Quick Answers about Colon Cancer
- Colon Cancer Overview
- Colon Cancer Causes
- Colon Cancer Symptoms
- Diagnosing Colon Cancer
- Prognosis and Treatments
Colon Cancer Overview
Colon cancer involves abnormal cells growing out of control in the large intestine of the digestive system. Most cases originate as adenomatous polyps (small, benign [non-cancerous] tumors) that form in the inner walls of the colon (large intestine). Over time, the polyps can become malignant if not removed during a surgical procedure or colonoscopy. Without treatment and surgical removal, the malignant cancer cells have the potential of invading healthy tissue, causing damage and unexpected serious consequences to the patient’s overall health.
Colon cancer can metastasize or spread throughout the body by traveling through the lymph system and blood system to invade other body parts, tissues, and organs. If allowed to metastasize, the disease can become extremely difficult to treat. Many individuals suffer from rectal cancer, which is slightly different than colon cancer and originates in the rectum located within the last several inches of the colon next to the anus.
Statistics maintained by the American Cancer Society revealed that doctors will diagnose more than 95,000 new cases of colon cancer this year. These statistics also reveal there is a more than 65 percent chance of surviving the disease five years after the initial diagnosis. However, almost 50,000 individuals in the United States will die of colon cancer this year, which represents approximately eight percent of all cancer deaths.
Colon Cancer Causes
The typical lifespan of a normal cell involves growing, dividing (reproducing) and dying. However, cancer cells do not follow this pattern and instead remain alive and grow uncontrollably, while continuously creating more abnormal cells. Researchers have yet found the exact reason why abnormal cells behave in this erratic manner. However, scientists have determined numerous potential risk factors known to cause colon cancer. These include:
- Polyps – Many cases of colon cancer originate from precancerous polyps existing in the colon. These polyps are classified in three different categories including:
- Adenomas – These polyps can develop into cancerous cells, but are easy to detect and remove during a colonoscopy.
- Hyperplastic Polyps – These polyps rarely develop into life-threatening colon cancer.
- Inflammatory Polyps – These polyps typically develop after the colon becomes inflamed (colitis) and have the potential of becoming cancerous.
- DNA Type Genes – Any mutation or damage to DNA can cause the cells to grow uncontrollably, damaging the gene at the DNA level during cell division (reproduction). Any mutation can take the cell’s control away from correcting DNA damage and its ability to die off naturally. Cancer usually develops due to a mutation that will impede specific gene functions and eventually cause uncontrollable cell growth.
- Lifestyle Choices and Traits – Old age is a crucial factor that correlates to colon cancer, where approximately 90 percent of all individuals diagnosed with the disease are 50 years and older. However, there are other factors, traits and lifestyle choices that directly increased the potential of developing colon cancer. Some of these include:
- Sedentary lifestyle
- Diet choices
Researchers have determined that eating a healthy diet can minimize the potential of colon cancer whereas diets high in fat, low in fiber, have excessive calories or filled with processed meats or red meat increases the potential risk of developing colon cancer.
- Specific Medical Factors – Specific conditions and diseases directly linked to the increased potential of developing colon cancer include:
- Growth Hormone Disorder (acromegaly)
- Radiotherapy used to treat other cancers
- Crohn’s disease
- Ulcerative colitis
Colon Cancer Symptoms
Every case of colon cancer is unique, where the individual experiences their own set of symptoms or no symptoms when the disease is in its early stage. The most common colon cancer symptoms include:
- Constipation or diarrhea
- Narrow stools
- Changing stool consistency
- Fatigue or weakness
- Continuing urge to defecate
- Abdominal gas, cramps or pain
- Painful bowel movements
- Rectal bleeding
- Anemia (iron deficiency)
- IBS (irritable bowel syndrome)
- Unexplained weight loss
As the disease progresses, the tumor can grow exponentially in size and eventually spread (metastasize) to other areas of the colon, body or other organs, especially the liver.
Diagnosing Colon Cancer
To successfully diagnose colon cancer, the doctor will need to perform a comprehensive physical exam, obtain a family and personal medical history, and conduct a barium enema x-ray or colonoscopy.
- Colonoscopy – The doctor performing colonoscopy will use a flexible, long tube constructed with a camera and light system on one end. The tube is inserted into the patient’s rectum and used to inspect the interior of the large intestine. If the doctor locates a polyp, it is usually removed through a safe biopsy surgical procedure and sent to the laboratory for examination by a pathologist. Using a microscope, the pathologist can detect and identify pre-cancerous or cancerous cells.
- Barium Enema – The patient will be instructed to avoid food or drink several hours prior to the barium enema procedure. During the procedure, a barium-laced liquid solution will be injected into the large intestine through the rectum before taking x-rays of the patient’s colon and rectum. The x-ray will reveal areas with barium in white and reveal polyps and tumors in dark outlines.
If the biopsy, x-rays or barium enema substantiated the diagnosis of colon cancer, the patient’s physician will typically order other tests including ultrasounds, chest x-rays and CT (computerized tomography) scans of the abdomen, liver, and lungs to see if cancer has metastasized (spread to other areas of the body). A CEA (carcinoembryonic antigen) blood test might also be performed.
Prognosis and Treatments
Before the doctor to make a prognosis of the disease, the cancer must first be staged using the TNM (Tumor, Node, Metastasize) system. During staging, the doctor will determine how progressive the disease has become. Stage 0 refers to the beginning stages of the disease where Stage IV indicates that the cancer has become advanced and has likely spread to other organs and distant sites throughout the body.
There are effective treatment options during the early stages of the disease. Usually, the doctor will choose a combination of treatment options that likely include surgery, radiation therapy, and chemotherapy.
- Surgery – The surgeon will remove a portion or the entire large intestine through a colectomy procedure. In addition, the nearby lymph nodes might be removed. Using an endoscope, the surgeon can remove localized cancer areas. Laparoscopic surgery can remove large polyps, while palliative surgery is effective for relieving colon cancer symptoms if the disease has become untreatable or advanced.
- Chemotherapy – The doctor can utilize chemicals proven effective at interfering with the process of cell division to ensure that the abnormal cell is damaged and killed. Chemotherapy has been proven effective for cancers that have metastasized. However, there are significant side effects including hair loss, vomiting, fatigue, and nausea.
- Radiation – Radiotherapy is an effective tool for destroying cancerous cells. The machine focuses high beams rays of energy on the affected area to destroy cancer cells. However, there are significant side effects including mild skin changes (sun burning or sun tanning), vomiting, nausea, fatigue and diarrhea.
Doctors typically recommend that their patients follow preventative measures including maintaining a healthy weight, increasing the intake of vegetables, fruits, and whole grains and exercising routinely.