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Information for patients and families
What is this information about?
This information is about pembrolizumab treatment before and after an operation (surgery) for some head and neck cancers.
It explains:
- what pembrolizumab is
- why your cancer team may offer it
- who may be able to have it
- the tests you may need
- what happens before, during and after your operation
- possible side effects and when to get urgent help
- who will care for you and how to contact the team.
Why have I been given this information?
Your cancer team is considering treating you with pembrolizumab because you have a type of head and neck cancer that an operation can remove. You may benefit from treatment before and after your operation.
Be aware,
your team is still waiting for the PD-L1 test result from your biopsy. If the tumour PD-L1 test is positive, your team will advise you to have pembrolizumab.
The aims of pembrolizumab treatment are to:
- help your immune system target cancer cells before your operation
- cut the chance of the cancer coming back after treatment
- improve long-term cancer outcomes.
Reading this information will help you to know what to expect from pembrolizumab treatment.
What is pembrolizumab?
Pembrolizumab (Keytruda®) is a type of treatment called immunotherapy. It helps your body’s immune system find and attack cancer cells.
Your team uses it with an operation and, where needed, radiotherapy or chemoradiotherapy. Chemoradiotherapy means radiotherapy and chemotherapy given as part of the same treatment. This treatment is for some head and neck cancers.
What tests may I need before treatment?
You may need some or all of these tests to help your team plan the best treatment for you:
- a biopsy of the tumour
- a PD-L1 test on the biopsy sample
- a CT scan, an MRI scan or both of your neck
- a CT scan of your chest
- a PET-CT scan
- blood tests.
What will happen during my treatment?
Before your operation
You will have one dose of pembrolizumab as an injection under your skin (subcutaneous injection). You will usually have it about 6 weeks before your planned operation.
During this time:
- your cancer team will check your health and your cancer
- you may have further scans or checks
- your team will confirm the date of your operation.
Your operation
Your surgeon will carry out your operation in line with standard cancer treatment. They will:
- aim to remove all cancer that they can see with a clear edge of tissue around it (clear margins)
- remove any lymph nodes that need treatment
- rebuild the area if needed (do reconstruction surgery).
After your operation
Doctors who study tissue (pathologists) will check the tissue removed during your operation. The results will help your team decide if you need:
- radiotherapy on its own or
- chemoradiotherapy, which is radiotherapy with chemotherapy.
More pembrolizumab treatment
After your operation, you will have eight more doses of pembrolizumab. You will have:
- each dose as an injection under your skin
- one dose every 6 weeks
- treatment for 48 weeks.
You may have some doses while you are having radiotherapy or chemoradiotherapy. Your oncology team will explain your treatment plan to you.
You will have nine doses of pembrolizumab in total: one before your operation and eight after it.
What is the treatment timeline?
| Treatment Stage | What Happens |
| Diagnosis | You have scans, a biopsy and an MDT review. |
| Before your operation | You have one pembrolizumab injection under your skin. |
| About 6 weeks later | You have your operation. |
| After your surgery | The team reviews your tissue test results. |
| If needed | You have radiotherapy or chemoradiotherapy. |
| Ongoing treatment | You have eight pembrolizumab injections, one every 6 weeks. |
| Follow-up | You have regular clinic visits and checks. |
What side effects can pembrolizumab cause?
Pembrolizumab makes your immune system more active. It can sometimes cause your immune system to attack healthy tissue.
More usual side effects linked to the immune system include:
- a skin rash or itching
- thyroid problems, which may mean that you need hormone tablets for life
- watery poos (diarrhoea) or swelling in the bowel (colitis)
- swelling in the lungs (pneumonitis)
- swelling in the liver (hepatitis)
- kidney problems.
The team can treat most side effects with success if you report them early.
When should I contact my treatment team at once?
Contact your treatment team at once if you have:
- new breathlessness or breathlessness that gets worse
- a cough that does not go away
- severe diarrhoea
- a severe skin rash
- yellowing of your skin or eyes
- tiredness that is not usual for you
- any new symptom that concerns you.
Do not wait until your next appointment to tell us if you get any side effects.
Who will look after me?
A specialist head and neck MDT will plan and manage your care. The team may include:
- surgeons
- clinical oncologists
- pathologists
- radiologists
- clinical nurse specialists (CNS)
- speech and language therapists
- dietitians and other health care staff.
How do I contact the team?
Clinical Nurse Specialist
01273 696955
Ext. 67435
Out-of-hours contact
01273 696955
Ext. 67499 (24-hour helpline)
In an emergency
Phone: 01273 696955 and ask the switchboard to bleep 6060 or go to A&E straight away.
Where can I get more information?
If you have questions about your treatment, speak to your surgeon, oncologist or clinical nurse specialist.
This leaflet is based on the British Association of Head and Neck Oncologists (BAHNO) Clinical Guideline: Delivery of Perioperative Pembrolizumab for Resectable Locally Advanced Head and Neck Squamous Cell Carcinoma, version 1.0, August 2026.
This leaflet is intended for patients receiving care in Brighton and Hove.
The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.
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