colon cancer surgery and treatment

Question 1

What are the symptoms of colorectal cancer?

Answer 1

Colorectal cancer typically presents as chronic anaemia, loose more frequent stools, blood/mucus in the stool, tenesmus. Chronic anaemia typically presents if the cancer is of the right side (ascending colon), as the faeces is still liquidy here so there isn’t really any bowel obstruction effects. Therefore only usually anaemia is detected.

Question 2

What is tenesmus?

Answer 2

Tenesmus is the urge to go to the toilet despite just going. This occurs as the rectum stores faeces, however the mass prevents normal function. This makes you feel like you always need to go. This usually occurs in rectal masses.

Question 3

Why do patients typically present at late stages of disease?

Answer 3

As the symptoms are very general, they are often ignored by patients. It therefore doesn’t become apparent that a patient is suffering until the disease presents as an emergency, e.g. bowel perforation into the abdomen.

Question 4

What are the imaging tests associated with colorectal cancer diagnoses?

Answer 4

1. Rigid Sigmoidoscopy
2. Flexible Sigmoidoscopy
3. Endoscopy
4. Barium Enema
5. CT Colonoscopy

Question 5

What is a colonoscopy?

Answer 5

A colonoscopy involves an invasive procedure for which a camera is inserted through the rectum to visualise the colon epithelium and the presence of any masses/polyps. This is a long procedure for which the patient should be sedated, and requires bowel preparation beforehand to ensure the bowel is empty for clear visualisation.

Although the most widely used method, there are risks of bowel perforation in 1 in 1000 cases.

Question 6

Does an adenomatous polyp form cancer?

Answer 6

Although considered benign, adenomatous polyps may progress to cancer, therefore it may be preferred that these are removed.

Question 7

What are the downsides to rigid sigmoidoscopy?

Answer 7

This is not a pleasant procedure and can be very uncomfortable for the patient. Sigmoidoscopy only examines the lower third therefore it is not useful for visualising the whole colon.

Question 8

What is a CT Colonography?

Answer 8

This is a procedure by which a dye is injected into the anus, then a CT test is done. The images received from a CT test can be used to reconstruct a view so that it is as if we were doing a colonoscopy, however via a less invasive procedure. A downside to this is that you can’t see small polyps.

Question 9

What are the 2 types of polyps?

Answer 9

Hyperplastic and Adenomatous

Question 10

How are polyps removed?

Answer 10

The instrument is known as a diathermy snare. Using a colonoscope, the loop is fed round the stalk of the polyp and pulled up. This can then be sucked up. An endoscope is used for visualisation.

Question 11

What percentage of people with colorectal cancer present as incurable?

Answer 11

20%

Question 12

What must be done before colon cancer surgery?

Answer 12

We must establish baseline levels, e.g. FBC, U&Es, LFTs and most importantly carcinoma embryonic antigen (CEA). This is not a diagnostic biomarker, it is merely used to monitor the treatment response (should go down with increased treatment).
We must also stage the disease and look for metastasis via an Abdomen, Pelvis, and Chest CT scan.
At this stage, sometimes surgery is given first, however sometimes neoadjuvant therapy may be given.
We must also take anaesthesia pre-tests via an ECG.

Question 13

What is the Enhanced Recovery Programme?

Answer 13

This is a programme which assures all patients will have minimum recovery times, no lengthy fasting times, and fast mobilisation for surgery. This means laparoscopic surgery is often used more to prevent decreased recovery.

Question 14

What are the two most important things when removing a tumour?

Answer 14

1. The excision margins. Vary between hospitals but usually ~2mm.
2. Where the blood vessels are! We can’t interfere with the veins or arteries.

Question 15

What is a right and a left hemicolectomy?

Answer 15

A right hemicolectomy is the removal of the ascending colon. A left hemicolectomy is the removal of the descending colon.

Question 16

What is ‘anterior resection of the rectum’?

Answer 16

This occurs when the tumour mass is in the top part of the rectum. As a result, the sigmoid colon is joined to the anus.

Question 17

What happens if the cancer is lower down the rectum?

Answer 17

Have to do a abdominoperineal resection. The sigmoid colon is divided and closed - a colostomy.

Question 18

What happens to the tumour once it has been removed from the patient?

Answer 18

The tumour is sent to the pathology labs to look at the resection margins. The tumour must be situated within a decent proportion of mesorectal fat. Then the tumour will undergo staging and grading, however stage is more important than grade.

Question 19

What is the staging classification used for colorectal cancer?

Answer 19

Duke’s Staging is used and incorporates 5-year survival rates. There is A, B1, B2, C1, C2, D. This gives an idea of invasion and metastasis. Increased stage suggests decreased survival. Stage D refers to occurrence of distant metastases. This is associated with <1% 5-year survival.
There is also TNM classification, as used with breast cancer, where the T considers how far through the bowel wall the tumour has grown (invasion)

Question 20

How are rectal cancers diagnosed differently?

Answer 20

Rectal cancers may be preoperatively staged using an MRI. This allows us to see if the cancer is deep into the mesorectal fascia. If the tumour is near the mesorectal fascia then pre-operative radiotherapy is highly recommended as it has shown to reduce recurrence by ~50%

Question 21

What happens if secondary lesions occur in the liver?

Answer 21

There is possibility for liver resection. This does improve mortality and morbidity if given to the right patients. If the lesion is confined to the right/left lobe of the liver then the resection procedure is called ‘right/left hemicolectomy’. If there are multiple lesions confined to either lobe, it is called a hepatic trisegmentectomy.

Question 22

What are the therapeutic options for secondary liver lesions?

Answer 22

As well as resection, radiofrequency ablation may also be used. This involves an ultrasound probe and a radiofrequency ablation probe inserted into the tumour. The downsides to this procedure is that normal hepatic cells may also be killed.

Question 23

What occurs after surgery?

Answer 23

Follow up MUST occur, usually 4-6 weeks after. The patient must receive at least 2 CT scans in the first 3 years. They must have 6 monthly CEA tests for 3 years, as well as surveillance colonoscopy at years 1 and 5.