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SEER Inquiry System - Report
Produced: 10/14/2025 1:04 PM
Question 20240049
Inquiry Details
References:
2024 SEER Manual, 227-231. Neoadjuvant Therapy
Question:
First Course Treatment/Neoadjuvant Therapy--Breast: When are pre-operative therapies given as part of a clinical trial coded as neoadjuvant treatment versus limited systemic exposure in the Neoadjuvant Therapy data item? See Discussion.
Discussion:
The SEER Manual seems to give somewhat conflicting instructions for clinical trial therapies under the Neoadjuvant Therapy data item. One section states that limited systemic therapy may occur in clinical trials to impact the biology of a cancer, but is not a full course of neoadjuvant therapy with the intent to impact extent of surgical resection or other outcomes (organ preservation, function or quality of life); do not code as neoadjuvant therapy for the purposes of this data item. Then another section states for purposes of this data item, the criteria for neoadjuvant therapy include that treatment must follow recommended guidelines for the type and duration of treatment for that particular cancer site and/or histology, and that neoadjuvant therapy may be given as part of a clinical trial.
For example, a patient was diagnosed with invasive ductal carcinoma of the breast, 6 cm in size; treatment planning conference recommended neoadjuvant chemotherapy. The patient elected to participate in a clinical trial and was assigned to a group given the antibody drug conjugate datopotamab deruxtecan (Dato-DXd) plus durvalumab for 12 weeks. There was no physician documentation of intent or expected outcomes, nor yC staging or statement of clinical response. Post-therapy imaging showed no residual mass, and post-therapy mastectomy path report showed only residual ductal carcinoma in situ, stating "Treatment Effect (after neoadjuvant): Residual Cancer Burden - pCR, In the breast - complete response." The medical oncologist stated post-therapy stage was ypTis ypN0 cM0.
The trial drugs this patient were given do not appear to be approved or standard neoadjuvant/pre-operative drugs in SEER*Rx or NCCN guidelines for this type of cancer; however, the duration of treatment was fairly substantial, and although we don't have clear documentation from physicians as recommended in the SEER manual (which is usually not stated, in our experience), it seems like they may be considering it as neoadjuvant therapy. How should the Neoadjuvant Therapy data item be coded for cases like this? What is the best way to differentiate between clinical trial therapies that are "limited systemic exposure" (code 3) versus true neoadjuvant therapy (code 1)?
Answer:
When pre-operative therapies are given as part of a clinical trial, code as neoadjuvant treatment in the Neoadjuvant Therapy data item when the intent is neoadjuvant and/or when surgical resection follows the clinical trial therapies.
In the example, neoadjuvant chemotherapy was recommended in the treatment planning and the patient had the planned resection after neoadjuvant treatment. The treatment effect outcome is based on imaging that reported no mass and as documented by the physician, pathologist in this case as complete response to the neoadjuvant therapy based on the resection.
Use code 3 (limited systemic exposure) when treatment does not meet the definition of neoadjuvant therapy in the data item, Neoadjuvant Therapy. Limited exposure occurs when the patient receives some therapy prior to surgical resection, but the treatment is not enough to qualify for a full course of neoadjuvant therapy with the intent to impact extent of surgical resection or other outcomes. While this type of treatment may given as part of a clinical trial, it mostly refers to short term treatments such as hormone therapy.
When neoadjuvant therapy is given prior to surgical resection that is planned (intended) or performed to improve outcomes, use Code 1 or 2. Because a clinical trial is a type of research study that tests new methods of screening, prevention, diagnosis, or treatment of a disease, the treatment regimens likely will not be incorporated in recommended guidelines until all phases of the trial are completed and approved by the U.S. Food and Drug Administration. ClinicalTrials.gov is available to learn more about clinical studies around the world.
