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NAACCR Data Dictionary
Data Standards and Data Dictionary
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Version 26
Data Item #1178: Residual Cancer Burden (RCB)

* indicates required field

Length: 5
Source of Standard: NAACCR
Section Name: Stage/Prognostic Factors
Year Implemented: 2026
Version Implemented: 26
Record Types: I, M, C, A

XML NAACCR ID: residualCancerBurdenRCB

Parent XML Element: Tumor

Required Status:

NPCR Collect: . - No recommendations
CoC Collect: RS - Required, site specific
SEER Collect: RC - Collected by SEER from CoC-accredited hospitals
CCCR Collect: . - No recommendations

Description:

Residual Cancer Burden (RCB) is a score that measures the amount of cancer remaining in the breast and the regional lymph nodes after neoadjuvant therapy and surgical resection. The RCB score is based on 4 independent prognostic factors measuring the primary tumor bed and 2 independent factors measuring the lymph nodes. 

The RCB score combines these 6 independently prognostic factors from the surgical specimen after neoadjuvant therapy into a single continuous score. This score is prognostic across breast cancer subtypes, different treatments, and within existing stage groups. 

The independent prognostic factors include

  1. Primary Tumor Bed
    1. Primary Tumor Bed area (measured in millimeters)
      1. Includes the largest two dimensions
    2. Overall Cancer Cellularity (as percentage of area)
    3. Percentage of cancer that is invasive disease
    4. Percentage of cancer that is in situ disease
  2. Lymph nodes
    1. Number of positive lymph nodes
    2. Diameter of largest metastasis

Rationale:

Neoadjuvant therapy is now standard of care for HER2+ and triple negative breast carcinoma. Quantification of residual disease after neoadjuvant therapy determines further patient management in this setting. The Residual Cancer Burden (RCB) is the most validated measure of volume of residual disease post neoadjuvant for breast cancer and has prognostic value.

Item Data Type:

text

Allowable Values

0.000-9.999, X.777, X.888, X.999, Blank

Codes:

0.000-9.999

0.000 – 9.999 score

X.777

Patient had neoadjuvant therapy, but not a post neoadjuvant surgical resection.

Patient did not have neoadjuvant therapy.

X.888

Not applicable: information not collected for this case (If this item is required by your standard setter, use of code X.8 will result in an edit error).

X.999

Post neoadjuvant surgery completed and RCB burden not documented in CAP Protocol or synoptic pathology report.

Post neoadjuvant surgery completed and surgical pathology report not available.

Blank

Must be blank if diagnosis year is before 2026.