T2 is usually used to describe the size of a cancer, also called its stage. So, it sounds as if your mother's tests have shown not that she has T2 'cancer cells' but that the stage of her cancer is T2. This means the growth is in the larynx and has spread a little way into nearby tissue. Most T2 cancers of the larynx are cured with radiotherapy or surgery.

Doctors rely on information about the stage of a cancer - its size and whether it has spread - to decide how best to treat it.

As well as being helpful in planning treatment knowing the stage of a cancer, (along with other factors) can help to predict the outcome of treatment.

There are different ways of describing the stages of a cancer these are called staging systems.

One of the most widely used is called the TNM system. This looks at three things:

• T - the size of the primary tumour: numbers from 0 to 4 are used to describe this. 0 means there is no tumour present and 4 that the tumour is large. So the primary tumour will be staged between T0 to T4
• N - whether or not the cancer has spread to nearby lymph nodes: N0, means no lymph nodes are affected, N1 means the cancer has spread to the nodes.
• M - whether the cancer has spread (metastasised) to other parts of the body: M0 means no sign of metastases, M1 means the cancer has spread elsewhere.