Colon Cancer

Environmental Factors That Raise Risk

An Article by Dr. William D. Lyday

Colon Cancer or Colorectal Cancer (CRC) is unfortunately a common occurrence in the US and can be deadly if left untreated. This cancer originates in the cells lining the colon. It is thought that over time, environmental exposures – what we eat, drink and ingest- can cause a series of genetic mutations within the cells of the colon in which normal cells gain cancerous properties. Normal colon cells have a predictable life cycle of growth and cell death. On the other hand, cancerous cells have lost the signal to die. In fact, cancer cells are referred to as “immortalized” they grow uncontrollably and as more cellular mutations occur, cancer cells gain the ability to spread into local lymph nodes, blood vessels, and travel to distant organs in other regions of the body.

Colon Cancer occurs around the world. A 2015 report suggests 1.65 million were newly diagnosed and 835,000 died.  In the US, 140,250 new cases were identified and 97,220 deaths occurred. It is believed through many years of observation and scientific research that colon cancer is caused by two primary factors – environmental exposure and genetic predisposition.

Reducing Colon Cancer

In this segment we will discuss the environmental risk factors for colon cancer and how to reduce them. There is a lot of information to cover, so we will summarize and try to review the major points. Risk factors for colon cancer include environmental and genetic. What do we mean by environmental? Basically, anything our body is exposed – foods we eat, medications, radiation, toxins, etc…The list is very long and we may not even be aware of some of these exposures. Genetics refers to the DNA within the cells of your body and specifically the cells lining the colon. Every cell in the body has DNA, the genetic program for how that cell functions. Changes in the DNA can occur as a result of a toxic exposure or may be inherited and present since conception. Determining risk of colon cancer requires some thought about all of these factors and how they may have contributed.

Environmental Factors with Possible Association with Colon Cancer

1. Red Meat:

• Particularly Salted
• Barbecued
• Processed – Examples include: bacon, ham, sausage, beef jerky, corned beef

2. Tobacco:  Smoking cigarettes has been associated with increased formation of colon polyps, cancers and death from cancer.

3. Alcohol:  Several studies have demonstrated a connection between alcohol consumption both moderate and heavy.

4. Androgen Deprivation Therapy:  Say what? This refers primarily to men who are being treated for prostate cancer. A common therapy to decrease prostate cancer growth is to block hormonal stimulation. For unclear reasons, these hormonal blocking agents have been associated with some increased risk of colon cancer. This association has not been proven.

5. Cholecystectomy:  Some studies have demonstrated a slight increase risk in colon cancer as a result of the gallbladder being removed. Bile is produced by the liver and stored in the gallbladder. When there is no gallbladder, bile constantly flows into the intestinal tract and perhaps stimulates cancers in the colon. This is definitely controversial and not proven.

Other Possible Risk Factors

1. Coronary Heart Disease:  Individuals with heart disease may have higher risk. Not clear why.

2. Urinary Bladder Surgery:  When the urinary bladder has been re-routed to drain into the intestinal tract – a uterocolic anastomosis is surgically created. It has been suggested that the site where bladder is connected to colon may have increased likelihood for cancers.

3. BRCA1 Gene Mutation:  This genetic mutation is often discovered in women with breast cancer. An increased risk of colon cancer in BRCA1 carriers has been suggested.

4. Women with Endometrial Cancer:  The association with colon cancer has been reported. This linkage may be related to a genetic trait known as  “Lynch Syndrome.” These individuals have inherited a powerful gene which raises the risk of several cancers including endometrial and colon.

5. Bad Bacteria:  Bad bacteria may have some role in colon cancer – there are numerous bacterial and viral strains with an apparent association to colon cancer, but not proven.

More Conditions Associated with Elevated Risk of Colon Cancer

1. Race:  African Americans appear to have a 20% higher mortality (risk of dying) from colon cancer.

2. Gender:  Men appear to have a 25% higher mortality from colon cancer.

3. Acromegaly:  Excessive production of growth hormone often caused by a benign pituitary tumor. Growth hormone may stimulate tumors in the colon.

4. Renal (kidney) Transplant:  Most transplant patients require longterm immunosuppressant medications to prevent organ rejection. It is possible that suppressing the immune system with these medications over many years may raise cancer risk.

5. Obesity:  Numerous studies have demonstrated a connection between being overweight or obese with colon cancer risk.

6. Diabetes:  A review of 14 different studies concluded that colon cancer risk was almost 38% higher in diabetics when compared to non-diabetics. The cause of cancer may be related to excessive insulin levels which stimulated colon cells to mutate. Many type II diabetics have elevated insulin levels.