A great deal of time, energy, and resource have been poured into the search for the causes of cancer, but one important fact is often overlooked: When exposed to known cancer-producing substances, most people still remain healthy. It is quite clear, for example, that the incidence of lung cancer goes up sharply with heavy smoking. But if all it took to get cancer was exposure to nicotine and tars, then all heavy smokers would contract the disease. Yet most heavy smokers do not get lung cancer. To understand the disease, then, we have to consider not only what causes some people to get cancer, we also have to consider what keeps most people from getting it—in other words, what maintains health?
One of the most important factors in sickness and health is the body's natural defenses. All of us are regularly exposed to disease, whether it is simply a cold, flu, or a more serious infectious disease. Yet the mere fact of exposure does not mean that we become ill. For the body's defense system—the immune system—is so powerful and effective that most people would not see a doctor for years unless reminded to take periodic checkups.
Greatly simplified, the immune system is composed of several kinds of cells designed to attack and destroy foreign substances. Anytime you see pus gathering in a cut, it is a reminder of the body's immune system at work. Pus is nothing more than a mass of white blood cells—a major part of the immune system—that have rushed to the site of the cut to isolate or destroy the infection. This self-healing process takes place constantly, on all levels within the body.
There are numerous cases on record in which chest X-rays revealed that individuals had at some time contracted mild cases of tuberculosis, for example, but that their bodies' defenses had fought back and destroyed the disease—all without the patients' being aware that they had even had any disease in the first place. In much the same way, the body does battle with cancerous cells on a routine basis, and routinely the cancerous cells are contained or destroyed so that they can do no harm.
In fact, the effectiveness of the body's natural defense system in rejecting anything foreign or abnormal is so great that it becomes a major problem in transplanting organs such as a heart or a kidney. Ordinarily this rejection phenomenon has great survival value, but in the case of a transplant, the foreign organ must be accepted by the body if the patient is to survive. For this reason, transplant patients are given a number of drugs designed to suppress the body's defenses. And here a problem arises, for the drugs that reduce the body's rejection of the transplanted organ also reduce the body's ability to defend itself against other dangers such as infectious I disease or abnormal cells such as cancer. Hospitals therefore take great care to ensure that the transplant patient is not exposed to disease during this period, and the transplanted tissue is thoroughly checked to ensure that it is normal and healthy. But when something goes wrong with these painstaking procedures, the effect can be lethal.
Such a case was reported by Dr. Ronald Glasser in his book, The Body Is the Hero. In a rare incident, even though everything possible had been done to ensure that the kidney donor was healthy, a kidney with unobserved cancer nodules was placed in a person who had received drugs to suppress his immune system for the transplant. After the operation, the patient was given further medication to continue suppressing the immune system and thereby prevent the body from rejecting the kidney. Within days, the transplanted kidney began to enlarge. The reaction looked like some form of active rejection, but the kidney continued to function normally. A few days later, I a routine X-ray revealed a tumor in the patient's chest. Since j chest X-rays taken four days earlier had showed no such mass, clearly it was something that had developed since the operation.
A day later a similar tumor could be seen in the other lung. When an emergency operation was performed, the upper half of the transplanted kidney was found to be three times the size of its lower half. A biopsy of the abnormal portion showed it to be full of malignant cells. The physicians concluded that the masses in the lung were metastatic cancer (that is, malignant cells had broken away from the original cancerous mass and begun to reproduce in other parts of the body). The startling thing was the speed with which the masses had grown. Within days, cancerous masses had appeared that would normally have taken months or even years to develop. There was no choice but to stop administering the drugs that suppressed the body's defenses.
Within days, as the patient's immune system came back to normal, the masses in his lung began to disappear and his transplanted kidney began to shrink in size. But with the stoppage of the drugs, it became obvious to the physicians that as the patient began to "reject" his cancerous cells, he also began to reject his transplanted kidney. They had no choice. They could not run the risk of the cancer returning, so they kept the patient off his immunosuppressive drugs; the cancer was destroyed but the kidney was also completely rejected. The rejected kidney was removed and the patient put back on chronic dialysis. He survived with no further evidence of cancer.
The physicians concluded that the donor's immune system had kept these cells in his own kidney in check, preventing them from spreading. It is even possible that the donor's natural defenses were sufficiently strong that he might never have been aware of the presence of malignant cells, but when the organ was transplanted into a person whose defenses were suppressed by drugs, there was nothing to prevent them from running rampant. Despite the rapid spread of the cancer—and this is most important—when the body's normal defenses were allowed to function again, the cancer was quickly destroyed.
This story and a significant body of other research demonstrate that the development of a cancer does not require just the presence of abnormal cells, it also requires a suppression of the body's normal defenses. This research has led to broad medical acceptance of what is called the "surveillance theory" of cancer development.
The Surveillance Theory and Susceptibility to Cancer
According to this theory, everyone produces abnormal cells in the body from time to time, either because of external factors or simply because of inaccurate cellular reproduction.
Normally, the body's immune system keeps close watch out for any abnormal cells and destroys them (thus the term "surveillance"). For cancer to occur, then, the immune system must be inhibited in some way.
We will explore the possible causes of this suppression in later chapters, but the important point here is that something is happening in the person who contracts the cancer to create a susceptibility.
External agents, radiation, genetics, diet—all four factors may play a role in the causation of the disease, but none of them is a full explanation without considering why particular individuals, at particular points in their lives, contract cancer. They have certainly been exposed to harmful substances or radiation at other times. If there has been a genetic predisposition, it has been there all along. Their diet is likely to have been stable for a number of years. And, based on current medical theory, as we have said, abnormal cells are present in everybody's body occasionally throughout life. So, whether abnormal cells are created by external factors or simply occur naturally, the crucial questions become: What lapse in the body's defenses allows these cells to reproduce into a life-threatening tumor at this time? What inhibits the body's immune system from performing the function that it has performed successfully for many years?
The answers to these questions bring us back to emotional and mental factors in health and illness. The same factors that may determine why one patient lives and another with the identical diagnosis and treatment dies also influence why one person contracts a disease and another does not. As we shall see in the next two chapters, there are already several valuable clues to justify this line of assault on the causes.
First, there is a strong link between stress and illness. Second, the incidence of cancer in laboratory animals is greatly increased when they are placed under stress. Third, there are substantially different incidence rates for cancer among patients with different kinds of mental and emotional problems. These clues point to significant connections between emotional states and illness.
It is time to consider how the interrelationship of mind, body, and emotions may give us important new insights into the increased susceptibility to illness in general, cancer in particular, and into the question, "Why me?"