Colorectal Cancer

Introduction

Colorectal cancer occurs when healthy cells of the rectum or colon change and grow out of control. A tumour can either be benign or cancerous. A malignant, cancerous tumour can spread to other parts of the body. A benign tumour can grow but not spread. These changes can take many years to occur.
The changes can be caused by both genetic and environmental factors. However, if a person is born with an uncommon inherited syndrome, the changes may occur in months or even years.

Anatomy of the colon and rectum

The large intestine forms part of the body’s digestive tract (GI) or gastrointestinal system. The large intestine is made up of the colon and the rectum. They play a crucial role in the body’s ability to waste can be processed. The colon occupies the first 5-6 feet of the large intestine. The rectum covers the 6th inch, ending at the anus.

Colorectal Polyps

A polyp is a benign growth that can develop on the colon and rectum as people age. It is often the first sign of colorectal cancer. If not treated, a polyp could become a life-threatening form of cancer. Precancerous polyps that are not removed or found early can help prevent colorectal carcinoma.
Hyperplastic polyps can also form in the colon or rectum. They are not precancerous.
Different types of colorectal cancer
Colorectal carcinoma can start in the colon or the rectum. Colon cancer is a form of cancer that starts in the colon. Rectal Cancer is a form of cancer that starts in the rectum.
Adenocarcinoma is the most common type of cancer in colon and rectal cancers. It is a cancer of cells lining the inside of the colon and rectum.
Risk Factors
An average person at risk for colorectal carcinoma has a 5% chance of developing it. Most colorectal cancers, which are about 95 per cent, are considered sporadic. It means genetic changes occur by chance and cannot be passed on to children.
It is less common than 5% to develop colorectal cancers from inheritance. These are caused by gene mutations or changes that are passed down through the family. The cause of colorectal carcinoma is often unknown. The following factors can increase a person’s chance of developing colorectal carcinoma:
✔ Age. As we age, our risk of developing colorectal cancer rises. Most colorectal cancers are found in those over 50.
The average age of diagnosis for colon cancer is 68 for men and 72 for women.
Retinal Cancer is diagnosed at age 63 in both men and women. Colorectal cancer is a serious condition that affects older adults.
✔ Race. The highest rate of colorectal cancer, or sporadic, in America is found among Blacks. Blacks are also at the highest risk for cancer-related deaths from colorectal cancer.
✔ Gender. The risk of colorectal cancer in men is slightly higher than in women.
✔ A family history of colorectal carcinoma. A family member who has had colorectal carcinoma may have the same genetic mutation as their parents. It is especially true if family members have been diagnosed with colorectal carcinoma before age 60.
The risk of developing colorectal cancer is almost double for those with a history of the disease in their family. If a close relative has been diagnosed with colorectal cancer or the first-degree relative was diagnosed earlier in life, this increases the risk.
✔ Rarely inherited conditions. People whose families have certain rare inherited conditions are at greater risk for colorectal and other forms of cancer.
✔ Inflammatory bowel disorder (IBD). Chronic inflammation of the large intestine may occur in people with IBD, such as Crohn’s disease or ulcerative colitis. This can increase your risk of developing colorectal carcinoma. IBD is not the same as IBS, which does not increase your chance of developing colorectal carcinoma.
✔ Adenomatous polyps (adenomas). Although polyps aren’t cancerous, some adenomas may develop into colorectal carcinoma. A colonoscopy is a procedure that examines the colon with a light tube. After the patient has been sedated, many polyps can be removed completely. Polyp removal can prevent colorectal cancer.
✔ A personal history of certain types of cancer. Colorectal Cancer is more common in people with colorectal, ovarian, or uterine cancer diagnoses.
✔ Obesity and physical inactivity. An inactive lifestyle with a lot of sitting and no exercise is a risk factor for colorectal cancer.
✔ Food/diet. Research shows that eating more processed and red meats is associated with a higher risk of developing diseases.
✔ Smoking. Recent studies show that smokers are three times more likely to die of colorectal cancer than those who do not smoke.
Prevention
Different factors can cause different types of cancer. There is no way to prevent colorectal carcinoma. However, there are ways to reduce your chances.
Colorectal cancer can be prevented by having polyps removed during a colonoscopy.
These actions may lower your risk of developing colorectal carcinoma.
✔ Aspirin and non-steroidal anti-inflammatory drug (NSAIDs) Studies have shown that aspirin and other NSAIDs may help reduce the risk of developing polyps in patients with a history of either colorectal cancer or polyps.
Regular colorectal cancer screenings should not be replaced by aspirin and other NSAIDs.
✔ Supplements and food choices. A diet high in fruits and vegetables and low in red meat can help lower the risk of developing colorectal carcinoma.
Several studies also showed that those who take vitamin D and calcium supplements are less likely to develop colorectal cancer.

Screening for colorectal cancer

Regular screening is a good way to prevent colorectal carcinoma. It can detect polyps before they turn cancerous. For people at average risk, it is recommended that they start screening around age 45.
Colorectal cancer is not usually diagnosed until it is too late. It is important to discuss with your doctor the pros and cons of each screening test, as well as how often you should be tested.
The guidelines below recommend that people start colorectal screening sooner and have screenings more frequently if they have any risk factors for colorectal disease.
✔ Your personal history of colorectal or adenomatous cancer
✔ Strong family history of colorectal disease or polyps. This includes cancer or polyps in a second-degree relative younger than 60 years old or two relatives older than 60. A parent, sibling or child is a first-degree relative.
✔ An individual’s personal history of IBD
✔ Family history of any hereditary colorectal carcinoma syndrome such as FAP, Lynch syndrome or other syndromes
Below are the tests that can be used to screen for colorectal carcinoma.
✔ Colonoscopy: This allows the doctor to examine the entire colon and rectum while the patient is asleep. To look for cancerous polyps or other problems, a flexible, lighted tube called the colonoscope is inserted into both the rectum (and the entire colon).
✔ Computed colonography (CT) or CAT colonography: CT colonography, also known as virtual colonoscopy or CT colonography, is a screening technique that some centres have studied. People who are unable to have a standard colonoscopy may consider CT colonography.
✔ Sigmoidoscopy. A sigmoidoscopy is performed using a flexible, lighted tube inserted into the lower colon and rectum to check for cancerous polyps.
✔ Faecal occult test blood (FOBT) or faecal immunochemical test (FIT). A faecal-occult blood test can detect blood in stool or faeces, which could indicate cancer or polyps. If blood is detected in the faeces due to a positive test, it could be a sign of cancer, bleeding in the stomach or upper GI tract, or even eating rare meats or other foods.
✔ Double-contrast barium enema (DCBE). Patients unable to have a colonoscopy can use an enema containing barium. This helps the rectum and colon stand out on X-rays. The colon and rectum are then examined with a series of X-rays.
✔ DNA testing of stool. This test looks for signs of cancer by analysing stool samples. To determine if a patient should have a colonoscopy, DNA changes are used present in cancers and polyps.

Screening recommendations

Different organisations have different recommendations for colorectal screening. Below are two sets.
To help people at average risk of developing colorectal cancer, the American Society of Clinical Oncology has established guidelines for screening for this disease. These testing schedules should be followed by men and women with a high risk of developing colorectal cancer starting at 50.
These tests can detect cancerous polyps:
✔ Flexible sigmoidoscopy every five years, or every ten with FIT or FOBT every other year
✔ Colonoscopy once every ten years
✔ DCBE every five years
✔ Colonography by CT, as often and as recommended by your doctor
These tests are used to detect primary Cancer.
✔ Guaiac-based FOBT every year
✔ FIT every year
✔ Take a stool DNA test as often as your doctor recommends

Colorectal Cancer: Signs and Symptoms

Colorectal cancer patients may experience these symptoms:
✔ Constipation or diarrhoea (feeling that your bowel is not emptying).
✔ The stool may contain very dark or bright red blood.
✔ Stools that are narrower or smaller than normal
✔ Gas pains in the abdomen: frequent gas pains, bloating and fullness.
✔ Weight loss without any known reason
✔ Constant fatigue or tiredness
✔ Unexplained iron deficiency is a low level of red blood cells.
Talk to your doctor if these symptoms persist for more than a week or become more severe.
Colorectal cancer can develop in individuals younger than the recommended screening age or older people who have not had screenings. Anyone experiencing these symptoms should see a doctor immediately to determine if they need a colonoscopy.

Colorectal Cancer Treatment Options

Surgery

The surgeon removes the tumour and any surrounding healthy tissue during an operation. This is also known as surgical resection. It is the most popular treatment for colorectal carcinoma. It will also remove a portion of the healthy colon, rectum, and lymph nodes nearby.
A surgical oncologist is a doctor specialising in treating cancer by surgery. A colorectal surgeon is a doctor trained to treat rectum, colon and anus diseases.
There are many surgical options available for colorectal carcinoma, including resection.
✔ Laparoscopic surgery. While the patient is still under anaesthesia, this technique inserts several viewing scopes into his abdomen. These incisions are usually smaller and require a shorter recovery time than traditional colon surgery.
✔ Colostomy to treat rectal Cancer: This is a surgical opening or stoma through which the colon connects to the abdominal surface to allow waste to escape the body. The colostomy may only be temporary in order to allow the rectum time to heal. However, it could become permanent.
✔ Radiofrequency ablation (RFA) or cryoablation. Some patients will need surgery to remove cancerous growths from the liver and lungs. Radiation frequency waves are used to heat or freeze tumours.

Radiation therapy

Radiation therapy uses high-energy X-rays to kill cancer cells. Radiation therapy is often used to treat rectal cancer, as this tumour tends to recur close to where it was originally found. Radiation oncologists are doctors who specialise in radiation therapy to treat tumours.
Radiation therapy schedules usually consist of several treatments over a specified period.
External beam radiation therapy. External beam radiation therapy uses a machine that delivers x-rays directly to the cancer site. Radiation therapy is generally given five days per week over several weeks.
Stereotactic radiation therapy. Stereotactic radiation therapy can be used to treat cancer that has spread to the liver and lungs. This radiation therapy uses a high radiation dose to treat a specific area. This technique can save liver tissue and lung tissue from being removed in surgery.
There are other types of radiation therapy. Some people may benefit from specialised radiation therapy, such as intraoperative radiation treatment or brachytherapy. It can help to eliminate small areas of cancer that cannot be treated with surgery.
✔ Intraoperative radiation therapy. Intraoperative radiation therapy is a single, high-dose radiation therapy used during surgery.
✔ Brachytherapy. The body is exposed to radioactive seeds. Although limited information is available on the practicality of this method, some studies have shown that it can slow down the growth and spread of cancer cells.
Radiation therapy for rectal carcinoma. Radiation therapy for rectal cancer (also called Neoadjuvant Therapy) may be used before surgery to shrink the tumour, making it easier to remove.
It can also be used to kill any remaining cancer cells after surgery. Both methods have been successful in treating this condition. To increase the effectiveness of radiation therapy, chemotherapy is often combined with radiation therapy (chemoradiation therapy).
Rectal Cancer is treated with chemotherapy before surgery. This helps to prevent colostomy and reduce the risk of recurrence. This treatment had many benefits, including a lower incidence of cancer returning to the original site, fewer patients needing permanent colostomies and less scarring in the bowel.
A newer treatment for rectal cancer is being developed and used by certain individuals. This is known as total neoadjuvant treatment (or TNT). TNT is a combination of chemotherapy and radiation therapy that lasts approximately six months before surgery.

Treatments with medication

To destroy cancer cells, medication is used. Medication may be administered through the bloodstream to reach all cancer cells in the body. This is known as systemic therapy. Local medication delivery may be possible if the medication is directly applied to cancer or is kept in one body part.
A medical oncologist is a specialist in treating cancer with medication and will usually prescribe this type of medication.
Many medications are administered intravenously (IV) using a tube inserted into a vein with a needle or in pill or capsule form. Ask your healthcare team about how to store and handle oral medications safely.
Many medications are used to treat colorectal carcinoma.
✔ Chemotherapy
✔ Targeted therapy
✔ Immunotherapy
One type of medication can be given at a time, or all three. They may also be part of a treatment that includes radiation therapy and surgery.
Chemotherapy
Chemotherapy is a treatment that uses drugs to kill cancer cells. It usually works by stopping them from growing, dividing and multiplying.
A chemotherapy schedule is a list of prescribed cycles repeated over a specified period. One drug may be given at a time or multiple drugs at once.
To eliminate any remaining cancer cells, chemotherapy may be administered after surgery. Some people with rectal cancer will undergo chemotherapy and radiation before surgery. This is to shrink the tumour size and reduce the likelihood of it returning.

Targeted therapy

Targeted therapy refers to a treatment that targets specific genes, proteins or tissue environments that are associated with cancer growth and survival. This treatment prevents the spread and growth of cancer cells and limits damage to healthy cells.
Different types of tumours may have different targets. Your doctor may perform tests to determine the genes, proteins, or other factors that make your tumours grow. This will help you choose the best treatment. This allows doctors to match patients with the best treatment possible.
Targeted therapies can be beneficial for older patients, as well as those who are younger. Studies have proven this. Both older and younger patients can usually handle side effects.
The following targeted therapies might be an option for colorectal carcinoma.
– Anti-angiogenesis therapy. It aims to stop angiogenesis, the process of creating new blood vessels. Anti-angiogenesis therapies are designed to “starve” cancer cells.
– Epidermal Growth Factor receptor (EGFR) inhibitors. Researchers discovered that drugs that block EGFR might effectively slow or stop the growth of colorectal carcinoma.
– Combination targeted therapies. A specific mutation known as BRAF V600E is found in some cancers. An FDA-approved test can detect it. This mutation is treatable with a targeted treatment called BRAF inhibitors.

Immunotherapy
The body’s natural defences are boosted to combat cancer with immunotherapy (also known as biological therapy). It utilises materials from the body or laboratory to enhance, target, or restore immune system function.

Physical, emotional, and social effects of cancer

Cancer treatment can cause side effects and physical symptoms as well as emotional, financial, and social effects. Palliative or supportive care is a way to manage all these effects.
Palliative care is about improving your quality of life during cancer treatment. It helps you manage symptoms and supports patients and their families with non-medical needs. This care is available to anyone, regardless of age, stage or type of cancer. It is often best to start this care right after a cancer diagnosis. Palliative and cancer treatment often results in less severe symptoms, a better quality of life, and more satisfaction with the treatment.
Palliative therapies can include medication, nutritional changes, and relaxation techniques. They may also include emotional and spiritual support. Palliative treatments may be similar to the ones used to eradicate cancer, such as surgery, chemotherapy, and radiation therapy.