Breast Cancer Clinical Prognostic Staging

Adapted from Hortobagyi GN, Connolly JL, D’Orsi CJ, Edge SB, Mittendorf EA, et al: Breast. In: Amin MB, Edge S, Greene F, et al, eds; American Joint Committee on Cancer. AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer. 2017.

Tis = ductal carcinoma in situ (DCIS) or Paget disease (Tis [Paget]) of the nipple with no tumor (Paget disease with a tumor is classified by tumor size); T1 = tumor ≤ 2 cm; T1mi ≤ 0.1 cm; T2 ≥ 2 but ≤ 5 cm; T3 ≥ 5 cm; T4 = any size tumor with direct extension to chest wall and/or skin (ulceration or macroscopic nodules) or inflammatory carcinoma.

HER2 = human epidermal growth factor receptor 2; ER = estrogen receptor; PR = progesterone receptor

* T1 includes T1mi

† N1 does not include N1mi. T1 N1mi M0 and T0 N1mi M0 cancers are included for prognostic staging with T1 N0 M0 cancers of the same prognostic factor status.

‡ N1 includes N1mi. T2, T3, and T4 cancers and N1mi are included for prognostic staging with T2 N1, T3 N1 and T4 N1, respectively.

Notes: Because N1mi categorization requires evaluation of the entire node, and cannot be assigned on the basis of a fine needle aspiration or core biopsy, N1mi can only be used with Clinical Prognostic Stage when clinical staging is based on a resected lymph node in the absence of resection of the primary cancer, such as when a sentinel node biopsy is performed prior to neoadjuvant chemotherapy or endocrine therapy.

For patients with lymph node involvement with no evidence of primary tumor (eg, T0/N1) or with breast ductal carcinoma in situ (eg, Tis/N1), the grade, HER2, ER, and PR information from the tumor in the lymph node should be used for assigning stage group.

For cases where HER2 is determined to be equivocal by in situ hybridization testing under the 2013 ASCO/CAP HER2 testing guidelines, the HER2-negative category should be used for clinical prognostic staging. The prognostic value of these prognostic stage groups is based on populations of persons with breast cancer who have been offered and mostly treated with appropriate endocrine and/or systemic chemotherapy (including anti-HER2 therapy).

Clinical NX (cNX) = Regional lymph nodes cannot be assessed (eg, previously removed). The cNX category is used infrequently and applies only to cases where regional lymph nodes have previously been surgically removed or where there is no documentation of physical examination of the axilla; cN0 = No regional lymph node metastases; cN1 = Metastases to movable ipsilateral Level I, II axillary lymph node(s); cN1mi = Micrometastases (approximately 200 cells > 0.2 mm, but none > 2 mm). cN1mi is rarely used but may be appropriate in cases where sentinel node biopsy is performed before tumor resection, most likely to occur in cases treated with neoadjuvant therapy; cN2 = Metastases in ipsilateral Level I, II axillary lymph nodes that are clinically fixed or matted; or in ipsilateral internal mammary nodes in the absence of axillary lymph node metastases.