Which category of immunotherapy is characterized by its ability to remember cancer cells after treatment?

Active immunotherapy is characterized by its ability to stimulate the body's immune system to recognize and combat cancer cells. This type of immunotherapy works by involving the patient's immune cells in a way that not only targets the cancer cells present at the time of treatment but also establishes a memory response within the immune system. This memory allows the immune system to recognize and respond to any returning cancer cells even after treatment has concluded, providing a form of long-term protection and reducing the risk of recurrence.

In contrast, passive immunotherapy typically involves administering pre-formed antibodies or immune cells to help fight cancer, which does not lead to the development of this immunological memory. Nonspecific immunotherapy targets a broader range of cell types but lacks the specificity and memory aspect inherent to active immunotherapy. Specific immunotherapy is generally more focused on targeting particular antigens associated with a specific cancer type, but it may not create the same robust immune memory as active immunotherapy does. Thus, the defining characteristic of active immunotherapy is its ability to foster an enduring immune response capable of remembering and attacking cancer cells, making it a powerful tool in cancer treatment strategies.