On March 12, 2021, the National Comprehensive Cancer Network (NCCN) released an update to its clinical practice guideline for breast cancer.
An algorithm was added for HR-positive – HER2-negative disease, postmenopausal patients with pT1-3 and pN0 or pN+ tumors. The branches were modified to tumor ≤0.5 cm and pN0; tumor >0.5 cm or pN1 mi (≤2 mm axillary node metastases) or pN1 (1-3 positive nodes); and pN2/pN3 (≥4 ipsilateral metastases >2 mm).
For tumor >0.5 cm or pN1 mi (≤2 mm axillary node metastases) or pN1 (1-3 positive nodes), the next step was modified to “strongly consider 21-gene RT-PCR assay if candidate for chemotherapy (category 1).”
For treatment, the pathways for recurrence score 26-30 and ≥31 were replaced with a single pathway for recurrence score ≥26. For recurrence score <26, adjuvant endocrine therapy was changed to a category 1 recommendation. For recurrence score ≥26, adjuvant chemotherapy followed by endocrine therapy was changed to a category 1 recommendation.
An algorithm was added for HR-positive – HER2-negative disease, premenopausal patients with pT1-3 and pN+ tumors
Additionally, an algorithm was added for HR-positive – HER2-negative disease, premenopausal patients with pT1-3 and pN0 tumors. For patients not a candidate for chemotherapy, treatment was modified to adjuvant endocrine therapy + ovarian suppression/ablation. For candidate for chemotherapy, consider gene expression assay to assess prognosis was added, and treatment was modified to adjuvant chemotherapy followed by endocrine therapy or adjuvant endocrine therapy + ovarian suppression/ablation.
Under gene expression assays for consideration of adjuvant systemic therapy, the table was updated based on the RxPONDER trial. Assay was modified to 21-gene (Oncotype Dx) for pN1 (1-3 positive nodes), predictive was changed to “yes,” and NCCN category of preference/evidence consensus was modified to “postmenopausal: Preferred; 1” and “premenopausal: other; 2A.”
Under systemic therapy regimens for recurrent unresectable (local or regional) or stage IV (M1) disease, the table was reorganized to list regimens by setting/line of therapy. For third-line therapy and beyond, margetuximab-cmkb + chemotherapy (capecitabine, eribulin, gemcitabine, or vinorelbine) was added. Additionally, doing was added for margetuximab-cmkb + capecitabine, margetuximab-cmkb + eribulin, margetuximab-cmkb + gemcitabine, and margetuximab-cmkb + vinorelbine.—Janelle Bradley