Multidisciplinary Management Considerations in Invasive Lobular Breast Cancer: It Isn't Just Ductal.

BACKGROUND: Invasive lobular carcinoma (ILC) is the second most common histologic subtype of breast cancer and presents histologically with a unique pattern of discohesive growth. An expert consensus panel was convened at the annual meeting of the American Society of Breast Surgeons to discuss disease specific management considerations and best practice when caring for women with ILC. METHODS: At the annual meeting of the American Society of Breast Surgeons held in Las Vegas, Nevada from April 30 to May 4, 2025, a panel convened to specifically address the intricacies of managing ILC. Panelists completed an independent literature review for each identified subtopic that was summarized and reviewed by panel moderators. RESULTS: The multidisciplinary management of ILC is nuanced and special considerations are essential to optimize treatment. Magnetic resonance imaging of the breast can improve the accuracy of preoperative staging. Surgeons should account for the limitations of imaging with respect to margin resection in lumpectomy. When considering the application of trials guiding omission of ALND in surgery for ILC, surgeons can rely on several studies that have included subanalyses of patients with ILC confirming safety in appropriately selected patients. Use of neoadjuvant therapy should be based on molecular subtype rather than tumor histology. Genetic testing for patients with ILC should include analysis of CDH1 mutations. DISCUSSION: Awareness and consideration of nuances around the management of ILC, including those discussed in the present study, can help clinicians provide optimal, evidenced based care to women presenting with ILC.