Stages of vulval cancer

The stage of cancer tells the doctor how large the cancer is and how far it has spread. The tests and scans you have when diagnosing your cancer give some information about the stage. It is important because treatment is often decided according to the stage of a cancer. The lower the stage, the earlier the cancer has been diagnosed. Generally, the earlier a cancer is diagnosed, the more likely it is to be successfully treated and cured.

There are different ways of staging cancers. The two main ways are the TNM (tumour, node, metastasis) system and number systems. There is more about staging cancers in the about cancer section on how cancers grow.

Vulval cancer is usually staged according to the FIGO (International Federation of Gynaecology and Obstetrics) system. There are 5 main stages. Stage 0 is the earliest stage and stage 4 the most advanced. Doctors usually write these in Roman numerals as 0, I, II, III and IV.

Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the vulva (local recurrence) or in another part of the body.

This is a very, very early stage. The cancer has not yet begun to invade the tissues, but there are cancerous cells in the uppermost layer of skin of the vulva. It is sometimes called carcinoma in situ (CIS). This stage is not an invasive cancer. Many doctors now say this stage is the same as VIN3, a pre-cancerous stage that may never go on to develop into a cancer.

In stage 1, the cancer is found only in your vulva, or in the vulva and perineum (the space between the anus and the vagina). There is no obvious cancer in the lymph nodes.

Stage 1 can be divided into stages 1A and 1B. Stage 1A cancer is 2cm or less in size and has only grown 1 millimetre or less into the skin. Stage 1B cancer measures more than 2cm across and has grown more than 1 millimetre into the skin.

Doctors distinguish between these 2 groups because it is extremely rare for stage 1A cancers to have spread to the lymph nodes. So if you have a stage 1A cancer, your specialist may not think it necessary to remove lymph nodes to check for signs of spread.

If you have a stage 1B cancer, your specialist may be more likely to want to check your lymph nodes. But it is still not common for stage 1B cancers to spread to the lymph nodes.

In stage 2, the cancer has spread from the vulva to nearby tissues such as the lower part of the vagina, the lower part of the tube urine passes through (the urethra) or the anus. There is no obvious cancer in the lymph nodes.

Stage 3 means the cancer has spread to nearby tissues, such as the vagina, anus or the lower part of the tube urine passes through (the urethra). The cancer has also spread to nearby lymph nodes. And it may have spread outside the lymph nodes into the surrounding tissue. 

Stage 4 vulval cancer is advanced cancer. This stage is divided into stages 4A and 4B.

In stage 4A, the cancer has spread into the upper urethra, the lining of the vagina or the lining of the anus. Or into the lining of the bladder or bowel. And it may have spread to lymph nodes on both sides of your groin.

In stage 4B, the cancer has spread to the lymph nodes in your pelvis or other parts of your body further away from the vulva.

Normal body cells are quite specialised. This means that cell types look different from one another under a microscope. So doctors can look at them and say where in the body they have come from. Doctors describe this development of cells as 'differentiation'. Cancer cells are more primitive than normal cells and tend to have lost some or all of this specialisation.

Cancer cells are graded, according to how they look under a microscope. In other words, they are graded according to how specialised they are. The more normal (or specialised) the cells look, the lower the grade. The lower the grade, the slower the cancer is likely to grow, the less likely it is to spread and the less likely it is to come back after successful treatment. This is only a rule of thumb. But doctors tend to look at stage and grade together in order to decide on the best treatment for you. Vulval cancer usually has 3 grades

• Grade 1 cells are low grade or 'well differentiated' - they look very much like normal vulval cells
• Grade 2 cells are medium grade or 'moderately differentiated' - they look more abnormal than grade 1 cells, but not so much as grade 3 cells
• Grade 3 cells are high grade or 'poorly differentiated' - they are very unlike normal vulval cells

Sometimes cancer cells can be 'undifferentiated'. These cells have lost all their specialisation. These may also be described as high grade. Unfortunately, undifferentiated cancers tend to be quite aggressive and fast growing. Sometimes, it is hard for a pathologist to decide where undifferentiated cancer cells originally came from in the body. So if you have undifferentiated cells in your lymph nodes, the pathologist cannot always tell what type of cancer it is.