What is neoadjuvant therapy primarily used for?

Neoadjuvant therapy is primarily used to shrink a tumor before surgery or radiation, which is precisely why this answer is correct. The goal of administering neoadjuvant therapy, which commonly involves chemotherapy, targeted therapy, or immunotherapy, is to reduce the size of the tumor to facilitate a more effective surgical procedure. By minimizing the tumor burden before the primary treatment, it can potentially lead to better surgical outcomes, allow for less extensive surgery, and improve the overall prognosis for the patient.

This approach can also help in assessing the cancer's response to the treatment, thus providing valuable information about the tumor's sensitivity to therapies. This information can guide postoperative treatment decisions to reduce the risk of recurrence.

In contrast, the other options do not accurately describe the primary purpose of neoadjuvant therapy. Managing pain after surgery relates more to postoperative care rather than tumor reduction prior to surgery. Treating recurrences of cancer typically involves different strategies, often classified as adjuvant therapy. Preventing secondary cancers is not the focus of neoadjuvant therapy, which is concentrated on addressing the primary tumor initially.