Cancer Glossary & Scientific Reference

Colon Cancer

”Malignancies typical for affluent societies are cancers of the breast, colon/rectum, uterus (endometrial carcinoma), gallbladder, kidney and adenocarcinoma of the oesophagus. ... Since they have a common cause, these neoplasms typically go together. There is no region in the world that has a high incidence of breast cancer without a concurrent colon cancer burden.”
From The World Cancer Report: “Action on smoking, diet and infections can prevent one third of cancers.”

Colon cancer
Large intestinal cancer
Colorectal cancer

compiled by Healing Cancer Naturally from material © Encyclopædia Britannica, Inc.

Definitions: colon & large intestine

Colon: in physiology, that segment constituting most of the length of the large intestine in mammals. The term is often used synonymously with "large intestine" or in reference to a corresponding region of the vertebrate gut.

The human colon extends from the end of the small intestine and cecum up the right side of the abdomen (ascending colon), across to the left side (transverse colon), down the left side (descending colon), and loops (sigmoid flexure, or sigmoid colon) to join the rectum.

In humans, the colon has no digestive function. Its purpose is to lubricate waste products, absorb remaining fluids and salts, and store waste products until they are ready to be passed from the body.

Most absorption occurs in the ascending and transverse regions, where the liquid material received from the small intestine is dehydrated to form a fecal mass.

The inner wall of the colon consists of a mucous membrane that absorbs the fluids and gives off mucus to lubricate the waste materials. The deeper muscle layer is composed of circular and longitudinal muscles. Circular muscles produce the mild churning and mixing motions of the intestine, while the longitudinal ones create the strong massive muscle contractions that actually move the feces.

Large intestine: posterior section of the vertebrate intestine, consisting typically of four regions: the cecum, colon, rectum, and anal canal. The term colon is sometimes used to refer to the entire large intestine.

The large intestine is wider and shorter than the small (in humans, approximately 5 feet, or 1.5 metres, in length as compared with 22 to 25 feet, or 6.7 to 7.6 metres, for the small intestine) and has a smooth inner wall.

In the proximal, or upper, half of the large intestine, enzymes from the small intestine complete the digestive process, and bacteria produce the B vitamins (B12, thiamin, and riboflavin) as well as vitamin K. The large intestine's primary function, however, is absorption of water and electrolytes from digestive residues (which in humans usually takes about 24 to 30 hours) and storage of fecal matter until it can be expelled.

Churning movements of the intestine gradually expose digestive residue to the absorbing walls. A progressive and more vigorous type of movement known as mass movement (gastrocolic reflex), which occurs only two or three times daily, propels the material toward the anus.

In primarily vegetarian animals the large intestine is usually longer. The immature frog (or tadpole), for example, eats mainly plant matter and has a long, highly coiled large intestine. As the frog matures and begins to eat mostly insects, its intestine becomes considerably shorter.

High-protein food, such as meat, can readily be digested by the small intestine; much more chemical action and agitation are required, however, to reduce the tough cellulose fibres of plant cells. The large intestine performs this function with its slow digestive process. Common afflictions of the large intestine include inflammation, such as colitis; diverticulosis; and abnormal growths, such as benign or malignant tumours.

Cancer of the colon and rectum

Colorectal cancer is very common in the Western world, a more common tumor than is cancer of the stomach, with an equal incidence in males and females. By contrast, its incidence in Japan, many South American countries, and sub-Saharan African countries is very low.
Compare Epidemiology.

Numerous studies aimed at identifying the early precursor lesions seem to indicate that the majority of cases of cancer of the large intestine arise from certain types of preexisting polyps (precancerous adenomas which are often multiple) and that these may remain benign for many months before becoming malignant.

The tumors are adenocarcinomas, and some apparently also grow very slowly, taking as long as six to eight years to reach a size of about 2.4 inches (six centimetres).

The tumours are round and raised and may be ulcerated. Once the tumor has grown through the wall of the bowel, successful treatment becomes more difficult. The tumors metastasize to the liver, lung, and other distant sites. Surgery is the most favoured treatment [by mainstream oncologists].

Symptoms are highly variable, the main feature being blood in the stools, but this may be detectable only by chemical testing. Cancers compress the colonic lumen to produce obstruction, they attach to neighbouring structures to produce pain, and they perforate to give rise to peritonitis.

Cancers also may metastasize to distant organs before local symptoms appear. Nevertheless, the prognosis for patients with this tumour is considerably better than it is for cancer of the stomach. About half the patients who have a colonic cancer removed surgically live at least five years.

Spread of cancer and survival

Clinical experience with the relation of the spread of cancer to patient survival is dramatically emphasized by the statistics of cancer of the colon and rectum.

In both the colon and the rectum, cancer begins in the cells that line the inner surface of the thin-walled, sausage-like connective tissue structure of the organ. If the cancer cells are localized to and within the wall, 94 percent of patients survive five years after surgical removal of the cancer; when the cancer has spread through the wall, but has not entered the adjacent lymph nodes, five-year survival is 88 percent.

On the other hand, once cancer has involved the lymph nodes, the five-year survival decreases to 55 percent. It is important, therefore, to diagnose cancer and begin treatment before cancer cells begin to spread.

Note by Healing Cancer Naturally: the above statistics appear to apply to persons choosing conventional cancer treatment. Compare Why Choose Alternative Cancer Treatment, particularly On Conventional Cancer Treatment and On Chemotherapy.

Epidemiology

Epidemiological studies of the worldwide incidence of cancers have identified striking differences among countries and population groups. The importance of environmental influences is highlighted by comparing the incidence of and death rates for cancers among populations in different geographic regions.

For example, prostate and colon cancer rates in Japanese persons living in Japan differ from the rates in Japanese persons who have emigrated to the United States, the rates of their offspring born in California, and the rates of long-term white residents of that state.

These rates are much lower among Japanese living in Japan than they are in white Californians. However, the rates for each type of tumour among first-generation Japanese immigrants are intermediate between the rates in Japan and those in California.

Similarly, their children, and the children of other immigrant ethnic groups from countries with low incidence, have incidences for colon and rectal cancer equal to those of other Americans.

[In other words,] Japanese immigrants to the United States within a generation acquire a much higher incidence of colorectal cancer than their counterparts in Japan. This is an excellent example suggesting that environmental and cultural factors may play a [much] more important role than genetic ones in the causation of cancer.

Epidemiological studies suggest that a major risk factor may be the low fibre content and high meat protein and fat content of the Western diet. Several studies both within and between countries suggest a pathogenic association between total fat intake and cancer of the colon or rectum and that both wheat fibre and brassica vegetables may protect against it.

Meat consumption is usually correlated with fat but is less consistently related to cancer of the large intestine. Some types of beer have been associated with cancer of the rectum (the lower end of the large intestine). There have, however, been variations and inconsistencies in all the epidemiological studies.

Compare Nutrition, particularly The importance of minerals & trace elements for health & cancer prevention: a US-Sri Lanka cancer mortality comparison — colon cancer mortality in Sri Lanka is 187 (!) times lower than in the US, and Dr. Johanna Budwig Diet & Protocol. Also Meat & colon cancer link, Vegetarians live longer (Vegetarians Study of German Cancer Research Center), Brassica vegetables and cancer risk and “Brassica family prevents pre-cancerous cells turning into potentially deadly cancer cells”.

Exercise & colon cancer

A number of studies have linked low physical activity / sedentary habits with a higher risk of developing certain cancers, particularly colon cancer. See details at On cancer prevention and exercise: scientific research studies into protective effects of physical activity & training on cancer incidence, risk & mortality.
Compare Activate Your Lymphathic System.

Dental metals, other toxins, and intestinal cancer

As with a number of tumors, malignant growths of the intestines are frequently found to contain high concentrations of mercury, palladium, nickel and other metals used in dentistry (Dr. Max Daunderer), pointing to a contributing role of these and other toxins in cancerogenesis. For details compare On the cancer tumor as a "second liver" (toxin reservoir and neutralizer).

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after studying the subject for some twenty years, click here.

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Cancer glossary & scientific reference