What is Colorectal Cancer? And How to reduce your risk?

The large intestine (or large bowel) is made up of the colon and rectum and is part of the digestive system, also known as the gastrointestinal (GI) system. The colon and rectum play critical roles in water and salt absorption as well as waste disposal in the form of stool. Meanwhile, many people suffer from abnormalities in the colon and rectum, which have a significant impact on their quality of life, the most common of which is colorectal cancer. This article will explain colorectal cancer, how it affects the colon and rectum, and how to avoid it.

What is Colorectal Cancer?

Colorectal cancer, also known as bowel cancer or colon cancer, is characterized by the growth of cancerous cells in the colon or rectum, which are both parts of the large intestine. The colon is the lower part of the large intestine that connects to the anus and absorbs water and nutrients from food. Colorectal cancer symptoms include worsening constipation, blood in the stool, decreased stool thickness, loss of appetite, weight loss, nausea, and vomiting. Rectal bleeding or anaemia may also occur in patients over the age of 50.

Most colorectal cancers start as a growth on the inner lining of the colon or rectum, or polyps, which can be classified as 

• Adenomatous polyps, or adenomas: These polyps can sometimes develop into cancer. As a result, adenomas are classified as precancerous conditions and can be tubular, villous, or tubulovillous. 
• Hyperplastic polyps and inflammatory polyps: These polyps are more common, but they are not precancerous in most cases. Some people with large (more than 1cm) hyperplastic polyps may require more frequent colorectal cancer screening with a colonoscopy. 
• Sessile serrated polyps (SSP) and traditional serrated adenomas (TSA): These polyps are frequently treated as adenomas because they are more likely to progress to colorectal cancer.

If a polyp is larger than 1 cm, there are more than 3 polyps found, or dysplasia – an area in a polyp or the lining of the colon or rectum where the cells look abnormal – is seen in the polyp after the polyp is removed, there is a higher risk of colorectal cancer developing. 

If cancer develops in a polyp, it can spread to the colon or rectum wall over time. Because the colon and rectum are made up of numerous layers of tissue. Colorectal cancer begins in the innermost layer of the mucosa and spreads to the outer layer, where it can then spread into blood and lymph vessels, and then to nearby lymph nodes or other parts of your body.

Colorectal cancer can be classified into types including

• Adenocarcinomas: The most common types of cancer begin in cells that produce mucus to lubricate the inside of the colon and rectum. There are also subtypes of adenocarcinoma that have a worse prognosis than others, such as signet ring and mucinous.
• Carcinoid tumors: These begin in the intestine from hormone-producing cells. 
• Gastrointestinal stromal tumors (GISTs): These begin with special cells in the colon’s wall known as interstitial cells of Caja, some of which are benign and do not cause cancer. These tumors can occur anywhere in the digestive tract, but they are uncommon in the colon.
• Lymphomas: These are immune system cell cancers. They typically begin in the lymph nodes, but they can also begin in the colon, rectum, or other organs. 
• Sarcomas: This cancer can begin in the blood vessels, muscle layers, or other connective tissues of the colon and rectum wall. Colon or rectum sarcomas are uncommon.

What leads to and increases the risk of Colorectal cancer?

Colorectal cancer is caused by a combination of genetic, environmental, and lifestyle factors. While not all cases of colorectal cancer can be avoided, there are certain risk factors that increase the likelihood of developing the disease. Some of these elements are as follows:

• Age: Colorectal cancer risk increases with age, with most cases diagnosed in people over the age of 50.
• Family History and Genetics: A family history of colorectal cancer or certain genetic syndromes, such as Hereditary non-polyposis colon cancer or Lynch syndrome, Familial adenomatous polyposis (FAP), Peutz-Jeghers syndrome (PJS), MUTYH-associated polyposis (MAP), and Cystic Fibrosis can significantly increase the risk.
• Personal History of Polyps or Inflammatory Bowel Disease (IBD): People who have had adenomatous polyps (precancerous growths) or certain types of inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, are at a higher risk.
• Type II Diabetes: People with type II diabetes, mostly non-insulin dependent patients, are at a higher risk of developing colorectal cancer.
• Certain Genetic Mutations: Certain genetic mutations can predispose individuals to colorectal cancer, such as mutations in the APC, KRAS, and TP53 genes.
• Radiation Exposure: Prior exposure to radiation, particularly in the abdominal area, can increase the risk.
• Race and Ethnicity: Jews of Eastern European descent (Ashkenazi Jews) have one of the highest risks, while American Indians and African Americans have a higher incidence of colorectal cancer compared to some other racial and ethnic groups.
• Diet: A diet high in red and processed meats, as well as low in fiber, fruits, and vegetables, may increase the risk of colorectal cancer. Also, the digestion of Streptococcus gallolyticus and Escherichia coli can increase the risk of cancer.
• Obesity: Being overweight or obese is linked to a higher risk of colorectal cancer.
• Physical Inactivity: Leading a sedentary lifestyle and not engaging in regular physical activity can contribute to a higher risk of various cancers.
• Smoking and Alcohol Consumption: Smoking tobacco is a known risk factor for most cancer, while heavy and excessive alcohol consumption is associated with an increased risk of many cancer including colorectal cancer.

Meanwhile, some of these risk factors are avoidable, lowering your chances of developing colorectal cancer. As a result, maintaining a healthy weight, increasing the amount and intensity of your physical activity, limiting red and processed meats, eating more vegetables, fruits, and whole grains, and refraining from smoking and drinking can all help to reduce your risk.

How do I know about my conditions of the Colon and Lower Intestines?

American Cancer Society recommended people age over 45 regularly take a screening for colorectal cancers, which can be done through stool-based tests such as Highly sensitive fecal immunochemical test (FIT), Highly sensitive guaiac-based fecal occult blood test (gFOBT), and Multi-targeted stool DNA test (mt-sDNA), or through visual-based test including colonoscopy, CT colonography, and Flexible sigmoidoscopy (FSIG). 

Although colonoscopy, which uses a long, flexible tube equipped with a tiny camera and a light source to visually inspect the conditions and spreads of tumors within the colon, and histopathology of the tumor cell to confirm that the tumor has progressed into cancers, are meant to be used to confirm the diagnosis. Colorectal cancers are classified from Stage 0 (very early cancer that does not spread beyond the inner layer) to Stage IVC (cancer that spreads through the peritoneum or the lining of the abdominal cavity). 

What do I need to do with Colorectal cancer?

Depending on the stages of cancer and the patient’s condition, options for the treatment of  colorectal cancer are variables, which include

• Surgery: Surgery is often the primary treatment for colorectal cancer. The goal is to remove the cancerous tumor and nearby lymph nodes. Depending on the tumor’s location and size, different surgical procedures may be performed:
  • Polypectomy: For small, localized polyps, they can often be removed during a colonoscopy.
  • Laparoscopic Surgery: Minimally invasive surgery using small incisions and a camera-equipped scope to remove the tumor.
  • Colectomy: Removal of a portion of the colon containing the tumor. Depending on the location, this could be a partial colectomy (removing a segment of the colon) or a total colectomy (removing the entire colon).
  • Colostomy: In some cases, when the rectum is removed, a colostomy may be necessary, creating an opening in the abdominal wall to allow waste to exit the body.
• Chemotherapy: Chemotherapy involves the use of drugs to kill cancer cells or stop their growth. It’s often used in combination with surgery, especially in cases where the cancer has spread to nearby lymph nodes or other organs. Chemotherapy can also be used before surgery (neoadjuvant chemotherapy) to shrink the tumor, making it easier to remove.
• Radiation Therapy: Radiation therapy uses high-energy rays to target and kill cancer cells. It’s often used before surgery to shrink the tumor, making it more operable, or after surgery to destroy any remaining cancer cells. In some cases, radiation therapy can help alleviate symptoms in advanced cancer cases.
• Targeted Therapies: These drugs target specific molecules or pathways involved in cancer growth and progression. They are used in combination with chemotherapy and are often more focused in their action, leading to potentially fewer side effects.
• Immunotherapy: Immunotherapy helps the body’s immune system recognize and attack cancer cells. It’s a newer treatment option for colorectal cancer and is more commonly used for specific subtypes of colorectal cancer that exhibit certain genetic features.
• Palliative Care: In cases where the cancer is advanced and cannot be completely cured, palliative care focuses on managing symptoms and improving the patient’s quality of life. This can include pain management, nutrition support, and emotional and psychological support.

Dealing with Colorectal cancer at Phyathai 1 International

The Great Life Center at Phyathai 1 International is highly experienced in dealing with patients with colorectal cancer. With the advanced CT colonography machine available for quick and non-invasive diagnostic. Also, our skilled and trained multidisciplinary team consists of specialists in Gastrointestinal Medicine, Cancer treatment, Surgeons, radiologists, as well as nutritionists, and psychologists who are available to offer complete treatment plans for colorectal cancer.

If you currently seek for colorectal cancer screening, or you are at risk of colorectal cancer, we recommend you to consult with our MDT team at the Great Life Center of Phyathai 1 International directly as its open daily from 7 am to 5 pm. the consult can be done by phone at number (+66)2-201-4600 ext.2377 or by E-mail at [email protected].