Overview

• The ACS estimates about 33,600 U.S. women will be diagnosed with invasive lobular carcinoma (ILC) in 2025.
• ILC incidence has been rising roughly 2.8–3% per year since 2012, about triple the pace of other breast cancers.
• Because ILC spreads in linear or sheet-like patterns rather than forming a lump, it is harder to spot on mammograms and often requires ultrasound, contrast-enhanced mammography, or MRI.
• Long-term outcomes are worse when ILC is advanced, with women about half as likely to be alive at 10 years compared with ductal cancer, despite strong survival when found early.
• Rates are increasing fastest among Asian American and Pacific Islander women (about 4.4% annually), while white women have the highest incidence overall, prompting calls to separate ILC in research and clinical trials.