Role of Patient and Disease Factors in Adjuvant Systemic Therapy Decision Making for Early-Stage, Operable Breast Cancer: American Society of Clinical Oncology Endorsement of Cancer Care Ontario Guideline Recommendations

PURPOSE: An American Society of Clinical Oncology (ASCO) panel considered the Cancer Care Ontario (CCO) recommendations on the role of patient and disease factors in selecting adjuvant therapy for women with early-stage breast cancer for endorsement. METHODS: ASCO staff reviewed the CCO guideline for methodologic rigor, and an ASCO panel of content experts reviewed the content of the recommendations. CCO RECOMMENDATIONS: For making decisions regarding adjuvant therapy, nodal status, tumor size, estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2) status, tumor grade, and lymphovascular invasion are relevant; Oncotype DX score and Adjuvant! Online may be used as risk stratification tools; and age, menopausal status, and medical comorbidities should be considered. Chemotherapy should be considered for patients with positive lymph nodes, ER-negative disease, HER2-positive disease, Adjuvant! Online mortality greater than 10%, grade 3 lymph node-negative tumors (T > 5 mm), triple-negative (ER-negative, PgR-negative, HER2-negative) tumors, lymphovascular invasion positivity, or estimated distant relapse risk of greater than 15% at 10 years based on Oncotype DX recurrence score (RS). Chemotherapy may not be beneficial or required for small node-negative tumors (T < 5 mm) without high-risk features or for patients with HER2-negative, strongly ER-positive, and PgR-positive cancer with micrometastatic nodal disease, T less than 5 mm, or Oncotype DX RS with an estimated distant relapse risk of less than 15% at 10 years. ASCO PANEL CONCLUSION: The ASCO panel endorses the recommendations with minor suggested revisions and highlights three areas that warrant further consideration: tumor histology and adjuvant therapy recommendations, risk stratification tools and proposed Oncotype DX RS thresholds to guide decisions about chemotherapy, and patient factors in decision making.