The colorectal cancer usually starts as the growth in the form of polyps which can be of two types ;

• Adenomatous polyps (adenomas): These polyps have high propensity to develop into cancer. Thus, presence of adenomas is considered pre-cancerous condition.
• Hyperplastic polyps and inflammatory polyps: The presence of these polyps is more common, but in general they are not cancerous.

Signs and symptoms of colorectal cancer

• Change in bowel habits such as diarrhoea, constipation that may last few days
• Blood in the stool or Rectal bleeding
• Feeling to frequently evacuate stools but is not relieved by having one
• Abdominal pain
• Excessive gas
• Abdominal cramps

Risk factors of colorectal cancer

The person has a control over certain risk factors like smoking but other factors like a person’s age or family history, can’t be changed.

Modifiable risk factors:

Overweight or obesity: Being overweight or obese increases your risk of developing colorectal cancer in both men and women.

Physical inactivity: The more you are physically inactive, there is a greater chance of developing colorectal cancer.

Certain dietary patterns: A diet rich in red meats and processed meats increases the risk of colorectal cancer.

Smoking: If you have a smoking habit from a long time you are likely to develop colorectal cancer.

Alcohol consumption: A positive link has been demonstrated between colorectal cancer and moderate to heavy alcohol consumption.

Non-modifiable risk factors:

Age: As age increase, risk of developing colorectal cancer goes up. The incidence of colorectal cancer is common after the age of 50.

Personal history of colorectal polyps or colorectal cancer: You are more likely to develop colorectal cancer if you have a history of adenomatous polyps (adenomas). This is especially true when the polyps are large or polyps show dysplasia.
The chances of developing cancer in other parts of colon and rectum increases, if you had colorectal cancer at younger age.

Personal history of Inflammatory bowel disease: If you have a history of inflammatory bowel disease (IBD), including either ulcerative colitis or Crohn’s disease you may be at an increased risk of developing colorectal cancer.

Family history of colorectal cancer or adenomatous polyps: Approximately, 1 in 3 people who develop colorectal cancer have had a family history of it. if you have a family history of colorectal cancer in your first degree relative (parent, sibling, or child) you may be at an increased risk of colorectal cancer. A person with the family history of adenomatous polyps or colorectal cancer, should be screened before 45 years of age.

Presence of inherited syndrome: Approximately, 5% of people who develop colorectal cancer have inherited mutations which develops family cancer syndrome (Hereditary non-polyposis colorectal cancer, or HNPCC) or familial adenomatous polyposis (FAP), leading to colorectal cancer.

Type II diabetes: if you have type II diabetes you may be at an increased risk of developing colorectal cancer. Both the colorectal cancer and type II diabetes share of the same risk factors (such as being overweight and physical inactivity).

Prevention of colorectal cancer:

There are things you can do to lower the risk of cancer, such as changing the risk factors that you can control.

Treatment options of colorectal cancer:

The treatment of colorectal cancer depends on the stage of the cancer and your doctor will be able to devise the proper treatment plan for you depending on your overall health and stage of the cancer.

• Surgery: The doctor will remove polyps if you are in earliest stages of colorectal cancer.

• Polypectomy and local excision: In polypectomy, cancer is removed as a part of the polyp which is done by passing wire loop through colonoscope with an electric current. Local excision is slightly more invasive procedure wherein tools are used through colonoscope to remove small cancer growths along the lining of the colon

• Colectomy: It is a surgery to remove all or part of the colon along with lymph nodes. Colectomy can be done in two ways; open colectomy and laparoscopic assisted colectomy.

• Chemotherapy: For colorectal cancer, chemotherapy is usually given after surgery to kill remaining cancerous cells. Although, it provides symptom relief at later stage of cancer but is associated with side-effects. Chemotherapy is given in two ways; systemic chemotherapy in which drugs are put directly in vein or through oral route and other way is regional chemotherapy in which drugs are put into artery leading to the tumour. Chemotherapy can be given at different times as adjuvant chemo (given after surgery) and as neoadjuvant chemo (with radiation or before surgery).

Commonly used chemotherapy drugs are

Radiation therapy:

• In addition to other treatments, you might need radiation therapy. The need for radiation therapy depends on what type of surgery you have had, whether your cancer has spread to the lymph nodes or somewhere else in your body, and your age. You might have just one type of radiation or a combination of different types. It is generally performed alongside chemotherapy to destroy cancerous cells before and after surgery.
• Types of radiation therapy used to treat rectal and colon cancers are:
• External beam radiation therapy (EBRT): It is commonly used for people with colon or rectal cancer and radiation is focused on tumour from outside the body.
• Internal radiation therapy (brachytherapy): A radioactive source is put inside your rectum next to or into the tumor and it’s less likely to damage tissues.

Targeted therapy:

Targeted therapy, sometimes called biological therapy interfere with the working of the cancerous cells. Examples of targeted therapies include:
1. Cetuximab and Panitumumab: They are EGFR inhibitors which stop cancer cells from growing.
2. Bevacizumab, Ramucirumab and Regorafenib: They are angiogenesis inhibitors and they prevent cancerous cells from developing blood vessels.

Immunotherapy:

Drugs like check point inhibitors like PD1 inhibitors (boost immune response against cancerous cells) and CTLA-4 inhibitors (CTLA-4 inhibitors binds to CTLA-4 and boosts immune response) can be used in people with colorectal cancer are tested positive for specific gene changes such as high levels of microsatellite instability or changes in one of the mismatch repair (MMR) genes.

Life of a colorectal cancer after treatment:

The patient can do following things to live with cancer at ease:

• Ask doctor for a care plan
• Follow up schedules after colorectal cancer
• Regular follow up tests