jersey, investigating toxic exposures. From 1980 to 1989, he worked for the Centers for Disease Control and Prevention first as a epidemic intelligence service officer, and later supervising and conducting research on occupationally induced cancer at the National Institute for Occupational Safety and Health in Cincinnati. In 1989, Dr. Thun became the Director of Analytic Epidemiology at the American Cancer Society. Since 1998, Dr. Thun has served as vice president of Epidemiology and Surveillance Research, overseeing both cancer surveillance and studies of the causes and prevention of cancer.

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washingtonpost.com: Thank you for joining us today Dr. Thun. What were the major findings of the latest American Cancer Society Facts & Figures report? Any big surprises?

Dr. Michael J. Thun: To put it in perspective, we realize this is the 51st edition of cancer Facts and Figures. It's grown from a four page leaflet to this two-volume publication that tries to provide information that estimates the number of cancer cases and deaths by state and progress in reducing the major causes of cancer.

One piece that is new is a special section on smoking cessation. The reason for emphasising that is because smoking is stil contributing 1/3 of all cancer deaths and there have been major advances in quitting smoking and helping smokers quit is one way we can reduce the burden of cancer and other diseases to the 46 people who currently smoke.

Some other points are that in 2003 we estimate 1,334,100 new cancer cases at 556,500 deaths from cancer. This represents an increase of 3.8 percent in the percentage of deaths but roughly the same number of deaths as last year.

The increase in the number of new cases is attributable to the aging of the population and it illustrates that even though death rates are decreasing but the number can be expected to rise because of the age of the population.

Washington, D.C.: What is the American Cancer Society's position on preemptive screening -- like regular MRI's, etc. -- to catch cancer in its very earliest stages? Many HMOs do not want to pay for this kind of preventative care. Does the ACS lobby for more preventative care?

Dr. Michael J. Thun: The American Cancer Society definitely lobbies for more preventative care, but for particular screening tests that have been proven effective in finding cancers in stages where they can be cure. So we don't lobby currently for full body CATscans, etc., because there's no evidence that this is effective in changing the course of cancer.

The tests that have been shown effective are mammography, colorectal screenings, including -- beginning at age 50 a test for blood and stool every year ad flexible sigmoidoscopy every five years and a colonoscopy every 10 years. Of course, for cervical cancer.

Arlington, Va.: Hi Dr. Thun. Thanks for answering our questions. There has been a lot in the press lately about more and more people managing cancer and dealing with it as a "chronic" condition. Are there some cancers that are more "manageable" than others?

Dr. Michael J. Thun: That's a good question. Some cancers are more lethal than others and are not manageable because of that.

In general the earlier a cancer is diagnosed the better the chance of obtaining a complete cure, particularly for ones treatable by surgery or local radiation. In addition to the stage of diagnosis, the type of cancer also affects survival. Certain cancers, like lung cancer and pancreatic cancer, can generally still have poor survival rates. And then for cancers in which people are substantially surviving for five or more years, the difficulty of living with cancer depends largely on the extent of treatment that was necessary as well as on the cancer itself.

Cancers vary greatly in the symptoms and in problems -- even within cancers of the same site.

Washington, D.C.: It's clear that there have been huge strides in the fight against cancer. There are also reports that some cancers will be wiped out, entirely, in the next 10-20 years. Which ones are they?

Dr. Michael J. Thun: Cancers for which a vaccine may be effective probably offer the best chance of eliminating the cancers with the information that is currently available. One area of enormous strides has been understanding the fundamental biological basis of cancers, so the example of treating the specific leukemia -- CML -- with a drug that blocks the activity of the genetic damage within the tumor cell is an example of how treatment developments may rapidly improve the treatment of specific cancers.

To go back to vaccines -- for example, there's now a vaccine being tested against HPV infection and if this is as effective as early indications show it could largely eliminate this very common cancer in parts of the world. Similarly vaccination for Hepatitis B could eliminate a very large faction of liver cancer in Asian countries.

Despite pessimism, major progress is being made in reducing tobacco use. The percentage of high school students who smoke has dropped dramatically since 1997 and since tobacco causes 30 percent of all cancer deaths, even small progress has a big impact in reducing cancer.

Less than half the population currently is being screened for colorectal cancer. Increasing this screening could cause an important reduction both in the incidence of colon cancer and in colon cancer death rates because the cancers can be removed surgically and treated and curable. Colon cancer accounts for approx. 11 percent of incident cancers and 10 percent of cancer deaths in the United States.

Iowa: I read an article recently that talked about the fact that poor people and minorities have much lower cancer survival rates. How does the ACS plan to remedy this disparity in quality of care?

Dr. Michael J. Thun: Yes, the ACS is working to address this disparity.

This is a huge problem. This is a large problem with many dimensions and the ACS continues to look for ways in which it can intervene effectively. It's main approach has been to try to work collaboratively with other organizations -- both at the national and local levels.

Washington, D.C.: Hi Dr. Thun,
Thank you for answering our questions. In reading about how cancer patients are surviving longer and longer, I am wondering if there have been any significant advances or improvements in treating the cancers that still have truly dismal survival rates, like esophageal or pancreatic cancer.
Thank you.

Dr. Michael J. Thun: Thank you for your question. These cancers are particularly resistant to conventional treatments. The approaches that offer the most promise in my view are development of ways to detect these cancers early. Of ways to, in the case of esophageal cancer, treat premalignant changes before they become cancer.

For example, with the increase in obesity there has been a large increase in the incidence of esophageal adnocarcinoma in the lower esophagus. They are people who reflux stomach acid and bile into the lower esophagus develop premalignant changes that in a small fraction of patients go on to become cancer. There is research about ways to prevent and treat this problem. For example, there are randomized clinical trials of treatment with selenium or various anti-inflammatories to prevent progression. These studies are still in an early stage, but approaches to prevent or reverse this process in high risk patients may be more effective than our current approaches.

Dr. Michael J. Thun: For pancreatic cancer in particular the tumors are usually diagnosed at a stage when surgical removal is impossible and a non-invasive test that detected this cancer at an early stage might improve survival. The ability to develop these tests has improved enormously with advances in lab tools, for instance, a combination of proteins measured in the blood seems to find ovarian cancers at an early stage very effectively and the test for ovarian cancer needs to be perfected and we need similar tests for other hard to diagnose types of cancer.

Anchorage, Alaska: People may be living with cancer but what is their quality of life? As a nurse I've seen way too many patients undergo "curative" surgeries that gave them a longer, but impaired, painful existence. How do well are we addressing the needs of these people?

Dr. Michael J. Thun: Also a very good question. Making appropriate pain medication available is a large first step. Ultimately improving cancer treatments so that they avoid much of the toxicity and side effects of current drugs is the longterm solution. The area of quality of care is not my personal area of expertise, but I know that there is a lot of research on this topic sponsored by the ACS and the NCI.

Washington, D.C.: What kinds of cancers are becoming more prevalent in the U.S.?

Dr. Michael J. Thun: Although the incidence, the occurrence, of many types of cancer is decreasing the prevalence, or number of people living with cancer, increases as survival improves and the population ages. This is seen particularly for breast and prostate cancer in which the majority of people who are diagnosed may be either cured or live with the cancer for many years. The number of women with breast cancer has also increased because the rate of new diagnoses has been improving slowly for many years. This is largely because of the difference in reproductive patterns -- fewer children, children at later birth... and probably because of increasing obesity and the use of post-menopausal hormones.

The occurrence of several uncommon cancers is also increasing, in particular Adenocarcinoma of the lower esophagus and non-Hodgkins Lymphoma.

washingtonpost.com: Is there progress being made in developing indicators of how aggressive a cancer is likely to be?

Dr. Michael J. Thun: This is an extremely important area, particularly for cancers like prostate cancers. Many of the cancers that are diagnosed may not be life threatening. There is extensive research trying to identify the markers for aggressive cancers so treatment can be tailored to people who will benefit from it. This is still in an early stage, but is based on specific genetic mutations in agressive cancers and the products that these mutated genes produce.

Washington, D.C.: Dear Dr. Thun,

Why aren't the cancers/diseases that kill/effect the most people the best funded? Why does politics play such a role?

Dr. Michael J. Thun: Lung cancer is the most common type of fatal cancer and it causes roughly 28 percent of all cancer deaths. The prevention of lung cancer relies principally on preventing the uptake of tobacco use among kids and helping addicted smokers to quit. Because lung and other smoking related cancers kill people quickly, there's been less of a constituency for it than other cancers like breast cancer. Consequently, it is very difficult to have states spend money from their tobacco settlement or excise taxes to fund adequate tobacco control programs. And with the current state budget crises, many states are diverting money away from tobacco control to other needs. Trying to correct this problem requires continuous pressure.

For perspective, cancers of the colon and rectum account for just over 10 percent of cancer deaths, breast for 7 percent and prostate cancer for 5 percent.

Arlington, Va.: How widely used and successful is the oft-maligned thalidomide in the treatment of cancer? What kinds of cancers does it work for?

Dr. Michael J. Thun: I do not know how widely used thalidomide is at present. It is remarkable that a drug which had such devastating effects on birth defects has proven useful as an anti-angiogenesis drug.

Harrisburg, Pa.: Have there been any recent studies on whether there is any correlations between nuclear radiation leaks and cancer? Legally, the courts have answered and stated there is no correlation. Yet, for those of us in the Harrisburg area who wonder if our cancer rates indeed are normal, or whether there are long term affects to the Three Mile Island leakages, questions continue. These concerns remain, especially when we observe that questions of increased infertility were never addressed, nor does there seem to be much of an effort to obtain data from people present who lived in the area and then moved away. Do you any thoughts on the effects of radiation as a cancer risk?

Dr. Michael J. Thun: Yes. Since I grew up within 50 miles of Harrisburg I share your interest in Three Mile Island. Several large studies of the episode have not found any relationship with cancer. Radiation is carcinogenic, but the affect is related to dose. Unlike the catostrophic release at Chernobyl, the type and amound at the Three Mile Island episode has not resulted in a detectable uptick in cancer.

Dr. Michael J. Thun: Progress in identifying the genes that underly cancer provide opportunities to prevent and treat cancers that have never existed before. This is much like the invention of the microscope in understanding and treating infectious diseases. The combination of basic research to understand and develop better approaches to treating cancer and the application of knowledge we already have to prevent cancer provides a great opportunity for progress.

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