Neoadjuvant therapy refers to treatment — most often chemotherapy, targeted therapy, or hormone therapy — given before the primary surgical procedure to remove a tumor. In breast cancer, the goal is usually to shrink a large tumor enough to allow breast-conserving surgery, or to see how the cancer responds to a particular drug regimen before surgery.
What is neoadjuvant therapy?
The prefix "neo-" means new or before, and neoadjuvant therapy is treatment that comes before the primary intervention — in most cases, surgery. In breast cancer care, neoadjuvant chemotherapy, targeted therapy, immunotherapy, or hormone therapy may be recommended when a tumor is large, when the cancer has spread to lymph nodes, or when testing the tumor's response to treatment before removal provides valuable information for ongoing care.
One of the key advantages of neoadjuvant therapy is the ability to observe the tumor's response in real time. If the tumor shrinks significantly — a result called pathologic complete response (pCR) when no residual cancer is found in the removed tissue — this is a strong positive indicator. If the tumor does not respond well, the oncologist can adjust the plan before surgery. This approach allows therapy to be tailored based on how the individual cancer actually behaves.
Neoadjuvant therapy has also expanded surgical options for some women. A tumor that was too large for lumpectomy at diagnosis may become amenable to breast-conserving surgery after it shrinks with treatment. Not all breast cancers are treated this way — the decision depends on tumor size, type, receptor status, lymph node involvement, and the individual treatment goals discussed between you and your oncology team.
Why it matters
If your oncologist recommends starting chemotherapy or another systemic treatment before your surgery, it can feel counterintuitive — many people expect surgery to happen first. Understanding why neoadjuvant therapy is being recommended, and what your team hopes to learn from it, helps you feel more confident in the plan and more engaged in the process.
The ability to observe your cancer's response to treatment is genuinely useful information. Achieving a pathologic complete response after neoadjuvant therapy is associated with better long-term outcomes for certain cancer types. And for women who want to preserve their breast if possible, neoadjuvant therapy may be what makes that option available. Asking your oncologist about the goals of neoadjuvant treatment in your specific case is a great place to start the conversation.
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