Overview of the Event and Its Purpose
Last week, invasive lobular breast cancer (ILC) patients and healthcare providers gathered at Fred Hutch Cancer Center for a two-hour program dedicated to Global Lobular Breast Cancer Awareness Day. The event highlighted patient stories, epidemiological findings, and cutting-edge developments in screening and clinical trials for this common breast cancer subtype. Recognized globally by advocates and led by advocates, the day underscored that about 15% of breast cancer diagnoses are invasive lobular carcinoma each year.
The gathering echoed across the United States and beyond, with 24 state governors issuing proclamations in support. In tandem, the American Cancer Society released its inaugural report on ILC occurrence and outcomes, noting a notable rise in rates in recent years.
Why Lobular Cancers Are Often Found Later
One of the recurring themes at the event was the tendency of ILC to be diagnosed at more advanced stages. As Fred Hutch radiologist Diana Lam, MD, explained, invasive lobular carcinoma frequently does not form discrete lumps that are easy to feel or easily detected on standard imaging. This “lumpless” pattern can delay recognition and diagnosis, even when symptoms arise or imaging is performed.
A Patient Perspective: Lessons from a Delayed Diagnosis
Educator Stefanie LeJeunesse shared her personal journey from a seemingly routine diagnostic process to a much more extensive disease picture. Diagnosed with metastatic lobular breast cancer at 39, she recounted a sequence of tests that initially suggested stage II cancer with questionable lymph nodes. A second opinion at Fred Hutch revealed a much more complex reality: a 14-centimeter disease burden with widespread metastases. Her story underscored the variability in diagnostic pathways, particularly in rural settings, and the crucial role of comprehensive evaluation and second opinions.
Biology and Risk: What We Know About ILC
Christopher Li, MD, PhD, shared a public health lens on ILC, tracing a rise in rates over recent decades. Analyses suggest that hormone exposure is a key driver. The team’s SHARE study linked longer use of combined hormone replacement therapy (estrogen plus progestin) to significantly higher ILC risk—an association not as strong for ductal breast cancer. The research also noted that a large proportion of women in the U.S. used HRT at the time, highlighting how hormonal factors intersect with cancer risk.
Alcohol emerged as another important risk factor, with studies indicating a stronger link to lobular cancer than to ductal cancer. The combination of hormonal exposure and alcohol use is described as a potent driver for ILC, illustrating its uniquely hormonally sensitive biology.
New Frontiers in Screening and Trials
On the clinical side, Fred Hutch physician-scientist Hannah Linden, MD, PhD, spotlighted advances in imaging and trial enrollment. The FES-PET tracer, which targets estrogen receptors, has gained FDA approval and offers a new avenue for identifying lobular disease. While FDG-PET remains valuable for monitoring certain metastases, FES-PET can enhance trial eligibility, particularly for patients with bone-dominant disease, by aligning with newer response criteria like PERCIST alongside traditional RECIST measures.
Guidance during the event emphasized that lobular disease can metastasize to bone, lung, lymph nodes, brain, and even the peritoneal cavity, with diagnostic challenges in the liver met area. The conversation also highlighted ongoing and upcoming trials, including Evangeline (endoxifen for ER+ premenopausal patients), FFNP PET/CT, and KAT6 inhibitor studies, as well as the LuMIERE FAPI trial aimed at targeting the tumor microenvironment with theranostics.
Practical Takeaways for Patients and Clinicians
Experts stressed the importance of accurate diagnostic workups, including metastatic biopsies, to ensure proper staging and treatment planning for ILC patients. Linden noted that underdiagnosis remains a concern in some regions, reinforcing the need for heightened awareness and access to specialized care. She urged clinicians to consider imaging and biopsy strategies that capture the diffuse, yet often elusive, spread of lobular tumors.
For patients, the event reinforced key cautions: avoid extended use of combined HRT beyond three years, be mindful of alcohol consumption, and seek care at experienced centers with expertise in lobular disease. As researchers continue to refine imaging and expand trials, the outlook for ER+ ILC patients appears increasingly personalized and less toxic, with targeted therapies and novel diagnostics shaping a hopeful future.
Closing Reflections and Community Voices
The day closed with a Q&A session that stressed the risks of prolonged hormone therapy and alcohol-related risks, as well as the value of choosing diverse, high-quality care. Patient advocates and clinicians alike emphasized that access to advanced imaging, accurate biopsies, and inclusive trials can markedly influence outcomes for women facing invasive lobular breast cancer.
