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Osteosarcoma Toolkit

Welcome to our Osteosarcoma Toolkit. Here you will find information on what osteosarcoma is and how it is diagnosed and treated.

Read our whole toolkit or click on the links below to jump to specific sections.

What is Cancer? 

What is Osteosarcoma? 

What Causes Osteosarcoma? 

What are the Symptoms of Osteosarcoma? 

How is Osteosarcoma Diagnosed? 

What does the Cancer Grade and Stage Mean? 

How is Osteosarcoma Treated? 

Living With and Beyond Osteosarcoma. 

Other Resources about Osteosarcoma. 

What is Cancer?

The body is made up of trillions of cells that contain DNA, the body’s genetic code. This code is like a recipe that determines how we grow and develop and ultimately make us us. Cells are constantly dividing and during this process the genetic code is copied. Sometimes mistakes happen and the code is copied incorrectly. These changes in genetic code are known as mutations and most of the time they are harmless (the recipe still works).  However in some cases mutations result in cells that divide uncontrollably leading to cancer.

Cancer cells will often start in one place and form a mass known as a tumour. These cells can spread to other areas of the body in a process known as metastasis.  It is important to note that some tumors are benign (not cancerous) and do not spread to other areas. 

There are many different types of cancer and diagnosing which cancer you have is the first step to developing a treatment plan.

What is Osteosarcoma?

Osteosarcoma is a type of cancer that arises in the bone and affects 3.4 people per million every year worldwide. It most frequently arises at the ends of long bones (e.g. leg and arm bones), in an area known as the metaphysis. Bone growth is regulated by cells called osteoclasts and osteoblasts, which work together to keep bones healthy. Osteoclasts remove old bone, while osteoblasts make new bone. In osteosarcoma, the cancer cells cause the signals between these cells to be disrupted resulting in the osteoclasts destroying healthy bone and leading to tumour growth.

What Causes Osteosarcoma?

The cause of osteosarcoma is unknown. No environmental factors or specific mutation have been identified as a causative factor. However, there are certain factors that may increase an individual’s risk of developing osteosarcoma. In other words having these risk factors doesn’t mean you will develop osteosarcoma but that you are at greater risk than someone who doesn’t have these factors.  

Risk Factors  

  • Genetic Conditions (Li Fraumeni syndrome and Retinoblastoma)
  • Age (Adolescents and young adults – may be associated with bone growth)
  • Paget’s disease (A condition that causes abnormal bone formation)
  • Previous Radiotherapy (Radiotherapy is used to treat cancer but involves high doses of radiation, which can increase your risk of developing cancer in the future)

What are the symptoms of Osteosarcoma?

The most common symptom of osteosarcoma are: 

  • Progressive bone pain that is usually worse at night and disrupts sleep. 
  • Swelling which can restrict movement.
  • Breaks from minor injuries.

There are also non specific symptoms that are seen across all cancers which include loss of appetite and weight loss.

How is Osteosarcoma Diagnosed?

Here we provide an overview of If a doctor suspects osteosarcoma, they will organise a number of scans to look at the bone(s) in more detail. This will normally include an x-ray followed by an MRI or CT scan (see our ‘Types of Scan’ page to find out more).  Next, a biopsy will be taken. This involves using a needle to remove some cells from the bone. A doctor known as a pathologist will examine the cells under a microscope and confirm if the cells are cancerous and what type of cancer it is. If osteosarcoma is confirmed, a full body scan known as a staging scan (or PET scan) will be performed to see if the cancerous cells have spread to other areas in the body.  The case will then usually be referred to a team of specialist sarcoma doctors who will meet to formulate a personalised treatment plan. The meeting is known as a Multidisciplinary Team Meeting (MDT). 

Each person’s diagnostic pathway will be slightly different. We have provided an overview of what to expect but a diagnosis may be made at any point during the investigations. 


01 | X-Ray

A scan is performed to look at the bone in more detail.

02 | MRI/CT

This is followed by scans that build more detailed images of the bone and surrounding structures.

03 | Biopsy

A small sample of cells is then removed from bone and examined under a microscope.

04 | PET Scan

A scan to see if the cancer cells are elsewhere in the body will be performed. This will be used to stage the cancer.

05 | MDT 

Experts come together to discuss your case and create a treatment plan.

What does the Cancer Grade and Stage Mean?

You may hear doctors refer to your cancer as a certain grade or stage. The stage and grade of your cancer helps doctors to formulate a treatment plan.

The grade of a cancer refers to how it looks under the microscope.

  • Low Grade Cancers – The cells look relatively normal and usually divide slowly. These cancers are slow growing and less likely to spread.
  • High Grade Cancer – The cells look abnormal and usually divide quickly. These cancers are normally fast growing and may spread to other areas in the body.

The stage of your cancer refers to its size and whether it has spread to other areas of the body. It is used by doctors to create treatment plans. There are several different staging systems used for osteosarcoma with the most common being TNM (tumour, node, metastasis) and Enneking staging system

TNM Staging

TNM stands for tumour, node, metastasis. 

Tumour refers to how big the mass is. 

  • T1 – The tumour is less than 8cm wide.
  • T2 – The tumour is more than 8cm wide.
  • T3 – There is more than one area of cancer in the same bone.

Nodes describe if the cancer has spread to lymph nodes.

  • N0 – No lymph nodes involved.
  • N1  – Lymph nodes are involved.

M describes if the cancer has spread to other areas of the body.

  • M0   – The cancer has not spread to other parts of the body.
  • M1a  – The cancer has spread to the lungs.
  • M1b  – The cancer has spread to other parts of the body (excluding the lung).

Once the cancer has been assigned a TMN stage is then combined with the cancer grade to determine the stage of the cancer (between 1 and 4). The table below demonstrates how they are combined. This does not include osteosarcoma that originates in the spine or pelvis. Find out more about the staging for these types of osteosarcoma at The American Society of Oncology.  



Size (T)

Node (N)

Spread (M)

1A Low T1 N0 M0
1B Low T2/T3 N0 M0
2A High T1 N0 M0
2B High T2 N0 M0
3 High T3 N0 M0
4A High or Low T1/T2/T3 N0 M1a
4B High or Low T1/T2/T3 N1 M1b


How is Osteosarcoma Treated?

Although treatment varies slightly in different countries, most people will be offered chemotherapy and/or surgery depending on the stage and grade of the cancer. Chemotherapy is a group of drugs that work by killing cells that are rapidly dividing. It has a systemic effect and may be given before and/or after surgery.

Surgery is performed to remove the primary tumour (the origin of the cancer cells). Surgeons are trained to preserve as much of the limb as possible but there are cases where amputation is required. The Bone Cancer Research Trust has resources dedicated to providing support and information about amputations. In some cases, people will also have an operation known as a metastasectomy to remove any tumours that have formed in the lungs (the most common site of metastasis in osteosarcoma) .

Not everyone will respond to chemotherapy and alternative treatment options are limited. Fortunately, there are a number of drugs being tested in clinical trials. Clinical trials are medical research studies requiring patient participation to test a new treatment. You can find out more about clinical trials here.  

Living With and Beyond Osteosarcoma?

Everyone’s cancer journey is different, and many people benefit from support during and after treatment. Throughout and after your treatment journey your consultant will book regular appointments to monitor your progress and address any concerns.  You will usually be monitored for at least 10 years after finishing treatment although the frequency of visits will decrease.

There are also a number of wonderful organisations that provide mental and physical support for those living with and beyond osteosarcoma including loved ones. You can find a list of global organisations here.

Other Resources About Osteosarcoma

The Bone Cancer Research Trust have fact sheets and booklets about osteosarcoma for both adults and teenagers.

Sarcoma UK has information about osteosarcoma. 

MIB agents have a book written by osteosarcoma families to support families through the treatment journey. The book is available in multiple different languages. 

The NHS provides information about osteosarcoma.    

It’s that connection between the patient and the team and myself and also the interplay between looking after a teenager and their parents and the rest of the family I found really rewarding

Dr Sandra StraussUCL

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