Overview

Colorectal cancer, which includes both colon and rectal cancers, arises in the colon (large intestine) or rectum, important parts of the digestive system. This type of cancer typically begins as small, noncancerous clusters of cells called polyps inside the colon, which can slowly become cancerous over time. The good news is that early-stage colorectal cancer can often be treated and, in some cases, cured with timely intervention, emphasizing the importance of regular screening and early detection.

The risk increases with age, especially after 50, but colorectal cancer is also on the rise in younger adults. Contributing factors include diet, lifestyle, genetics, and certain medical conditions. Understanding the early symptoms of colorectal cancer and having regular colorectal cancer screening tests, such as a colonoscopy, can be life-saving.

Types of Colorectal Cancer

Adenocarcinoma: The most common type of colorectal cancer. It begins in the cells lining the colon or rectum that produce proteins.

Carcinoid tumors: It develops in the hormone-producing cells of the large intestine. They may cause symptoms like pain, bleeding, or constipation in the rectum.

Gastrointestinal stromal tumors (GISTs): It begins in the nerve cells of the digestive tract. Some are harmless but can become cancerous over time.

Lymphoma: It is a cancer that begins in immune system cells, often in the lymph nodes, but it can also start in the colon or rectum.

Sarcomas: Sarcomas are rare tumors that begin in the blood vessels, muscles, or connective tissues of the colon or rectum.

Squamous cell carcinoma: It is usually linked to skin cancer, and can also develop in the colon or rectum.

Stages of Colorectal Cancer based on its progression:

Localised: Colorectal cancer stays within the colon or rectum, offering better treatment options.

Regional: Colorectal cancer spreads to nearby lymph nodes but can still be treated effectively.

Distant: Colorectal cancer spreads to other organs, but advanced treatments provide hope.

Symptoms

The symptoms of colorectal cancer can be very subtle at first, making early detection challenging. Here is a closer look at some commonly reported symptoms:

• Changes in bowel habits: Changes in bowel regularity, including frequent diarrhea, constipation, or a change in stool consistency, may be a sign of colorectal cancer. While minor changes may be normal, long-term changes should be discussed with a doctor.
• Blood in the stool or rectal bleeding: Blood in the stool may appear as bright red or dark streaks. Bleeding can be a sign of rectal or colon cancer and should always be investigated to rule out other conditions.
• Abdominal Pain or Discomfort: Persistent abdominal pain, gas, bloating, or cramps may be signs of an obstruction caused by a colon tumor.
• Unexplained weight loss: Sudden weight loss without diet or lifestyle changes can be a warning sign, as cancer can cause changes in metabolism, leading to weight loss.
• Fatigue and weakness: Cancer-related fatigue can be caused by blood loss and the body's response to fight the disease.

Recognizing symptoms early improves survival rates, as symptoms such as unexplained weight loss, rectal bleeding, or extreme fatigue can be signs of a serious problem in the body.

When to See a Doctor

It is important to see a doctor if any symptoms occur, such as a persistent change in bowel habits, rectal bleeding, or unexplained weight loss. Early symptoms of colon cancer are often mistaken for less serious digestive conditions, so persistent or worsening symptoms require medical attention. For people with a family history of colorectal cancer, regular screening can help detect precancerous polyps early.

Screening tests, such as colonoscopy, are the best standard for early detection. Other options, including stool testing, can also help identify early-stage colorectal cancer.

Causes

The exact causes of colorectal cancer are still unclear, but several factors that increase the risk are known:

Age: Colorectal cancer is more prevalent in individuals over the age of 50, although younger adults are also being affected.

Dietary habits: A high-fat, low-fiber diet, especially rich in processed meats, increases the risk of colorectal cancer. In contrast, a diet rich in vegetables, fruits, and whole grains is associated with a lower risk.

Lifestyle choices: Sedentary lifestyle, smoking, and excessive alcohol consumption increase the risk of developing colorectal cancer.

Genetic factors: Individuals who have a family history of colorectal cancer or a genetic condition such as Lynch syndrome have a higher risk.

Medical conditions: Conditions such as inflammatory bowel disease (IBD), Crohn's disease, and ulcerative colitis increase the risk of colorectal cancer due to long-term inflammation in the intestine.

Understanding these risk factors is essential for prevention and early detection, especially for individuals with a family history of the disease.

Complications

Colorectal cancer can lead to a variety of complications, including

• Bowel obstruction: The tumor may cause an obstruction in the colon, blocking the normal passage of stool and causing considerable pain and discomfort.
• Cancer metastasis: If left untreated, colorectal cancer can spread to other organs, including the liver and lungs, complicating treatment and decreasing the chance of survival.
• Anemia: Continued blood loss from the cancerous area can cause anemia, which can lead to fatigue and weakness.
• Malnutrition: When colorectal cancer affects digestion and nutrient absorption, patients may experience significant weight loss and nutrient deficiencies.

Timely intervention is essential to avoid or minimize these complications, as advanced stages of cancer can significantly impact overall health and quality of life.

Risk Factors for Colorectal Cancer

Age: Risk increases as you get older.

Family History: A family history of colorectal cancer can raise your risk.

Diet: A diet high in fat may contribute to higher risk.

Smoking: Smoking can increase the likelihood of developing colorectal cancer.

Lack of Exercise: A sedentary lifestyle can raise your risk.

Making healthier choices can help lower your chances of developing colorectal cancer.

Preventions

Taking proactive steps can help prevent colorectal cancer, and regular screenings are key to early detection. Here are some preventive measures:

• Regular screening: Screening is one of the most effective ways to detect early-stage colorectal cancer. Tests such as colonoscopy allow both the detection of polyps and their removal before they turn into cancer.
• Healthy diet: Eating a diet rich in fruits, vegetables, and whole grains and reducing your intake of red and processed meat may reduce your risk of colorectal cancer.
• Physical activity: Regular exercise helps improve digestion and overall health, reducing the risk of colorectal cancer. Physical activity has been linked to better gut health and improved immune function.
• Quit smoking: Smoking is a known carcinogen, and quitting can significantly reduce your risk of many cancers, including colorectal cancer.
• Limit alcohol consumption: Excessive alcohol consumption is associated with an increased risk of colorectal cancer. Moderation is key to cancer prevention.
• Maintain a healthy weight: Obesity increases the risk of colorectal cancer, especially in young adults. Healthy weight management through diet and exercise is an important preventive measure.

Colorectal cancer is a potentially life-threatening disease, but awareness, regular screenings, and lifestyle changes can dramatically reduce the risk. By focusing on preventive measures and recognizing early symptoms, individuals can take responsibility for their health and increase the chances of early detection and successful treatment.