Colorectal Cancer (IV)

Bowel movement is a private activity taboo to discuss for majority of the people.  As a result, when they get anal bleeding, it is merely passed off silently without informing their family members or consult a doctor.  Instead, they may treat the symptom with ineffective 'pile cures'.

Colon structure

 

The large intestine is made up of the colon (upper) and the rectum (lower). Being the last stage of digestion, it merely absorbs water from the indigestible residue of food to be recirculated into the body and extract important vitamins such as vitamins K and B12, riboflavin and thiamine. The waste is stored in the rectum before sending out to the anus as faeces.

 

How cancer develops

As colorectal cancer currently ranks third most common cancer worldwide and fourth leading cause of cancer, leading a healthy lifestyle is of paramount importance and taking all necessary prevention is better than cure, especially those over their prime age.

 

Cancer of the colon and rectum (colorectal cancer) starts when the process of the normal replacement of lining cells goes wrong. Mistakes in mucosal cell division occur resulting in cells dividing independently of the normal checks and balances that control growth. As these abnormal cells mutate, they can lead to growths within the colon known as polyps.

 

Polyps are usually precancerous tumors that grow slowly over the course of years and remain localised for a long time. As polyps grow, additional genetic mutations further destabilize the cells and may invade other layers of the large intestine turning it cancerous. This is a gradual process and takes more than 8 to 10 years to be fully blown. Hence, early detection should see 3 out of 4 patients with colorectal cancer saved.

Two possibilities can happen.

 

First, the cancer can grow locally and extend through the wall of the intestine and invade adjacent structures, creating a bigger mass harder to remove. This may bring symptoms such as pain or fullness, or cause blockages of the colon or nearby structures. In advanced stage, the 5 year survival rate is under 50%.

 

Second, as the cancer grows and metastasise, shedding thousands of cells a day into the blood and lymphatic system that can cause cancers to form in distant locations. In fact, colorectal cancer usually spreads first to local lymph nodes before traveling to common destinations like the liver, the abdominal cavity and the lung.

Symptoms

 

When colorectal cancer first develops, there may not be symptoms at all. As the cancer grows, watch for common signs and symptoms like:

• a change in the frequency of bowel movements
• diarrhea, constipation or feeling that the bowel does not empty completely
• either bright red or very dark blood in the stool (rectal bleeding)
• stools that are narrower than usual
• general abdominal discomfort such as frequent gas pains, bloating, fullness and/or cramps
• significant weight loss
• constant tiredness
• vomiting
• unexplained anemia

The patient tends to look pale, easily tired and often breathless after moderate exertion.

Risk factors

Males are generally meat eaters, rendering them prone to colon cancer. Factors that increase a person’s risk of colorectal cancer include:

(1) High fat intake - It is believed that the digestion of fat that occurs in the small intestine and the colon leads to the formation of cancer-causing chemicals (carcinogens).

(2) Family history - Approximately 20% of colon cancers are hereditary. Chromosomal defects inherited at birth develop into polyps and/or cancer as early as infancy.

(3) Accumulation of toxins likely due to other diseases eg. diabetes. 

Prevention

Study showed majority (80%) of colon cancer patients do not have family history. Hence, it has to do with lifestyle choices which are controllable to a large extent.

+ Two contributing factors are alcohol usage and smoking.

-  Moderate and heavy drinkers have a 20% and 50% higher chance of getting this cancer as compared to non-drinkers.

-  Smokers have 18% higher risk of developing colorectal cancer and 25% higher risk of dying from cancer as compared with non-smokers.

+ People can change their eating habits by reducing fat intake and increasing fiber in their diet.

 

-  Major sources of fat are red meat, eggs, dairy products, salad dressings and oils used in cooking.

 

-  Fiber is the insoluble, nondigestible part of plant material present in fruits, vegetables, whole-grain breads and cereals. With the bulk provided, fiber leads to the more rapid transit of fecal material through the intestine, thus allowing less time for a potential carcinogen to react with the intestinal lining.

 

+ While consumers are told to cook meat thoroughly to remove pathogens that are eliminated by intense heat, there are dangers from overcooking.

-  Dripping fat from frying, broiling and grilling protein foods like beef, pork, poultry and even fish can produce cancer-causing compounds linked to stomach, colon, bladder and several other cancers.

-  Avoid processed foods like bacon, luncheon meat, ham and hot dogs that are pre-treated with nitrites to kill food-borne germs and maintain a natural color. Carcinogens appear when nitrites become nitrosamines.

+ Drinking chlorinated water has been linked to a great incidence of colon cancer. On the other hand, some researchers believe coffee has positive effects on reducing colon cancer risk.

+ Studies have shown the risk of developing colorectal cancer is 1.5 fold higher for obese people over people of normal weight. To combat this cancer, regular exercise can possibly reduce the risk by 20%.

+ As colorectal cancer displays no early symptoms, screening can help to detect abnormal growths. People above 50 years old are advised to take an annual faecal occult blood test (FOBT) and colonoscopy every 10 years.

Treatment

As mentioned, the earlier the cancer is detected, the higher the chance of cure.

-  For Stages 1 to 3, surgery is recommended. It involves truncating a portion of the large intestine and reconnecting to the healthy segment of the organ. The survival rate for Stage 1 to 2B can be as high as 80-90%. Follow-up chemotherapy is usually arranged to clear residual cancer cells that may not have been surgically removed with the tumor.

-  For tumor occurring in the rectum around the anus, the patient needs a stoma instead. This is a surgically created opening which connects the large intestine to a pouch on the exterior body where faecal matter is collected and disposed off.

-  At the final stage 4, survival rate is as low as 5% only. As this is a complicated process, specialists involved may include surgeons, oncologists and radiation oncologists. Chemotherapy is applied to control the spread of wildfire, reduce the tumor size and relieve symptoms but no promise to arrest the deteriorating condition.

Recommendations

Besides avoiding the risk factors mentioned above, do observe methods of food preparation:

- Cooking should be done simply by steaming or little oil used.

- Microwave ovens should be avoided due to the potential low-level radiation leakage damaging foods leading to stomach and intestinal cancerous growths.

- The best method of eating is raw. It has been found that cancer patients who used fresh raw cabbage and carrot juice reported excellent results.

- Consume as little barbecued foods as possible as high temperature cooking results in certain chemicals with carcinogenic effect formed.

Whether you are taking precaution or already got colorectal cancer, nutritional supplements should be seriously considered.  Potent antioxidants like Beta-carotene, selenium, Vitamin C, A and E are helpful in combating colorectal cancer.