The digestive system of the body includes the colon. Digestive system helps the body expel waste by removing and processing nutrients (vitamins, minerals, carbs, fats, proteins, and water) from meals. The digestive system comprises of the various organs such as, esophagus, stomach, and small and large intestines. The major parts of the large intestine include the colon and the rectum. Colon cancer develops in the colon of the large intestine which is the final part of the digestive tract. Colon cancer can affect any individual of any age, but it often affects older people. Small, benign (noncancerous) cell clusters called polyps commonly grow on the interior of the colon as the first signs of the condition. Some of these polyps may eventually develop into colon. Due to this, medical professionals advise routine screening exams to help prevent colon by locating and eliminating polyps before they develop into cancer.

Signs and Symptoms of Colon Cancer

• Unusual changes in the bowel habits
• Constipation 
• Diarrhea 
• Change in stool consistency
• Blood in stool 
• Persistent bloating, cramps 
• Abdominal pain 
• Unexplained weight loss

Staging of Colon Cancer

Colon cancer staging is important in order to choose the most effective treatment strategy. The TNM staging technique is the common staging method in cases of colon. The system takes into account the following things:

Primary cancer (T)

T denotes the size of the initial tumor and whether or not the colon's wall has been affected by the cancer's growth or its metastasis to nearby organs or tissues.

Regional lymph nodes (N)

N stands for whether neighboring lymph nodes have been colonized by cancer cells.

Distant metastases (M)

M denotes if cancer has spread (metastasized) from the colon to the lungs or liver, among other organs. 

Metastasis denotes the spread of cancer cells to organs outside of the colon. This condition is also known as stage IV colon or advanced colon. If the tumor is spread to the adjacent organs, then it is Stage III colon, and if it affects other organs as well, then cancer has developed into Stage IV. If the tumor is diagnosed in both the rectum and the colon, then it can be colorectal.

Diagnosis of Colon Cancer

A physician can use one of the tests listed below to check for colon cancer:

• Fecal immunochemical testing (FIT)
• Colonoscopy 
• Sigmoidoscopy

Fecal Immunochemical Test

It is a diagnostic procedure that looks for blood traces in stool samples, which may be an indicator of diseases like colorectal cancer. Doctors usually recommend it if blood is visible in the stools.

Colonoscopy 

It is a screening procedure in which your doctor views the insides of your colon using a long, narrow tube that is attached to a small camera.

Sigmoidoscopy 

It is a minimally invasive medical procedure that examines the large intestine from the rectum to the sigmoid colon, which is the closest portion of the colon.

A healthcare provider must conduct a colonoscopy to confirm the diagnosis if the outcomes of your FIT or sigmoidoscopy point to colon cancer. However, additional tests are frequently necessary to establish the size of the tumor and whether it has spread outside of the colon if they discover colon tumor. They may do diagnostic procedures, including CT, MRI, and X-ray imaging of the chest, abdomen, and liver. However, in some cases, diagnosing the stage may not be possible until after the colon surgery. A pathologist can evaluate the main tumor and the lymph nodes removed following surgery to help establish the disease's stage.

Treatment Options for Colon Cancer

There are various treatment options available for colon cancer based on various factors. And so, the treatment will be according to the tumor stage and the patient's condition. 

Surgery

The surgeon may be able to surgically remove malignant polyps when colon cancer is still in its early stages. A good prognosis of whether the polyp hasn't grown into the gut wall.

The surgeon might also have to remove some of the lymph nodes close to the colon or rectum, if the cancer has spread to the gut walls. Moreover, the remaining healthy section of the colon may be able to be reattached to the rectum by your surgeon. In case this is not possible, then a colostomy may take place. For the purpose of removing waste, the surgeon will make an opening in the abdominal wall. A colostomy can be either short-term or long-term.

Chemotherapy

It uses medication to destroy cancer cells. Chemotherapy is frequently administered following surgery to patients with colon cancer in order to destroy any remaining malignant cells. The growth of cancers is also slowed down by chemotherapy.

The following are some examples of colon tumors chemotherapy drugs:

• irinotecan (Camptosar)
• capecitabine (Xeloda)
• oxaliplatin (Eloxatin)
• fluorouracil

Radiation

Before and after surgery, radiation uses a potent energy beam, comparable to that in X-rays, to target and eliminate malignant cells. Chemotherapy is frequently used in conjunction with radiation therapy.

There are various other treatment methods as well for colon cancer which will be suggested according to the condition of the individual.

Risk Factors of Colon Cancer

There are various risk factors for colon cancer, some might be genetic and some might be lifestyle risk factors. Keeping these risk factors in mind, we can reduce the risk of colon tumors. 

• Having a first-degree relative with a history of colon or rectal
• Alcohol consumption
• Smoking
• Increased consumption of processed foods
• Increased stress
• History of diabetes
• Red meat consumption

Conclusion 

The rate of spread of colon cancer or metastasis of the colon can be different according to each individual. However, an early diagnosis and proper treatment can prevent the metastasis of cancer and help achieve a cure for it. And so, it is important to consult a doctor immediately in case of signs and symptoms to avoid any further complications.