Colorectal Cancer

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Colorectal cancer is a type of cancer that develops in the large intestine. The colon, the longest part of the large intestine which ends in the anus. Colorectal cancer is the fourth most common cause of death due to cancer globally and ranks in the top 10 among causes of death due to cancer among Indians, according to the Indian Council of Medical Research.


    • Adenocarcinoma: Tumour that originates from cells in the lining of the gut that secretes mucus and other fluids.
    • Gastrointestinal Stromal Tumours (GIST): These are tumours that start in the muscle tissue of the digestive tract.
    • Lymphoma: These tumours start in the lymph nodes which are part of the body’s immune system.
    • Carcinoids: These are tumours that start in special hormone-producing cells in the intestine
    • Rarer syndromes involved with colorectal tumours: Turcot Syndrome, Peutz-Jeghers Syndrome ,Familial Colorectal Cancer, Juvenile Polyposis Coli.

This classification can be determined by the pathologist based on the sample taken during surgery or colonoscopy.


If you are diagnosed with colorectal cancer, your doctor will run more tests to determine the extent (stage) of your cancer. The stage of your cancer is based on the size and spread of the tumour and helps your doctor decide which treatments are optimum.

  • Stage 0: The cancer is in its earliest stage and has not grown beyond the inner layer of the colon or rectum (carcinoma in-situ or intramucosal carcinoma)
  • Stage I: The cancer has grown through the innermost layer into the second or third layer of the colon or rectum but has not spread to nearby lymph nodes or other organs in the body.
  • Stage II: It is divided in to three subgroups: Stage IIA (The cancer has grown to the outermost layers of the colon or rectum but has not gone through them and has not spread to nearby organs, lymph nodes or other organs in the body), Stage IIB (The cancer has grown through the wall of the colon or rectum but has not grown into other nearby tissues or organs, nearby lymph nodes, or other organs in the body), Stage IIC (The cancer has grown through the wall of the colon or rectum and is attached to or has grown into other adjacent tissues or organs but has not yet spread to nearby lymph nodes or to other organs in the body.
  • Stage III: It is also subdivided in to three subgroups: Stage IIIA (The cancer has grown through the layers of the colon or rectum and has spread to nearby lymph nodes but not to distant organs), Stage IIIB (The cancer has grown into the outermost layers of the colon or rectum and has spread to nearby lymph nodes but has not reached nearby tissue and distant organs), Stage IIIC (The cancer has grown into the outermost layers of the colon or rectum but has not reached nearby organs or distant site but has spread to 7 or more nearby lymph nodes).
  • Stage IV: It is subdivided in to three subtypes: Stage IVA (The cancer may or may not have grown through the wall of the colon or rectum, to the nearby lymph nodes but has spread to a distant organ (e.g. liver, lung, distant lymph nodes), Stage IVB (The cancer may or may not have grown through the wall of the colon or rectum, spread to nearby lymph nodes but has spread to more than one distant organ not including the lining of the abdominal cavity), Stage IVC (The cancer may or may not have grown through the wall of the colon or rectum, spread to nearby lymph nodes and distant organs but has spread to the lining of the abdominal cavity).

Sources: European Society for Medical Oncology (ESMO); American Cancer Society; ICMR; Stanford Health; 


  • Screening for colorectal cancers: Screening is sometimes conducted for individuals over the age of 50 and may involve examination for Faecal Occult Blood Test (traces of blood in the stool that may not be seen) and a colonoscopy.
  • Clinical History & Examination: The clinician will conduct a clinical history for symptoms such as changes in bowel habits, abdominal pain and discomfort, recent history of unexplained weight loss and fatigue. The physical examination will include an abdomen examination, to look for swelling and pain, and a digital rectal examination using a finger of a gloved hand to examine the interior of the anus and the rectum.
  • Routine blood tests: These include complete blood count, liver function and kidney function tests. These tests often provide signs of colorectal cancer and spread of the cancer to other organs.
  • Endoscopy: A thin tube with a camera is inserted through the anus into the large intestine to inspect the bowel for abnormal growths and/or to perform a biopsy for histopathological examination by the pathologist. There are various terms used by the clinicians for different types of endoscopy based on what part of the intestine is examined: rectum only (rectoscopy), lowest part of the large intestine, above the rectum (sigmoidoscopy) and the entire large intestine (colonoscopy). During your endoscopy, the doctor may also take tissue samples for biopsy. A pathologist examines this sample from a biopsy under a microscope to confirm the diagnosis of colorectal cancer and reveal specific characteristics of the tumour.
  • Radiological Test: Barium enema - This test involves the use of barium sulphate to visualize an outline of the wall of the colon and rectum. Computed Tomography (CT) - Using a CT colonography, a 3-dimensional image of the interior wall of the large intestine is formed. It is useful when a colonoscopy is difficult. A CT of the chest and the abdomen may be performed to detect the metastatic spread of the tumour. Ultrasound - An ultrasound is used to search for the spread of cancer, especially to the liver, or for fluid in the abdomen. Magnetic resonance imaging (MRI)- An MRI is useful to detect or confirm the presence of metastases (spread of cancer) as well as staging of the colorectal cancer. Positron emission tomography (PET)- It is performed to detect metastases (spread of cancer in the body).
  • Carcinoembryonic antigen (CEA): CEA is a protein found in many types of cells. CEA can be tested through a blood test. CEA is also known as a tumour marker because it may be useful in some situations when the cancer cells produce the CEA. CEA testing is useful for evaluation of prognosis and follow-up after treatment.
  • Molecular profiling: This are tests that study the entire set of genes or analyse the tumour for chemicals released by a particular gene. These are sometimes used to tailor the chemotherapy to improve the response. that one may hear include RAS mutations, BRAF mutation, MLH1 mutation, chromosomal instability and microsatellite instability etc.


The management of cancer depends on various factors, including the stage of the cancer, additional health issues, age etc. Surgery, radiation or chemotherapy may be used.

  • Surgery: The surgeon aims to remove the primary tumour and, in advanced cases, to remove metastatic lesions. The type of surgery performed depends on how advanced the cancer is. It may be Simple excision (tumour is removed from the inner layer of the bowel wall), polypectomy (if the cancer develops from a polyp, the entire polyp is removed), segmental resection (a section of bowel is surgically removed, and the two cut ends are reconnected). Depending on the section removed the surgeries are named differently: ascending colon removed (right hemicolectomy), descending colon removed (left hemicolectomy), sigmoid colon removed (sigmoid resection), right and left hemicolectomy extended to the transverse colon (extended hemicolectomy). Anastomosis is the procedure which connects the two cut ends of the bowel after resection.
  • In certain patients, a temporary outlet directly to the abdomen (bypassing the rectum and anus) may need to be created called a stoma. If it involves the small intestine, it is called ileostomy, and a stoma procedure of the large intestine is called colostomy. In some cancer the surgeon may put a stent (tube) if the cancer is obstructing the colon. Minimally invasive procedures are used in early-stage disease such as Endoscopic mucosal resection (removal of polyps along with the inner lining of the colon removed during colonoscopy). Laparoscopic surgery can be indicated for polyps that can't be removed during a colonoscopy using a key-hole size excision and inserting cameras in the abdomen along with surgical instruments.
  • In rectal cancer, the entire rectum, along with the lymph node associated with it is removed. This procedure is called total mesorectal excision. Side effects: Adverse events of surgery may include intestinal symptoms (such as pain, diarrhoea, constipation and nausea), intestinal obstruction (a surgical emergency in which the intestine is blocked and the obstruction need to relieved immediately).
  • Chemotherapy: Chemotherapy is given orally or through a vein and kills the cancer cells systemically. Various agents may be used and can be given as single therapy (monotherapy), or in combination with other drugs (combination therapy). Side effects: The most frequent side effects experienced with chemotherapy include anaemia, bleeding, bruising, infections, fatigue, nausea or vomiting, diarrhoea, mouth ulcers, reddening of the palms and soles, skin rashes, muscle cramps, abdominal pain etc.
  • Radiotherapy: Radiotherapy destroys tumour cells using ionizing irradiation and may be used alone or in combination with chemotherapy, especially prior to surgery or post-surgery in selected patients. Radiotherapy may be external source radiotherapy or internal radiation (brachytherapy), which involves injecting tiny microspheres or radioactive material into arteries that supply the tumour. Side effects: Adverse effects of radiotherapy may include rectal discomfort, diarrhea, mucus and blood in the stool, painful urination, blood in urine etc.
  • Targeted drug treatments: These agents block specific chemical pathways present in cancer cells. It is usually combined with chemotherapy and is typically reserved for people with advanced colon cancer. Side effects: The adverse effects depend on the agent used but common side effects include rashes, allergic reactions, headaches, fatigue, hypertension, diarrhoea etc.
  • Immunotherapy: Immunotherapy uses the body’s immune system to fight against cancer cells. Your body’s immune system may not attack cancer because the cancer cells produce proteins that blind the immune system cells from recognising cancer cells and prevent their destruction. Immunotherapy works by interfering with this process. It is usually reserved for patients with advanced colon cancer.
  • Proton beam therapy: This is one of the latest advances in colorectal cancer that may benefit young adults and patients with cancers close to critical organs. Proton Beam Therapy allows radiation oncologists to destroy cancer and spare healthy tissue.
  • Supportive (palliative) care: Palliative care focuses on providing relief for the patient and caregiver, especially from pain, anxiety and other symptoms. The key objective is to improve the quality of life for people with cancer and their families.

Sources: European Society for Medical Oncology (ESMO); Mayo Clinic

MULTI-DISCIPLINARY TEAM (MDT): Unlike most other diseases, cancer treatment requires an integrated approach from several specialists, each with their own expertise. This team of specialists who would work together on your cancer, is referred to as the Multi-Disciplinary Team (MDT). Many global organisations have recognized the importance of a MDT for cancer treatment, as it improves coordinated care to you, as a patient. Your MDT would include specialists from the following:

  • Gastroenterologists: Conduct procedures such as endoscopies (colonoscopy, sigmoidoscopy etc.)
  • Colon and rectal surgeons
  • Medical oncologists: Decide on the type of chemotherapy to be administered
  • Radiation oncologists: Specialists trained in administering radiotherapy
  • Radiologists: Conduct radiological diagnostic procedures such as ultrasounds, CT, MRI etc.
  • Pathologists: Conduct histopathological evaluations of the tumour sample or biopsy sample to offer details on the type of tumour
  • Palliative Care specialists
  • Nutritionists: To customise diets post-surgery
  • Stoma care specialists: To help care for patients post ileostomy or colostomy
  • Other specialists that are less often called upon may include medical geneticists (for genetic profiling of the tumour), general surgery, gynaecologic surgery or urologic surgery (in case of involvement of other organs).

Some hospitals that take an organ-based approach to cancer, have a separate department for Gastrointestinal Cancers. These teams comprise of specialists who have dedicated training in cancers of the digestive system.

TUMOR BOARD: A tumor board is a meeting where a Multi-Disciplinary Team discusses cancer cases and share knowledge. The board’s goal is to determine the best possible cancer treatment and care plan for an individual patient. Having fresh perspectives from other doctors makes it much easier to come up with that plan.

In some hospitals, all cancer cases are discussed at the Tumor Board, while in other hospitals the Tumor Board focuses on cases where a doctor seeks inputs from other specialists on the patient's case. It’s OK to ask your doctor if or why your case was discussed at a tumor board. Or if it wasn’t, why not? In some cases, a patient’s treatment plan is very straightforward using standard treatment guidelines, and the doctor may feel a tumor board review isn’t needed. However, you can request that one be done.

SUPPORT GROUPS: These are offline or online groups that connect patients suffering from cancer. Do find out about a support group around you. The hospital where you are being treated may have a support group that you could join.

Sources:  Mayo Clinic

Choosing your oncologist and hospital is a very important decision, we recommend you make the time to research your options. We profile doctors and hospitals based on their range of services to treat colorectal cancer. Use our search tools to find a suitable medical provider. You may call us for assistance to find a medical provider or make a booking.

If you’ve been diagnosed with cancer, you need to find an oncologist to begin your treatment. An oncologist is a doctor who specializes in treating cancer. For colorectal cancer, you can start by visiting a surgical oncologist, a gastrointestinal surgical oncologist or a medical oncologist. Choose someone you are not only confident about but also comfortable with.


  1. Look for Specialists: Look for doctors who treat your specific type of cancer - colorectal cancer or digestive tract cancers. You may need to work with more than one type of oncologists – surgical, medical or radiation oncologists.
  2. Gather Feedback: Discuss with friends and family, especially those who’ve taken similar treatment before. Online communities are a quick way to get feedback from others who’ve experienced your type of cancer before.
  3. Check the doctor’s credentials: Find out if the doctor has received any advanced training. There may be super-specialists available for gastrointestinal cancers, who have received special training on treating colorectal If doctor’s credentials are not available easily, you have the right to ask for it from the doctor directly.
  4. Review doctor’s experience: Check how long the doctor has been practicing after completion of formal oncology education. How many patients with your type of cancer – colorectal cancer – does the doctor see every year? In case of surgeons, studies have proven that higher volumes of surgeries lead to better outcomes. Organ-specific surgeons are also available in some hospitals, they have advance training and experience in operating cancers in specific organs.
  5. Find out hospital affiliations: Which hospitals does the doctor practice in? The availability of a multiple types of doctors at the hospital where you get treated is important. Find out what support staff is available at the hospital e.g. dietitian, counselor, stoma care, home healthcare facilities etc.


  1. Lookout for hospitals with lot of experts: Look for hospitals that offer a multi-disciplinary approach to gastrointestinal cancer treatment. This means each you receive inputs from many cancer experts. You will be helped by specialists including surgeons, medical oncologists, radiation oncologists, stoma care nurses, oncology nurses and other supporting staff. Find out if the hospital has surgeons with dedicated training for gastrointestinal cancers? Does the hospital have Tumor Board reviews – how often are they conducted and will your case be discussed there if you wish?
  2. Work with a major cancer hospital, even if it is far: Most experts in high-volume centers are willing to work with your local doctors. Usually, part of the treatment (for example, surgery) can be executed in the major center and the post-surgery treatment is executed locally.
  3. Research hospital’s Gastrointestinal Cancer volumes: How many cases of gastrointestinal cancer are treated in the hospital every year? High volume centers with multiple specialists available for gastrointestinal cancers may have better expertise and specialized medical infrastructure required.
  4. Consider Clinical Trials Availability: Ask whether the doctor or hospital has access to clinical trials and if you are eligible for any. Clinical trials are research studies that test new ways to treat cancer that you can be involved with. By being involved, you can help improve treatments and outcomes for future patients.
  5. Insurance Acceptance: Check if the hospital accepts your insurance. Check if the hospital has a desk that can assist you with claims.

Sources: Rogel Cancer Center; Cancer.Net

Section: Cancer Basics

How do Cancer cells behave differently from healthy ones?

Source: TEDed

Understanding Colorectal Cancer

Source: Nucleus Medical Media

Types of Colorectal cancers and Stages


Section: Tests for Colorectal Cancer

Screening Tests: Digital Rectal Exam, Blood test, Colonoscopy

Source: Mechanisms in Medicine

Barium Enema Test

Source: Nucleus Medical Media

CT Scan

Source: Nucleus Medical Media

What is a colonoscopy and how do I prepare for it?

Source: You and Colonoscopy

Colonoscopy Procedure

Source: MD Anderson Cancer Center

Colonoscopy and Biopsy

Source: Nucleus Medical Media

Flexible Sigmoidoscopy

Source: American Cancer Society

Tracking Cancer with Blood Tests

Source: Cancer Research UK


Source: Blausen Medical

Section: Treatments for Colorectal Cancer

Colon Resection Surgery

Source: Nucleus Medical Media

Colorectal Cancer Surgery - Laparoscopic Procedure

Source: Amerra Medical

Ileostomy Surgery and Stoma Care

Source: Animated IBD Patient

Caring for a Stoma

Source: Macmillan Cancer Support


Source: Nucleus Medical Media

Targeted Cancer Cell Therapy

Source: Nucleus Medical Media

Radiation Therapy: What to Expect

Source: Accelerated Education Program

Cancer Radiotherapy

Source: Cancer Research UK

Radiation Sickness

Source: Blausen Medical

What is Palliative Care

Source: Get Palliative Care

What are Clinical Trials

Source: Cancer Research UK

Section: Useful Resources

Downloadable Guide for Colon Cancer by NCCN

Downloadable Guide for Rectal Cancer by NCCN