Item #	Length	Source of Standard	Year Implemented	Version Implemented	Year Retired	Version Retired
1179	1	NAACCR	2026	26

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.

See Residual Cancer Burden (RCB) Score for further information on these prognostic factors.

Based on the RCB score, patients are then divided into four different classes. These classes are used to determine the likelihood of a patient being cancer free after treatment.

RCB-0 (pathologic complete response). No residual invasive cancer is present.
RCB-1 (minimal burden). Very little residual invasive cancer is present.
RCB-2 (moderate burden). A moderate amount of residual invasive cancer is present.
RCB-3 (extensive burden). A large amount of residual invasive cancer is present.

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.

0	RCB-0 (pCR)
1	RCB-I
2	RCB-II
3	RCB-III
7	Patient had neoadjuvant therapy, but no post neoadjuvant surgical resection Patient did not have neoadjuvant therapy.
8	Not applicable: information not collected for this case (If this item is required by your standard setter, use of code 8 will result in an edit error).
9	Post neoadjuvant surgery completed and RCB class 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.