Colorectal cancer is a condition where malignant cells form in the tissues of the colon—a five-foot section of the large intestine—or the rectum, which connects the colon to the anus. Colon and rectal cancers are often grouped together as they share many symptoms and risk factors, although their treatment approaches may differ slightly.
Colorectal cancer typically begins as a growth of tissue called a polyp within the lining of the colon or rectum. While most polyps are not cancerous, some—primarily adenomas, which originate in mucus-producing gland cells—are considered pre-cancerous growths. If an adenoma develops into cancer, it is termed adenocarcinoma, which is the most common type of colorectal cancer.
The disease is a significant health concern, with many diagnoses in India. Historically, the disease was most common in people over the age of 55, but in recent years, there has been an increase in diagnoses among adults under 55. SSCHRC offers a dedicated Young-onset Colorectal Cancer Programme with specialised services for this patient group, including fertility care and genetic counselling.
In its earliest stages, colorectal cancer may not cause any noticeable symptoms, especially when it starts as a small polyp. As the disease progresses, a variety of symptoms may appear.
If you notice any unexplained changes that persist for more than two weeks, you should consult your doctor.
Key symptoms may include:
It is important to remember that these symptoms can also be caused by other less serious conditions, such as hemorrhoids, anal fissures, irritable bowel syndrome, or inflammatory bowel disease.
Routine screening is vital for colorectal cancer, as it allows doctors to detect and remove polyps before they become cancerous, thus preventing most cases. Early detection also significantly increases the likelihood of successful treatment.
For most individuals, colorectal cancer screening begins at age 45. Those considered high-risk due to a personal or family history, certain genetic conditions, or inflammatory bowel disease may need to begin screening earlier.
These are considered the most effective tests and are often performed under sedation for patient comfort. They allow the doctor to directly view the inside of the colon and rectum.
These non-invasive tests can indicate the need for a more accurate diagnostic test, but they do not provide a definitive diagnosis and are typically not used for patients already experiencing symptoms.
If symptoms are present or an initial screening is abnormal, your doctor may recommend further tests to confirm a diagnosis, check for spread, or monitor treatment response.
While no single blood test can diagnose the cancer, tests can assess organ function and blood counts. A test for the carcinoembryonic antigen (CEA) protein can monitor tumour growth and treatment response. Circulating tumour DNA (ctDNA) testing can also help detect recurring cancer early in successfully treated patients.
These provide detailed information on the tumour's size, location, and if it has spread (metastasis). Common imaging includes:
These may include Virtual Colonoscopy (a focused CT scan), Endoscopic Ultrasound (EUS), and Double Contrast Barium Enema (DCBE).
Treatment at SSCHRC's Gastrointestinal Centre is provided by a multidisciplinary team, combining the latest technology and research, and is tailored to the patient's unique needs. Surgeons at SSCHRC are experienced in minimally invasive techniques, including advanced robotic surgery, which helps reduce recovery time. SSCHRC also offers various clinical trials for patients at every stage of the disease.
The type of treatment depends on whether the cancer has spread and its location (colon vs. rectum).
Usually treated with surgery, often followed by chemotherapy to eliminate any remaining cancer cells. Radiation therapy is rarely used.
Also treated with surgery. Patients may receive chemotherapy and/or radiation therapy before the procedure to shrink the tumour, or afterwards to kill any remaining cells. Rectal cancer surgery is often more complex than colon cancer surgery.
While more advanced, some patients can still be cured. New treatments often allow metastatic cancer to be managed like a chronic condition to prolong life and preserve quality of life. Treatment may include surgery, radiation therapy, ablation therapies, and cancer drugs.
The most common treatment, especially for cancer that has not spread. The type of surgery depends on the stage and location of the tumour.
Uses drugs to kill cancer cells, control their growth, or relieve symptoms. It may involve a single drug or a combination.
Uses powerful, focused beams of energy to destroy cancer cells while minimising damage to healthy tissue. It is frequently used for rectal cancer but only in limited situations for colon cancer.
Drugs designed to interfere with specific molecules that cancer cells need to survive, multiply, and spread.
Improves the immune system's ability to find and eliminate cancer cells. This includes Immune Checkpoint Inhibitors and Monoclonal Antibodies.
Minimally invasive procedures to destroy tumour cells.
Drugs that disrupt the creation of new blood vessels, thus starving the tumour of blood supply needed for rapid growth.