- 10/29/2005
- Washington, DC
- Denise Mann
- WebMD (www.webmd.com)
With cancer survivor Lance Armstrong winning his seventh Tour de France, and walks, runs and other highly visible fund-raising opportunities — often overflowing with survivors and their families — taking place almost ubiquitously across the map, it certainly seems that doctors are finally winning, or at least making some significant strides — in the war against cancer.
But are they?
The word “cancer” still strikes a chord of fear in most people, but the truth is that today many cancers including breast, colon and prostate may no longer be the death sentences that they once were. Others like melanoma and pancreatic cancer, however, are still proving somewhat vexing and insurmountable. But ultimately, we are turning a corner: survival statistics are up for many cancers, smoking is down, and some of the best minds in the world are trying to crack the cancer codes.
Today, Armstrong is seen as an anomaly, but that may not always be the case. “Lance Armstrong is such an inspirational story that cancer is not only not a death sentence, but he can say, ‘I beat it and I am doing something about’ it by setting up a foundation and speaking out,” says Thomas Glynn, PhD, the director of cancer science and trends at the American Cancer Society (ACS) in Washington, D.C. “I think as survival rates continue to rise, we will see people like him who shine and not only survive disease and actually do well with it.”
Judah Folkman, MD, the Andrus Professor of Pediatric Surgery and professor of cell biology at Harvard Medical School and director of the vascular biology program at Children’s Hospital, both in Boston, agrees: “Lance Armstrong is really amazing, and the fact that we can do it once means you can maybe do it again,” he says.
Here’s how we are doing so far.
Multifront War Waged
Make no mistake, “we are winning this war, but progress has been slower than we would have expected in 1971 when war [on cancer] was declared by President Richard Nixon,” says Glynn.
Calling it a “multifront” war, Glynn tells WebMD that “there is no such thing as one cure for cancer because we are dealing with hundreds of different diseases all gathered under the [category] cancer.”
When President Nixon declared war, the “assumption was that to beat cancer, a switch needed to be turned off and we just needed to find that switch,” he says. “What we are finding out is that there are multiple switches and different things that turn them on and off.”
Victories in the Fight Against Cancer
In 2005, there will be 1,372,910 new cancer cases in the U.S. and 570,280 cancer deaths (about 1,500 per day), according to statistics from the ACS.
Overall, “if you look across the board, there are very few cancers in which we are not seeing declines in mortality,” Glynn says. “We are seeing reductions in prostate, colorectal, and breast cancers, and stomach cancer has basically fallen off of the edge of the earth in the U.S.,” he says. “In lung cancer among men, we are seeing a drop, and we will be seeing a drop among women by 2010,” he predicts. Still, lung cancer remains the top cancer killer in both sexes, according to the ACS. It is responsible for nearly one in three cancer deaths in men and about one in four among women.
According to the latest ACS statistics, death rates for all cancer sites combined decreased 1.5% per year from 1993 to 2001 in men and 0.8% per year from 1992 to 2001 in women.
“Five-year survival for all cancers combined used to be about 50% and now it’s 75%,” Glynn says. “We have made a lot of progress in early detection,” he says. “Fewer than 1/2 of all women were receiving mammograms several years ago and now it’s close to 80%, we have mapped the human genome, which will eventually lead to individual treatment and prevention, and smoking is down in women to under 20%,” he says.
Five-year survival describes the percentage of people still alive within a five-year period after diagnosis or treatment of cancer.
The Katie Couric Curve
Survival is way up in colon cancer because it is caught earlier due to routine colonoscopy (which is the method recommended by most major medical institutions), says Vijay Trisal, MD, an assistant professor of oncological surgery at the City of Hope National Cancer Center in Duarte, Calif. After her husband died of colon cancer, NBC newswoman Katie Couric had a colonoscopy live on national television. In the following weeks and months, the numbers of people across the country having colonoscopies increased more than 20%, according to researchers at the University of Michigan Health System and the University of Iowa.
“We are picking up earlier cancers and that’s making a difference, and part of the difference is also very good chemotherapy for colon cancer,” he says. For example, it used to be that if colon cancer had spread to the liver, “survival was nine to 11 months, but now we can resect the liver and chemotherapy kills the microscopic disease, so we seeing survival in the range of 50%,” he tells WebMD.
Overall, “advances in cancer have been in treating the microscopic disease,” he says. “Chemotherapy for breast cancer and colon cancer has significantly improved because we can kill the small disease that is not visible and regrows either in the vicinity of the cancer or spreads throughout the body.” Chemotherapy can knock out errant cancer cells along with the main tumor.
The rates of colorectal cancer have dropped between 1998 and 2001 in both men and women. Prostate and female breast cancer rates have continued to increase, although at a slower rate than in the past. However, the increase may be due to increased detection because of higher rates of screening using prostate specific antigen test for prostate cancer and breast X-ray or mammography for breast cancer.
New Warriors Join Battle
New “smart” drugs are also promising weapons in this war. “This year, there has been enormous progress in the angiogenesis inhibitors, and it is the first year that there has been a significant increase in survival of the three top cancers – colon, breast, and lung — due to antiangiogenic therapies being introduced,” Folkman tells WebMD. Antiangiogenic drugs, also called angiogenesis inhibitors, starve tumors to death by cutting off their blood supply.
For example, Avastin targets a protein called vascular endothelial growth factor (VEGF), which plays a role in making new blood vessels for tumors (a process called angiogenesis). This drug was approved in the U.S. for colon cancer in February 2004, and by January 2005 it had been approved in 27 other countries, he says.
Other antiangiogensis drugs being used include thalidomide and Tarceva. Tarceva blocks tumor cell growth by targeting a protein called HER1/EGFR that is important for cell growth in advanced nonsmall cell lung cancer. Tarceva “blocks three angiogenic proteins and really is an angiogenic inhibitor,” Folkman says. Thalidomide became notorious in the 1960s when it was prescribed to pregnant women to ease morning sickness, but was found to cause severe birth defects by limiting the blood flow to developing limbs. As a result, many children were born limbless or with severely shortened limbs. Now scientists are capitalizing on these same blood-limiting properties to help block the blood supply to tumors.
Treatment No Longer Worse Than the Disease
“[These drugs] have changed our thinking,” he says. “We don’t use the word cure, but we now think of converting cancer to a chronic manageable disease like diabetes,” he says. “When you see these patients, they are not very sick, their hair doesn’t fall out, they don’t have massive diarrhea and their spouses stay with them,” he says. New treatments have decreased the toxicity and decreased the chance of drug resistance, he explains. “There are at least 40 other antiangiogenic drugs in the pipeline and some are doing very well,” he says.
The bottom line is that “you can live with cancer today,” he says.
Coming Soon?
“The newer things are biomarkers of angiogensis or blood tests that are so sensitive they can pick up a 1-millimeter tumor in a mouse just before it switches on,” he says. “Say you have colon cancer. We could do a urine or blood test every four months and if levels of a certain protein stays flat, you are fine, but if it goes up we know the cancer may be returning,” he says.
“Drugs like angiogenesis inhibitors that are approved are not as toxic as older cancer therapies, so you can take them for longer times, you don’t develop resistance as fast and this is intersecting with biomarkers where we can diagnose cancers earlier and earlier,” he says. “We are beginning to ask why do we care where the cancer is,” he says. “If test is rising, why not treat with nontoxic antiangiogensis inhibitor until the numbers come down?”
Other targeted drugs include Erbitux for colon cancer and herceptin for breast cancer. Both are considered antibodies, which are produced in a laboratory to target a very specific portion of foreign substances. Another drug, Gleevec, is a small-molecule drug that targets abnormal proteins that form inside cancer cells and stimulate uncontrolled growth. It is approved for certain forms of leukemia and rare stomach cancers.
Overall, these new drugs “absolutely do help, but so far they are not revolutionary in seeing a halving of incidence of death rates or mortality rates,” he says. “But they certainly suggest that we are making progress and are perhaps on the edge of making revolutionary progress,” ACS’ Glynn says. “We are in the early stage of drug development and need to now how best to use these drugs.”
Cancer: the Bad and the Ugly
“Some tumors are ugly,” says Robert J. Morgan Jr., MD, the section head of neuro-oncology and a physician in the division of medical oncology and therapeutics research at the City of Hope National Medical Center in Duarte, Calif. For example, there has been little progress with treating and beating brain cancer, he says. “There are two problems,” Morgan tells WebMD. “The first is finding an effective agent and the second is making sure this agent can cross the blood-brain barrier and get to the tumor,” he says.
In 2005, doctors will diagnose 18,500 malignant tumors of the brain or spinal cord in the U.S. and approximately 12,760 people will die from these tumors, according to the ACS.
“Pancreatic cancer too turns out to be difficult to detect and treat,” he says. In fact, pancreatic cancer is the fourth leading cause of cancer death.
Another cancer that doctors have not mastered yet is ovarian cancer. “Unfortunately, we do not have a reliable screening test for ovarian cancer because it’s a tumor that is 100% curable if caught in stage I with surgery alone or surgery and chemotherapy, whereas once it has traveled the chances of cure can drop to as low 5%,” he says.
A good screening tool for lung cancer could also help doctors turn a corner on the disease that recently took the life of ABC News Anchor Peter Jennings. “People are being hammered to not smoke, but a large number of patients who don’t smoke do develop lung cancers,” he says. “We do know that tumors are different in smokers vs. nonsmokers and we need a better screening test because low-dose spiral computed tomography (CT) scans are expensive, insurance doesn’t pay, and it has a high rate of false-positives leading to unnecessary surgeries to remove the suspicious nodules.”
Melanoma is also proving tricky, says City of Hope’s Trisal. “The major reason is that we don’t have any effective therapy for melanoma except surgical therapy,” he tells WebMD. “We don’t have any effective chemotherapy drugs, and we have been looking to vaccines and biological therapy, but the response rate is minimal.” Biological therapies such as interferon utilize substances that occur naturally in the body to attack cancer cells.
“Earlier detection of melanoma is very effective and we are picking it up earlier now [due to routine skin checks], but it will take 10 years to see if we made a difference,” he says. But right now, “it’s an all-or-none phenomenon, [meaning that] if you have metastatic (spreading) melanoma in the lymph nodes, we are fighting a losing battle.” If not, it looks good. It’s a big watershed area where people will either be OK or not be OK.”
Summing It All Up
“President Richard Nixon declared war against cancer about 30 years ago, and we were woefully lacking in biology of cancer and how it worked, we thought it was one disease, and I think only in the last five years that we are starting to understand that the biology of tumors are quite different,” City of Hope’s Morgan says. “It turned out to be a lot more complicated than we thought, but we are heading to a much broader understanding of biology.
“I’d have to give us a C-plus/B-minus in treating advanced cancer because we still have to use a lot of toxic treatments to obtain good results and we still don’t have anything to cure cancer, but we are clearly improving,” he says. “For new agent development, we get a B-plus, and for understanding the biology of cancer, we also get a B-plus, “he says. “For screening, we get a B because we have good screening tools for colon, breast, and our effort is clearly an A, but we could use more funding for prevention.”
However, “we haven’t received an A in anything except in certain types of cancer,” he says.
Published Aug. 12, 2005.
Sources:
Thomas Glynn, PhD, the director of cancer science and trends, American Cancer Society, Washington, D.C., Judah Folkman, MD, Andrus Professor of Pediatric Surgery, professor of cell biology, Harvard Medical School. Vijay Trisal, MD, assistant professor of oncological surgery, City of Hope National Cancer Center, Duarte, Calif. Robert J. Morgan Jr., MD, head of neuro-oncology, division of medical oncology and therapeutics research, City of Hope National Medical Center, Duarte, Calif.
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