Your chemotherapy plan

Chemotherapy drugs are usually given in cycles over several months. A series of cycles is called a course of treatment.

How you have your course of chemotherapy is called your treatment plan or chemotherapy regimen.

How doctors choose your treatment

The treatment plan that your doctor chooses depends on a number of things including:

  • the type of cancer you have
  • where it is in your body
  • if it has spread and where to

Your doctor will also take your general health and fitness into account. Some drugs have more of an effect on your body than others. You need to be well enough to cope with any side effects of the treatment before you start. 

Length of treatment

A course of chemotherapy usually lasts between 3 to 6 months, although it can be more or less than that. How often you have each cycle, and how long your treatment course lasts, depends on many factors. These include:

  • type of cancer
  • stage of the cancer
  • types of drugs that you’re having
  • side effects the drugs might cause
  • time you’ll need to recover from side effects

Treatment cycles and courses of treatment have been developed through clinical trials. This has helped doctors determine which treatments have the most benefit with the least side effects. 

Cycles of treatment

You have chemotherapy treatment in cycles. A cycle is the time between one round of treatment until the start of the next. During a course of chemotherapy, you usually have around 4 to 8 cycles of treatment. 

After each round of treatment you have a break. This allows your body to recover. For example, if your cycle lasts 4 weeks, you may have treatment on the 1st, 2nd and 3rd days. You then have nothing from the 4th to the 28th day. Then the cycle starts again.

Or you may have a 3 week cycle where you have treatment on the 1st and 8th days. You then have nothing on days 2 to 7 and days 9 to 21.

Your treatment cycles might be weekly or take 2, 3, or 4 weeks or more, depending on the drugs and your treatment plan. Some treatment cycles are quite complicated. 

How often you have chemotherapy

Each treatment can last from a few hours up to a few weeks. How often you have chemotherapy depends on which drugs you are having and your treatment plan. 

Why you have chemotherapy in cycles

Treatment plans are based on years of research. Your doctor will suggest the best combination of drugs based on the results of these trials. The drugs aim to kill the cancer cells while causing as little harm as possible to normal, healthy cells.

You have chemotherapy as a course of treatments over a few months because:  

  • it allows the chemotherapy to kill more cancer cells
  • the rest between treatments allows your body to recover

At any one time, some of the cancer cells will be resting. Chemotherapy attacks cells that are in the process of splitting into two (dividing). So resting cells are not killed.

Some of the cancer cells that were resting during your first treatment will be dividing by the time your second treatment comes around. So they should be killed off.

Normal cells usually repair the damage from chemotherapy more effectively than cancer cells. So damage to cancer cells builds up without causing permanent damage to normal cells.

Checks during your treatment

Before you have each cycle of treatment your healthcare team will check how you are and do blood tests. They will also check how you're coping with any side effects. 

After a few cycles they might also check how the treatment is working. Some people might need a change in their treatment plan. This change may be a delay before your next treatment or a reduction in the dose of chemotherapy.

Sometimes it can be difficult to assess whether chemotherapy is working. For example, if you’re having chemotherapy after surgery to remove cancer. This treatment aims to kill off any cancer cells that may have broken away before your operation. These cells are too small to see on scans.

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Last reviewed: 
05 Dec 2023
Next review due: 
04 Dec 2026

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