How can cancer spread to other organs or structures?

The process by which cancer spreads to other organs or structures is termed metastasis, and it often involves a trail of tumor cells that detach from the primary tumor. Once these cells enter the bloodstream or lymphatic system, they can travel to distant sites in the body, where they may establish new tumors. This mechanism demonstrates the aggressive nature of cancer, as the ability of cells to migrate and proliferate in new environments enhances the disease's severity.

Surgical removal of a tumor does not cause cancer spread; rather, it can be a treatment method aimed at controlling or eliminating cancer. While direct contact with other tissues can sometimes lead to local invasion of cancer cells, it is not the primary mechanism for spreading cancer to distant organs, which is primarily achieved through systemic circulation. Accidental exposure during treatment may introduce risks but does not directly lead to the spread of cancer itself. Thus, the movement of tumor cells from the primary tumor site is the definitive process that underlies metastasis and explains why tumor cells can establish secondary growths in other parts of the body.