Neoadjuvant Chemotherapy and Interval Debulking: Capturing Sequencing Correctly
A 71-year-old woman with a 12 cm pelvic mass, omental caking, and CA-125 of 1,850 U/mL is diagnosed with advanced high-grade serous ovarian carcinoma by core biopsy. Because of medical comorbidities, she receives 3 cycles of neoadjuvant carboplatin/paclitaxel, followed by interval debulking surgery with residual disease <1 cm, then 3 more cycles of adjuvant chemotherapy. The abstractor must capture treatment sequencing and stage.
1. How should the abstractor assign stage when the diagnosis was made by biopsy and surgery occurred after neoadjuvant chemotherapy?
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Stage should be assigned based on the pretreatment (clinical) extent of disease documented at diagnosis, not solely on the post-chemotherapy surgical findings, because neoadjuvant therapy can downstage the pathologic findings.
Reasoning:
- The diagnostic imaging and biopsy documented omental caking and a large pelvic mass consistent with peritoneal spread beyond the pelvis → stage IIIC (or IIIB depending on implant size) clinically.
- Post-neoadjuvant surgery showing residual disease <1 cm reflects response to therapy, not the original stage.
- The abstractor should record the clinical stage based on pretreatment imaging and document the post-treatment pathologic findings separately.
- If the registry uses pathologic stage, the abstractor must note that it is a post-neoadjuvant pathologic stage (yp) and not use it to override the clinical stage for staging purposes.
2. What treatment-sequence fields must be captured, and in what order?
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Capture the sequence explicitly:
- Neoadjuvant chemotherapy: 3 cycles carboplatin/paclitaxel, start and end dates.
- Interval debulking surgery: date, procedure, residual disease <1 cm.
- Adjuvant chemotherapy: 3 cycles, start and end dates.
- Total cycles: 6.
Data-quality notes:
- Record the sequence as neoadjuvant → surgery → adjuvant; do not record surgery as the first treatment.
- Capture residual disease status as a discrete field because it is prognostic.
- Ensure the treatment fields align with the diagnosis date and that no cycle is double-counted.
- Document the reason for neoadjuvant approach (comorbidities) in text.
3. What staging and treatment-related data-quality pitfalls should the abstractor avoid in this case?
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Pitfalls:
- Staging from post-treatment pathology: Using the interval debulking specimen to assign a lower stage than the pretreatment clinical stage.
- Misordering treatment: Recording surgery before neoadjuvant chemotherapy.
- Incomplete sequencing: Omitting either the neoadjuvant or adjuvant phase, leading to undercounting of cycles.
- Residual disease omission: Failing to capture <1 cm residual disease, which affects prognosis and treatment reporting.
- Schema confusion: Not documenting whether clinical or pathologic (yp) stage is being reported.
- Date errors: Using the surgery date as the diagnosis date instead of the biopsy/imaging date.