A few years ago, I was asked to co-author a book on prostate cancer (The Prostate Miracle: New Natural Therapies That Can Save Your Life, available at amazon.com.) In researching that book, I read a large body of material on cancer in general and came to the conclusion that cancer, or, really, cancer-like and cancer-related changes in the body, often are more environmental than genetic. They are closely related to our habits and our environment and these factors go a long way towards determining whether genetic risks are activated or controlled. Many women at this point in time may not find such a conclusion at all surprising—more than a decade ago, analyses of large trials using hormone replacement therapy to treat menopause revealed that hormone replacement quite significantly increased one or more “women’s” cancers. Moreover, a radical reduction in the use of hormone replacement therapy since that time has been rewarded with a similar reduction in female cancers, thus providing convincing proof for this line of argument. We do not seem to have such an undeniable “smoking gun” for prostate cancer, yet environmental factors (low vitamin D, exposure to environmental or “xeno” estrogens) are clearly at work in this “male” cancer, as well.
Indeed, an emphasis on environmental exposures and habits is becoming more frequent in cancer research, in part due to the combination of success and failure that has marked new cancer therapies, such as “targeted” therapies designed to focus on apparently unique metabolic aspects of many cancers. Certain pathways, for instance, related to “sonic hedgehog” metabolism in normal cells usually are active only during gestation and infancy and then are mostly (not entirely!) dormant after early childhood. Hedgehog inhibitors have achieved some instances of amazing clearance of particular cancers, such as basal cell carcinoma, with promising leads involving breast and pancreatic cancers, yet rebound regrowth of treated cancers resembles that of chemotherapy. This is because cancer “stem” or “progenitor” cells usually escape destruction and are activated by cancer-related changes in the local tumor environments. The DNA of the local tissues and the tumor cells remains unchanged in most such cases; the cancer stem cells are activated by what are called “epigenetic” or local environmental factors that do not alter the underlying DNA sequences found in cells. Among cancer researchers, the most famous of such local factors is the “Warburg” effect discussed below.
Chemotherapy remains most successful against some childhood and blood cancers as well as, oddly, testicular cancer. Overall, unfortunately, the vast sums spent on cancer research over the last 50 years have not confirmed many new successes in this area. Variations on the themes of surgery and radiation remain the most successful of treatments. These facts warrant the average person paying close attention to ways of preventing the initial activation of cancers and paying close attention to natural means of bringing fledgling cancer cells to the attention of the body’s immune system while these cancers can still be terminated by immune action. After tumor cells have reached a level of “critical mass,” termination by the body’s immune system is more difficult due to the fact that cancers can reshape their local tumor environments to activate epigenetic factors. Hence, the adage “an ounce of prevention is worth a pound of cure” remains especially true of cancer. Controlling the diet (e.g., reducing the consumption of refined carbohydrates), modifying habits (moderating weight gain as we age, getting adequate exercise and regularly obtaining adequate sunlight to keep vitamin D levels in the normal range), and even regulating one’s emotions (maintaining a balance, finding positive ways to not bottle up anger or grief, and so forth) all play their roles.
What Is Cancer?
Medical textbooks will tell you that there are hundreds of types of cancer, but the common thread is that cancer cells are abnormal and they are malignant. Whereas normal cells play specific roles in the body and have their growth closely regulated by various signals, cancer cells seemingly exist primarily to reproduce. These wild cells typically expand beyond their local origin to invade adjacent tissues. Often stray cells will break free into the bloodstream and implant themselves in other parts of the body distant from the original site. These propensities to invade surrounding tissues and to metastasize separate cancers from benign tumors (which include warts and polyps).
The body is a system made up of tissues and each tissue, in turn, is made up of a variety of cells. Not all of these cells are dividing at any one time. Instead, the functions and replication rates of the cells are closely regulated by the cellular DNA (deoxyribonucleic acid), the genetic “blue print” of the cells that is found inside each nucleus. The DNA strands themselves consist of genes, the individual packets of instructions. Chemical signals, usually in the form of small protein molecules, constantly enter each cell from the blood stream and interact with the mechanisms that control which genes are active and which are not. Similarly, microscopic tubules undergird the structure of the cell and extend outside of the cell to touch neighboring cells. These tubules, too, are part of the body’s communications network. Cancer cells are cells that in some fashion either have ceased to respond to the body’s communications network or are responding in a way which is hazardous to order and survival of the whole.
One way of looking at cancer cells is to view them as permanently juvenile cells, cells that never “grow up.” Mature normal cells are said to be “differentiated,” which means that they have taken on shapes and characteristics that make them specific to their particular functions in the body and different from other cells. Cancer cells might be said to have their development arrested at a stage prior to full differentiation. This way of looking at cancer cells is important in treatment because cancer cells which are forced to differentiate are less virulent, less damaging, and act more like normal cells. It is sometimes possible through the use of nutrients to return cancer cells to normal or near normal.
Normal cells, “good” cells, can go “bad” in several ways. In one of these, the genes that normally provide the instructions for the process of replication (proto-oncogenes) themselves become damaged in some fashion. When this happens, the resulting oncogene becomes like a switch that has been left in the “on” position when it should have been turned off and the cell replicates uncontrollably. In the new cells into which the cell divides, the oncogene is now the pattern for replication and cell division is no longer properly linked to the cell’s tissue function and the needs and signals from the body as a whole.
The proto-oncogenes of normal cells are themselves regulated or controlled by tumor suppressor genes, genes that usually serve as watch dogs to make sure that the cell is acting as it should. There are, in fact, two identical sets of tumor suppressor genes in each cell so that if one set fails, the other set will still be able to oversee cellular operations. These genes are, in effect, the master set of rules for how the other instructions (genes) that make up the cellular DNA are to be read and acted upon. If both sets somehow become damaged, the cell will cease to behave like a normal cell of its kind; it may radically change its shape, and it may begin to replicate itself without any control.
The body has a variety of mechanisms for protecting itself against unwanted changes in the DNA inasmuch as the genes are the basic code for the regulation of all physiologic processes. One of the most important of these mechanisms, a mechanism that is lately becoming increasingly appreciated by scientists for its significance, is called methylation. Methyl groups are single carbon units with the structure CH3 (one carbon and three hydrogen atoms). Methylation refers to the attachment of one or more methyl groups to different substances. Methylation has an impact upon the body that starts at the most elementary level, the expression of the DNA found in the genes. Methyl groups are attached at special sites to the DNA to provide protection against the expression or activation of genes that are responsible for many diseases, one of which is cancer. Indeed, almost all cancers become much more common in later life, not just prostate cancer, and the fact that our ability to replace the methyl groups located on the DNA strands declines dramatically as we grow older is a primary reason for this. Unfortunately, there are also aspects of cancers that can lead to “hypermethylation” of DNA, but the point remains that, in general, our body’s ability to completely regulate methylation declines with advancing age.
Cancers are classified according to the type of tissue from which they originated. The four major types of cancer are carcinoma, sarcoma, lymphoma and leukemia. Leukemia is the cancer of the blood cells and typically begins in the bone marrow, the site of the formation of new blood cells. Lymphoma, as name suggests, arises in the tissues of lymphatic system, such as the lymph nodes. Sarcoma develops in bone or connective tissues.
Prostate cancer is a form of carcinoma, as are the preponderance of all cancers, including lung, breast, colon and skin cancers. These cancers all develop into solid tumors and arise from epithelial tissues. Epithelial tissues are those that cover the surface of the body (i.e., the skin) and also line all the internal cavities of the body.
Unfortunately, both patients and their doctors tend to think of cancer as being a largely autonomous growth which no longer fits into the body’s regulatory, signaling and communications networks. Yet it has long been known that surgery upon the primary site of a cancer very often will affect the rate of growth and other aspect of metastasized portions of the cancer found in distant parts of the body. Considerable evidence supports the view that cancerous cells are, in fact, responding to at least some of the signals being sent out by the organism as a whole. Even the common explanation of dysfunctional oncogenes and failed tumor suppressor genes largely assumes that these alterations do not reflect in any important sense actual signals being sent by the system as a whole and/or that the development of the cancer is not an extension of normal cellular responses to an abnormal internal environment. In a famous article published in Science in 1956, Otto Warburg argued that cancer cells originate as a long-term response to failures in energy production within tissues. Some aspects of this line of argument have been revived by a number of our contemporary oncologists.
In passing, it is worthwhile to note that there are distinctions other than tissue types that should be kept in mind with regard to cancer. One such distinction, albeit not strictly speaking one drawn in textbooks, is between “internal” versus “external” cancers. The vast majority of cancers are “internal” and closely tied to the general health of the body. There are, however, a few cancers whose genesis in typical cases is only loosely tied to general health. Basal cell skin cancer is an example of this. Basal cell, as opposed to squamous skin cancer, seems to be derived from the derangement of hair follicles to be in permanent repair mode, hence the characteristic finding of basal cell cancers at the hairline. Basal cell cancers arise in response to sun and other sources of damage to the skin and unless allowed to expand enormously over a period of years, basal cell cancers seldom metastasize.
Very curiously, cancer relatively uncommonly develops in contractile tissues, that is, in muscle tissues. One can, of course, perhaps give all sorts of chemical and genetic explanations for this exception. However, it is very tempting to wonder whether, in a more than figurative sense, this is because muscle tissues can contract to release tension and stress. Just as there are personality types, which manifest elevated rates of heart disease, so there are personality types, which manifest elevated rates of cancer. The emotions and “fuzzy” factors such as purpose, fulfillment and peace of mind feedback powerfully into the immune system and the endocrine system—the system which releases hormones. Both of these systems are intimately linked to the development of cancer.
Searching for Protective Measures Researchers giving advice of preventing cancer usually present cancer as developing in three distinct stages: initiation, promotion, and progression. The existence of these stages suggests that there are distinct measures that can be taken to protect against cancer.
Next month, we will explore options for preventing initiation and promotion as well as courses of action for those who already are beyond the “prevention” stage and want to be proactive in their own treatment.