In a human body, the colon is a part of the large intestine which belongs to your digestive system. The primary function of the colon is to reabsorb fluids and process waste products to prepare them for the elimination from the body. Since colon plays an important role in process of digestion and it works hard on a daily basis, this organ is prone to damage and diseases influenced by many factors.
Table of Contents [Hide]
- What is colon cancer?
- Colon and rectal (colorectal) cancer
- Colon cancer prevalence
- Causes of colon cancer
- Colon cancer risk factors
- Symptoms of colon cancer
- How is colon cancer diagnosed?
- Colon cancer stages
- Treatment options for colon cancer
- Coping with colon cancer
Colon cancer is the most severe disease affecting this organ, which is why it is important to get more insight into its causes, symptoms, and treatments. Throughout this post, you’re going to learn everything you should know about colon cancer and different ways to prevent it.
What is Colon Cancer?
Cancer occurs when some cells in the body begin to divide uncontrollably and spread into surrounding tissues. Colon cancer is defined as a cancer of large intestine, the final part of a human digestive tract. The disease usually starts with polyps in the intestinal wall.
Polyps are abnormal tissue growths that tend to look like small, flat bumps, or tiny mushroom-like stalks. Polyps mainly develop in colon, but they can also grow in other areas of the body. Over time, these polyps can evolve into colon cancers.
It is important to mention that other types of cancer such as lymphoma (cancer of the lymphatic system and affects the immune system), carcinoid tumors, melanoma (the most severe form of skin cancer), and sarcomas ( a tumor that affects connective tissues) can affect colon too. That being said, the post will focus on colon cancer itself, not other diseases that can spread to this part of your body.
Colon and Rectal (colorectal) Cancer
Chances are high you are more likely to come across the term colorectal cancer rather than colon cancer. Naturally, colorectal cancer refers to cancer that begins in colon or rectum. Depending on where the cancer stars it can be called either colon or rectum cancer. Since one name is widely used to refer to these diseases it is not uncommon for people to assume it’s the same disease.
Sure, colon and rectal cancers are similar but they do have their differences. Before we move on to causes, symptoms, and treatment options for colon cancer, it’s essential to clarify and discuss colon vs. rectal cancer.
Both colon and rectal cancer affect the large intestine, but they start in different places within it. In most cases, colon cancer can develop just about anywhere in the colon which is about five feet long. On the other hand, rectal cancers start in the rectum which accounts for the last five inches (12 centimeters) of your colon.
The International Journal of Colorectal Disease published a study which found that short-term mortality is higher for patients with colon cancer, particularly those who experience complications, than for their counterparts with rectal cancer. Due to similarities of symptoms associated with these two types of cancer, scientists usually focus on studying them both which explains why you are more likely to come across information for colorectal cancer.
Colon Cancer Prevalence
Colorectal cancers are more prevalent than you think. According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in the US men and women, right after skin cancers. Estimates show that 2017 will end with 95,520 new cases of colon cancer and 39,910 new cases of rectal cancer.
The same report also shows that colorectal cancer is the third leading cause of cancer-related death in the US women and the second leading cause of cancer-related death in men. It is expected that 2017 will end with a total of 50,260 deaths due to colon and rectal cancers.
On a global level, colon cancer is one of four most prevalent types of this severe disease including lung, breast, and prostate cancers. These four cancers account for four in 10 all cancers diagnosed on a global level.
What are the Causes of Colon Cancer?
Cancer is a consequence of the abnormal growth of cells in the affected tissue, but in many instances, the underlying cause is not clear. Colon cancer beings when healthy cells in a patient’s colon develop in their DNA.
In healthy people, these cells grow and divide in an orderly manner and their purpose is to ensure normal function of the entire body. However, when cell’s DNA is damaged it becomes cancerous and cells start dividing even when new cells aren’t necessary at that point. The accumulation of these cells creates tumors and, with time, they invade surrounding tissues where they form deposits or metastasis.
In many cases, colon cancer originates from noncancerous or benign tumors (the above-mentioned polyps) while in other instances, cancerous cells can spread from malignant tumors to other areas of the body through blood and lymph.
Speaking of polyps, the most common types include:
- Adenomas – Resembling the normal lining of the colon, but they look different under a microscope. Adenomas can become cancerous
- Hyperplastic polyps – Usually benign, colon cancer rarely develops from these polyps
Generally, if polyps aren’t removed during the early stages of the treatment, they can develop into cancer.
Some people have a genetic predisposition to colon cancer, but the inherited genes are associated with only a small percentage of colon cancers. Bear in mind that inherited gene mutations don’t make cancer inevitable, but they do increase* the risk of developing the severe disease.
The most prevalent types of inherited colon cancers are:
- FAP (familial adenomatous polyposis) – People with a classic type of FAP may begin developing multiple benign polyps in the colon in their teenage years. This type of cancer is indicated by the onset of hundreds of adenomatous polyps throughout the colon
- HNPCC(hereditary nonpolyposis colorectal cancer) – Also referred to as Lynch syndrome, it is a condition wherein the tendency to develop colon cancer is inherited while the term nonpolyposis means that colon cancer can occur when a small number of polyps is present, or no polyps are present at all
While it is clear that genes play a role and cancer can develop from polyps (or no polyps), the underlying cause that leads to these consequences is unknown. Colon cancer doesn’t have a single cause, but it is more likely that a combination of different risk factors contributes to the onset of this severe disease.
What are the Risk Factors of Colon Cancer?
Based on a wide prevalence of the disease, it’s easy to conclude that everyone can develop colon cancer. That being said, some people have a higher risk of developing cancer in their colon than others.
Understanding risk factors behind this health problem can help you minimize the likelihood of developing cancer and improve* your overall health and wellbeing. Below, you can see the most common risk factors that increase* your odds of getting colon cancer.
Advancing age is the number one risk factor for colon cancer. In fact, more than 90% of colon cancers are diagnosed in patients who are older than 50. Although the American Cancer Society’s report that increasing* number of younger individuals are developing colon cancer, their health problem is a result of other factors, not the age itself.
The risk of developing colon cancer varies significantly among different races. Generally, African-Americans are more likely to get this serious disease than other races. African-Americans are followed by Caucasians, Native Americans, Asian/Pacific Islanders, and Hispanics. Evidence shows that racial differences in colon cancer risk are due to sociodemographic and cultural factors. In terms of ethnical backgrounds, persons of eastern European descent have high chances of developing colon cancer.
Alcohol intake is strongly linked to a number of health conditions and colon cancer is one of them. The risk of developing colon cancer due to alcohol intake is directly related to the amount of alcohol you consume. People who drink 50 or more grams of alcohol a day (about 3.5 drinks) have 1.5 times the risk of developing colorectal cancer compared to occasional drinkers and nondrinkers.
Alcohol contributes to cancer in more ways such as:
- Breaking down or metabolizing ethanol from your drink to acetaldehyde, a toxic chemical, and a potential human carcinogen, acetaldehyde can damage proteins and DNA in your body
- Impairing the body’s ability to break down and absorb various nutrients such as vitamins A, C, D, E, and many others that are necessary for good health
- Generating free radicals which can damage proteins, DNA, and lipids through a process called oxidation
More than 25 million people older than 20 years of age are diagnosed with diabetes, a condition which occurs when blood glucose (sugar) is too high. People with diabetes and insulin resistance are at a higher risk of developing heart disease, stroke, nerve damage, eye problems, and colon cancer. Scientists theorize that abnormally high levels of insulin and blood glucose create an environment in the colon that promotes* the development and growth of cancer.
Since colon is a part of the digestive system it is impossible for diet not to play any role in colon cancer. The food you eat can either decrease* the risk of colon cancer or it can increase* it. A person who eats low-fiber and high-fat diet is more likely to develop colon cancer. It is also important to mention that consumption of processed meats also contributes to this disease.
Red meat is yet another risk factor for colon cancer, but moderate consumption and healthy cooking technique can help you avoid putting your colon health at risk.
Sedentary Lifestyle and Obesity
Sedentary lifestyle and overweight or obesity go hand in hand and they have a major potential to jeopardize your health. If you’re inactive and you also carry the excess weight you are more likely to develop colon cancer than a person who is active and also happens to be within a healthy weight range.
We tend to associate smoking with lung cancer, but the effects of this unhealthy habit extend to many other health conditions. Evidence shows that smoking is the number one modifiable risk factor for most cancers. The term modifiable means it is a risk factor you can change. Smoking speeds up polyp growth and the delivery of carcinogens to the mucosal tissues of the colon.
Other risk factors
Along with the above-mentioned contributors to colon cancer, other risk factors include:
- Family History – As seen above, some people have a genetic predisposition for colon cancer. This doesn’t mean you’ll get it for sure, just indicates there is a risk
- Personal History of Colorectal Cancer and Polyps – You are more likely to develop this cancer if you’ve already had it before
- Health conditions such as inflammatory bowel disease like ulcerative colitis and Crohn’s disease, acromegaly (a growth hormone disorder)
- Radiation treatment for other cancers
Unlike many other cancers that are linked to gender preferences, men and women are equally at risk of colon cancer.
What are the Symptoms of Colon Cancer?
In the early stage of this disease, signs, and symptoms tend to be absent. Patients start experiencing different symptoms of colon cancer when it progresses or becomes more severe. Due to the fact that colon cancer symptoms are nonspecific, they are easily attributed to some other health problems.
As a result, a person isn’t aware of his/her health problem because it’s so easy to mistake them for something else. That’s why cancer screening is strongly recommended for individuals who are 50 or older.
In addition, it’s always useful to consult a doctor when experiencing symptoms listed below and your healthcare provider will make an accurate diagnosis. Let’s take a look at the most common symptoms linked with colon cancer:
- Change in bowel habits including constipation, diarrhea, or change in the stool consistency that last four weeks or longer
- Fatigue or weakness
- Feeling that your bowel doesn’t empty completely
- Iron deficiency or anemia
- Pain during bowel movements
- Pelvic pain (in the late stages of the disease)
- Persistent abdominal discomforts such as pain, gas or cramps
- Persistent urge to defecate
- Rectal bleeding/blood in your stool
- Shortness of breath
- Unexplained weight loss* (you drop weight without even trying)
Interestingly, symptoms of colon cancer can depend on the location within the intestine where the tumor was formed. For example, the right colon is wider, spacious, and more flexible and cancers that develop in this area get larger in sizes (due to more space) before they cause any symptom. Cancer in the right colon causes iron-deficiency anemia because it leads to the loss of blood over a longer period of time. Anemia is linked to fatigue, shortness of breath, and weakness.
On the other hand, the left colon is narrower and cancers in this area cause a complete or partial bowel obstruction. Left-sided colon cancers are related to symptoms such as narrowed stool, constipation, abdominal pain, diarrhea, bloating, and cramps. If a patient notices blood in the stool, it indicates the cancer is located near the end of the left colon.
Due to the similarity of colon cancer symptoms to other health conditions, the best way to alleviate them properly is to see your doctor. This is particularly important if you notice blood in your stool.
How is Colon Cancer Diagnosed?
Since colon cancer is a common health problem, doctors recommend that both healthy and high-risk individuals screen for this disease. The need for screening is even more important for adults over the age of 50. Early detection of the disease is vital for treatment success.
Doctors use different tests for colon cancer screening, and the most common approaches include:
- High-Sensitivity Fecal Occult Blood Tests(FOBT) – checks for tiny amounts of blood in feces that cannot be seen with the naked eye
- Stool DNA Test – A multi-target test that detects tiny amounts of blood in stool and nine DNA biomarkers in three genes that are associated with colorectal cancers (both colon and rectal) and precancerous advanced adenomas
In instances when a patient schedules an appointment due to symptoms he/she experiences, the doctor will start by asking you a few questions. For example, the doctor may ask you when you started experiencing symptoms, whether you have a history of colon cancer or other cancers in your family or if you had them before, how severe are your symptoms, among other things. Be ready to give accurate and honest answers because the doctor needs this information for the next steps.
Based on the symptoms you describe, the doctor will already suspect you have some specific health problem such as colon cancer, but to rule out other conditions with similar symptoms he/she may order different tests. Tests that are used for colon cancer diagnosis are:
- Barium Enema – X-ray procedure which uses a liquid called barium for clearer imaging results than standard x-rays. A liquid solution is injected through the rectum into a patient’s colon followed by a brief pumping of air to smooth over barium layer for precise results. Then, the doctor takes an x-ray of colon and rectum. If there are any tumors or polyps, they appear as dark outlines due to barium
- Colonoscopy – The most common procedure that doctors use to confirm the colon cancer diagnosis and locate the tumor. During the procedure, a healthcare practitioner inserts a long, flexible viewing tube into a patient’s rectum to inspect the inside of the entire colon. Colonoscopy is regarded as more reliable than barium enema X-rays, particularly for detection of tiny polyps. If the doctor finds polyps during the procedure, they remove* them with a colonoscope. Then, polyps are sent to a pathologist who uses a microscope to look for cancer
- Sigmoidoscopy – A procedure where the doctor examines just the left side of the colon and a patient’s rectum using a shorter flexible scope. Unlike colonoscopy, this procedure doesn’t allow the doctor to inspect the entire colon. When polyps are detected, removal is performed with sigmoidoscope
If these tests show a patient has blood cancer, the doctor may also order a tumor marker blood test called CEA (carcinoembryonic antigen). CEA is a substance that some colon, rectal, and some other cancers produce. In colon cancer patients the substance is typically found in high amounts, particularly if the disease has spread.
To doctors, CEA test can be very practical as it tells them whether the presence of this substance has increased before cancer removal. It is also important to mention that not all patients have elevated CEA. This test also shows whether a patient’s body is responding to the treatment.
Doctors can also order complete blood count (CBC) test to check for anemia. In general, doctors rely on blood tests to get clues about a patient’s overall health and to test their kidney and liver functions. These tests also indicate whether a patient is responding to the therapy and they also depict the severity of the disease.
What are the Stages of Colon Cancer?
When the doctor diagnoses colon cancer, he/she will obtain a few tests in order to determine the staging of this disease. Common tests used for this purpose include pelvic, abdominal, and chest CT scans, but in some cases, the stage can only be determined during the surgery.
Colon cancer stages are:
- Stage 0 – Cancer is in the early stage, known as carcinoma in situand it is located at the innermost layer of the intestine
- Stage I – Cancer has grown through the mucosa (superficial lining) of the colon, but it hasn’t spread to nearby lymph nodes and distant sites
- Stage II – Cancer has grown in the outermost layers of the colon, but it hasn’t gone through them. In this stage, cancer didn’t reach other organs, lymph nodes, or distant sites
- Stage III – Cancer has grown through the outer layers of the colon and it reached one to three lymph nodes, but it hasn’t spread to distant sites
- Stage IV – Cancer has spread to other tissues beyond colon wall. As this stage progresses, cancer reaches distant sites or organs like lung and liver in the body
Once the doctor determines the stage of colon cancer, he/she is ready to propose an adequate treatment.
What are the Treatment Options for Colon Cancer?
Even though colon cancer is a serious disease, different treatment options are available and their goal is to relieve symptoms and remove* the cancer. When detected in early stages and with a right therapy, it is entirely possible to beat colon cancer. Although stage IV indicates cancer that spread to other tissues and organs, it is possible to treat* it and downplay the intensity of symptoms.
Colon Treatment by Stages
Treatment for this disease depends on the stage:
- Stage 0 – Due to the fact that cancer in this stage hasn’t grown beyond the colon’s inner lining, a patient usually needs surgery only. During the procedure, the surgeon performs polypectomy (removal of polyps) or uses a colonoscope for local excision. In cases when tumor is too big to be removed through local excision, then partial colectomy (removal of part of the colon) is necessary
- Stage I – This stage includes cancers that were a part of polyp which is why removal of the polyp during colonoscopy is usually the only treatment a patient needs. Of course, this is only in the case when the microscopic inspection finds no cancer cells at the margins or edges of the polyp sample. If a patient has a high-grade polyp cancer or cancer cells are found at the margins, the doctor recommends more surgery. In cases when stage I cancer isn’t in a polyp, doctor recommends partial colectomy
- Stage II – Partial colectomy is usually the first line of treatment for cancer that is at this stage. That being said, the doctor may also suggest adjuvant chemotherapy (chemo after surgery) if there’s a high risk of recurring (cancer coming back)
- Stage III – Standard treatment for cancer in this stage is partial colectomy followed by adjuvant chemotherapy
- Stage IV – Due to the fact that cancer spread to other sites and lymph nodes, surgery is unlikely to cure* cancer at this stage. However, the doctor may still recommend surgical procedure if there are only a few metastases in liver and lungs. Surgery in advanced cancer stage is usually performed to alleviate symptoms, but it can also cure* a patient.
The procedure involves removal of the section of the cancer-affected colon, nearby lymph nodes, and areas of cancer spread. Patients with stage IV colon cancer receive chemo before and after surgery. If cancer reached the liver, doctors may also use hepatic artery infusion, which delivers high concentrations of cytotoxic agents directly to liver metastases with minimal systemic toxicity.
To sum up the common treatment approach for colon cancer; if the colon cancer is small, the doctor recommends minimally-invasive procedures such as polyp removal during colonoscopy, endoscopic mucosal resection (to remove* larger polyps), and laparoscopic surgery.
During a laparoscopic procedure, the surgeon makes several small incisions in the abdominal walls to insert instruments and monitor the inside of the colon thanks to cameras that are attached to the instruments. For more advanced cancers, the doctor recommends partial colectomy, lymph node removal, and a procedure called ostomy to create a way for feces to leave the body. In some cases, an ostomy is only a temporary solution.
Any Other Lines of Treatment
Although surgery is the standard approach to treat* colon cancer and alleviate symptoms, other treatment options are also available, such as:
- Chemotherapy – This treatment option uses drugs to destroy cancer cells and, as mentioned above, it is usually given after the surgery in cases when the disease has reached lymph nodes. It is not uncommon for doctors to recommend chemotherapy to patients before surgery if their cancer is too big and they want it to shrink before the procedure
- Immunotherapy – The use of antibodies such as nivolumab (Opdivo) and pembrolizumab (Keytruda), recommended to patients with advanced colon cancer
- Palliative Care – Supportive of palliative care has the goal to help patients experience relief from colon cancer symptoms. Basically, palliative care specialists work closely with patients and their families to provide support and improve* quality of life. This is a complementary treatment option i.e. addition to other means of colon cancer treatment
- Radiation Therapy – The use of x-rays or other powerful energy sources to destroy cancer cells or decrease* the size of large tumors prior to the surgery. The radiation therapy can also be used to alleviate symptoms of colon cancer
- Targeted Drug Therapy – The use of medications that target specific malfunctions which promote cancer growth. These drugs usually include Bevacizumab (Avastin), Cetuximab (Erbitux), Panitumumab (Vectibix), Ramucirumab (Cyramza), Regorafenib (Stivarga), and Ziv-aflibercept (Zaltrap). These drugs are given together with chemotherapy or alone and they are prescribed to patients with advanced colon cancer
Based on the cancer stage, the health status of the patient, and other factors, the doctor recommends an adequate treatment option. This only intensifies the need for scheduling an appointment to see the doctor when symptoms occur, rather than assume they’re not a “big deal”.
What are the Prognosis of Colon Cancer?
Colon cancer belongs to the group of slow-growing cancers that take several years to form. Due to the fact it grows in stages, screening can decrease* the risk of death due to this cause. Despite the fact that cancer diagnosis can make a person feel like nothing can be done, it is entirely possible to beat colon cancer, especially when detected early.
Generally, the likelihood of surviving at least five years after colorectal cancer stage I diagnosis is 92%. On the other hand, stage IV colon cancer patients have only 11% chance of surviving at least five years after diagnosis. That’s why annual screening is highly recommended for high-risk individuals, but doctors also suggest healthy persons should screen for colon cancer too. If colon cancer doesn’t recur within five years, it is considered cured.
How to Cope Up with Colon Cancer?
It is entirely normal to feel stressed and overwhelmed after receiving colon cancer diagnosis. The worst-case scenario runs through a patient’s mind and he/she is not sure what to do now. The key is to consult with a doctor and ask him/her everything you want to know about the disease and treatment options as well as their risks and benefits. Fighting cancer is not the easiest thing in the world, but it’s not impossible either.
Different coping strategies can help you alleviate stress and get more strength to find the disease. Studies show that emotion-based and problem-focused coping strategies that target both coping and well-being in cancer patients are necessary for all patients and their families, and they show great effects.
People learn to cope with colon cancer, and any other serious disease, in their own unique ways. Approaches you can take include:
- Education – It can be very useful to get informed and learn about colon cancer. The more you know about the disease, the more confident in treatment you’ll get. The word cancerevokes all the negative thoughts in your mind, but it’s possible to beat it. As you learn about cancer and its stages, including the stage in your case, you’ll start thinking positively. In turn, stress levels will decrease*
- Let Others Help You/Seek Support – Support from family members and friends is much-needed for the fight against colon cancer. However, some patients don’t want to “depress” others with their disease and they don’t want their support. There are also those who don’t like to admit they need someone’s help or support at all. This is a huge mistake; all of us need someone to lean on (in general) and colon cancer fight isn’t the exception. Let others provide their love and support to give you more strength and alleviate stress you feel
- Join a Support Group – Today, there’s a support group for just about anything and it’s a good thing. Support groups allow people who are in the same situation, in this case, colon cancer, to talk about their struggles, trade experiences, and help one another
- Don’t Play the Blame Game – Such a serious diagnosis like colon cancer may make you start blaming yourself for the disease. Avoid doing that and focus on the treatment and coping techniques that will help you beat cancer
- Exercise – Strive to be physically active or exercise (no vigorous activities) to keep your body healthy and beat stress
- Try Therapy – Therapy sessions can be of huge help for colon cancer patients as they teach you how to cope with overwhelming situations and alleviate stress effectively
- Financial Assistance – To many colon cancer patients financial situation is an additional stress. Treatment expenses can be massive and they’re not sure how they can afford them. Fortunately, many organizations provide help with medical billing, insurance coverage, and reimbursement issues. They also provide financial assistance to patients who can’t afford their medications. A great place to start is the Cancer Financial Assistance Coalition or Partnership for Prescription Assistance
What are the of Prevention Colon Cancer?
Bearing in mind that colon cancer is such a common disease, it is important to discuss preventive measures. There are many things you can do to minimize the risk of colon cancer and the most important measures are discussed below.
As mentioned throughout this post, annual screening is the best way to detect cancer in the early stages, but it also helps you prevent it. Several screening options exist and it’s important to discuss them with the healthcare provider.
Maintaining Healthy Weight
Overweight and obesity are major risk factors for colon cancer. In fact, carrying excess weight raises the odds of many health problems besides this one. An important colon cancer preventive measure is a healthy weight. If you’re already within healthy weight range, then strive to maintain it. On the other hand, men and women who are overweight or obese should adopt lifestyle changes to slim down.
A sedentary lifestyle is a risk factor for both overweight/obesity and colon cancer. Therefore, a useful way to help prevent the disease is to exercise regularly and increase* activity levels. Besides regular training, you can also try to move more such as choosing stairs instead of the elevator, going to short walks around the neighborhood every day etc. Don’t consider exercise as a sort of punishment, but an inseparable part of a healthy lifestyle.
Eat a Well-Balanced Diet
A diet that is low in fiber and high in fat contributes to colon cancer. To prevent this disease, you should make some diet changes by limiting (or avoiding) consumption of junk food and increasing* the intake of fiber-rich foods such as whole grains, fruits, and vegetables. Just like exercise, a healthy diet is not a punishment but a part of your lifestyle. Fiber is necessary because it is vital for digestion. Healthy digestion is also necessary for colon health.
Smoking increases* the risk of colon cancer and puts your overall health in great danger. Therefore, the logical thing to do is to quit smoking. To active smokers, it may seem impossible to simply ditch this habit, but with strong willpower you and support you can do it.
Other Things to do
Typically, maintaining a healthy lifestyle is important for colon cancer prevention. In addition to the above-mentioned preventive measures, you should also:
- Consume alcohol moderately or avoid drinking alcohol beverages
- Limit consumption of red meat and avoid consuming processed meats at all
- Consume sufficient levels of calcium and vitamin D
- Take an Aspirin or baby Aspirin every day
- Get enough sleep
- Manage stress
- Avoid unhealthy methods of food preparation, instead of frying you can cook
Colon cancer is one of the most common cancers in the US and around the globe. Although the exact cause of the abnormal growth of cells is unknown, different factors play a role. Regular, annual, screening is the best way to prevent colon cancer and detect it in early stages. With adequate treatment options, patients can beat the disease, especially when detected early. A healthy lifestyle is important for prevention of colon cancer.
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