Adenocarcinoma of colon: learn the early symptoms and improve your outcome

Gayane Badalian-Very MD, PhD
Dana Farber Cancer Institute
Harvard Medical School

What is the frequency of the disease?

The rate of Adenocarcinoma of colon has been steadily increasing in frequency in the United States. Colon cancers rank second to lung cancer in men and third to breast cancer and lung cancer in women in developed countries. 140,000 new cases are diagnosed each year making colon cancers one of the major life threatening malignancies in the United States.

What is the survival rate of the disease?

The overall 5-year survival rate is about 45%; however, patients diagnosed early demonstrate a survival rate of 70-80%. Therefore, patients’ awareness of the risk factors and the early symptoms of colon cancers could have a dramatic effect on their therapeutic outcome and overall survival.

What is the nature of affected cells in colon cancer?

Adenocarcinoma of colon begins in the glandular structure of colon and spreads through the lymphatic system to distant organs. The lungs and liver are frequently involved in advanced disease; however, bones could also be affected.

What are the risk factors?

Diet: High amounts of red meat and animal fat in the diet reduce the bulk of the stool and the frequency of defecations. A high fat diet also induces the growth of bacterial strains that produce carcinogens in the lumen of the large bowel. Longer exposure to toxic materials and presence of carcinogens in the large bowel slowly leads to permanent damage of glandular cells, and possibly colon cancer. It is easy to overcome this by incorporating fibers into your diet. Fibers contain cellulose, which can be neither digested nor absorbed, so most of the fibers end up in stool. This automatically increases the bulk of the stool, and the frequency of defecation. This simply means that the toxins are washed away more frequently. By reducing the exposure of our intestinal cells to the noxious materials, we reduce the risk of developing cancers.

Genetic: It is demonstrated that first-degree relatives of patients with carcinoma or polyps have a threefold to fivefold increased risk of development of colorectal cancers. Familiar adenomatous polyposis (FAP) accounts for 1% of colorectal cancers, whereas hereditary non-polyposis colorectal cancer (HNPCC) family syndromes account for 5-10% of colorectal cancers.

Other risk factors: Ulcerative colitis, familial polyposis syndrome, history of female genital or breast cancer, history of juvenile polyps, family cancer syndrome and immunodeficiency disease.

What are the early signs of the disease?

Most colorectal cancers do not present symptoms in the very early stages of the disease. Most early stage cancers are found through physical examinations like digital rectal exams (DRE). Ensure that you are paying regular visits to your primary care physician and remember to ask him/her for DRE if you are 50 years or older.

Late signs and symptoms vary, depending on the location and size of the tumor. Tumors in the left colon may manifest as obstructions. Right colon tumors frequently demonstrate the symptoms of iron deficiency anemia and are associated with fatigue. Pay attention to any change in your bowel habit (constipations, decrease in stool size, obvious blood in the stool, etc.). Do not ignore your abdominal discomfort if it is associated with changes in your bowel habits, and contact your primary care physician for additional evaluations.

How is colon cancer treated?

Treatment options are surgery, chemotherapy and radiation therapy. Surgery is the recommended treatment option for tumors above the peritoneal refection and usually involves partial colectomy. In the absence of colonic obstructions and the presence of metastatic disease, chemotherapy is recommended. Radiation therapy is usually used post operatively to relieve the symptoms of advanced colon cancer.

How could I combat colon cancer?

  • Incorporate fiber into your diet
  • Do frequent screenings (physical exam, colonoscopy) if you are 50 years old or older
  • Remember the risk factors of the disease, and if you are in the risk group consult your primary care physician.
  • Do not ignore changes in your bowel habits