What is colon cancer?
Colon cancer is a malignant tumor that develops in the large intestine (colon). The most common type of colon cancer is adenocarcinoma.
What are the causes of colon cancer?
Genetic and dietary factors may contribute to the occurrence of colon cancer. Genetic factors include people who have a personal history of polyps or colon cancer, people with long-standing ulcerative colitis or Crohn’s disease, and people with a family history of colon cancer.
Dietary factors thought to contribute to the development of this cancer include:
- excessive consumption of red meat (more than 3-4 times a week) and animal fat.
- obesity and lack of physical exercise.
What are the symptoms of colon cancer?
The symptoms caused by colon cancer are related to the location of the tumor in the intestine, its size and the damage it has caused.
Symptoms include intestinal obstruction mainly on the left side where the lumen is narrower. That may cause persistent constipation or a change in bowel habits, i.e. someone who with regular bowel movements gets constipated, or someone otherwise constipated has a high frequency of small bowel movements.
Other symptoms include intestinal colic, bright red blood in stools, weight loss without a clear cause, a feeling that the bowel does not empty completely after bowel movements, unjustified anemia, etc.
How is colon cancer diagnosed?
The following tests help diagnose colon cancer:
- Colonoscopy and sigmoidoscopy, which are performed by a gastroenterologist. Below you can watch a polyp removal during colonoscopy.
- Fecal occult blood test (FOBT), which is easily carried out at home (a small amount of feces is placed on a special strip and the detection takes place – however, special instructions from the attending physician are necessary before the test).
- Computed tomography (CT) of upper and lower abdomen with oral and intravenous contrast. This test is essential for staging the cancer.
- If the cancer affects the rectum or anus, magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are essential tests.
Colon cancer surgery
The treatment of colon cancer requires the surgical removal of the part of the colon bearing the tumor (colectomy) as well as any lymph nodes in the area. After the removal of the affected part of the intestine, the remaining bowel is then sutured (anastomosis) to restore continuity to the gastrointestinal tract.
International guidelines require the removal of a sufficient part of the colon and a great number of lymph nodes in order for the surgery to be oncologically adequate. Also, the surgical resection margins must be “clean” of cancer cells.
Colectomies have evolved into even more radical operations in order to have a better oncological outcome. The concept of Complete Mesocolic Excision (CME) has been well established in colon oncological surgery, its oncological benefit for the patient has been proven and is thus applied in our clinic.
Depending on the location of the tumor, the types of surgery that may be carried out include:
- Right colectomy
- Extended right colectomy
- Transversectomy (in special cases)
- Left colectomy
- Subtotal colectomy
- Low anterior resection
- Abdominal resection
Laparoscopic or Robotic Colectomy
The vast majority of these operation are performed with laparoscopy or robotic surgery, offering the patient maximum cure rates and at the same time all the advantages of minimally invasive surgery. With either laparoscopy or robotic surgery patients suffer minimal pain postoperatively and return to their daily activities and work much faster. Also, patients have much smaller incisions and significantly lower rate of complications, such as wound infection, postoperative hernias, ileal adhesions, etc.
Robotic colectomy is essentially a laparoscopic colectomy performed with more modern – modular tools with better, three-dimensional visual access on the surgical field. These advantages contribute to better carrying out anastomoses of the intestine within the body as well as sensitive lymph node resection next to large vessels.
Whenever the use of minimally invasive techniques is not feasible, open surgery is performed.
The main and objective of the operation is to perform an oncologically adequate surgery. All other goals are secondary to that. It is evident in international literature that with laparoscopic and therefore with robotic colectomy, the removal of the tumor and the neighboring lymph nodes is entirely safe and as adequate as in open surgery. Adjuvant treatment for colon cancer is chemotherapy, pre- and post-operatively or only post-operatively, applied on a case-by-case basis and depending on the staging of the cancer.
In special cases of intraperitoneal tumor spread, surgical techniques such as peritonectomy, and cytoreduction with or without intraperitoneal chemotherapy (HIPEC) are applied.
After the operation, the patient must undergo check-ups periodically in the form of:
- physical examination of the patient by the doctor
- measurement of liver enzymes in the blood
- CT scan of the abdomen and chest
- colonoscopy and
- measurement of certain cancer markers in the blood such as CEA and CA19-9
How can colon cancer be prevented?
To prevent colon cancer:
- Eat fruit, vegetables and calcium-rich food.
- Avoid smoking and a sedentary lifestyle and exercise regularly, e.g. half an hour of walking a day.
- The removal of colon polyps is important.
- After 50 years of age all people should visit a gastroenterologist and undergo a colonoscopy. This age tends to be revised down, due to the high incidence of colon cancer we are seeing lately at younger and younger ages.
- If the 1st colonoscopy is ‘clear’ it should be repeated every 5 years.
- People with a family history or other risk factors should have a colonoscopy starting at age 35-40.
Early diagnosis of colon cancer is very important. Early diagnosis and proper treatment leads to a complete cure in 90% of cases. This is why preventive colonoscopy according to the guidelines mentioned above is of great importance.
For more information you can read the relevant article by Surgeon General Pericles Chrysocheris published on the hygeia.gr website.