Invasion

Invasion is the movement of cancer cells from their original location into the surrounding non-cancerous tissue. Another term for invasion is infiltration.

Importance of invasion

Pathologists consider invasion a crucial feature when determining if a tumor is benign (non-cancerous) or malignant (cancerous). While benign tumors can grow larger, their cells typically do not invade surrounding normal tissue. In contrast, cancer cells almost always break away from their original location and invade surrounding tissue.

Metastasis and invasion

Once cancer cells invade the surrounding tissue, they can spread to other parts of the body, a process known as metastasis. This ability to metastasize makes cancer particularly dangerous and highlights the importance of early detection and treatment.

In situ cancer

Cancer cells that have not yet invaded the surrounding normal tissue are called in situ. In situ cancers carry a high risk of becoming invasive without appropriate treatment. Detecting and treating in situ cancers early can prevent them from developing into more dangerous invasive cancers.

Special types of invasion

Invasion can occur in several specific ways, each with its own implications for cancer progression and treatment.

• Vascular invasion: This occurs when cancer cells penetrate blood vessels. Vascular invasion allows cancer cells to enter the bloodstream and spread to distant organs, increasing the risk of metastasis.
• Lymphatic invasion: Cancer cells can also invade the lymphatic system, spreading through lymphatic vessels. This type of invasion often leads to the cancer spreading to nearby lymph nodes and potentially to other parts of the body.
• Perineural invasion: This involves cancer cells spreading along nerves. Perineural invasion can cause significant pain and neurological symptoms, and it is often associated with a more aggressive tumor and a poorer prognosis.

Learn more pathology

Atlas of Pathology