- What is Colon Cancer?
- Causes of Colon Cancer
- Diagnosis of Colon Cancer
- Prognosis of Colon Cancer
- Colon Cancer Treatment
- Preventing Colon Cancer
When we say colon we refer to a significant part of the digestive system that many may know as large intestine. The colon is responsible for a plethora of processes leading to eventual removal of the waste from the organism. The focus of our article will be primarily on colon cancers, their typical symptoms, treatment methods, consequences, and possible causation.
What is Colon Cancer?
Cancer in general is a disease characterized by an uncontrollable growth of cells. In our case, this growth occurs in the large intestine. Colon is often covered with small polyps from the inside. These polyps have a noncancerous nature and often do not cause any problems. However, benign tumors may transform into cancerous tumors. Oftentimes, preemptive surgical removal of such initially harmless tumors is a solid cancer prevention measure. These tumors are discovered via colonoscopy fairly easily.
Upon turning into cancerous tumors, cells start grow and divide spreading and infesting surrounding tissues inducing negative effects. In some cases, these cells not only provoke problematic issues inside the colon, but also spread through the whole organism using blood vessel system as a mean of transportation. This may lead to sporadically appearing tumors in other parts of the body.
This spreading process is called metastasis and causes even worse health issues. Note that an indistinct line can be drawn between rectal and colon cancers despite the fact that their simultaneous occurrence is not a rare phenomenon. Rectal cancer, however, starts near the anus.
Causes of Colon Cancer
All cells in our body follow the same cycle of birth, growth, and death. However, sometimes, rebel cells appear that refuse to follow the pattern and do not die. Cells have a law “apoptosis” that forces them to die when it’s needed. When cells refuse to abide and start growing uncontrollably, cancer occurs. The exact reason of this disease is still a mystery to modern science, but there are factors that can likely cause cancer.
The large intestine is fairly often occupied by various polyps. In fact, it is extremely rare that one’s colon is completely smooth and has no polyps at all.
There are three types of polyps that may result in cancer:
- Adenomas that present certain danger and immediately removed surgically upon discovering;
- Hyperplastic types that usually do not lead to cancer;
- Inflammatory types that, as the name suggests, appear in case of recent inflammation and in some cases may transform into malignant tumors.
The whole process of cell division, growth, and death is controlled by their DNA which is not perfect and can have mutations that will negatively affect cell management.
Cells should be ready to willingly die when their functions are exhausted and this command is written in their DNA. However, mutations may prevent cells to fix the DNA and cells start to behave in a bizarre way.
Specific gene mutations can be inherited. Some people are born with mutations that may increase the likelihood of cancer. Such mutations are hard to detect and their ability to transit to next generation is not entirely studied.
There are other possible factors that may increase the probability of getting cancer. Amongst them age. The overwhelming majority of people with cancer are older than 50. The likelihood of cancer is increased by bad habits such as tobacco smoking, low physical activity, and obesity.
Imbalanced diets also may cause cancer. People who do not consume enough fiber and have a lot of fats in their diets are diagnosed with colon cancer more frequently.
As a matter of fact, people living in developing countries rarely develop colon cancer due to a healthier diet with lots of fiber and less fats and sugars. Another risk increasing factor is alcohol. Frequent drinkers are likely to develop colon cancer.
There are strictly medical causes of colon cancer. Research showed that diabetes, growth hormone disorder, ulcerative colitis, and even some means of cancer treatment themselves (radiation) may lead to colon cancer.
Cancer is often hard to detect without testing due to the rich variety of symptoms it can induce. The list of symptoms differs depending on the type of cancer.
Amongst the most common manifestations of colon cancer are those listed below:
- Problems with defecation including constipation and/or diarrhea;
- Stools have a very narrow shape;
- Stools often have blood;
- Rectal bleeding;
- Discomfort, gases, aches, and other abnormal feelings in the abdomen;
- Bowel movement often causes pain or heavy discomfort;
- Uncharacteristically often and long lasting urges to defecate;
- Feeling weak or exhausted;
- Sudden loos of weight without a reason;
This is an incomplete list of possible symptoms. In addition, metastatic tumors may induce other symptoms and further worsen the condition. One of the most frequent location of metastasis is liver.
Diagnosis of Colon Cancer
Without a holistic picture of the medical condition of a patient, doctors will struggle to diagnose colon cancer. Specialists will require extensive medical histories of both the patient and his close relatives. Specific tests are also conducted.
One of the most effective early-stage tests is a colonoscopy when a camera on a long tube is used to inspect the insides of the colon. The purpose of this procedure is to find polyps. Upon discovering, they are surgically removed and samples are examined by a specialist in order to determine whether tumor cells are cancerous.
Another test is barium enema X-ray inspection. Barium absorbs X-ray radiation and appears completely white. The barium-containing liquid evenly covers the walls of the colon allowing for a thorough inspection via X-ray scan. If dark shapes start appearing on the white field, it means that there are polyps or cancerous tumors in the colon.
Biopsy is a one of the most certain ways to diagnose cancer. When cancerous cells are found, other medical diagnostic procedures may be scheduled including computerized tomography of various body parts, ultrasound scans, additional x-ray scans, etc. These tests will allow to determine how far cancerous cells spread in the organism.
Prognosis of Colon Cancer
Depending on the results of the diagnosis, the stage of cancer is determined. Based on the stage various treatment methods will be suggested that better suit specific stage of cancer.
There are distinct stages described in the commonly accepted system called TNM:
- T (tumor) characterizes the tumor itself, its size and extent (possible descriptions include Tx, Tis, T0-4).
- N (nodes) characterizes how cancer affects surrounding lymph nodes (Nx, N0-4).
- M (metastasis) characterizes whether metastasis has taken place.
For example, an extremely developed cancer will be written as (T4, N4, M1) meaning that a big tumor has spread to nearby lymph nodes and across the body.
Colon cancer stages are also described based on this TNM system.
Stage 0 is frequently (Tis, N0, M0). This means that the tumor is a carcinoma in situ; lymph nodes are not yet affected; the tumor resides only in the colon. Stage 0 means that metastasis has not started and cancerous cells did not invade other parts of the body.
Stage IV is characterized by (T>0, N>0, M1). This means that metastasis has begun and cancerous cells can be found in various parts of the body.
Colon Cancer Treatment
There are various factors that heavily affect the treatment course. Available treatment methods depend on the patient’s medical condition, age, cancer stage, and other factors. Note that it is impossible to cure cancer with any one specific treatment method. In the vast majority of cases, various combination of surgeries, radiation therapy, and chemotherapy are employed. The main purpose of treatment is to ultimately cure cancer, but also to inhibit symptoms.
A surgical procedure that removes the colon or parts of it is referred to as colectomy. During this procedure, parts of the colon infested with cancerous cells is removed. In addition, surrounding tissues also removed in order to avoid the return of cancer.
Surrounding lymph nodes should be also removed. There are two potential outcomes of the operation. If the colon removed partially, remaining parts of the organ will be attached back to the rectum. In this case, the functionality is untouched. If a significant part of the colon is removed, the remaining part is connected to a stoma with a colostomy bag that collects the waste coming from the organism.
Another surgical operation is endoscopy when small tumors are treated without invasive surgery. Larger tumors can be treated with laparoscopy that is less invasive than colectomy.
When cancer is untreatable, surgical removal of colon blockages is applied in order to inhibit cancer symptoms that drastically decrease the quality of life by inducing pain, causing bleeding, and preventing normal defecation.
Cancer cells are generally weaker than healthy cells in terms of resisting aggressive chemical treatment. During chemotherapy, various compounds are used in order to destruct proteins and damage cells’ DNA. This heavily inhibits cells’ ability to divide and affects both cancerous and healthy cells. However, normal cells can recover or be replenished.
Chemotherapy is used to attack cancer in metastasis when cancerous cells spread across the body uncontrollably. Localized treatment has from little to no effect in such cases and chemicals can freely travel across the body attacking cancerous cells everywhere. This therapy should be applied with pauses to give the organism enough time to recover. The therapy causes multiple side effects including complete hair loss, extreme fatigue, vomiting, etc.
While various combinations of chemicals are used during the chemotherapy, another medication is largely consumed by patients – aspirin. Medicine is still not quite sure how aspirin can have a positive effect, but it does and often becomes an important part of the treatment course.
Radiotherapy employs intense gamma-ray radiation targeting tumors and cancer cells. Intense radiation heavily damages cells on the molecular level effectively killing them in the process.
Radiotherapy can be used as the one and only method of cancer treatment, but in the vast majority of cases, it should be combined with other procedures in order to be as efficient as possible.
In rare cases, this type of treatment can be employed for treating early stages of cancer. This happens when cancer starts spreading to surrounding lymph nodes and invaded deeper tissues.
Obviously, intense gamma-ray radiation is harmful and causes specific side effects. During this kind of treatment, patients struggle to maintain the body weight due to the loss of appetite. Extreme fatigue, burns on skin, and other effects are also common. Negative side effects are usually gone in a couple of weeks after the treatment.
Preventing Colon Cancer
Colon cancer is more than simply prevalent. It is the second most frequently diagnosed type of cancer in the U.S. Simultaneously, this type of cancer is responsible for millions of deaths annually being the 3rd most common natural cause of death in America. Annual screening is recommended for people over 50 years in order to diagnose colon cancer early.
Colonoscopy is recommended as the best test for early colon cancer detection. During this procedure, small polyps can be easily identified, localized, and removed if necessary. In order to detect colon cancer quicker, other diagnostic methods can be employed such as fecal blood tests, DNA tests, etc. Some tests can be conducted rarer. For example, sigmoidoscopy is recommended once in 5 years just like colonography.
However, choosing the right frequency of testing should be slightly adjusted based on the individual specifics of the patient.
The best way of preventing colon cancer is leading a healthy lifestyle. Regular exercises, weight control, and including lots of fiber in your diet (fruits, vegetables, whole grain) are the best way of reducing the risk of colon cancer. Balancing diet is an important part of prevention care and reducing the share of alcohol, fats, and meat is a good idea. Smoking is also a risk increasing factor.