Having existed as a part of humanity through the ages, cancer is now one of the leading killers and cause of poor health in our civilization. History has observed the struggle against cancer by our Chinese ancestors, with their wealth of accumulated experience. There are many records and descriptions of tumors in the long history of Traditional Chinese Medicine (TCM)).
In the inscriptions on oracle bones and tortoise shells, found in the ruins of the Yin Dynasty (1700-1100B.C.), the character ¡§Liu¡¨ (tumor) is mentioned. In Zhou Rituals of the 11th century B. C., it is recorded by physicians who specialised in tumor treatments, who were referred to as ¡§Yang Doctors¡¨.
Today tumors are still called Zhong Yang (inflamed ulcers) in Korea and Japan. Liu Xi, a physician of the Western Han Dynasty (206B. C. ¡V A. D. 25), described tumors as ¡§inflamed with an uneven surface like a rock.¡¨ The term ¡§Yan¡¨ became a synonym for ¡§rock¡¨. This term for the external manifestations of cancer is still used in modern biomedicine.
The archaic descriptions of Changqin, Shixia in the Yellow Emperor¡¦s Canon of Internal Medicine, Jiju in The Classic on Difficulty, and Zhengjia, Shiyi, Fanwei and Yingliu in the General Treaties on Causes and Symptoms of Diseases, about the causes, pathogenesis, signs and symptoms, all resemble the descriptions of tumors of the gastrointestinal organs, liver, spleen, pancreas, uterus, ovaries and thyroid glands, in modern biomedicine.
In 1171, Dongxian Jushi of the Southern Song Dynasty first mentioned the term ¡§Ai¡¨ (cancer) for an inflamed ulcer in his Wei Ji Bao Shu. Since the Ming Dynasty (A.D. 1368-1644), ¡§Ai¡¨ was widely adopted as a general term for cancer of the mammary gland and others. Since then, knowledge about cancer has become more specific regarding its pathogenesis. Valuable experience has been accumulated regarding treatment, which now plays an important role in the modern clinical practice of oncology.
Though still not subdued, cancer has been intensively studied at the bimolecular level. This research indicated the causes of cancer are to be found in the molecular changes of DNA in organic cells being invaded by carcinogenic factors, external or internal. This causes mutations or gradual changes in cellular genes, or the abnormalities of genes due to disturbance in cellular differentiation.
This theory opens a new path for the prevention and treatment of tumors. Possessing the essence of TCM, integrated with modern biomedicine, this new branch of science for the prevention and treatment of tumors, may prove superior to either TCM or western medicine (WM) when applied alone, and will undoubtedly make many contributions to the health of mankind.
Etiology and Pathogenesis of Cancer in TCM
Viewing the human body as an organic whole, TCM believes, the influence of internal and external factors which cause disharmony at certain points, precipitate pathological and physiological changes, which then the manifest themselves at certain locations as tumors, or a local lesion of a general disease. There are no exceptions to the fact that all diseases, including tumors, occur because of external, as well as internal conditions.
The internal factors include weakening of the body¡¦s resistance, disharmony of visceral functions, Qi as well as blood and emotional changes, the lowering of the body¡¦s resistance being of vital importance. The external factors refer to the six abnormal climatic factors or six exogenous evils, of wind, cold, summer heat, dampness, dryness and fire, as well as evil Qi.
Once the body¡¦s resistance decreases, the disease causing factors make use of asthenia of the body, resulting in a subsequent illness. This is the reason TCM states categorically, ¡§Where there is disease, there is asthenia of Qi.¡¨
Based on holistic thinking, TCM stresses disease occurs as a result of combined internal and external causes. TCM therefore treats etiology and pathogenesis as a whole.
1. Emotional Disturbance
TCM embodies changes of spirit and sentiment as the ¡§seven emotions¡¨: pleasure, anger, grief, fear, yearning, sorrow, surprise, all of which are emotional, physiological reactions of an organism towards external changes in its environment. Emotional disturbance refers to reactions, either excessive (excitation) or insufficient (inhibition) which will ultimately lead to disturbances in the flowing of Qi and blood, and the visceral functions, with subsequent illness.
TCM claims rage harms the liver, excessive stimulation harms the heart, grief harms the spleen, great sorrow harms the lungs and fear harms the kidneys. Though not necessarily precise, this belief definitely points out that emotional injury will affect the physiological functions of the Qi, blood, viscera, and channels, lower the body resistance, resulting in disease. The human body is susceptible to cancer when under emotional stress or disturbance. This is mentioned early in Chinese medical classics, such as the Yellow Emperor¡¦s canon of Internal Medicine, and the Golden Mirror of Original Medicine.
2. Damage of the Viscera
Through the flow of Qi and blood, the vital energy circulating along the channels, and the distribution of body fluids, the internal viscera, extremities and other body parts function as a whole and life supporting activities are well maintained. The condition of the internal viscera is closely connected with the occurrence and growth of tumors and subsequent convalescence of the organism.
Disharmony and weakness of visceral functions, usually manifesting abnormalities of the spleen and kidney have a direct bearing on the incidence of tumors. TCM holds that in addition to the digestive and urinary systems the spleen and kidney represent respectively, they include the nervous system, the psyche, endocrine functions and part of the circulatory system. When functions of the spleen and kidney are weakened, manifesting asthenia body resistance, tumors are apt to occur.
3. Disharmony of Qi and Blood
TCM maintains that Qi is the impetus for life supporting activities, while blood, derived from the essence of food and drink (nutrients) through digestion and absorption, is in turn, the material basis for Qi activities. Being mutual transformable and coexisting interdependently, the whole body is nourished by its ceaseless flowing through the channels. Disharmony of Qi and blood occurs when either one of them is defective. Stagnation of Qi can lead to stasis of blood.
Prolonged stagnation of Qi and blood will inevitably lead to the occurrence of a tumor. Wang Qingren, a famous physician of the Qing Dynasty (A. D. 1616-1911), pointed out that abdominal lumps are blood masses, denoting a tumor mass in the abdomen, and are formed of stagnant blood. This provides theoretical background for the principal of activating the blood circulation and eliminating blood masses in tumor therapy. This has long been one of the main therapeutic rules for tumors.
4. The Exogenous Pathogens
TCM holds cancer is related to exogenous pathogens. Seasonal climatic changes include wind, cold, summer heat, dampness, dryness, and fire, called ¡§The six Qi¡¨ which can, when in excess, be the direct etiological factors in cancer. In fact, this agrees with the chemical, physical and biological (bacteria, virus, and parasites) factors of exogenous origin of cancer in modern investigations.
Under their contemporary circumstances, our ancestors, though not expressed explicitly in definite terms or with clear interpretations, made valuable contributions to the understanding of external pathogenic factors causing cancer over a period of 1000 years prior to the practice of western medicine.
5. Inappropriate Diet
5.1 Excessive Drinking and Hard, Cold, Hot and Roasted Food
The ancient physicians asserted drinkers and those who like hot foods are apt to develop dysphagia. This indicates that the drinking of hard liquor, eating an excess of hot hard, roasted or glutinous food or food difficult to digest, can stimulate and damage the mucous membrane of the esophagus and stomach, and lead to epithelial hyperplasia and eventually canceration.
5.2 Excessive Fish, Dairy Products and Greasy Food
Modern medicine has proven, too much greasy food may produce carcinoma of the colon, ovary or mammary glands. Experiments reveal, when feeding animals with fatty food, the more unsaturated fatty acid the food contains, the higher the incidence of cancer caused by its carcinogenic factors. Some authors claim the high incidence of stomach cancer in Japanese and Icelanders, may be the result of addiction to dry salted fish, pickled vegetables, smoked trout and salmon. The higher incidence of cancer in coastal regions compared to that of inland inhabitants may also result for the same reasons.
5.3 Injury of the Spleen and Stomach, a Result of Irregular Meals
The spleen and stomach will inevitably be injured by irregular meals, unlimited food and drink. The functions of these viscera are adversely affected by abnormal digestion, absorption and distribution of food essence. A disturbance of meridian and visceral function results in circulatory disturbances of Qi and blood, followed by stagnation and ensuing lumps.
Modern medicine concurs with the fact that rapid swallowing during meals or eating in a squatting posture can cause retention of food in the esophagus. Such stimulation of the esophagus leads to inflammation or hyperplasia and canceration of the epithelial cells.
Etiology of Cancer in Modern Medicine
Though the causes of cancer are not yet fully understood, through the vast multi-disciplinary research of the past half century, we have learned there are many factors related to cancer: chemical, physical, biological, inherited, endocrine, psyche, immunological and nutritional, any of which may cause cancer either individually or in combination with other factors.
1. The Chemical Carcinogenic Factors
Investigation of chemical carcinogenic substance began with the establishment of industry and developed rapidly. It has been verified that about one thousand varieties of chemical substances, artificially produced, are carcinogenic. According to some investigators, they represent 80% of the causes of cancer, and are included in the following categories:
Polycyclic aromatic hydrocarbons, with 3,4 benzopyrene representing the carcinogenic substance prevalent in coal tar, bitumen, nicotine, creosote, and anthranol; in alkylating agents, aromatic amino compounds, aminoazo dyes; nitrosamine, nitrogencompound (butter yellow), in metalic carcinogenic compounds (cadmium, zinc, arsenals, nickel), and in the phytotoxins (cycasin, fern toxins, safrole, senecionine). The mechanism of the carcinogenic action of these substances is as follows: the direct cause of cellular mutation, causing the body¡¦s metabolism to produce carcinogenic metabolites, or causing a transformation of body enzymes, such as polycyclic aromatic hydrocarbons, which, when entering the body, exert a toxic action on the body cells by the transformation of the enzymes which then activate the polycyclic aromatic hydrocarbons.
2. The Physical Carcinogenic Factors
These factors include electrolyte radiation, sunlight and ultraviolet radiation, chronic stimulation and the persistent stimulation of fibrous materials.
Observations and experiments have proven that radiation of whatever origin, such as radiation and X ¡V ray result in carcinogenic actions of varying degrees, to higher animals. Included among them, the most common are carcinoma of the skin, lungs, thyroid glands, leukemia and malignant lymphoma. Persons exposed to perennial ultraviolet and heat radiation are apt to suffer third degree burns.
About 20-30% of osteosarcoma cases evolve from local wounds. Women who have experienced multiple births with repeated cervical laceration are more susceptible to cervical carcinoma. Cancer of tongue edges and check are usually the result of chronic stimulation by the sharp edges of remaining teeth or unsuitable dentures.
Asbestos and fibreglass are the most common carcinogenic materials. Perennial inhalation of dust containing asbestos will result in extensive fibrosis of the lungs in a number of cases, half of which will eventually terminate in lung carcinoma or pleuro-mesothelioma.
The three common features of physical carcinogenic factors are: a prolonged latent period, low incidence of carcinoma, and definite carcinogenic agents, which can easily be avoided. It seems, therefore, physical factors are not the most serious threatening factors as causes.
3. The Biological Carcinogenic Factors
The most important, the virus deserves attention. As many as 30 types of animal tumors reveal the presence of a virus. In the human body, a virus is also found in African Burkitt¡¦s lymphoma, nasopharyngeal carcinoma, cancer of the mammary gland, liver carcinoma, cervical carcinoma and leukemia. However, the theory of an etiological virus is questionable since not all cancers show the presence of viruses in the tissues.
Many diseases other than cancer, such as lupus erythematosus and nodular leprosy, reveal a virus in their serum. Whether a virus is the root cause or just a coincidental factor in tumor etiology is still open for investigation.
The second category of biological carcinogenic factors is fungus. In nature, mycotoxins, the metabolites from many fungi, are harmful to the nervous, digestive, urinary and blood systems and are potent carcinogenic agents. Such toxins, identified at present include aflatoxin B1, B2, G1, M1, parti-coloured aspertoxins, albomycotoxin, fusarium and purapen toxin.
Under conditions of high temperature and humidity, aspergills flavus grows and proliferates on peanuts, soybean, maize, rice, potato powder and cotton seeds. The toxicity of the fungus produced under these conditions is 75 times higher than that of 2 ¡V methy1 ¡V nitrosamine and can cause liver carcinoma and cancer of many kinds of the viscera in animals. Moreover, the toxicity of this substance can be destroyed only by strong ultraviolet light or temperatures as high as 280 „aC.
In addition parasitosis also causes canceration in certain internal organs. For example, schistosoma japonicum is apt to grow in the human rectum and liver. The incidence of liver and rectum carcinoma in endemic areas of schistosomiasis are rather high, while liver carcinoma is also frequently seen in clonorchiasis patients.
4. The Inherited Factor
Derived from normal cells, tumor cells are the result of mutation of cellular genes, under the influence of extra ¡V or intra ¡V cellular carcinogenic factors. Such cells, once having become tumor cells, posses the indigenous biological features of tumors and will produce progeny with its own defective characteristics and unlimited growth potential. It has been observed clinically and proven some tumors reveal a hereditary tendency. These include multi ¡V neurofibroma, retinoblastoma, rectal ¡V polyp¡¦s syndrome, nephrobalstoma, multilipoma.
Moreover, it is not uncommon to observe carcinoma of the liver, stomach, colon, mammary gland and cervix occurring in members of the same clan or nationality. Although related and with the same habits and environment, members of the same family, when inhabiting a different place, with a different life style, always reveal the same high susceptibility to tumors. This point deserves further research.
5. The Endocrine Factors
Hormones are an essential substance for the regulation of physical growth, and the physiological functions of an organism. Various endocrine glands maintain the internal stability of the human body. Due to the redundant stimulation of certain tissues and organs by some hormones, the result of hormone imbalance causes cancerization and cell proliferation of the affected tissues or cells. Carcinogenic actions have been observed in the ovarian hormone, pituitary gonadotropic hormone, thyrotropic hormone, and lactogenic hormone.
For example, carcinoma of the mammary gland, which has been attributed to the estrogenic hormone, can be ameliorated by castration of the ovaries or administration of progesterone. Men receiving perennial estrogen therapy are also apt to develop carcinoma of the mammary gland. Orchiectomy or estrogen administration yields satisfactory results in prosthetic carcinoma. Oral administration of thyroxin inhibits the secretion of pituitary thyrotropic hormone and is helpful in thyroid cancer treatment. By making use of the fluctuation of hormone secretion and its feed back action, cancers due to endocrine disorders can be treated. This explains the close relationship between cancer and endocrine disturbance.
6. The Nutritional Factor
Affected directly by the nutritional state of the organism, tumors grow at the expense of the host nutrition and even in excess of the normal cell needs. In case of pernicious anemia, B12 deficiency increases the incidence of leukemia and carcinoma of the stomach, vitamin C interrupts the synthesis of nitrosamine in vivo and hence decreases the carcinogenic action of the latter. Ample supplements of microelements, including iodine, copper, zinc, magnesium, molybden and selenium in food, inhibits or retards the growth of tumors in experimental animals.
Epidemiological studies of tumors have shown, in human groups with a high fat, low fibrous tissue diet, the incidence of colon and mammary carcinoma is higher, while among those with low fat and high fibrous tissues diet, the incidence is lower. Restriction of nutrition inhibits the tumor growth, but decreases the nutritional needs of normal cells. This leads to physiologic ¡V pathological changes in the body, lowers the immune function and therefore the body becomes susceptible to tumor invasion. Rational nutrition will maintain good health and help prevent the occurrence of tumors.
7. The Immune Factor
There are two kinds of body resistance to tumor invasion, specific and non-specific, each embraces cellular and humoral immune function. There are three kinds of cells participating in the immune reaction, namely, T ¡V lymphocytes on which the thymus relies, B ¡V lymphocytes derived from bone ¡V marrow and macrophagocytes. Neutralphilic granulocytes and platelets also play a role in immune reaction.
Immune reaction reflects the capacity of the body¡¦s reaction to antigenic materials. Tumor cells are a ¡§foreign body¡¨ with antigenicity, to which the body reacts with the production of antibody and immune cells, which monitor, rejects, resists, and even destroy the tumor cells. Immunity defects, whether congenital or acquired, diminish the reaction of the body¡¦s immunity and may cause cancer to occur.
The factors responsible for the growth or inhibition of tumor cells are very complicated and are closely related to the strength of the body resistance, toxicity of tumor cells and the presence of ¡§close factor¡¨ that counteracts with the body resistance.
8. The Psyche Factor
The stability and balance of the neuro ¡V psyche system, the highest center of the body, has a direct bearing on the development of a tumor.
Clinically, it is not unusual to find tumors in people with poor mental health as well as the ¡§tumor ¡V phobia¡¨ people. For patients with the same cancer, satisfactory results are likely to be obtained in cases where patients are optimistic and fully confident that they can conquer the ailment. It has been estimated that 75% of all cancer cases have a history of poor mental health or melancholy.
In summary, one strong carcinogenic factor alone may cause cancer, but such a circumstance is rarely encountered. In most cases, two or more factors, together with tumor promoting, yet non-carcinogenic factors, are responsible for the cancerization of normal cells under long and repeated stimulation. The cancerization process is affected by various factors including changes of geographical environment, changes of habits, the persistence or interruption of carcinogenic stimulation, the state of the body resistance, the condition of nutrition and the mental state, which can all terminate in either cancer formation, or interruption of cancer development, or total reversion to normal cells. It is essential, therefore, to continue to study the causes, prevention and treatment of human cancer on an overall comprehensive basis.