Types of surgery for anal cancer

You might have surgery for anal cancer if you have a very early cancer (stage 1) of the anal margin. Or if you've had chemoradiotherapy that didn't get rid of the cancer completely.

There are different types of surgery for anal cancer. These include:

• removing the area containing the cancer cells in the anus. This is called a local excision.
• removing the anus, rectum and part of the large bowel (colon). This is called abdominal-perineal resection (APR).

When do you have surgery?

The main treatment for anal cancer is a combination of chemotherapy and radiotherapy (chemoradiotherapy). 

But you might have surgery as your main treatment if you have a very small cancer in the lower part of the anus (the anal margin).

You might also have surgery if:

• chemoradiotherapy didn't get rid of the cancer completely - you might hear this called salvage treatment
• your cancer comes back after having chemoradiotherapy

Before your operation, your doctor will talk to you about the best type of surgery for you. 

Removing an early cancer of the anal margin

Your surgeon removes the cancer in an operation called a local resection. They leave the muscles around the anus (anal sphincter) intact so you can still control your bowel. 

Your surgeon will send the cancer tissue to the laboratory. A specialist doctor (pathologist) examines it under a microscope. They check that the border of tissue around the tumour is free of cancer cells. This is called a clear margin.

You need a general anaesthetic for this operation and usually stay in hospital for a few days.

Removing the anus, rectum and part of the large bowel

This operation is called an abdominoperineal resection (APR). You might have an APR if your cancer has come back or if it hasn’t gone completely after chemoradiotherapy.

A small number of people might have an APR as their first treatment instead of chemoradiotherapy. This can be when you:

• had previous radiotherapy to your lower tummy (pelvis), and you can’t have more radiotherapy to cure the cancer
• have a type of anal cancer called adenocarcinoma or adenosquamous carcinoma, which doesn’t respond that well to radiotherapy
• are having drugs to suppress your immune system as part of a transplant, and you might not be fit enough to complete chemoradiotherapy without taking breaks
• decide against having chemoradiotherapy

 Your surgeon removes: 

• the anus
• the rectum
• a part of your colon

They might also remove: 

• some of the lymph nodes near your anus
• the lymph nodes in your groin

As part of this surgery, you will need to have a permanent colostomy. This is when the surgeon makes an opening in the skin of your tummy and stitches the end of your bowel to the opening. The opening is called a stoma. You wear a bag over the stoma to collect your poo (faeces) and will have this for the rest of your life. 

How you have surgery to remove the anus, rectum and part of the large bowel

To remove cancer of the anus, you might have open, keyhole or robotic surgery.

Open surgery

This means your surgeon makes one long cut down your abdomen to remove the cancer. 

Keyhole surgery

You might have part of this operation as keyhole (laparoscopic) surgery. Your surgeon makes several small cuts in your tummy (abdomen). This is instead of one large cut that you'd have with open surgery.

Your surgeon passes a long, narrow, bendy tube called a laparoscope through one of the cuts. The laparoscope connects to a camera that shows pictures of the inside of the body on a video screen. The surgeon then passes other instruments through the other cuts. They watch what they do on the screen. 

You might have one slightly larger cut in your tummy, where your surgeon carries out some of the surgery and takes out the tumour. With both open and laparoscopic surgery you will also have a wound around the anus, in the perineum.

Keyhole surgery seems to be as good as traditional open surgery at getting rid of the cancer. But the operation can take longer. People who have keyhole surgery may have:

• less pain
• less blood loss
• leave hospital sooner
• fewer wound infections

Your surgeon will discuss the risks and benefits of both types of surgery with you.

Robotic surgery

Some surgeons may use a robotic machine to do part of the keyhole operation. The surgeon controls the machine using a specialised unit. The robotic machine gives the surgeon a better view of the inside of your tummy and allows surgeons to make finer movements.

Robotic surgery is still a newer technique, and not all NHS hospitals in the UK have this. Doctors hope that robotic surgery will cause less nerve damage and have fewer side effects.