Colon Cancer Information

Colon Cancer We supply medical testing to medical standards from a medical laboratory to help diagnose medical conditions.

Our Colon Cancer laboratory test is an accurate test measuring intestinal inflammation. When the colon is inflamed or diseased a protein called Calprotectin is found in the stool. Research shows that the levels of calprotectin found in the stool samples are raised with certain bowel conditions, Low levels indicate irritable bowel conditions and higher levels indicate inflammatory bowel disease such as Chrohns Disease or Ulcerative colitis or Adenamatous polyps. Sufficiently high levels are a strong indicator of the possibility of precancerous polyps and higher levels indicate the possibility of colon cancer.

If the calprotectin test is strongly positive then it indicates that more invasive and specific examinations such as colonoscopy may be required. If the calprotectin test is negative, then it is highly unlikely that you have any of the bowel conditions mentioned. If there are symptoms, other medical investigations may be necessary and your GP should be consulted.

This test is as reliable as a colonoscopy. If a colon polyp is discovered at an early stage your survival rate is 90%-100% as it can be easily removed before it becomes cancerous.

Colon Cancer

Colon cancer is the second most common tumour or cancer in the United Kingdom. One in every twenty seven people will suffer with colon cancer. The risk is one in fifteen if a first degree relative has been affected. The risk rises considerably if more members of the family are affected. Early detection increases survival rates by over 90%.

The average age when colon cancer is diagnosed is between 60-65 years. Colon Cancer is more common in the Western world as we have a high consumption of meat and dairy products, with low consumption of dietary fibre. These factors tend to slow down transit through the bowel and increase time for a potential colon cancer agent to remain in contact with the bowel wall.

Colon Cancer is a general term which is usually called Colorectal cancer by the medical profession. This is because the colon and the rectum are a continuous organ. The National Cancer Institute defines Colon Cancer as a cancer that forms in the tissues of the colon, (the longest part of the large intestine). Most colon cancers are Adenocarcenomas , or cancers that begin in cells that make and release mucus and other fluids. Rectal cancer is a cancer that forms in the tissues of the rectum. (This is the last several inches of the large intestine before the anus)

Most colorectal cancers, (including colon cancers), progress from the colon wall being normal, to a colon polyp (LINK) forming in the colon wall. The polyp or polyps develop to invasive colon cancer. Early detection is vital as the prognosis of colon cancer treatment depends on intervention at an early level. A five year colon cancer survival rate at the earliest stage will be 90%-100%. This is when the colon cancer is likely to have no symptoms at all. Sadly, only one in ten people with colon cancer present at this early stage. This is why colon cancer is known as ‘the silent killer’. Once the colon cancer has spread from this early stage the survival rate reduces dramatically.

Clinical Features of Colon Cancer

No symptoms at all ( known as the ’silent killer’)
Other family members affected with colon cancer
Alteration in bowel habit with or without pain
Blood may be present in a stool
Intestinal Obstruction. This may present with difficulty passing a stool or severe vomiting as food is unable to travel through the intestines

Medical Investigations for Colon Cancer

It has been recommended that all adults begin regular screening for colon cancer at the age of 50 years.

Methods of screening to detect precancerous polyps

Calprotectin Stool Test
Blood Count and Routine Biochemistry
Digital Rectal Examination
Double Contrast Barium Enema
Colonoscopy and Sigmoidoscopy

Methods of screening to detect existing colon cancer

Calprotectin Stool Test
Faecal Occult Stool Test
Blood Count and Routine Biochemistry
Digital Rectal Examination
Double Contrast Barium Enema
Colonoscopy and Sigmoidoscopy

Advantages and Disadvantages of Different Colorectal Cancer Screening Tests

Test	Advantages	Disadvantages
Calprotectin Stool Test	As reliable as a colonoscopy Can detect precancerous polyps not visible in a colonoscopy No preparation of the bowel is necessary Samples can be collected at home Cost is low Does not cause bleeding or tears to the bowel This test can indicate the presence of precancerous polyps in the bowel No dietary limitations prior to testing False positives are unlikely Can distinguish between levels of inflammation and provide diagnostic accuracy between irritable bowel, inflammatory bowel conditions and colon cancer	Positive results may require further investigation
Faecal Occult Blood Test	No preparation of the bowel is necessary Samples can be collected at home Cost is low Does not cause bleeding or tears to the colon	This test fails to detect precancerous polyps and some cancers False Positive results are possible resulting in unnecessary additional procedures. This would include blood consumes in food (red meat), menstrual blood, tears in the rectum or haemarrhoids (piles) Dietary limitations are recommended for several days before the test, avoiding meat, certain vegetables, vitamin C, Iron and Aspirin
Blood Count and Routine Biochemistry	Provides a window into overall health at the time the test is done	Tests are not specific to the detection of colon cancer Tests are unlikely to be done in the absence of symptoms
Digital Rectal Examination	No preparation of the bowel is necessary The test is usually quick and painless	The test can only detect abnormalities in the lower part of the colon. Only 10% of cancer tumours are in this region The test is unreliable Further testing is necessary if anything suspicious is found
Colonoscopy	This test allows the Doctor to view the rectum and the entire colon The Doctor can perform a biopsy and remove polyps during the test	This test may not detect all small polyps and cancers.
Sigmoidoscopy	The test is quick with few complications Discomfort is minimal The Doctor may be able to perform a biopsy and remove polyps during a test Less preparation of the bowel is necessary for this test as for colonoscopy	The Doctor can only view only the rectum and the lower part of the colon. Any polyps further up will be missed Risk of bleeding or perforation of the bowel Additional procedures such as colonoscopy may be necessary if the test appears abnormal

Colon Polyps

A colon polyp is an elevated area above the inner surface of the colon. The majority of colorectal polyps are adenomas with malignant potential. They are common and 90% of colon polyps are innocent. Most colon polyps are asymptomatic and are found by chance when other things are investigated, such as pain, altered bowel habit, bleeding haemorrhoids or other reasons.

What is a Tumour?

A tumour is a mass of cells or lump which has no useful function. The cells divide and grow and can be either benign or malignant. Another name for a tumour is a neoplasm

What is a Tumour Grade?

A tumour grade is a system used to classify cancer cells by how abnormal they look under the microscope and how quickly the tumour is likely to spread and grow

How is Colon Cancer or Colorectal Cancer Staged?

A stage is a standardised way that a cancer is described. It is based on how far the cancer has grown into the wall of the colon and whether it has spread to near or distant structures or to the lymph nodes. The most common staging system used in America is the TNM system. There are older systems of classifying colorectal carcinoma or colon cancer such as The Duke’s Classification and The Astler-Coller System. Some Doctors may use different classifications in describing a tumour. The National Health Service in the United Kingdom use The Dukes Classification.

What are the Different Types of Staging?

There are three types of staging.

The clinical stage determines how much cancer there is based on the physical examination, imaging investigations such as MRI scans, or CT scans and any biopsies.
Pathologic Staging can only be done when surgery has been done to remove or explore the extent of the cancer. The results of the clinical stage and this are combined.
Restaging occurs if a cancer returns after treatment. This type of staging is less common

The Dukes Classification showing survival rates of people with Colon Cancer

Dukes	Description	% of cases	5 year Survival Rate
A	Colon Cancer confined to Bowel Wall	10%	90-100%
B	Colon Cancer extending beyond bowel wall, but without metastases	35%	65-75%
C	Colon Cancer involving lymph nodes	30%	30-40%
D	Cancer with distant metastases or with residual disease following surgery	25%	Less than 5%

Calprotectin

Neutrophils are the most common type of white blood cell, comprising about 50-70% of all white blood cells and are part of the body’s immune system. They are a type of white blood cell known as a granulocyte. Granulocytes contain substances which release into the body when they ingest (eat) cells which the body recognises as ‘foreign’ Neutrophils are phagocytic, meaning that they can ingest other cells and they do not survive once they have done this. Neutrophils are granulocytes, which means that they contain calprotectin within their cytosol. Neutrophils are the first immune cells to arrive at a site of infection, through a process known as chemotaxis. They are an important part of the immune response and are present in the blood and attracted to sites of infection. They ingest any pathogen or foreign cells and once they die Calprotectin is released.

Plasma concentrations of Calprotectin are raised in diseases involving increased neutrophil activity. During any condition increasing intestinal inflammation the neutrophils travel from the blood through the intestinal wall. They commence ingesting cells of disease. Once they have ingested a disease cell they die and the Calprotectin held in their cytosol is released into the bowel. Calprotectin is then detectable in the faeces. Research shows that faecal calprotectin is significantly increased in intestinal diseases such as Inflammatory Bowel Disease (IBD), Crohn's disease, colorectal inflammation, ulcerative colitis, necrotizing enterocolitis and in colon cancer.

Calprotectin is stable at room temperature and allows for samples to be sent to our laboratory by post.

All Health Clinic, 191 Kimbolton Road, Bedford, MK41 8DR - 01234 294954