A 42-year-old woman came to your clinic, anxious about a mass in her left breast.On physical examination, the mass was hard and fixed neither to skin nor to muscle.No axillary lymph nodes were palpated on either side. Mammography showed a 2.5-cm lesion with spiculae. Histo-pathological findings from the biopsy showed an invasive ductal carcinoma. No metastases were detected on chest/abdominal CT or on bone scintigraphy.

What is the most appropriate plan at present?