|How Does Vulva Cancer Spread?
Like all cancers, cancer of the vulva can spread through the body in 3 ways:
Tissue: It directly invades surrounding tissues.
Lymph System: This enables it to invade other parts of the body.
Blood System: This enables it to travel through the veins to invade other organs of the body.
Cancer which breaks away from the original primary tumor site can travel through the body's lymph or blood system to affect other areas such as the lungs or bones. If a tumor develops in the lungs for example it is considered a secondary tumor. This process of spreading is called metastasis. The secondary tumor is the same type of cancer as the primary tumor. So if vulva cancer spreads to the lungs it is still known as vulvar cancer. The name of the disease is metastatic vulva cancer and not lung cancer. Knowing the stage provides crucial information for helping to determine vulva cancer treatment. It also helps determine the chances of a patient's survival (vulva cancer survival rate).
This will all be explained during the vulva cancer diagnosis process.
How Is It Staged?
Vulva cancer is usually staged according to 2 systems: The International Federation of Gynecology and Obstetrics System (FIGO) and the American Joint Committee on Cancers (AJCC) TNM Classification. Both are very similar and we have included both systems here. The TNM definition bases staging on the size of the primary tumor (T), the amount of lymph nodes affected (N) and if metastasis is detected (M). So for example, the most curable and early stage of cancer would be reported as T0 N0 M0. These systems are not used to stage vulvar melanoma which it is staged according to melanoma skin cancer staging system.
Below is a more detailed definition of each TNM vulva cancer classification, issued by the AJCC in January 2010.
Primary Tumor (T)
Tis/0: Pre-cancer stage: Carcinoma in situ or vulvar intraepithelial neoplasia (VIN).
T1: There is a tumor and it is confined to the vulva and/or perineum.
T1a: Tumor has grown no more than 1mm into underlying stroma tissue and no more than 2cm wide.
T1b: Tumor is more 2cm wide or it has grown more than 1 mm into stroma tissue.
T2: Tumor is any size and is growing into the lower third of the vagina or urethra or anus.
T3: Tumor is any size and cancer is spreading to the upper urethra, rectum, bladder or pubic bone.
Regional Lymph Nodes (N)
N0: Cancer has not spread to lymph nodes.
N1: 1 to 2 lymph nodes have become infected in the groin area. Either:
N1a:1 or 2 lymph nodes affected and area of cancer spread in both is less than 5mm.
N1b: 1 lymph node is affected and the area of cancer spread is more than 5mm.
N2: Cancer has spread to the lymph nodes in the groin with one of the following features:
N2a: 3 or more lymph nodes affected but each area of spread is less than 5mm.
N2b: 2 or more lymph nodes affected, all with area of spread 5mm or more.
N2c: Cancer has spread to lymph nodes and has started to grow through the outer covering of a least one node (known as extracapsular spread).
N3: Cancer has spread to the lymph nodes causing the development of open sores (ulcerations). The lymph nodes become stuck to the tissue near it.
Distant Metastasis (M)
M0: Cancer has not spread to distant sites (no metastasis).
M1: Cancer has spread to distant sites, metastasis. This includes spread to pelvic lymph nodes.
Interesting Article: Vulva Cancer Prevention.
The Stages Explained
FIGO Stage (0): Carcinoma in Situ/VIN
TNM: Tis, N0, M0
This is a pre-cancerous stage which was formerly known as Bowen disease. It is usually first discovered during a routine Pap test for cervical cancer, but the patient may request a check-up because of persistent itching of the vulva which will not go away. It may even be mistaken for thrush or a vaginal yeast infection.
FIGO Stage 1: Tumor confined to vulva or perineum
TNM:T1, N0, M0
Cancer is confined to the vulva or the space between the vagina and rectum called the perineum. The tumor has not spread to lymph nodes or distant sites.
FIGO Stage 1a: Tumor is still confined and less than 2cm
TNM: T1a, N0, M0
Cancer is less than 2cm wide and has not invaded the underlying tissue by more than 1mm.
FIGO Stage 1b: Tumor is still confined but larger than 2cm
TNM: T1b, N0, M0
Cancer has invaded the underlying stroma tissue by more than 1mm and/or is larger than 2cm in diameter.
FIGO Stage 2: Cancer has spread outside the vulva
TNM: T2, N0, M0
Cancer has spread beyond the vulva or perineum to the lower third of the vagina, or the anus or urethra (T2). It has not spread to the lymph nodes (N0) or distant sites (M0). According to the FIGO system T3, N0, M0 is still stage 2.
FIGO Stage 3a: Cancer has spread to lymph nodes
TNM: T1 or T2, N1a or N1b, M0
Cancer may have spread to the lower vagina, anus or lower urethra (T2). Either a single nearby node is affected with cancer spread of 5mm or more (N1a) or it has spread to 1 or 2 nodes with cancer spread less than 5mm (N1b). It has not spread to distant organs.
FIGO Stage 3b: Greater spread of cancer to lymph nodes
TNM: T1 or T2, N2a or N2b, M0
Cancer is found in the perineum and/or vulva (T1) or it may be growing into the anus, vagina or lower urethra (T2). It has either spread to 3 or more local lymph nodes with cancer spread of less than 5mm wide (N2a) or it has spread to 2 or more nodes with cancer spread of more than 5mm (N2b). It has not spread to distant organs (M0).
FIGO Stage 3c: Signs of extracapsular spread
TNM: T1 or T2, N2c, M0
Cancer may be spreading to the anus, lower urethra and vagina (T2). See also, Cancer of the Vagina. It has spread to local lymph nodes and started growing through the outer covering of at least one node (extracapsular spread). No sign yet of metastasis (M0).
FIGO Stage 4a: Cancer may spread to nearby tissues or caused ulcerations
TNM: T1 or T2, N3, M0 or/ T3, any N, M0
Either - Cancer may be spreading to the anus, vagina and lower urethra (T2) and has caused local lymph nodes to stick to underlying tissues or caused ulcerations (sores, N3). It has not spread to distant sites (M0).
Or - Cancer has spread to nearby tissues including the pelvic bone, bladder, rectum or upper part of the urethra (T3); it has not yet affected lymph nodes (N) or distant sites (M0).
FIGO Stage 4b: Cancer has spread to other organs or lymph nodes
TNM: Any T, any N, M1
This is the most advanced stage of the cancer where it has spread to distant organs such as the lungs or the lymph nodes. Life expectancy is dramatically reduced and patients can become terminally ill. However treatment may still be possible. It is more common for women with recurrent vulva cancer than those with a first diagnosis to reach this stage.
What Are The Early Signs? See Symptoms of Vulva Cancer.