ER-positive breast cancer recurrence after DCIS: chemotherapy, nodal surgery, radiation, and endocrine therapy

What happened, in summary

A 41-year-old woman had ductal carcinoma in situ of the left breast treated with total mastectomy and implant reconstruction in 2002. Tamoxifen was not given at that time. Five years later, she developed a 5 mm red nodule in the skin above the left breast incision scar, with a palpable density underneath. Biopsy showed estrogen receptor-positive, HER2/neu-negative invasive breast cancer. There were no palpable axillary lymph nodes, but the team performed lymphatic mapping around the recurrent skin-flap tumor on the morning of surgery. The mapping showed drainage to the ipsilateral axillary basin, so sentinel lymph-node biopsy was attempted. During surgery, 3 blue, radioactive sentinel lymph nodes were identified. The recurrent tumor was widely excised and the implant removed. Pathology found a 1.3 cm ER-positive invasive breast cancer, and all 3 sentinel nodes contained metastatic cancer. She then received adjuvant chemotherapy with doxorubicin, cyclophosphamide, and docetaxel. After chemotherapy, completion axillary lymph-node dissection removed 20 additional nodes, all negative for malignancy. She also received 50.4 Gy of external-beam radiotherapy to the left chest wall, axilla, and supraclavicular areas, followed by endocrine therapy with exemestane. The case highlights invasive breast cancer recurrence after prior mastectomy for DCIS and shows that sentinel-node mapping can still identify axillary involvement. She remained disease-free for 33 months. Although the visible recurrence was small, the finding of cancer in all 3 sentinel nodes changed the risk assessment and justified systemic chemotherapy, completion nodal surgery, radiation to regional areas, and ongoing endocrine therapy. This made the recurrence clinically more significant than its small skin size suggested.