Cancer is a major killer of people all around the globe. We do not have a definite cure,
but the amount of research done on this one disease costs on the average of $1.2 billion dollars
annually, and $20 billion annually in care of cancer patients.
What is Cancer?
Cancer is a broad ranging term that is used by many people, including medical
professionals such as doctors. Cancer, in its most fatal and aggressive form, is of a larger class of diseases known as neoplasms. There are two forms of a neoplasm: benign or malignant. A benign neoplasm is encapsulated, or surrounded, so that it's growth is restricted, whereas a malignant neoplasm is not closed in. Malignant tumors grow much more quickly than benign forms and spread into the surrounding normal tissue, and virtually destroy it, (Grolier Electronic Encyclopedia, Cancer).
The question is, what exactly is cancer? Cancer, is the break down and mutation of the
cells of the body, when the DNA (Deoxyribonucleic Acid) sequences in those molecules are
disrupted and errors form in the structures, (Grolier, Genetic Code). This mutation spreads
through surrounding tissue until it disrupts major systems in the body (such as respiratory,
digestive and waste management) cause that system to fail.
What causes Cancer to become active?
Since it is believed that almost all people have some type of cancer in their body, (although
benign), any person that comes in contact with a carcinogen, (any cancer-causing agent), will
cause these benign cells to become malignant.
It is when the cells become malignant, that cancer actually occurs. Cancer, in this context,
can be caused by many different agents; chemical, biological or physical.
Chemical Agents
Chemicals that can cause a benign cell to become active include things such as complex
hydrocarbons, aromatic amines, certain metals, drugs, hormones, and naturally occurring
chemicals in plants and molds. Hydrocarbons and nitrosamines can be found in cigarette smoke and may contribute to the condition called "lung cancer". Other chemicals that seem to cause incidents of "bladder cancer", such as 2-naphthylamine, were used in the dye industry for dyeing cloth, but when a number of cases of cancer turned up, its use was discontinued. Vinyl Chloride, a chemical gas, has also appeared, seeming to cause "liver cancer" ,(Grolier, Cancer)
Drugs, such as some cancer-treating alkylating agents, are also carcinogens. These agents
are used to break the DNA strands in the cells, thereby killing the cells, but it also effects the cells surrounding the tumor, actually making them malignant. When these chemicals are used to treat cancer in this way, they must in exact proportions for each person and if the dosage is incorrect, the chemical will create a cancerous effect. Estrogens, a group of female hormones, usually administered to women after menopause seem to cause an increased incidence of cancer of the uterus. This has been alleviated today by administering estrogen in combination with progesterone. Certain salts, that contain arsenic, are suspected to casually relate to cancer of the skin and liver, (Grolier, Cancer).
The suggestion that cancer is caused by an alteration of DNA within the benign cell, was proposed by James and Elizabeth Miller in the 1960s, who demonstrated that chemical carcinogens must be metabolized and broken down so that they may interact with the DNA of the cells in question, directly, (Grolier, Cancer).
Biological Agents
Our own bodies, in conjunction with parasites found in different parts of the world, have been related to the causes of many types of cancer. Some of the most clearly established biological agents are the oncogenic (cancer-causing) viruses that commonly cause the formation of neoplasms in lower animals have been linked to some human cancers, and at least one has been definitely proven to cause cancer of the blood (leukemia), (Grolier, Cancer).
Physical Agents
High energy and ultraviolet radiation are two of the major causes of human and animal cancer. It has been proven that there is a relation between the sun's ultraviolet rays, and the development of skin cancer in humans. Cancer caused by radiation include just about every known variety, including leukemia, cancer of the thyroid, breast, stomach, uterus and bone, (Grolier, Cancer).
It has also been suggested that electromagnetic fields can pose a risk of contracting cancer
when the field strength is extremely high. Power lines running through cities and through the country, including large hydro towers that carry power through the countryside, create such electromagnetic fields. These fields are strong enough, in most cases, to light a oi= scent tube that a person is holding just by walking underneath the power lines. In several instances in the United States, especially in Washington and New York, the fields are so strong that people are fearing that the exposure may be hurting their children, (Fortune, p. 80).
It is recommended that pregnant women do not use electric heating blankets for extended periods, (sleeping, etc.), as the blankets create a low electromagnetic field that may actually creating cancer in the fetus during development.
Inherited Cancer
As was stated earlier, everyone has cancer, although benign. It is passed from one
generation to the next, and depending on the amount of carcinogens the previous generation has had contact with, will be relative to the risk placed on their offspring. Some carcinogens can be stored in the body and not used, and can be replicated in the next generation because the body has the ability to create DNA and RNA sequences that represent their carcinogens.
This is not necessarily the cause for inherited cancer, nor why it affects some offspring and not others. It has been shown that cancer can remain dormant in several generations, and then suddenly become active in a healthy generation.
Stages
Cancer does not jump out of the woodwork in a day; in most cases, it takes a long time
for cancer to become detectable, depending on the type, and where it is growing. It has shown
that cancer detected in the earliest stages of its growth is far easier to stop, and so the American
Cancer Society has begun to promote public awareness of the seven warning signs to look for:
(1) a change in bowel or bladder function; (2) a sore that does not heal; (3) unusual bleeding or discharge; (4) a thickening or lump in the breast or elsewhere; (5) indigestion or difficulty in swallowing; (6) an obvious change in a wart or a mole; and, (7) a nagging cough or hoarseness. Should anyone exhibit any of these symptoms, they should see a physician immediately. (Groiler, Cancer)
Initiation and Promotion
One of the characteristics in the development of cancer in an organism is the amount of
time between initial exposure to a carcinogen, and the actual development of a malignant
cancerous tumor:
Beginning in the late 1940s, a number of investigators defined the early stages in the development, or natural history, of cancer. In a classical experiment pertormed on the skin of mice, a single application of an agent induced no neoplasms, but when it was followed by several applications of a second agent, termed the promoter, neoplasms developed. (Grolier, Cancer)
It was found that initiation by the first agent is irreversible once the reaction has begun,
however, it was also noted that if the addition of the promoter was done in several doses, over a long period of time, no neoplasms would occur, even though the actual dosage of the promoter was the same. In humans for instance, alcoholic beverages, dietary fat, and many of the components of cigarette smoke are shown to be effective promoting agents. (Grolier, Cancer)
Progression
Once a tumor has been created by initiation and promotion, it can progress from a benign
to malignant form, or from a slowly reproducing tumor to a rapidly growing malignant tumor. This progression has been shown to be related to the number of abnormalities within a cell's DNA. The cells surrounding the tumor will be assimilated into the tumor as it grows. It has been shown that tumors can suddenly stop growing, and then resume its growth at a later time. There is no evidence as to why this happens, and scientists believe it is related to unused portions of the DNA strands in cells that have been transformed into instructions regarding the tumors growth.
Treatment
Treatment of cancer seems to be more of an art than a science at the moment. Especially
in the areas of surgery, radiation treatment, chemotherapy and other areas.
Surgery
Surgical removal of a cancer from the body is the oldest and sometimes most effective
means of disrupting and stopping cancer growth. Surgery can be used to remove malignant or benign tumors within the body, although the practice of removing benign tumors is not practiced due to the possibility of making it active. Removal of complete malignant tumors is often successful in halting cancer growth in that particular region, when followed by radiation therapy. It is also possible to remove parts of tumors, to reduce the amount of cancerous tissue in the body as a whole. The one major drawback to surgery is that quite often a tumor is not accessible to a surgeon, or it may be attached to a major organ of the body, in which removing the tumor may cause serious side affects and even death. So long as a cancerous tumor has not spread to a major organ or tissue, the removal will be a safe and will be successful in most cases.
Surgical removal of a cancerous tumor may give people the extra months or years to carry
out things they want to do, especially for those people who can not be totally free of cancerous
tissue. Surgery to remove a tumor may give people the comfort in which to live out their lives,
even though it may not be the complete solution, (Encyclopedia Britannica, p. 541 )
Radiation
Radiation treatments are normally conducted after surgery if there was a large affected
area, or treatments can be used on small tumors when surgery is not possible. Irradiating a large
area of the body for a large tumor can create other types of cancer within the body.
Treatments can be carried out using gamma rays that are emitted by Cobalt-60, a
radioactive element, by focusing high powered X-rays (many times the strength of the normal Xray used to scan the body) or particles (electrons and neutrons). Although some of the surrounding cells are killed in the radiation process, the effect is minimized by shielding surrounding areas with dense materials, such as lead and gold. The source of the radiation and the sensitivity of the tumor are relative to the overall effect on the tumor.
Radiation treatments are extremely efective on leukemia and carcinomas (solid tumors
which forms the skin and linings of most glands and organs) as they are extremely sensitive to the
radiation.
If radiation therapy is unsuccessful in the first few treatments, it is unlikely to have any
significant impact on the cancer after this stage, and may cause more damage than it does good.
Chemotherapy
Chemotherapy
Chemotherapy is the process by which chemicals are administered into the body to fight
and destroy cancerous cells and tumors. At present, at least 10 types of human cancer can be
treated and cured by chemotherapy alone or in conjunction with surgery and/or radiation,
(Britannica, p. 558).
Chemotherapy has been proven successful against some strains of cancer such as
lymphocytic leukemia in children, Hodgkin's Disease, sarcomas (connective tissue such as bone
and fat) and kidney tumors. Chemotherapy is usually not a complete cure, but has helped to
drastically increase the useful lifetime of many patients with these diseases.
There is one major point to note about chemotherapy, and that is that it has been shown
that some chemicals used in the treatment of cancer will actually create other forms of cancer, or
speed the growth of those already malignant, if dosages or administration of the chemicals is
incorrect:
Compounds that have been effective in the chemotherapy of human cancer include certain hormones, especially the steroid sex hormones and those from the adrenal cortex; antibiotics produced naturally by a variety of microorganisms; plant alkaloids, including vinblastine and vincristine, derived from the periwinkle flower; alkylating agents--chemicals that react directly with DNA; and antimetabolites, which resemble normal metabolites (metabolic compounds) in structure and compete with them for some metabolic function, thus preventing further utilization of normal metabolic pathways. (Grolier, Cancer)
It has also been noted that as chemotherapy damages some of the surrounding tissue
around a tumor, chemotherapy can have some serious side effects. Some patients develop severe nausea and vomiting, become very tired, and lose their hair temporarily. Special drugs are given to alleviate some of these symptoms, particularly the nausea and vomiting, (Compton's Multimedia Encyclopedia, Cancer - Chemotherapy).
Immunotherapy
hile still a rather new form of treatment, it is looked as having great promise.
Immunotherapy is where the body's own immune system is used to combat the neoplasms situated in the body, with the help of "engineered" antibodies that are added to the patients immune system. The immune system will then replicate the antibody and send it out to destroy any cancerous cells matching the DNA and RNA sequences it was designed to track, while attaching itself to healthy cells to prevent assimilation by cancerous cells. This process has worked on a single-case basis with good results, but it is expected to be a while before its use is wide spread. (How it Works, p. 415)
Recent Trends
It has come about recently, that therapies combining less radical forms of surgery, with
radiation, chemotherapy and/or preventive medicine have been used:
Such therapy has been especially useful in the treatment of breast cancer, where the traditional radical mastectomy, involving removal of the breast, lymph nodes, and parts of the arm and chest muscles is becoming less common. It is being replaced by relatively simple surgery involving removal of only the lump itself or the breast, followed by chemotherapy or the use of preventive drugs. An example of the latter is tamoxifen, an anti-estrogen that prevents the growth of cancer cells with little or no toxicity to the host and remaining normal cells. (Grolier, Cancer)
Remission
Rehabilitation is an important and ongoing process after having cancer treatment(s) of any
kind. The majority of cancers are considered cured if there is no reoccurrence within five years after the last treatment. Other types of cancer are required to be monitored for ten years after treatments to be sure that no reoccurrence is to happen. It is also to be noted that many types of leukemia may seem to be none existent for several years, and then it may appear again. Also, it is generally harder to treat a reoccurrence such as this than in the original case.
Present and Future Research
Cancer is an elusive and stubborn disease that can be turn up in almost any system of the
body. With this in mind, it must be known that there must be a common reason for malignant cancer cells to continue to plague a large percentage of our population:
In 1983, for example, U.S. and British researchers determined that at least two genetic changes may be needed to transform cells into cancerous cells under laboratory conditions: one stage enables the cell to grow indefinitely; the other stage enables the cell to ignore signals from surrounding cells that would otherwise halt its growth. Also, because the means to identify most
of the carcinogenic agents in the environment are now available, a major program of cancer prevention is within reach. (Grolier, Cancer)
With this theory in mind, it will be relatively easy to control cancer once we are intelligent and wise enough to know how to directly manipulate the DNA sequences in cells, and place that information in the bodies of the patients in question. It will be a glorious day when we can alleviate cancer from this world, or will it?
My Thought and Ideas about the Future of Cancer
In the present day, our technology increases ten-fold each year. We are able to find out more, faster and more efficiently than in any other time in history. With our new knowledge that is forthcoming, I would predict the end of most major diseases early in the next century. Once we are able to read and modify the data and instructions found in our own DNA, we can directly access the way we as living beings will grow and evolve. However, we will have another problem, and that is of population. If there are no diseases to disrupt the growth of our population on this planet, we will soon overcrowd, and we may not yet have the technology to leave this world. However, I think we will still be better off without cancer.
References
Tetzeli, R. (1990). Can Power Lines Give You Cancer? FORTLINE Magazine, 49, 80-85
Pitot, H.C. M.D. et al. (1992) Cancer. Grolier Electronic Encyclopedia,1992 ed. Search
phrases: CANCER, GENETIC CODE, DNA, RNA
Clarke, D. & Dartford, M. ( 1992). Cancer Treatment. How It Works: The New Illustrated
Science and Invention Encyclopedia, 414-418
Abeloff, M.D. et al (1991) Cancer. Encyclopedia Britannica: Macropedia, 534-542
Drill, V.A. et al (1991) Drugs and Drug Action - Chemotherapy. Encyclopedia Britannica:
Macropedia, 553-560
American Cancer Society et al (1992) Cancer. Compton's Multimedia Encyclopedia,1992 ed.
Search phrases: CANCER, CHEMOTHERAPY, GENETICS
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