Neoadjuvant Therapy

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

For colorectal cancers, neoadjuvant therapy (chemoradiation) is used for tumors that have invaded beyond the muscularis propria into the subserosa, serosa, pericolic/perirectal tissues, visceral peritoneum, and adjacent organs.

Neoadjuvant therapy is used to shrink the tumor, which is then followed by surgery.

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

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 Colon NCCN Guidelines (PDF)or Rectum NCCN Guidelines (PDF) 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 not neoadjuvant therapy.

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 Colorectal Cancer Treatment

Updated: June 24, 2025