Colon cancer

Colon cancer often does not present symptoms, making regular screening essential for early diagnosis. If symptoms persist, they may include:

• Abdominal pain
• Body aches
• Cramps
• Diarrhea
• Constipation
• Feeling of incomplete evacuation
• Unexplained weight loss
• Rectal bleeding or blood in the stools
• Tiredness or fatigue

The presence of these symptoms alone does not confirm cancer. It is important to consult a doctor if you are experiencing any of these symptoms.

Here are some common signs and symptoms of cancer you need to know. Click To Know!

Every cell of the body follows a process of growth, division, and death. Cancer develops when cells multiply uncontrollably without dying. The exact cause of the abnormal multiplication of cells in the colon and rectum is not known. One potential reason is changes in the DNA that affect oncogenes—genes that help the cell to survive. Disturbance in the oncogenes predisposes an individual to colon cancer.

Colorectal cancer typically begins as precancerous polyps, which can slowly develop into cancerous tissue. Early diagnosis at the precancerous stage can prevent the progression to cancer.

Read about the common causes of colorectal cancer. Tap to read!

There are various risk factors that are associated with an increased chance of colon cancer:

Non-modifiable factors

1. Age
   The chances of precancerous polyps and colon cancer increase with age. The average age at which colon cancer is diagnosed is 68 years for men and 72 years for women. Individuals over the age of 65 have three times the risk of developing colon cancer compared to those aged 50 to 64 years. However, younger adults can also develop colon cancer.
2. Gender and race
   Studies suggest that men have a 30 times higher risk of developing colon cancer than women. The mortality rate from colon cancer is also higher in men. Race plays a role, with non-Hispanic blacks at a higher risk than Asians and non-Hispanic whites.
3. Medical history of cancer
   Individuals with a previous history of colon cancer or polyps are at greater risk. Larger polyps increase the likelihood of developing colon cancer.
4. Health conditions
   Certain health conditions increase the chances of colon cancer, including:
   • Inflammatory bowel diseases (IBDs): These conditions cause inflammation in the gut, including ulcerative colitis and Crohn’s disease. Individuals diagnosed with IBDs have a 2-6 times higher risk of colon cancer, especially if the disease is severe and prolonged.
   • Colon polyps: Approximately 95% of colorectal cancer develops from polyps, which are tissue growths from the lining of the colon. The risk increases with larger polyp size and patient age.
   • Diabetes mellitus: Diabetes can induce chronic inflammation, potentially triggering the growth of cancer cells in the colon.
   • Cholecystectomy: The surgical removal of the gallbladder can lead to continuous bile acid flow, which may damage colon cells and predispose individuals to colon cancer.
5. Genetic conditions
   The two most significant genetic disorders related to colon cancer are:
   • Nonpolyposis colorectal cancer (NPCC): Also known as Lynch syndrome, this inherited condition involves a gene abnormality that impairs DNA repair.
   • Familial adenomatous polyposis (FAP): This rare inherited disorder can lead to the development of thousands of polyps in the colon, with untreated individuals at risk of colon cancer by age 35-40.
   Other genetic conditions include:
   • Gardner syndrome (a variant of FAP)
   • Juvenile polyposis syndrome
   • Muir-Torre syndrome (a variant of Lynch syndrome)
   • MUTYH-associated polyposis
   • Peutz-Jeghers syndrome
   • Turcot syndrome (another variant)
6. Family history
   Individuals with first-degree relatives (parents, siblings, and children) diagnosed with colon cancer have twice the risk of developing it. The risk is further increased if relatives were diagnosed before age 60. Factors influencing risk include:
   • Generational distance from the affected relative
   • The age at which the relative developed colon cancer
   • The number of affected family members
   • Diagnosis of other cancers (ovarian, pancreatic, endometrial, and urinary tract) in the family

Modifiable or lifestyle factors

1. Unhealthy diet
   Diet plays a crucial role in maintaining colon health. Excessive consumption of saturated fats, red meat, and processed meat increases the risk of colon cancer. A diet low in fiber, fruits, vegetables, calcium, and Vitamin D also contributes to the development of colon cancer.
2. Alcohol
   Excessive alcohol consumption raises the risk of colon cancer. Studies suggest a 20% increase in risk for individuals consuming 2-3 drinks daily, with further increases for those consuming 4 or more drinks per day.
3. Smoking
   Smokers have a 2 to 3 fold increased risk of developing colon cancer compared to non-smokers. The risk escalates with the dose and duration of tobacco exposure.
4. Sedentary lifestyle
   A lack of physical activity is closely linked to colon cancer. Regular exercise improves immunity, reduces inflammation and stress, regulates metabolic rates and hormone levels, and helps prevent obesity, potentially protecting against cancer development.
5. Being overweight/obese
   Obesity is a known risk factor for colon cancer. Overweight and obese individuals have a 50% and 20% greater risk of developing colorectal cancer compared to those with normal weight, respectively.
6. Gut microbiota
   The gut microbiota, which includes diverse microorganisms in the gastrointestinal tract, plays a key role in metabolizing toxins, synthesizing vitamins, and defending against infections. Changes in the composition and functionality of gut microbiota may lead to the initiation, promotion, and progression of colon cancer.

Note: Radiation therapy that focuses on the abdomen may also increase the risk of colon cancer.

The colon cancer develops gradually in the following stages:

• Stage 0 (cancer in situ): The cancer cells are limited to the inner lining of the colon.
• Stage I: The cancer cells start attacking the muscular layer of the colon or rectum.
• Stage II A: The tumor starts growing into the outermost layers of the colon or rectum.
• Stage II B: The tumor starts growing into the innermost layers of the colon or rectum.
• Stage II C: The tumor starts spreading to the nearby tissues.
• Stage III A: The tumor starts growing into the muscular layers of the intestine and starts invading the nearby 1-3 lymph nodes.
• Stage III B: The tumor starts growing into the bowel wall or to surrounding organs and 1-3 lymph nodes.
• Stage III C: The cancer has spread to 4 or more lymph nodes.
• Stage IV A: The cancer has spread to one distant part of the body such as the lungs and liver.
• Stage IV B: The cancer has spread to more than one distant part of the body.
• Stage IV C: The cancer has spread to the lining of the abdominal cavity.

The screening tests for colon cancer are recommended for all individuals aged between 45-75 years. Individuals who have higher risks or are older than 75 years should consult their doctor about their screening. The type of screening tests used usually depends on:

• Preferences of the patient
• Medical condition of the patient
• Personal or family history of colorectal cancer
• Resources available

The common screening tests include:

• A. Stool-based tests: These tests examine the stool for any signs of colon cancer. They are easier than colonoscopy because patients can perform them at home. However, colonoscopy is recommended if stool-based tests are positive. This includes:
• 1. Fecal immunochemical test (FIT): This test detects hidden blood in the stool using antibodies. The stool is collected at home using a kit provided by your healthcare provider.
• 2. Guaiac-based fecal occult blood test (gFOBT): This test uses a chemical known as guaiac to detect blood in the stool. The sample is collected at home using a home kit, which is then evaluated in the lab. gFOBT test results are affected by diet and some drugs. Therefore, individuals going for this test are advised to avoid the following:
• NSAIDs such as ibuprofen and aspirin 7 days before testing as they can give false-positive results due to their bleeding tendencies.
• Vitamin C from citrus fruits or supplements 3-7 days before testing as it can interfere with the chemical used in the test.
• Red meat, as it can give false-positive results.
• 3. FIT-DNA test: Also known as stool DNA test or multitarget stool DNA (MT-sDNA) test, this test combines the FIT test along with a test that detects abnormal DNA in the stool. Colon cancer or polyp cells have DNA mutations in certain cells. This test detects these mutations along with hidden blood in the stool.
• B. Colonoscopy: This test uses a long, thin, and flexible tube with a camera on its end to check for polyps and cancer in the rectum and colon. During colonoscopy, abnormal tissues can also be removed. This examination requires bowel cleansing before the test. It is recommended to be done once every 10 years for individuals without risk factors.
• C. Flexible sigmoidoscopy: This test detects polyps and cancer in the rectum and sigmoid colon using a sigmoidoscope. A sigmoidoscope is a short tube with a camera and tool attached to it. The tool is used to remove polyps and abnormal tissues. Special preparations, such as cleansing of the rectum and colon, are required before the test.
• D. CT colonography (virtual colonoscopy): This test captures images of the entire colon using X-rays. The images are then studied by a doctor using a computer screen. Colonoscopy is usually performed to remove polyps after CT colonography if it confirms the presence of polyps or cancer.
• E. Biopsy: In a biopsy, a small amount of tissue is studied under a microscope. The tissue can be collected either through colonoscopy or surgery. Sometimes, the tissue is taken using needle biopsy, which collects the tissue through the skin with the help of a needle. A CT scan or ultrasound helps to locate the tumor.
• F. Biomarker testing: This test is used to detect certain genes, proteins, and other factors that are highly specific to the tumor. The test is performed on a tumor sample taken from a biopsy.
• G. Blood test: People with colon cancer often become anemic due to continuous bleeding in the rectum and colon. A complete blood count test indicates the status of red blood cells (RBCs) in the blood, aiding in the detection of anemia. Blood tests are also used to detect the level of carcinoembryonic antigen (CEA), a protein that indicates the spread of the tumor to other parts of the body. However, it is not highly specific to cancer, so it is mostly used in patients who are already undergoing treatment to track progress.
• H. Magnetic resonance imaging (MRI): MRI uses a magnetic field to produce detailed images of the body with the help of a dye, which provides a clear picture of the organs. It is used to measure tumor size and track the location of colon cancer.
• I. Ultrasound: Ultrasound uses sound waves to produce detailed images of internal organs. It is used to find the locations where a tumor has spread. Endorectal ultrasound is most commonly used to detect how deep colon cancer has spread.
• J. Chest X-rays: X-rays of the chest are used to detect whether colon cancer has spread to the lungs.

Apart from these diagnostic tests, some methods can help identify whether one has the cancer-causing gene. Read more about inherited cancers and the role of genetic cancer tests.

There is no sure way to prevent colon cancer. However, some measures can decrease the risk of developing colon cancer:

• Go for regular screening: Most colon cancer develops from precancerous polyps with no symptoms. The most effective way to prevent colon cancer is through regular screening, starting at 45 years of age. This helps in the detection and removal of polyps in their initial stage before they turn into cancer.
• Eat a healthy diet: A diet low in saturated and trans fats, high in fiber from fruits, vegetables, and whole grains, and rich in calcium and Vitamin D is associated with a decreased risk of colon cancer. Diets that include red meat (beef, pork, or lamb) and processed meat increase the risk of colon cancer. Avoiding such foods can help in prevention.
• Consult a doctor before taking NSAIDs: Consult your healthcare provider before starting certain medications such as NSAIDs, as they can cause side effects like gastrointestinal bleeding and ulcers. However, some studies suggest that medications such as ibuprofen, naproxen, and aspirin may decrease the risk of colon cancer.
• Maintain a healthy body weight: Overweight and obesity are linked to colon cancer. Maintaining a healthy weight through physical activity, exercise, and a good diet helps in prevention.
• Quit alcohol and smoking: Long-term use of alcohol and smoking is associated with an increased risk of various cancers. Quitting both can help in the prevention of colon cancer as well as other types of cancers such as lung and mouth cancer.
• Increase the intake of vitamins and minerals: Some studies suggest that vitamins and minerals such as folic acid, Vitamin D, calcium, and magnesium may decrease the chances of colon cancer. One can prevent colon cancer by consuming foods rich in these nutrients, such as milk, cheese, and eggs.

There are various treatment options for colon cancer which are given considering the risk factors, stage of colon cancer, side effects, and age of the patient. The treatment options include:

1. Surgery

It includes removal of cancer through an operation. It is one of the most commonly used methods in all the stages of colon cancer. It can be performed in either of the two ways:

• Local excision: In this, the tumor is removed through a tube inserted in the colon with a cutting tool at its end. It is mostly used in the early stages of cancer.
• Resection of colon: In this, a part of the colon is also removed along with the cancer. It is used when the tumor is large.

2. Ablation technique

This technique is used to kill small tumors which are usually less than 4 cm in size. Ablation technique includes:

• Radiofrequency ablation: In this, the tumor is killed by a needle inserted through the skin. The needle is guided by a CT scan or ultrasound. The technique uses radio waves to kill the cancer cells.
• Microwave ablation: This technique uses electromagnetic waves that create a high temperature in the body. The high temperature kills cancer cells. This treatment is usually used to kill large tumors (up to 6 cm).
• Ethanol (alcohol) ablation: Also known as percutaneous ethanol injection (PEI). In this procedure, concentrated alcohol is injected into the tumor using a needle, guided through an ultrasound or CT scan. In some cases, multiple exposures of alcohol are required to kill cancer cells.
• Cryoablation (cryosurgery or cryotherapy): This technique uses a probe to freeze and kill cancer cells. The probe is guided into the skin using ultrasound with a needle.

3. Chemotherapy

Chemotherapy involves the use of anticancer drugs to kill cancer cells. They are available in the form of oral formulations and injections. Injections can be given directly into the vein over a few minutes or as an infusion over a long period of time. The medicines used to treat colon cancer include:

• 5-Fluorouracil (5FU)
• Leucovorin
• Oxaliplatin
• Capecitabine
• Irinotecan
• Cetuximab
• Panitumumab
• Regorafenib

These drugs are either used alone or in combinations. Chemotherapy is given in cycles that are often 2 to 3 weeks long. The duration of chemotherapy depends upon the type of drugs used and the side effects. The way in which chemotherapy is given depends upon the overall health of the patient and the stage of cancer.

How is chemotherapy given?

• Systemic chemotherapy: In this, the medicines are taken through the mouth or injected into the bloodstream. The drug reaches the tumor site through the blood and kills cancer cells.
• Regional chemotherapy: Drugs are directly injected into the artery that has access to the tumor site. This helps in reducing the side effects. One such example of regional chemotherapy is hepatic artery infusion in which a drug is directly injected into the hepatic artery. This is used in conditions where cancer has spread to the liver.

How chemotherapy is used in the entire course of colon cancer?

• Adjuvant chemotherapy: It is given after surgery to kill small cancer cells that might have been left behind. It reduces the chances of relapse of cancer after surgery.
• Neoadjuvant chemotherapy: This is given before radiation therapy to reduce the size of the tumor, making it easier to remove the tumor through radiation.

What are the side effects of chemotherapy?

The side effects of chemotherapy depend upon:

• Type of drug
• Dose of drug
• Duration of therapy

Some of the common side effects include:

• Hair loss
• Mouth ulcers
• Loss of appetite or weight loss
• Nausea and vomiting
• Diarrhea
• Nail changes
• Skin changes
• Hand-foot syndrome
• Neuropathy
• Tiredness
• Easy bleeding
• Allergic reactions

It is important to discuss the side effects with your cancer team so that the right treatment can be given timely.

4. Radiation therapy

It involves the use of high-energy rays such as X-rays to kill cancer cells. It can be used before, during, and after surgery. In various cases, it is given along with chemotherapy (chemoradiation). In advanced stages, when colon cancer has spread to other organs such as lungs, brain, and bones, radiotherapy is useful. It can be given in two ways:

• External beam radiation therapy (EBRT): EBRT is the most commonly used radiation therapy for colon cancer. In this, intense radiation is given from outside the body using a machine. This technique is used if there are a small number of tumors where surgery is contraindicated.
• Internal radiation therapy: In this, a radioactive substance is placed in the rectum near cancer cells. This helps in specific exposure of the radiation to the targeted site. This therapy has lesser side effects.

Radiation therapy can have some short and long-term side effects such as:

• Skin irritation
• Nausea
• Rectal irritation
• Bowel incontinence
• Bladder irritation
• Tiredness
• Sexual problems

5. Targeted therapy

This therapy involves the use of drugs to identify and kill specific cancer cells, resulting in fewer side effects than chemotherapy and radiation therapy. Various drugs used in targeted therapy include:

• Monoclonal antibodies: These are specialized proteins that can attach to cancer cells and inhibit their growth. They are given by infusion. Monoclonal antibodies can be:
• Vascular endothelial growth factor (VEGF) inhibitors: They kill cancer cells by inhibiting VEGF, a substance that helps in the formation of new blood vessels and aids in the growth of cancer. Examples include bevacizumab and ramucirumab.
• Epidermal growth factor receptor (EGFR) inhibitors: This class of monoclonal antibodies stops the growth of tumor cells by inhibiting EGFR, a protein that helps in the growth and multiplication of cancer cells. Examples include cetuximab and panitumumab.
• Angiogenesis inhibitors: This class inhibits the formation of new blood vessels that cancer cells require to grow and multiply. Examples include Ziv-aflibercept and regorafenib.
• Protein kinase inhibitors: They block special proteins needed for the multiplication of cancer cells. Encorafenib is one such drug used in colon cancer.

6. Immunotherapy

This therapy involves the use of drugs that modulate the immune system. Drugs given during immunotherapy boost the immune system of the patient, helping in the fight against cancer cells. It is mostly used in advanced stages of colon cancer. Common examples include ipilimumab, pembrolizumab, and nivolumab.

Cancer affects individuals physically, socially, emotionally, and financially. There are certain changes in the life of the patient that impact both the individual and their family. Medications should be taken as prescribed by a doctor. Several foods are known to boost immunity and help in fighting cancer cells; however, these should be used after consulting with a doctor. These include:

• Green tea: It contains antioxidants that help boost immunity. Caffeine-free products should be used. Green tea is contraindicated in certain individuals, such as those suffering from glaucoma. It should always be initiated after consulting your doctor.
• Reishi mushroom: Known for its cancer-fighting properties and immune-boosting effects.
• Turmeric (Haldi): Exhibits anti-cancer and anti-inflammatory properties. Curcumin present in turmeric aids in the prevention of colon cancer and helps in killing cancer cells.
• Probiotics: Since microbiota plays a crucial role in the progression of colon cancer, probiotics can be utilized for prevention or as adjuvant therapy in colon cancer treatment. Probiotics such as Lactobacillus, Streptococcus, Enterococcus, Lactococcus, Bifidobacterium, and Leuconostoc are essential for maintaining colon health. Individuals who consume yogurt have a lower risk of developing colon cancer.
• Polyphenols: Found in various plants, polyphenols possess anti-cancer properties. Many foods contain polyphenols, including cereals and legumes (barley, corn, nuts, oats, rice, sorghum, wheat, beans, and pulses), oilseeds (rapeseed, canola, flaxseed, and olive seeds), fruits and vegetables, and beverages (fruit juices, tea, and coffee). They also possess antioxidant properties, thus reducing the risk of colon cancer.

Ways to take care of yourself:

• Spend at least 15-30 minutes each day doing something you enjoy, such as going for a walk, practicing yoga, taking a nap, watching a movie, or talking with friends.
• Understand your feelings and emotions to better comprehend your needs.
• Join a support group, either in person, via phone, or online.
• Learn more about the types, stages, and treatments of cancer to be more aware of your condition and mentally prepared.
• Connect with a cancer survivor to boost your confidence and spread positivity to aid in your recovery.
• Note at least one positive feeling or gesture that you received from a nurse, doctor, or co-patient.

Role of caregivers:

Caregivers play a vital role in the overall disease outcome of patients diagnosed with colon cancer. The need for caregiver support increases with the age of the patient, as older individuals may require more assistance in treatment approaches and decision-making. The important roles of caregivers include:

• Providing emotional support so that patients do not feel alone.
• Making decisions regarding disease management options.
• Participating in doctor appointments.
• Providing professional support, as they are trained in handling patients.
• Administering medications on time, changing dressings, assisting with bathing, and checking surgery sites.
• Helping with meal preparation.

Colon cancer, if diagnosed at an early stage, can be treated effectively. However, if treatment is delayed for an extended period, it can become life-threatening. It is essential to screen and diagnose any related symptoms or risk factors. The complications of colon cancer include:

• Iron deficiency anemia
• Jaundice
• Bowel obstruction
• Blockage of the colon
• Spreading of cancer to other tissues (metastasis)
• Relapse of cancer
• Development of a secondary tumor in the colon
• Perforation of the colon

Acupuncture

Acupuncture helps alleviate cancer-related symptoms such as nausea and vomiting, which are the most common side effects of chemotherapy. It also reduces pain, shortness of breath, and breathlessness. This therapy can be used after medical treatment or during chemotherapy and radiation therapy.

Mind-Body Therapies

Mind-body therapies include relaxation techniques, yoga, meditation, tai chi, and art therapies. These approaches have been shown to:

• Reduce nausea and vomiting
• Alleviate pain
• Minimize fatigue
• Reduce anxiety
• Improve insomnia
• Address depressive symptoms
• Enhance overall quality of life

These therapies are particularly beneficial for patients undergoing surgery, chemotherapy, and radiation therapy.

Every cancer therapy has numerous physical changes. It is important to discuss every change occurring in your body with your doctor. This helps doctors modulate your treatment regimen to alleviate symptoms. Continuous follow-up, even after the end of therapy, is recommended to track long-term effects and the potential relapse of cancer.

Managing the fear of side effects

Every cancer therapy has side effects that may vary depending on various factors. It is common to have fears regarding side effects. However, various options are available to manage these side effects effectively, including:

• Taking an active role in your treatment plan to understand possible side effects in advance.
• Discussing side effects with your doctor, which may help alleviate and prevent them.
• Maintaining a journal to document your experiences.
• Sharing your fears with loved ones to reduce anxiety.

Managing emotional and social effects

The diagnosis of cancer can have emotional and social effects on the patient, including stress, anxiety, depression, sadness, and feelings of helplessness. Some steps to manage your emotional health include:

• Engaging in activities you enjoy, such as crafting, painting, or singing.
• Exercising regularly to help reduce stress.
• Joining a support group, either online or offline.
• Seeking help from a professional counselor.
• Connecting with someone undergoing the same type of treatment.
• Listening to podcasts featuring survival stories of patients with colon cancer.

Managing the cost of cancer treatment

Cancer treatment can be very expensive, leading to anxiety and stress for patients and their families. This can be managed through:

• Understanding the cost of therapy in advance.
• Communicating any financial issues with the cancer care team, allowing doctors to explore affordable alternatives.
• Finding financial support resources through oncology social workers, nurses, doctors, or online.
• Seeking assistance from your health insurance providers.

Watching for recurrence

Follow-up care after the completion of treatment is essential to monitor for relapse, manage long-term side effects, and maintain overall health. The first five years after treatment are crucial for colon cancer. Follow-up care includes regular physical examinations, tests, and counseling. Cancer rehabilitation may also include:

• Physical therapy
• Emotional counseling
• Managing long-term pain
• Nutritional guidance