Vulvar cancer is an uncommon malignancy affecting the external female genitalia. Like other cancers, it has the capacity to spread from its initial location to other areas of the body. Understanding how and where this spread typically occurs is important for diagnosis and management. This article explores the common patterns of vulvar cancer spread and the factors that influence this process.
Understanding Cancer Spread
Metastasis is the process where cancer cells detach from the primary tumor and travel to other parts of the body, forming new tumors. This occurs when cancer cells invade surrounding tissues and enter the body’s circulatory systems. These mobile cancer cells can then establish new tumors in distant organs or lymph nodes.
Cancer cells primarily spread through two main pathways: the lymphatic system and the bloodstream. In lymphatic spread, cancer cells enter the lymphatic vessels and travel to nearby lymph nodes. Hematogenous spread involves cancer cells entering the bloodstream, allowing them to travel to more distant organs.
Common Areas of Metastasis
Vulvar cancer commonly spreads first to regional lymph nodes, specifically the superficial and deep inguinal lymph nodes in the groin area. Lymphatic drainage from the vulva typically flows to these nodes, making them the initial site for cancer cell detection outside the primary tumor.
If the cancer progresses, it can then involve pelvic lymph nodes, indicating a more advanced stage. Beyond the lymphatic system, vulvar cancer can spread to distant organs, though this is less common. The most frequently reported distant metastatic sites include the lungs, liver, and bones, with skin being less common. Distant spread signifies a more advanced stage of the cancer.
Factors Affecting Spread
Several characteristics of the primary vulvar tumor influence its likelihood and pattern of spread. Larger tumors generally have a higher risk of metastasis. The depth of invasion, referring to how deeply the tumor has grown into the vulvar tissue, is also crucial. Tumors with a depth of invasion greater than 1 millimeter carry an increased risk of lymph node involvement.
The presence of lymphovascular invasion (LVI) indicates cancer cells have entered small lymphatic or blood vessels within the tumor, making them more likely to travel. This factor is a strong predictor for inguinal lymph node metastases. The histological type of vulvar cancer also plays a role; while squamous cell carcinoma is the most common type and often grows slowly, other types like melanoma can be more aggressive and spread more rapidly.
Diagnosing and Addressing Spread
Doctors use various methods to determine if vulvar cancer has spread beyond its original location. A physical examination, including a thorough assessment of the vulva and palpation of lymph nodes in the groin, is often the first step. Imaging tests are important tools for detecting cancer spread to lymph nodes or distant organs.
Common imaging techniques include computed tomography (CT) scans of the chest, abdomen, and pelvis. Magnetic resonance imaging (MRI) is also used to identify enlarged lymph nodes or assess local extension. Positron emission tomography (PET) scans, often combined with CT (PET-CT), can help identify small metastases or confirm cancer in enlarged lymph nodes.
If suspicious areas are found, a biopsy is performed to confirm the presence of cancer cells. The detection of metastasis influences treatment decisions, guiding approaches toward systemic therapies such as chemotherapy or radiation, alongside or instead of local surgery.