Management of Invasive Lobular Carcinoma

Initial Assessment and Staging

A thorough clinical staging workup, including bilateral diagnostic mammography, should be completed to identify potential multicentric disease or contralateral involvement, as recommended by the National Comprehensive Cancer Network 3, 4
Pathology review is necessary to confirm invasive lobular carcinoma diagnosis and determine hormone receptor status (ER/PR) and HER2 status, according to the American Cancer Society 5, 6
Genetic counseling should be considered, especially in young patients with large tumor sizes, to evaluate for hereditary breast cancer syndromes, as suggested by the National Comprehensive Cancer Network 3, 7
Full clinical staging is necessary to rule out metastatic disease due to the large tumor size and higher risk nature of the case, as indicated by the European Society for Medical Oncology 1

Modified radical mastectomy is indicated due to the large tumor size (7cm), which is a contraindication to breast-conserving surgery, according to the European Society for Medical Oncology and the British Cancer Society 1, 2
Axillary lymph node dissection is required as part of standard management for this large invasive cancer, as recommended by the European Society for Medical Oncology and the American Cancer Society 1, 6
Sentinel lymph node biopsy alone is not appropriate in this case due to the large tumor size (>3-4cm), as indicated by the European Society for Medical Oncology 1, 8

Post-mastectomy radiation therapy is strongly indicated due to the T3 tumor size (7cm), regardless of nodal status, as recommended by the European Society for Medical Oncology 1, 8
Systemic therapy decisions should be based on hormone receptor status (ER/PR), HER2 status, and nodal involvement found during surgery, according to the European Society for Medical Oncology and the American Cancer Society 1, 5, 6
Adjuvant chemotherapy should be administered if the tumor is hormone receptor-negative or if there is significant nodal involvement, as indicated by the European Society for Medical Oncology 1

Long-term survival will depend on final pathologic staging, receptor status, and response to therapy, as indicated by the European Society for Medical Oncology 1
Regular follow-up with interval history and physical examinations every 6-12 months and annual diagnostic mammography of the contralateral breast is recommended, as suggested by the National Comprehensive Cancer Network 7

At 40 years of age, this patient is considered young for breast cancer diagnosis, which is associated with increased risk of recurrence and may warrant more aggressive therapy, according to the American Society of Clinical Oncology 9
Pleomorphic variants of lobular carcinoma, if present, may have more aggressive behavior and worse prognosis, as indicated by the National Comprehensive Cancer Network 7

Do not attempt breast conservation for this large (7cm) tumor as it is a clear contraindication and associated with higher local recurrence rates, as recommended by the European Society for Medical Oncology and the British Cancer Society 1, 2
Do not omit post-mastectomy radiation therapy, as it is indicated for tumors >5cm even with negative nodes, according to the European Society for Medical Oncology 1, 8
Do not confuse invasive lobular carcinoma with lobular carcinoma in situ (LCIS), which is managed differently, as indicated by the National Comprehensive Cancer Network 3, 10