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. There is more about staging cancers in the about cancer section on how cancers grow. One staging system is the TNM (tumour, node, metastasis) and number system. Stage 0 is the earliest stage and stage 4 the most advanced.

In the UK, vulval cancer  is often staged according to the FIGO (International Federation of Gynaecology and Obstetrics) system. There are 4 main stages in this system. 

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.

Vulval intraepithelial neoplasia (VIN) is not vulval cancer, but could turn into a cancer. There are abnormal cells in the surface layer of the vulva. But the cells are only in the surface layer and have not begun to grow into the deeper tissues of the vulva. Some doctors call it precancer although many women with VIN will not develop cancer. Some women with VIN may have severe itching or an area of abnormal tissue. There are two types of VIN, undifferentiated and differentiated.

Undifferentiated VIN is the most common type. Many women who have it have ongoing infection with HPV (human papilloma virus). It occurs mainly in women aged between 30 and 40, and is more common in women who smoke. Undifferentiated VIN is divided into three grades called VIN 1, 2 and 3. VIN 1 is rare and generally not treated as it often goes away by itself. VIN 2 and 3 can spread into the deeper layers of the vulva over time and are generally treated. VIN 3 is also known as stage 0 or carcinoma in situ (CIS).

Differentiated VIN is much less common and tends to occur in women between 50 to 60 years of age. It is not linked to HPV infection, but is commonly found in women who have a vulval condition called lichen sclerosus. Lichen sclerosus is inflammation of the vulval skin. Differentiated VIN has a higher risk of developing into cancer than undifferentiated VIN. You can read about treatments for VIN in the vulval cancer treatment section.

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 and tissues underneath. Stage 1B cancer measures more than 2cm across or has grown more than 1 millimetre into the skin and tissues underneath.

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 into 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 urethra, the vagina or the lining of the anus. Or it has spread into the lining of the bladder or bowel. The affected lymph nodes in the groin may be fixed (stuck) to another structure or cause open sores (ulceration).

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.