Treatment options for cancer of unknown primary

The team looking after you will discuss your treatment options with you. Treatment for cancer of unknown primary (CUP) can include:

• chemotherapy

• immunotherapy or targeted cancer drugs

• radiotherapy

• surgery

• treatment to help control symptoms

You may also have treatment as part of a clinical trial. 

Deciding which treatment you need

A team of doctors and other professionals discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).

The treatment you have depends on:

• where your cancer is

• if it has spread to more than one area of the body

• where your doctor thinks the cancer may have started

• how abnormal the cells look under a microscope

• your general health and level of fitness

• your personal wishes

Your doctor will discuss your treatment, its benefits and the possible side effects with you.

Doctors can't cure most cases of CUP. This is because the cancer has already spread from one part of the body to another. But treatment can control it, relieve symptoms, and give you a good quality of life. Your doctor may also suggest holding off treatment for a while if you don't have many symptoms.

Finding out that your cancer can't be cured can be a big shock. It might help to talk to a close friend or relative about how you feel.

Chemotherapy

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. The drugs circulate throughout the body in the bloodstream.

You often have a combination of 2 or 3 chemotherapy drugs.

Immunotherapy or targeted cancer drugs

Immunotherapy uses your immune system to fight cancer. Targeted cancer drugs target the differences between cancer cells and normal cells that help them grow and survive.

Your doctor might do further tests on the tissue sample used to diagnose CUP. They might do tests called gene expression profiling or molecular profiling. They look for certain proteins or gene changes on the surface of the cancer cells. 

If certain changes are found you may be able to have treatment with a targeted cancer drug. Your doctor will tell you if this is possible. This may be as part of a clinical trial. 

Radiotherapy

Radiotherapy uses high energy rays to kill cancer cells. You might have radiotherapy:

• to help treat symptoms caused by the cancer, such as pain. This is called palliative radiotherapy
• very occasionally to try to cure the cancer. For example, if you only have cancer in the lymph nodes in one area such as the neck

Depending on why you are having radiotherapy, you may have a single treatment or a course of treatments over several days or weeks.

Surgery

Surgery is not often used to treat CUP. This is because:

• the position of the primary cancer is not known

• doctors can't usually remove all the secondary cancers

But doctors may offer it in a very small number of circumstances. 

Surgery to remove swollen (enlarged) lymph nodes in the head and neck area or groin

Tests may show that the cancer has spread to the lymph nodes in the head and neck area or groin. In this case, you usually have surgery to remove the lymph nodes in this area. This type of surgery is called lymph node dissection. This can cure some people with CUP if this is the only place where the cancer is. 

You often have radiotherapy to the area after this operation. This is to try to kill off any cancer cells that may have been left behind. Occasionally, you might also have radiotherapy to the area where your doctor thinks the primary cancer is most likely to be.

Surgery to help with symptoms

Your doctor may suggest surgery to relieve symptoms such as bleeding or blockages in the body caused by CUP. 

Clinical trials

Your doctor might suggest you take part in a clinical trial. Doctors and researchers do trials to make existing treatments better and develop new treatments.

Treatment to control symptoms

You might have other treatments to help control symptoms such as:

• painkillers

• anti sickness drugs

• steroids

• bone strengthening drugs such as denosumab

Your doctor might call this supportive or palliative care. You might have this in combination with the treatments mentioned above, or on its own.

Some people with advanced cancer might not be well enough to have certain treatments such as chemotherapy. Or they may choose not to have this kind of treatment. People can decide not to have treatment because of a number of reasons. For example, you may feel that the side effects of treatment outweigh the possible benefits.

Your medical team, including your specialist nurse, will support you. They can give you all the information you need to make decisions about treatment and answer any questions you have.

Your choices

Your doctor might offer you a choice of treatments. Discuss each treatment with them and ask how they can control any side effects. This helps you make the right decision for you. You also need to think about the other factors involved in each treatment, such as:

• whether you need extra appointments
• if you need more tests
• the distance you need to travel to and from hospital

You might have to make further choices as your situation changes. It helps to find out as much as possible each time. You can stop a treatment whenever you want to if you find it too much to cope with.

If you decide not to have treatment

You may decide not to have cancer treatments, such as chemotherapy. But you can still have medicines to help control symptoms, such as sickness or pain.

Your doctor or nurse will explain what could help you. You can also ask them to refer you to a local symptom control team to give you support at home.