Colon cancer is cancer in any part of the large bowel (colon or rectum). It is sometimes known as colorectal cancer or rectal cancer, depending on where it starts.
This type of cancer develops in the inner lining of the bowel (mucosa) from growths on the bowel wall called polyps. Most polyps are harmless (benign), but some become cancerous (malignant) over time.
Cancer can narrow and block the bowel or cause bleeding and if untreated, can grow into the deeper layers of the bowel wall and spread from there to the lymph nodes (glands). These small, bean-shaped masses are part of the body’s lymphatic system. If the cancer advances further, it can spread to other organs, such as the liver or lungs (metastasis).
In most cases, the cancer develops slowly and stays in the bowel for months or years before spreading.
Bowel cancer is the second most common cancer and in Australia. It is estimated that about 17,000 people are diagnosed with bowel cancer every year. About one in 19 men and one in 28 women will develop bowel cancer before the age of 75.
Signs and Symptoms
In its early stages, bowel cancer often has no symptoms. However, some people with bowel cancer may experience persistent symptoms.
- Changes in previously normal bowel habits such as
- Diarrhoea, constipation, smaller more frequent bowel movements
- Appearance of the stool may change (narrower stools or presence of mucous)
- Feeling of fullness or heaviness in the rectum or bowel
- A feeling that the bowel has not emptied completely after a bowel movement
- Blood in the stools or on the toilet paper
- Unexplained weight loss or loss of appetite
- Weakness or fatigue related to anaemia through chronic blood loss.
- Rectal or anal pain
- Please note: Not everyone who has these symptoms has bowel cancer. Other conditions such as Haemorrhoids, Diverticular disease (inflammation of pouches in the bowel wall) tears in the anal canal or some foods or medications can also cause these symptoms
Short-term changes in bowel function are very common and usually do not indicate a serious problem. However, if you have any of the above symptoms for more than four weeks, see your doctor promptly for a check-up.
- Age – most commonly affects people over the age of 50 but can occur at any age. The average age at diagnosed is 69 years, however, about 7% of bowel cancers are in people younger than 50.
- Polyps – the presence of polyps in the bowel.
- Bowel diseases – people who have an inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, have a significantly increased risk, particularly if they have had it for more than eight years
- Lifestyle factors – being overweight, having a diet high in red meat (particularly processed meats such as salami or ham), drinking alcohol and smoking increase the risk
- Other diseases – people who have had bowel cancer once are more likely to develop a second bowel cancer as are people who have had other cancers such as ovarian or endometrial cancer.
- Strong family history – bowel cancer may run in families especially if a parent or sibling has been diagnosed before they turned 55.
- Rare genetic disorders – Familial adenomatous polyposis (FAP) and Lynch Syndrome.
- These are rare and account for about 5-6% of bowel cancer cases.
Being physically active, maintaining a healthy weight and eating a high-fibre diet may help protect against bowel cancer.
Colectomy is the surgical procedure to treat colon cancer.
Please refer to the laparoscopic "For patients" page of the website for more information about the open management of this condition.
At Casey Surgical Group we recommend laparoscopic colectomy wherever possible.
During a laparoscopic colectomy, the surgeon makes a small incision approximately 1.5 cms through the abdominal wall. He/she enters the abdomen by placing a cannula or port (narrow tube-like instrument) through the small incision. Carbon dioxide (CO2) gas is then pumped into the abdomen through the port to create more space inside the abdomen. The laparoscope a tiny telescope connected to a video camera is then passed through the cannula to allow the surgeon to see a magnified, lighted view of the internal organs on a high-definition monitor screen. A television monitor will guide the surgeon in the insertion of slender specialised instrument to where the cancer is located. As many as five small incisions may be made to allow the surgeon and an assistant to effectively see and work inside the abdomen.
The segment of diseased bowel is then freed from its attachments to other organs and/or the abdominal wall. The blood vessels supplying only that segment are then sealed with a specially designed cutting instrument or clips and divided. An incision is made and the segment of colon is extracted out of the abdomen. The two remaining ends of the colon are then reconnected, either with a surgical stapler or sutures.
The surgery usually takes between 2 -4 hours. The exact same operation is performed on the inside as with an open colectomy. However, there is less pain and recovery is usually faster.
Rarely an operation that starts out as a laparoscopic colectomy turns into open surgery if the surgeon encounters unexpected difficulties.
Please refer to the Colorectal "For Patients" page for more information about the open management of this condition.
A hospital stay of 3-6 days is usual in 80% of patients after laparoscopic colectomy.
A longer hospital stay may be required if the bowel is slow to tolerate oral food intake or if infection is detected in the wound (from surgery) or the chest (from the anaesthetic).
Risks and Complications
As with any surgical procedure there is the possibility of complications
With Laparoscopic Colectomy these may include:
- Post-operative bleeding
- Injury to nearby structures including the intestines, the bladder, blood vessels and the ureter (a tube that carries urine from the kidney to the bladder).
- Anastomotic leak – The site where the two ends of bowel are reconnected (the anastomosis), is susceptible to possible leakage.
- Scarring leading to the formation of adhesions.
- Blood clots can occur in the veins, and these can travel to the lungs.
- Herniation at the surgical incisions sites.
- Bowel obstruction from internal scar tissue can also occur, even years later.