Colorectal Cancer: Know Everything from Symptoms to Treatment

04 April,2024

Colorectal cancer is a common type of cancer affecting the colon or rectum, both of which are vital parts of the digestive system. It is one of the most frequently diagnosed cancers in the world and can have severe consequences if not detected and treated early. Early detection of cancer/tumors greatly increases the chances of successful treatment. 

Oncologists can completely cure colorectal cancer if it has not spread outside the bowel. Once diagnosed, the treatment of colon cancer involves a multidisciplinary approach that may include surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy.

The blog aims to educate people about colorectal cancer, its symptoms, diagnosis, treatment, and prevention techniques. 

What is Colorectal Cancer?

Colorectal cancer is a disease marked by the unregulated growth of cells in the colon or rectum region. The colon is the large intestine, and the rectum is the passage that connects it to the anus. Both are an essential part of the human digestive system.

According to the data published by WHO, colorectal cancer was responsible for approximately 1 million deaths in 2020. It majorly affects people aged 50 and above. 

Polyps are the most common abnormal growths in the colon that turn into cancer if left untreated for a long time. Regular screening helps detect polyps and cancers in the colorectal region in the early stages. The chances of a complete cure are higher in the initial stages of the disease.

What are the Symptoms of Colorectal Cancer?

As with other cancers, colorectal cancer and polyps do not show any prominent signs and symptoms in the beginning. People can have colorectal cancer for quite some time, and they might not even know! This gives more and more reasons for people aged 40 and above to have regular screenings. 

Common symptoms of colorectal cancer include – 

• Persistent changes in bowel habits 
• Blood in stool
• Bloating
• Abdominal pain and cramps
• Unexplained weight loss
• Vomiting and nausea
• Fatigue and shortening of breath

These symptoms can also indicate less serious conditions of the gastrointestinal tract. Hence, it is vital to consult a specialist who can confirm the diagnosis.

What is Colorectal Cancer Screening?

Colorectal cancer screening is the best way to detect cancer of the colon and rectum in the early stages. It significantly helps in reducing the number of deaths caused by cancer. Screening tests for colorectal cancer are recommended for people having a personal or family history of colorectal cancer or for those suffering from chronic inflammatory bowel disease.

Tests done to screen colorectal cancer include – 

• Colonoscopy: Examines rectum and colon for polyps or cancer, allowing for removal and prevention of colorectal cancer.
• CT Colonography: Alternative for those who can't have a colonoscopy; requires skilled interpretation for accurate results.
• Sigmoidoscopy: Checks lower colon for abnormalities; colonoscopy is recommended if issues are found.
• Fecal Immunochemical Test (FIT) and Fecal Occult Blood Test (FOBT): These tests detect blood in stool and signs of polyps or cancer, requiring multiple samples annually.
• Stool DNA Test: Analyzes DNA in stool to detect cancerous changes, determining the need for colonoscopy.
• Double-Contrast Barium Enema (DCBE): This procedure examines the colon using a barium enema and X-rays. It is less effective than colonoscopy for detecting precancerous polyps.

The recommended schedule for various colorectal screening tests is as follows – 

• Flexible Sigmoidoscopy: Every 5 years
• Colonoscopy: Every 10 years
• DCBE: Every 5 years
• FOBT and FIT: Every year
• Stool DNA test and CT Colonography: As often as the doctor recommends

How is Colorectal Cancer Diagnosed?

Various diagnostic tests are available to detect colorectal cancers. Diagnostic tests are selected based on the patient's overall health, signs and symptoms, type of cancer suspected, and family history. 

The most frequently used tests for colorectal cancer diagnosis are –

• Colonoscopy: The gold standard for examining the entire colon, this procedure allows doctors to directly visualize polyps or tumors and potentially remove them for biopsy.
• Biopsy: The definitive test for colorectal cancer, biopsy involves taking a small sample of tissue for microscopic examination by a pathologist. It can be done during colonoscopy, surgery, or with needle guidance (CT or ultrasound).
• Biomarker Testing of Tumors analyzes the tumor's genetic makeup to identify specific characteristics. It helps determine the best treatment course, such as whether immunotherapy might be beneficial. 
• Blood Tests: A complete blood count (CBC) checks the red blood cell count, which might be low due to bleeding from colorectal cancer. Elevated levels of carcinoembryonic antigen (CEA) may indicate cancer spread, but this test is not perfect, as other factors can influence CEA levels. 
• CT Scans provide detailed 3D images of the body to measure tumor size and assess its spread to other organs (lungs, liver). 
• MRI Scan creates detailed images using magnetic fields, which are particularly useful for evaluating rectal cancer growth and staging. 
• Ultrasound uses sound waves to picture internal organs and is often used endo rectally to assess rectal cancer depth and plan treatment. 

What are the Treatment Options Available for Colorectal Cancer?

Continuous research and advancements in medical technology have made numerous treatment options available for colorectal cancer. Depending on your cancer stage and physical health, the oncologist may use a multidisciplinary approach, combining different treatments for optimized results.

Surgery

Surgical excision of the tumor is a primary treatment modality for most cancers, including colorectal cancer. 

• Laparoscopic surgery involves making a tiny incision in the abdomen and passing a viewing device (laparoscope) along with other devices to remove the tumor. It offers several benefits over traditional colorectal cancer surgeries, such as fewer post-operative complications and faster recovery.
• Robotic surgeries are also available at some advanced cancer hospitals. The surgeon uses robotic arms with smaller tools attached to them to remove the tumors. Robotic surgeries offer better precision, fewer cuts, and fewer side effects. 
• Polypectomy is done alongside colonoscopy to remove cancers confined within a polyp. 
• Colectomy is another surgical treatment of colorectal cancer in which either the whole (total colectomy) or a part of the colon (partial/hemicolectomy) is removed along with nearby lymph nodes.
• Colostomy surgery creates an opening in the body for the stool and gasses to pass from the large intestine to a pouch outside the body. It is a temporary procedure for rectal cancers. Once the rectum heals after the surgery, the stool can pass normally through the intestines. 
• Radiofrequency ablation, or cryoablation, involves using high-frequency waves to heat the cancer cells and ultimately destroy the tumor.

Chemotherapy

• Chemo involves the use of cancer-killing medications for the treatment of colorectal cancers.
• Chemotherapeutic drugs prevent cancer cells from dividing, growing, and multiplying.
• Common chemo drugs for colorectal cancer include Capecitabine, Fluorouracil (5-FU), Irinotecan, Oxaliplatin, and Trifluridine/tipiracil.
• A medical oncologist will decide the most suitable chemotherapeutic regimen for you. They might prescribe a single drug or use a combination of medications.

Radiation Therapy

• Radiation oncologists are the specialists who administer radiation therapy. In radiation therapy, high-frequency waves, mainly X-rays and proton beams, are used to destroy the tumor.
• Standard radiation techniques used for the treatment of colorectal cancer are external beam radiation therapy, stereotactic radiosurgery, intraoperative radiation therapy, and brachytherapy.
• Radiotherapy can cause side effects such as loose bowel movements, fatigue, upset stomach, skin reaction, and blood in stool. Most of these side effects are temporary and resolve on their own once the therapy is complete.

Targeted Therapy

• Certain genes, tissue environment, and proteins regulate cancer cell growth. Targeted therapy works by disrupting these growth factors, ultimately leading to cancer cell death. 
• Bevacizumab, fruquintinib, regorafenib, ziv-aflibercept, ramucirumab, cetuximab, and panitumumab are common targeted therapy drugs for treating colorectal cancers.
• Targeted therapy has minimal side effects as the drugs act specifically on cancer cells. Rash to the upper body and face is sometimes noticed in people receiving targeted therapy.

Immunotherapy

• The body's immune system protects it against various diseases. However, cancerous cells have a unique ability to hide from the immune system.
• Certain drugs, such as Pembrolizumab, Nivolumab, Dostarlimab, Nivolumab, and Ipilimumab, help the immune system identify and kill colorectal cancer cells. 
• Common side effects of immunotherapy include nausea, fever, decreased appetite, muscle pain, fatigue, rash, diarrhea, joint pain, and shortness of breath.

How is Colon Cancer Treated Based on Its Stage?

Oncologists worldwide use different treatment approaches for specific stages of colon cancer. Below is a general outline of the treatment approach for each stage of colon cancer:

• Stage 0 Colon Cancer: This stage is treated with a simple polypectomy surgery during colonoscopy. Additional surgeries are not required at this stage.
• Stage 1 Colon Cancer: The treatment plan for this stage involves surgical removal of the tumor.
• Stage 2 Colon Cancer: Procedures such as colectomy and laparoscopic surgery are the first line of treatment for stage 2 colon cancer. Adjuvant chemotherapy may be given to specific patients whose cancer has penetrated through the bowel walls and is at a high risk of recurrence.
• Stage 3 Colon Cancer: This stage is generally managed with surgical excision of the cancer and adjuvant chemotherapy. 
• Stage 4 Colon Cancer: In this stage, the cancer has spread to other body organs, and the treatment regimen involves multiple therapies and surgeries. Oncosurgeons remove the tumor from the colon and other body parts, like the lungs or liver, wherever the cancer has spread. Chemotherapy may be given before and after the surgery, and radiation therapy may also be used. Targeted therapy and immunotherapy are also part of the stage 4 colon cancer treatment approach.

What is the Cost of Colorectal Cancer Treatment?

The cost of colorectal cancer treatment varies worldwide. Western nations like the USA and the UK offer colon cancer treatment at approximately USD 30,000. But you don't need to be disheartened by these costs. Several countries, like India, Germany, Egypt, etc., offer high-quality cancer treatment at more affordable rates. 

The cost of colorectal cancer treatment in India ranges from USD 4,000 to USD 8,000. It includes diagnostic tests, hospital stays, medicines, surgeon's fees, OT charges, and post-operative costs.

• Chemotherapy: USD 600 – 1,000 
• Colonoscopy: USD 300 – 800
• Colectomy: USD 2,400 – 8,000
• Polypectomy: USD 1,200 – 1,600
• Radiotherapy: USD 2,000 – 6,000
• Immunotherapy: USD 1,500 – 5,000 
• Targeted Therapy: USD 2,500 – 5,200

Can Colorectal Cancer Be Prevented?

You can reduce the risk of having colorectal cancer by following a few measures. The first one involves regular colon cancer screening. Others include – 

• Eat a clean, healthy diet of fresh fruits, vegetables, and whole grains. Reduce your intake of high-cholesterol foods, red meat, and processed food.
• Avoid tobacco and alcohol consumption. Stopping smoking is one of the best gifts you can give yourself and to your loved ones. You can take the help of nicotine replacement therapy (NRT) if you find it difficult to go cold turkey. 
• Keep track of family history. Colorectal cancer is known to run in the family. If your parents, siblings, or children have had colon cancer, you must go for regular cancer screenings. 
• Maintaining an ideal body weight and regular exercise are necessary to prevent colorectal cancer. Try to exercise for at least 30 minutes on most days of the week.
• Certain drugs like NSAIDs and Aspirin can also lower the risk of developing colorectal cancer. However, they have side effects associated with them. It is best to consult a healthcare specialist before starting any medication. 

To Summarize 

Colorectal cancer is a serious issue, but early detection through screenings makes a big difference. Because more people are getting screened, doctors can find and treat the cancer before it causes problems. It leads to much better outcomes, with over 90% of people with early-stage colon cancer surviving for 5 years after diagnosis. There are even newer, targeted treatments available for colon cancer. Talk to your doctor about these options if you've been diagnosed.