How does cancer generally spread from its primary site to secondary sites in the body?

Cancer generally spreads from its primary site to secondary sites in the body primarily through lymph and blood vessels. This process is known as metastasis.

When cancer cells form in a primary tumor, some of these cells can invade nearby healthy tissues. They can then enter the lymphatic system or the bloodstream, which serves as a highway for these rogue cells to travel to distant parts of the body. Once cancer cells reach a new location through these vessels, they can settle and begin to grow, forming new tumors, which are referred to as metastatic tumors.

Understanding this mechanism of spread is crucial for developing treatment strategies and predicting the progression of cancer. The other methods mentioned, such as nerve connections, inhalation, and direct contact with tissues, are not typical pathways for the dissemination of cancer cells in the body.