Neoadjuvant Therapy

See the current version of the SEER Program Coding Manual under Section VII: First Course of Therapy, for complete coding instructions for the neoadjuvant data items. See also Appendix C.

Neoadjuvant therapy is systemic therapy that is administered prior to surgical resection. This may include chemotherapy, hormone, immunotherapy and/or radiation. For a treatment to be noted as neoadjuvant therapy, it must meet the treatment guidelines. (See the Central Nervous System NCCN Guidelines to determine the appropriate guidelines for neoadjuvant therapy.)

If only systemic therapy (chemo, hormone, immune) or radiation are given (no surgical resection), then this is adjuvant therapy.

Neoadjuvant therapy is not common for CNS tumors at this time; however, it is being actively explored.

Neoadjuvant therapy may be used for patients with brain metastasis for non-CNS tumors.

If neoadjuvant therapy is followed by surgery, do not record the size from the pathologic specimen. Code the largest size of tumor prior to neoadjuvant treatment; if unknown code size as 999.

Document neoadjuvant therapy details in NAACCR Item #’s (as applicable)

• 1632: Neoadjuvant Therapy
• 1633: Neoadjuvant Therapy-Clinical Response
• 1634: Neoadjuvant Therapy-Treatment Effect
• 2620: Text-Dx Proc-Radiation (Beam)
• 2630: Text-Dx Proc-Radiation Other
• 2640: Text-Chemo
• 2650: Text-Hormones
• 2660: Text-BRM
• 2670: Text-Other

See Additional Resources for Central Nervous System Cancer Treatment

Updated: September 23, 2026