Anal Cancer: Chemotherapy

What is chemotherapy? 

Chemotherapy (chemo) uses anticancer medicines to kill cancer cells. The medicines are made to attack and kill cancer cells that grow quickly. Some normal cells also grow quickly. Because of this, chemo can also harm those cells. This can cause side effects.

For this treatment, you’ll see a medical oncologist. This is a doctor who specializes in using medicines to treat cancer. For anal cancer, your doctor is likely to give you more than one medicine. This is called combination chemotherapy.

When might chemotherapy be used for anal cancer?

Chemo given at the same time as radiation (chemoradiation) is the first treatment used for most anal cancers. In some cases, it can cure the cancer without surgery. If chemoradiation doesn’t destroy the cancer, you may need more chemo.

Sometimes chemoradiation is given after surgery. This is done to help kill any cancer cells that may be left in your body. This can help lower the chance that the cancer will come back after treatment.

Chemo may be used if the anal cancer has spread to distant parts of your body. This can include your lungs or the liver. This can help keep the cancer from growing, slow its growth, or relieve problems the tumor is causing.

How is chemotherapy given for anal cancer?

You may receive these medicines intravenously (IV) into a vein. Chemo is a systemic treatment because the medicines travel all through the body in your bloodstream. Most people with anal cancer have chemo in an outpatient part of the hospital, at the healthcare provider’s office, or, less often, at home. In some cases, depending on your health or the medicines you take, you may need to stay in the hospital during treatment.

Chemo is given in cycles. This means you’re treated for a period of time with chemo and then you have a rest period. Each treatment and rest period make up one cycle. You'll likely have more than one cycle of treatment. Your healthcare provider will explain what your treatment plan will be and what you can expect. The length of each treatment period and the number of cycles differ depending on the type of medicines you take. With many types of chemo, monthly treatments are common. Sometimes you will get chemo more often.

If you need to have an IV for each cycle of chemotherapy, it can be helpful to have a vein (venous) access device or an indwelling catheter. A catheter is a thin, flexible tube. The catheter would stay in place between cycles so that you don't have a new IV started each time you get treatment. One end of the tube is placed into a vein near your heart. The other end is placed just under the skin or comes out through the skin. The chemo can then be connected to it when you have treatment. Your healthcare team can talk with you about the risks and benefits of these devices.

What are common chemotherapy combinations used to treat anal cancer?

These are the main chemo regimens healthcare providers use to treat anal cancer:

• 5-fluorouracil and mitomycin C

• 5-fluorouracil, mitomycin C, and cisplatin

What are common side effects of chemotherapy for anal cancer?

Chemo affects both normal cells and cancer cells. Side effects depend on the type and amount of drugs you take. Ask your healthcare provider which ones are the most likely to happen to you. Common side effects can include:

• Constipation

• Diarrhea

• Infections

• Fatigue

• Hair loss

• Mouth sores

• Nausea and vomiting 

• Loss of appetite

• Low blood cell counts

• Easy bleeding or bruising

• Numbness or tingling in fingers and toes

Most side effects will go away or get better between treatments and will go away over time after treatment ends. You may also be able to help control some of these side effects. Tell your healthcare providers about any side effects you have. They can help you manage your symptoms.

Working with your healthcare provider

It's important to know which medicines you're taking. Write your medicines down, and ask your healthcare team how they work and what side effects they might have.

Talk with your healthcare providers about what signs to look for and when to call them. For example, chemo can make you more likely to get infections. Make sure you know what number to call with questions. Is there a different number for evenings and weekends?

It may be helpful to keep a diary of your side effects. Write down physical, thinking, and emotional changes. A written list will make it easier for you to remember your questions when you go to your appointments. It will also make it easier for you to work with your healthcare team to make a plan to manage your side effects.