What causes colon cancer?
Colorectal cancer begins as a growth, known as a polyp, in the inner lining of the colon or rectum.
A polyp is a visible lump. Most polyps don’t become cancerous over time and the main types of polyps are:
- Adenomatous polyps. Adenomatous polyps can sometimes become cancerous, which is why they’re called precancerous adenomatous polyps.
- Inflammatory polyps and hyperplastic polyps normally aren’t precancerous.
Most cases of colon and rectal cancer develop from an adenoma, or an adenomatous polyp. Two or more usually are present and they’re often larger than one centimeter. In addition, dysplasia may also appear after removal.
Dysplasia are cells that appear to be abnormal but not to the extent of being cancerous cells. As time passes, they invade the colon and rectum walls.
These walls have different layers. Cancer forms in the deepest layer, the mucous membrane. Then, it spreads outwards as it grows, invading the other layers.
In addition, cancer can move towards the blood or lymphatic vessels through smaller pathways. By doing so, cancerous cells can move towards the nearby lymph nodes.
Also see: 3 Steps for a Healthy Colon
The following are the main symptoms of colorectal cancer. However, symptoms may vary depending on where the polyp develops:
- Bloody feces (blood may be red or black). Blood normally appears when in the cases tumors in the rectum, sigmoid and descending colon.
- People with colorectal cancer may develop anemia which leads to fatigue, palpitations, shortness of breath and dizziness.
- Change in bowel movement: problems with diarrhea or constipation.
- Narrower stool: this occurs when the tumor affects how the stool passes through the intestine.
- Feeling of incomplete stool passage: This is a common symptom when a tumor is present in the rectum or descending colon.
- Abdominal pain: abdominal pain is a frequent symptom. It results from the tumor blocking the opening of the intestinal tract. On some occasions, it can lead to vomiting and constipation.
- Extreme tiredness and unexplained weight loss.
When there’s a suspicious anomaly in the colon, a medical specialist will first gather the patient’s medical history and do a physical examination in order to check their overall health.
Afterwards, the specialist will follow with a rectal exam. A rectal exam is an examination of the anus and a portion of the rectum. Though it might be an uncomfortable test, it isn’t painful. The key is to relax the muscles.
We should highlight that a rectal exam isn’t enough to come to a final diagnosis. In order to reach a proper diagnosis, the patient needs to undergo a colonoscopy.
A colonoscopy is a test that allows a the doctor to see the colon and rectum’s entire mucous membrane by using a hose-like instrument (endoscope) that’s inserted into the anus. If the doctor finds a mass during the colonoscopy, a sample is taken from the suspicious area (biopsy) and examined under a microscope.
Also see: Colon Polyps: The Facts
Types of colorectal cancer
For the most part, the malignant tumors that are found in the colon develop over preexisting lesions in the mucous membrane. Examples of preexisting lesions are polyps or inflammatory diseases. By looking through a microscope lens, we can see different types of cancers.
For example, adenocarcinoma is one that can appear in the glands that cover the inner colon and rectum. Adenocarcinoma is so common that it appears in 90% of all cases.
However, the following types of cancer may also appear:
- Sarcomas: tumors in the connective tissue of the digestive tract.
- Lymphomas: cancer in the cells responsible for protecting the stomach and intestine.
- Carcinoid: carcinoid tumors appear in cells that produce hormones for the digestive tract.
Treating colon cancer
Colorectal cancer can be approached in through different treatments that compliment each other, helping to address the tumor. Choosing a treatment plan will depend on the decision of the patient (once he or she has been informed by the physician) as well as on a series of factors regarding the patient and the tumor. –García Álvarez
What factors are important?
Generally speaking, the factors that have an influence in colon cancer treatment are the following: the patient’s general state of health, the location of the tumor and the stage of the cancer.
Cancer treatment is divided into two types:
This type of colon cancer treatment is for tumors that are present in the lymph nodes. The divisions of this kind treatment are:
Surgery is used for both colon and rectal tumors. Normally, the patient is admitted into the medical site a day before the operation. It’s crucial that the patient follows the doctor’s orders and prepares accordingly 3 days before with a diet and laxatives in order to avoid complications.
- Colon cancer. Surgeons remove the area containing the tumor as well as the surrounding tissue and affected lymph nodes. After, the ends of each side of the colon are then connected.
- Rectal cancer. Surgeons remove the area with the tumor. Afterwards, the rectum and anus are connected.
Radiation therapy is a treatment for rectal cancer. It consists in using highly charged ionizing radiation in order to eliminate tumor cells. With radiation therapy, there are two ways for colon cancer treatment:
- External. External radiation is machine-based (linear accelerator). During the process, the patient must lie still on the examination bed. Administrators mark the affected area with ink, which needs to stay visible until the treatment is completed. Patients can receive daily sessions of a divided dose in order to prevent undesirable side-effects.
- Internal. This is also known as intracavity radiotherapy. To carry out internal radiation therapy, radioactive materials are placed in close proximity to the tumor. The procedure consists in the insertion of a wide endoscope in the final part of the rectum.
Colon cancer treatment (systemic)
This treatment method works in the entire body with the aim to eliminate malignant cells. Doctors use chemotherapy to carry out this process.
How can one prepare for colon cancer treatment?
- Share your fears and questions with medical specialists.
- Request information about the procedures and their side-effects.
- Learn relaxation techniques as they’ll be a great aid from an emotional standpoint.
- As treatments leave patients very tired, aim to rest as much as possible.