Colorectal (Colon) cancer

Symptoms may be common in other diseases which leads to late diagnosis.

Common symptoms:

Bloody stool
Change in bowel habits which may indicate constipation or diarrhea
Weight loss
Abdominal pain
Anemia
If you experienced symptoms of colorectal cancer,

visit your gastroenterologist who may direct you to an oncologist.

Several factors can increase the risk of getting colorectal cancer such as:

Age- 90% of cases occur in people more than 50 years old
History of colorectal polyps- They are precursors of colorectal cancer
Genetic factors
Personal history of inflammatory bowel disease
Family history of colorectal cancer
High meat and fat consumption
Physical inactivity
Obesity
Smoking
Alcohol consumption

Different tests and procedures may be used to diagnose and stage colorectal cancer such as:

Digital rectal examination: This is a physical examination done by the doctor through the rectum to detect any abnormalities.

Fecal occult blood test: A stool examination to detect the presence of blood in the stool which indicates gastrointestinal bleeding.

Colonoscopy: A device having a camera is used to get an image of the whole intestine to localize the tumor and a sample can be taken for examination.

Sigmoidoscopy: A device having a camera is used to get an image only of the lower part of the intestine to localize the tumor and a sample can be taken for examination.

Computed tomography (CT): An imaging procedure to get a picture of the colon before surgery, or to detect recurrence after surgery.

Positron emission tomography (PET)/Computed tomography (CT): An imaging procedure for the staging of cancer by detecting if it has spread to other parts.

Tumor markers: A test that uses blood or urine samples to measure the quantity of a specific substance that indicates the presence of a malignancy.

Staging

The staging of colorectal cancer depends on the tumor size, involvement of lymph nodes, and spreading to other parts of the body. It has stages from zero to four. stage four is the most severe one and indicates that cancer has spread to different organs.

Choosing the appropriate treatment depends on the size of the tumor, location, spreading, and the patient's general health.



Treatment options are:



Surgery: It’s the mainstay of treating colorectal cancer and depends on the location of the tumor.



Colon surgery: It may include removing cancer by laparoscopy, or removing part of the colon to remove the malignant tumor.



Rectal surgery: Different surgical methods can be used to remove the malignant tumor, The procedure's invasiveness depends on the stage of cancer.







Patients may require a preoperative procedure to divert the excretion of feces to a bag, to give the intestine the chance to heal after removing part of it, or in some cases, it can be permanent.



Chemotherapy: A type of medicine that kills cancer cells and is usually taken as a combination of two or more medicines. It is used in combination with radiotherapy before surgery to decrease the tumor size, or after surgery to kill any remaining cancer cells and stop the disease recurrence, or to relieve the symptoms in the advanced stages (ex: Fluorouracil, Capecitabine, Leucovorin, Oxaliplatin, and Irinotecan).



Radiotherapy: It is using radiation to kill cancer cells. This procedure can be used before surgery to decrease the size of the tumor, after surgery to kill any remaining cancer cells, instead of surgery to cure cancer or stop it if surgery is not applicable, or to control the symptoms in the advanced stages.



Targeted therapy: These are medicines with specific targets on cancer cells, They are usually used in combination with chemotherapy in advanced stages in which cancer has already spread (ex: Panitumumab, Bevacizumab, and Cetuximab).