Tumörspridning

Tumörspridning, also known as metastasis, is the process by which cancer cells spread from their original location, the primary tumor, to other parts of the body. This is a crucial aspect of cancer progression and a major cause of cancer-related mortality. The spread typically occurs through the bloodstream or the lymphatic system, allowing cancer cells to travel to distant organs and form secondary tumors, or metastases.

The process of metastasis involves several steps. First, cancer cells must detach from the primary tumor. They then invade the surrounding tissues, entering either blood vessels or lymphatic vessels. Once inside these circulatory systems, the cancer cells are transported to different parts of the body. Upon reaching a suitable new site, they can exit the bloodstream or lymphatic system, establish themselves in the new tissue, and begin to grow, forming a secondary tumor.

The likelihood and pattern of tumor spread depend on various factors, including the type of cancer, its stage, and the individual's biological characteristics. Some cancers are more prone to metastasizing than others, and certain cancers tend to spread to specific organs. For example, breast cancer often spreads to the bones, lungs, and brain, while colorectal cancer may spread to the liver and lungs.

Understanding tumor spread is vital for effective cancer diagnosis, staging, and treatment. Treatments aimed at controlling metastasis often involve systemic therapies like chemotherapy, targeted therapy, and immunotherapy, which can reach cancer cells throughout the body. Local treatments like surgery and radiation are used to remove or destroy primary tumors and any detected metastases.