Colon Cancer Symptoms and Treatment
What is colon cancer?
Colorectal cancer, also called bowel cancer, begins with the abnormal growth of cells in the large intestine. It may start in the colon or the rectum, leading to colon cancer or rectal cancer. Doctors usually place colon and rectal cancers in the same category because they have many common features. In most cases, colon cancer originates from benign growths on the inner lining of the colon, called polyps. Over time, some polyps may mutate and transform into cancerous tissue.
What causes colon cancer?
The exact cause of colorectal cancer is unknown, but certain risk factors are associated with the disease. Having a family history of colorectal cancer or ovarian, breast, and uterine cancer in women or having hereditary gene syndromes, previously detected polyps, or inflammatory bowel disease may increase your risk of developing colon cancer. Ulcerative colitis or Crohn’s disease are risk factors for developing colorectal cancer, especially in people who have had it for more than 10 years. However, behavioral risk factors, such as smoking, unhealthy diet, heavy alcohol intake, and physical inactivity account for a large proportion of cases. Eating a lot of red or processed meats and being overweight may also raise your risk. While you are more likely to develop colon cancer after the age of 60 years, it may occur at any age. According to studies, one-third of patients diagnosed with colorectal cancer are younger than 55.
Colon cancer in men
Bowel cancer affects men and women almost equally. However, the lifetime risk of developing the disease is slightly higher in men (4.3% versus 4%). According to some studies, men tend to be diagnosed at younger ages than women.
Colon cancer in women
Women may sometimes ignore the signs and symptoms of colon cancer, since some symptoms are similar to the discomfort associated with menstruation or other gynecological conditions. A woman’s risk of developing colon cancer increases after menopause.
Early signs of colon cancer
Very often, there are no specific early symptoms of colorectal cancer until the cancerous growth has advanced. For this reason, regular screening helps to detect the disease before symptoms develop; this is the stage when colon cancer is most curable.
Colon cancer symptoms
Symptoms of colon cancer become more noticeable with the progression of the disease. They may vary from person to person, depending on the location and size of the cancerous growth:
- Changes in bowel habits, such as the new onset of constipation or diarrhea
- Rectal bleeding, blood in the stool, or dark or narrow stools
- Change in stool consistency or odor
- Feeling as if the bowel is not empty
- Persistent abdominal discomfort, bloating, or pain
- Weakness, fatigue, pallor, and anemia caused by iron deficiency
- Loss of appetite or involuntary and unexplained weight loss
These symptoms do not necessarily indicate cancer. Many other disorders of the digestive tract can cause similar problems, including hemorrhoids, fissures, and irritable bowel syndrome. Visit a doctor for any complaints that last longer than a few days.
Colon cancer screening and diagnosis
Generally, regular screenings for colon cancer should start at the age of 50 for people who do not have a family history of the disease and have no complaints. Screening may need to begin at 40, or even earlier if there are any risk factors. In people with genetically inherited polyposis syndromes in their family, screening should start at the age of 15–18 years.
There are several screening options for the early detection of colon cancer, including a fecal occult blood test, fecal DNA test, colonoscopy, flexible sigmoidoscopy, and computed tomographic colonography. The best screening method is a colonoscopy. It uses a thin, flexible tube with a camera on the end to examine the large intestine from the inside. The procedure allows doctors to detect and remove polyps before they turn into cancer or to take samples (biopsy) from suspicious areas. Polyps removed during a colonoscopy are examined to determine if they have cancerous or precancerous cells.
If the diagnosis of colon cancer is confirmed, further blood and imaging tests will be performed to evaluate the exact type, stage, and spread of the disease. At Acibadem Cancer Centers, we provide rapid access to the latest imaging tools, including chest x-ray, abdominal computed tomography, ultrasonography, magnetic resonance imaging, endorectal ultrasonography, and positron emission tomography, for the detailed diagnosis of colorectal cancer.
Colon cancer survival rate
Colon cancer prognosis and treatment depend highly on the stage at which it is discovered. Stages are classified on a scale from 0 (carcinoma in situ) to IV. In the lower stages, cancer is confined to the colon wall, while in stage IV, cancer has spread to distant organs (metastasized). When the disease is detected at an early stage, the five-year survival rate exceeds 90%. Cancer is considered cured if it does not recur within five years. At an advanced stage, the survival rate is lower but steadily increasing.
The death rate for colorectal cancer has been decreasing over the last few decades. This is related to improved early detection due to screening programs. When cancer is detected early, it is easier to treat. Additionally, treatment methods have progressed over time. A multidisciplinary approach and comprehensive treatment received in experienced cancer centers, such as Acibadem, can contribute to better outcomes.
Colon cancer treatment
How colon cancer is treated depends on its location, stage, and many other factors. What you should know is that colorectal cancer is a treatable disease, especially if it is diagnosed early. Depending on the case, surgery, chemotherapy, targeted therapy, immunotherapy, or radiation may be used alone or in combination.
- Colon cancer surgery. The surgical removal of cancerous lesions is the best treatment. The type of surgery depends on the location of cancer within the large intestine and its stage. In stage 0, and some early stage I cases, cancerous polyps can be removed during a colonoscopy with polypectomy or local excision. Therapeutic endoscopy allows for treatment at the time of diagnosis without any incisions, and this is often enough to eliminate the disease. Advanced cases require more extensive surgery called colon resection (colectomy). This involves the removal of the part of the bowel that contains cancer along with surrounding tissues and adjacent lymph nodes. The remaining parts of the colon are reattached (anastomosis). Depending on the case, a partial or total colectomy may be needed. In some cases, patients may need a colostomy or ileostomy after resection surgery. This means that the surgeon creates an artificial opening in the abdominal wall called a stoma to provide a way out for digestive waste. This may be used as a temporary or permanent solution. Palliative surgery can also be used to relieve symptoms and prolong life at an advanced stage of cancer. At Acibadem, in most cases, colon cancer operations can be done using minimally invasive techniques instead of open surgery. Laparoscopy and robotic surgery help to reduce recovery time and improve patient comfort.
- Chemotherapy for colon cancer. This is a systemic treatment that uses drugs to kill cancer cells throughout the body. Even if a tumor is diagnosed at an early stage and removed completely by surgery, some remaining cancer cells can travel to various parts of the body via lymph and blood vessels. If these cells are not destroyed, they multiply and grow over time, causing the disease to recur in any part of the body. For this reason, preventive chemotherapy may be applied after surgery to destroy the remaining cancer cells. Chemotherapy can also be used before surgery to shrink a large tumor and make the surgery easier (neoadjuvant therapy).
- Targeted therapy for colorectal cancer. Unlike chemotherapy, which affects healthy cells along with cancerous tissues, targeted drugs attack only malignant cells and do not cause significant side effects. Targeted therapies are widely used in the treatment of colon cancer, especially in stage IV disease. According to some studies, when used with conventional chemotherapy, these drugs may increase performance of the treatment by 25–30%.
- Radiation therapy for colon cancer. Radiotherapy uses high doses of radiation to destroy or reduce the size of tumors. It is sometimes recommended for bowel cancer patients as a part of the treatment plan to eliminate residual cancer cells or metastases. At Acibadem, our facilities are equipped with the latest hi-tech devices for the delivery of radiotherapy, including MRIdian by ViewRay, which allows for ultra-accurate radiation treatment of hard-to-reach and moving tumors in the abdomen.
