Colorectal cancer is cancer that starts in the rectum or colon. Perhaps surprisingly, it is one of the most common cancers in the world. However, not many people are aware of its types, symptoms, and risk factors. In this article, we discuss the different types of colorectal cancer, as well as the risk factors and possible treatments for this disease.

What is colorectal cancer?

Colorectal cancer is a collection of cancerous cells appearing in the colon or rectum. This disease can also be called rectal cancer or colon cancer, depending on where the cancer begins. Rectal and colon cancer are often grouped together because they have many similar features.

According to the Global Cancer Observatory and the World Health Organization, colorectal cancer was the third most diagnosed cancer in the Philippines in 2020 with 17,364 new cases.

What are the types of colorectal cancer?

There are different kinds of colorectal cancer, which can have an impact on the kind of treatment a patient receives.

Colorectal Adenocarcinoma

Adenocarcinoma is cancer that begins in your body’s mucus-producing glandular cells. Those that start in the rectum and colon account for 95 percent of all cases of colorectal cancer.

Adenocarcinomas of the rectum or colon usually develop in the large intestine’s lining. However, it can spread to the other layers.

There are two subtypes of this, which are less common. The first is mucinous adenocarcinomas, which make up 10 to 15 percent of colorectal adenocarcinomas. Meanwhile, signet ring cell adenocarcinoma is often more difficult to treat and makes up less than 1 percent of all adenocarcinomas.

Primary Colorectal Lymphomas

This is a kind of non-Hodgkin lymphoma that develops in the lymphocytes in the lymphatic system. Lymphocytes are a kind of white blood cell, which helps ward off infections. It is also a rare kind of colorectal cancer.

Gastrointestinal Carcinoid Tumors

A carcinoid tumor develops in the neuroendocrine cells, which are nerve cells that aid the regulation of hormone production. The tumors are also part of a group of cancers that are called neuroendocrine tumors.

Carcinoid tumor cells grow slowly. They can also develop in the lungs.

Gastrointestinal Stromal Tumors (GIST)

GIST is a rare type of colorectal cancer that develops in the ICCs (interstitial cells of Cajal), which are cells in the gastrointestinal lining. These are also considered sarcomas, which are cancers that start in the connective tissues like fat, cartilage, and deep skin tissues.

Melanomas

Melanoma is often associated with skin cancer. However, these can develop anywhere, including the rectum or colon.

What are the symptoms of colorectal cancer?

People may not see colorectal cancer symptoms right away. Some common symptoms include:

• Constipation, diarrhea, and/or unexplained changes in your bowel habits
• Feeling like you have not fully emptied your bowels after using the toilet
• Tiredness or fatigue
• Unknown cause of iron deficiency in males or in females after menopause
• A lump in the back passage or abdomen (felt by a doctor)
• Weight loss with no known cause
• Feeling full in the abdomen, even when you have not eaten for several hours
• Bloating and pain in the abdomen
• Bright red blood that comes from the rectum or blood in feces (feces will look black)

Colorectal cancers can bleed into your digestive tract and make your feces look darker. Additionally, the blood loss can lead to anemia and the cancer can spread to other body parts like the liver. As a result of the latter, jaundice may occur.

Consult a doctor if you are experiencing symptoms, especially if they last for more than 4 weeks. These symptoms are also often present in irritable bowel syndrome.

What causes colorectal cancer?

Like most cancers, there is no clear cause of colorectal cancer. However, some factors can increase your risk for developing colorectal cancer, including:

• Obesity and being overweight
• Diets high in calories, saturated fats, and animal protein and low in fiber
• Being over 50 years old
• Having family members who had colorectal cancer
• Had or currently having uterine, ovary, or breast cancer
• Excessive alcohol consumption or smoking
• Lack of physical activity
• Polyps in the colon or rectum that could become cancerous

How Do You Treat Colorectal Cancer?

Most doctors will use a system of stages (0 to 4) to determine the burden of cancer on the body. Knowing what stage of cancer a patient has will help the doctor make an appropriate treatment plant. Some common forms of treatment include:

Surgery (surgical resection). Some patients may need surgery to remove the tumor and some of the surrounding healthy tissue. You may also get other surgeries like colostomy and laparoscopic surgery.

Radiation therapy. This destroys cancer cells by using high-energy x-rays. This is a common way to treat rectal cancer since the tumor usually recurs in the same general area.

Systemic therapy. This kind of treatment destroys cancer cells by using medication. Some examples of systemic therapy are chemotherapy, immunotherapy, and targeted therapy.

How Do You Prevent Colorectal Cancer?

Since the exact cause of colorectal cancer is not known, there is no surefire way to prevent it. However, you can try decreasing your risk by:

• Maintaining a healthy body weight
• Quitting smoking
• Moderate to no consumption of alcohol
• Regular screenings (especially for those with a family history or above the age of 50)
• A healthy diet and exercise

Key takeaways

Colorectal cancer can begin in the colon, rectum, or both, but it also can spread to other parts of the body. Similarly, there are many types of colorectal cancer. As a result, the treatments can vary based on the type of colorectal cancer a person has. Also, if you are at risk of developing the disease or are experiencing symptoms, it would be best to consult your doctor.

Learn more about Cancer here.