Chapter 1 - What Are We Doing To Prevent Cancer?
Why, despite the billions of dollars spent on research to find a cure, have we failed to make a dent in the overall mortality from cancer for over sixty years? Although the age-adjusted death rate from 1950 until now has halved for heart disease and pneumonia and nearly quartered for strokes, it has not budged for cancer. The reason is not because we are living longer. This is what “age adjusted” means in this statement. It would be easy to cast the evil eye at tobacco, but smoking during this time in the U.S. decreased from nearly 50 percent of adults to less than 25 percent. The incidence of cancer has risen steadily; however, in 2006 in the United States, it appears the incidence may be declining slightly. Unfortunately, the same experts who celebrate this exceptionally modest decline are not hopeful it will continue as the baby boom generation hits peak cancer time. According to the World Health Organization (WHO), global cancer rates could increase by 50 percent to 15 million by 2020. One out of every two American men and one out of every three American women will get cancer over the course of their lifetimes.
There are many foundations such as the American Cancer Society and the Leukemia and Lymphoma Society dedicated to finding cures. Signifianct advances have been made in the treatment and survival rates for a few types of cancer, such as childhood leukemia and Hodgkin's disease. Despite this, the five year survival rate for cancers overall has not changed significantly since 1950. Only about 50 percent of people diagnosed with cancer live longer than five years.
So what are we doing wrong? Why has the mortality from heart disease dropped dramatically, while that from cancer has remained essentially unchanged?
We believe a significant factor is that our society is driven by money, and that far more money is allocated to treating rather than preventing cancer. There is great potential for financial gain in developing and marketing an effective chemotherapy agent. There is little financial incentive in preventing the tumor the drug would treat. There is clear financial incentive in treating animals and crops with hormones, pesticides and antibiotics in order to raise production and increase crop yield. There is little financial reward in evaluating what these substances do to our bodies once we ingest them.
Perhaps we physicians should bear a burden to teach, yet we live in a managed-care society that increasingly requires physicians to see more patients with less financial reward. Insurance companies reimburse physicians to spend an hour counseling a patient about how to proceed after a cancer is diagnosed. There is little or no reimbursement for educating patients about how to prevent that cancer, or, for that matter, any cancer, in the first place.
As physicians, we are also limited by a lack of knowledge. I (Lynne) recall many lectures in medical school dealing with the diagnosis, etiology (cause), and treatment of various cancers, and spending many hours looking through a microscope discovering the differences between normal and malignant (cancerous) cells. I do not recall a single lecture on cancer prevention. I also recall many lectures discussing the biochemistry of proteins, carbohydrates, and fats, and studying the mechanisms by which vitamins work in our bodies. I recall only one lecture on clinical nutrition meant to apply this knowledge to practice.
We as consumers are also at fault. We want cheaper food. We want convienence. We do not want to go to the store daily, so we want foods with a long shelf life and, hence, preservatives. We are willing to spend thousands of dollars and explore alternative medical practices once we are diagnosed with a tumor, but we spend little to educate ourselves about ways of avoiding disease in the first place. Part of the problem is the magical thinking that we accuse our teens of having: it will be someone else, especially someone who is not as health-conscious, who will get sick. Yet of the 80-95 percent of cancers that have an environmental component, only one third are due to smoking.
Governmental agencies have limited funding and are not the answer. Despite anti-smoking campaigns, anyone over the age of eighteen can freely buy carcinogens at the corner store, and we have even spent our hard-earned dollars subsidizing the tobacco industry.
At least for now it is up to as individuals to educate ourselves and adopt lifestyles consistent with cancer prevention. Physicians do not have the time to educate patients sufficiently. The government in unable to protect us completely. The pharmaceutical companies are going to invest more of their resources into drugs rather than the prevention of something the drugs would treat, and this is to be expected. We would not expect the automotive industry to invest more money into developing methods of eliminating cars than in manufacturing them! Food manufacturers will continue to find methods of increasing supplies to respond to the consumer's demand for cheaper, longer-lasting food.
We can no longer be complacent and expect our best interests to be looked after by others. It is up to us to take charge of our own bodies and lives!
Chapter 2 - Cancer Prevention Quiz
Diet And Obesity - 25-30 percent - obesity, or being overweight, alone accounts for 14 percent of cancer deaths in men and 20 percent of cancer deaths in women in the United States. According to the International Agency for Research on Cancer (IARC), as many as 375,000 cases of cancer could be prevented each year in the U.S. through healthy dietary choices. In a person of normal weight, dietary changes can also play a significant role in decreasing the risk of cancer and are discussed in detail in chapters Six and Eight.
Infection - 10-25 percent - it is estimated that around 10 percent of cancer deaths are related to infection, whereas infections cause 25 percent of cases worldwide. The leading culprits in the U.S. include human immunodeficiency virus (HIV), giving rise to multiple cancers, human papillomavirus (HPV); which causes cervical, anal, vaginal, penile, and oral cancers, hepatitis B; associated with liver cancer, hepatitis C; associated with liver cancer and lymphomas, and H. pylori; associated with stomach cancer.
Ionizing/UV Radiation - 2-7 percent. UV radiation causes 90 percent of skin cancers. Radon is the second leading cause of lung cancer.
Occupational - 2-8 percent are due to exposure to occupational hazards, accounting for around 5 percent (6-10 percent in men and 1 percent in women) of cancer deaths, especially those involving cancers of the lung, bladder, and bone marrow.
Alcohol - 3 percent. Alcohol has been shown to have a causal link with the development of cancers of the breast, liver, mouth, esophagus, pharynx, larynx, colon, and rectum. Alcohol is currently felt to be responsible for 3.6 percent of all cancers; 5.2 percent of cancers in men, and 1.7 percent of cancers in women.
Pollution And Environmental Chemicals - less than 1 to 5 percent in the United States, chemicals and pollutants account for roughly 1 to 5 percent of cancers. In other regions of the world, for example Chernobyl, Ukraine, pollution accounts for a much higher percentage of cancer.
Physical Inactivity - 1–2 percent - regular physical activity is associated with a decreased risk of developing breast and colon cancers, probably decreases the risk of developing prostate cancer, and may lower the risk of developing lung and uterine cancers as well.
Since discussion concerning HPV covers several dimensions of prevention, both primary and secondary, in addition to being emotionally laden and confusing, we will expand on this in some depth. Primary prevention can be practiced by engaging in safe sex, being immunized against the virus, and by incorporating dietary changes that have been shown to help clear the infection and consequently lower the risk of cancer if you develop the infection. Secondary prevention through regular screening with PAP smears allows for early detection and treatment of cervical dysplasia, preventing its progressing to cancer.
A vaccine to prevent infection with several strains of HPV has now been released. In clinical trials, the vaccine has been shown to prevent infection with HPV 16 and HPV 18 100 percent of the time with protection still present after four to five years. These two strains of HPV cause 70 percent of cases of cervical cancer in the United States. This new vaccine prevents the infection that causes inflammation that can lead to cancer, should be given prior to women becoming sexually active.
Most infections with HPV resolve without progressing to dysplasia and cancer. For those diagnosed with HPV, studies have shown a diet high in vegetables correlates with a resolution of the infection. increased dietary intake of lutein/zeaxanthin, beta-cryptoxanthin, vitamin C, vitamin A, lycopene, and papaya lower the risk of persistent HPV and therefore the potential for cancer to develop. Good sources of these include:
• Lutein/zeaxanthin – spinach, kale, turnips, mustard and collard greens
• Beta-cryptoxanthin – pumpkins, red peppers, papayas, tangerines
• Vitamin C – orange juice, red peppers, grapefruit juice, peaches
• Vitamin A – turkey, carrot juice, pumpkins, sweet potatoes, carrots, spinach
• Lycopene – tomato products, especially sauces
• Papaya – fresh papaya, papaya nectar
In one study, the use of tampons decreased the rate of HPV clearance. Women diagnosed with high-risk strains of HPV may want to consider using sanitary napkins as an alternative.
Chapter 6 - Lifestyle And Cancer Prevention
Like a rose thorn in the thumb that eludes a tweezers, reasons why the life expectancy in a dozen major European countries is higher than that in the U.S. have been difficult to discern. Life expectancy in Norway, France, Austria, Finland, Switzerland, Italy, Spain, and Germany, to name a few, is higher than in the United States even though their rate of smoking is higher. There are more smokers in Japan and Australia as well, and residents there live longer than those that reside in the U.S. Greece has the highest rate of smoking in the world, yet the Greeks live longer than the average American!
The subject of tobacco use is not under debate. it has been shown beyond a shadow of a doubt that smoking causes cancer and kills prematurely. our question is, if Greeks, say, did not smoke, would the gap between their life expectancy and ours be greater still? Probably, given what we know about smoking, but why? What are they doing that we in the United States are not? Could it have anything to do with the average American walking a fraction of the distance the typical European does daily? Could it have anything to do with the casual observation that while walking through the Amsterdam airport to reach connecting flights, the authors couldn’t really find an overweight person, while in the United States, we simply need to open our eyes to see several overweight people instantly? Could it have anything to do with the typical European vacationing from the stress of work for a few months each year instead of the few weeks a typical U.S. citizen is granted?
We begin our discussion of lifestyle factors with a discussion of tobacco, since it is the number one cause of cancer in the United States, but as we see clearly through life-expectancy statistics, cancer prevention goes far beyond smoking cessation. Information on the hazards of smoking has been extensively publicized and many excellent resources are available to help those dedicated to quitting, so our emphasis in this chapter will be on lifestyle factors in addition to smoking that predispose a person to develop or help a person to prevent cancer.
This chapter reviews some of the medications and procedures that have posed some concern from a cancer prevention standpoint. In many cases, the need for medication or radiological procedures far outweighs any risk posed by the treatment and should not be a cause for alarm. We wish to reinforce, however, that sometimes several options exist. We hope to give you a few basics to help you discuss these with your healthcare provider so that you both can make an informed decision regarding your care. We then review some of the medical conditions that can predispose a person to developing cancer and discuss the role of family history in cancer.
The time-faded statement “you are what you eat” carries much truth. Lacking the chlorophyll plants have, we cannot stand still and obtain our energy from the sun. The remarkable food tablets common in science fiction decades ago have yet to become reality. our bodies are remarkably designed machines, and what we eat is the fuel that either helps us run smoothly, or makes us cough and sputter and sometimes die. Considering this, and the fact that the typical American diet has an analogous octane level lower than we would allow in our cars, it is astonishing we do not “break down” more often.
Controversy over what to eat abounds. “Fad” diets emerge and while the individual foods may have merit, isolating one food item to the exclusion of a balanced diet eventually leads to its rejection and replacement by the next miracle diet. An adequate amount of some foods and vitamins is good but, when eaten or taken in excess, can be dangerous. The recommendations of some studies have shifted 180 degrees over the last few decades. Controversy and 180-degree turns abound in medicine. in 1927, 10,000 physicians actually recommended smoking cigarettes for health! So how do we interpret the data? The conclusion of most studies end with a call for further studies—an honorable conclusion—but where does that leave us in our quest for knowledge about healthy foods and what to eat today?
Our number one recommendation is to consume a wide variety of foods. The principles behind this are the foundation of a cancer-prevention diet. eat a variety of foods so you are more likely to receive an ample supply of the nutrients you need to stay healthy. eat a variety of foods so you avoid repeated exposure to carcinogens that may be present in certain foods. Avoid diets that isolate and recommend excesses of certain foods. Avoid diets that eliminate foods, even if only for a few days or weeks, that are necessary for long-term health. eating five to nine servings of fruits and vegetables a day, minimizing fast food, and choosing products less likely to be contaminated by hormones or pesticides should cover the bases, allowing a home run against most opposing carcinogen teams. For those extra sneaky carcinogens, adding a variety of “super-foods and nutrients” could be an additional week of spring training in your nutritional fitness program to prevent cancer.
You can read more extensive excerpts from each chapter, at no charge, from Google Books.
Secondary prevention is the science of searching for disease in its early stages, when it may be curable. Procedures such as removing precancerous colon polyps and treating abnormal cells on the cervix have been shown to be very beneficial. We believe screening to look for early prostate cancer and breast cancer is important as well, although the impact of this is less clear. There have been some discussions that, through screening, some early cancers are simply picked up at an earlier stage, giving rise to the observed increases in life expectancies. For now, it is important to assume that finding these cancers early does make a difference and to practice the recommended screening guidelines. In addition to advocating the primary prevention concepts we have discussed at length, we strongly urge our readers to stay up to date on cancer screening and keep a record of tests they have taken. most people—87 percent in a study published in JAMA—believe routine cancer screening is a good idea (Schwarz, 2004). In our clinical practice, we have been surprised at the number of very conscientious people who have neglected their own health maintenance. Most of these people made sure their children were immunized, their cars tuned up, their furnaces inspected, their sprinkler systems blown out, their dogs treated for heartworm, and their smoke detectors working. make yourself a priority!
They carefully turned off lights at night. They respected the sun and limited their time outside during midday, using protective clothing and shelter rather than using chemicals to coat their bodies and erase all cause for concern. Drycleaners were used for wedding dresses and other items, where the expense justified the cost. Everything they ate or wore was prewashed, in case they contained germs or chemicals. They came inside at dusk rather than lathered themselves profusely with bug spray. They did not have the “privilege” of non-stick cookware or access to anything they could want packaged for instant microwave heating. They were suspicious of new medications, products, and fast food. They did not do things to excess, as we are so prone to do now, and they practiced moderation. They seemed to know intuitively when to keep a stiff reign and exhibit caution, and never had a chance to read our book!
There were things they did not understand. They did not have their home checked for radon. They ate out in restaurants filled with secondhand smoke. They stayed warm with the help of asbestos insulation. They painted their home and furniture with lead-based paint. They loved the taste of their well water and never had it tested. Nevertheless, when information about risk became available, they listened.
Some people seem to “get away with” eating too much, smoking and drinking too much, and exposing themselves to carcinogens. Others do not. Our grandparents did not “gamble” with their lives. Through their actions they also demonstrated that life is more than preventing cancer, and we cherish the memories we have of their playfulness, love, and smiles. We have witnessed those who have succumbed to cancer at young ages but who lived life passionately and fully. We have also seen those that lived to ninety without cancer, but who lacked a passion and love of life. This book was designed for those who have that zest of our ancestors, and who hope for a long, full, cancer-free life.