A powerful story of survival and scientific progress: Unveiling the truth about invasive lobular breast cancer.
Last week, a special event at Fred Hutch Cancer Center brought together patients and experts to raise awareness for a unique and often misunderstood form of breast cancer. With a focus on patient stories and the latest research, the event highlighted the importance of recognizing and understanding invasive lobular carcinoma (ILC), a subtype that affects 15% of breast cancer patients each year.
The Power of Awareness: Unveiling the Truth About Invasive Lobular Breast Cancer
On October 15th, a significant day for lobular breast cancer awareness, patients and advocates gathered at Fred Hutch to share their experiences and learn about the latest developments in screening and treatment. This global recognition, initiated by patient advocates, aims to shed light on a cancer subtype that often goes undetected until later stages.
The event was part of a larger movement, with similar gatherings across the U.S. and worldwide. Even state governors got involved, issuing official proclamations to acknowledge the day. This collective effort was further supported by the American Cancer Society, which released its first report on ILC, revealing a concerning rise in incidence rates over recent years.
Unraveling the Mysteries of Invasive Lobular Carcinoma
Dr. Diana Lam, a breast cancer radiologist at Fred Hutch, emphasized the unique challenges of ILC. "It's the second most common breast cancer subtype, but unfortunately, it often presents at advanced stages with larger tumors and lymph node involvement," she explained. This late detection is a critical issue, and experts at Fred Hutch were there to provide insights and potential solutions.
One of the key reasons for late detection is that ILC often doesn't form lumps or masses, making it difficult to detect through physical exams or imaging. This "lumpless" nature of ILC was brought to life through the story of Stefanie LeJeunesse, a 39-year-old mother diagnosed with metastatic lobular breast cancer (mILC).
Stefanie's journey began with a simple observation of dimpling in her breast, which led her to a local rural hospital. Despite undergoing various tests, including a mammogram, biopsy, MRI, and bone scan, she was initially misdiagnosed with stage II breast cancer. It was only when she sought a second opinion at Fred Hutch that the true extent of her cancer was revealed: a 14-centimeter tumor with extensive lymph node involvement and metastases in her spine and ribs.
The Biological Hallmarks of Lobular Cancer
ILC's distinct biological characteristics set it apart from other breast cancer subtypes. The absence of E-cadherin, a protein encoded by the CHD1 gene, is a key hallmark. This protein acts as a molecular glue, clumping cancer cells into lumps. Without it, ILC cells grow in a straight line or branching pattern, making them harder to detect on mammograms, especially in dense breast tissue.
Other unique characteristics of ILC include its tendency to avoid forming a distinct tumor mass, lack of microcalcifications, and its multi-focal and bilateral nature. When it metastasizes, ILC often spreads to unusual sites like the peritoneum, gastrointestinal tract, and ovaries, in addition to more common sites like bone.
The Challenges of Imaging and Screening
Dr. Lam highlighted the imperfections of mammograms, the only screening test proven to reduce breast cancer mortality. The challenge lies in the fact that cancer and dense breast tissue both appear white on mammograms, making it akin to "looking for a polar bear in a snowstorm."
As a result, mammogram sensitivity rates for ILC are lower than for the more common ductal type. However, digital breast tomosynthesis or 3D mammograms have improved sensitivity, especially for dense breast tissue. Additionally, the 2025 National Comprehensive Cancer Network (NCCN) guidelines now recommend MRI screening for average-risk women with extremely dense breasts, without the need for additional risk factors.
The Hormonal Connection: Unraveling Risk Factors
Dr. Christopher Li, an epidemiologist and holder of the Helen G. Edson Endowed Chair for Breast Cancer Research at Fred Hutch, shared his insights into the hormonal aspects of ILC. His research, inspired by the late Dr. Roger Moe, a breast surgeon who noted a rise in ILC rates in his practice, has led to significant findings.
Dr. Li and his colleagues discovered an association between hormone replacement therapy (HRT) and lobular risk. Women who used HRT had a 2.6 times higher risk of developing ILC, a finding that was unexpected due to its marked difference from ductal cancer risk. Further studies showed a similar effect with combined HRT, which includes estrogen and progestin.
Dr. Li's SHARE Breast Cancer study, a groundbreaking investigation into ILC risk factors, interviewed over 1,000 menopausal ILC patients. The study found that longer use of combined HRT increased the risk of lobular, sometimes four times higher. Alcohol use was also identified as a risk factor, with studies showing a higher risk for lobular compared to ductal cancer. Dr. Li cautioned against long-term use of combined HRT and certain types of birth control, such as DMPA, due to their impact on breast cancer risk.
Hopeful New Directions in Research and Treatment
Dr. Hannah Linden, a physician-scientist and clinical director of the Fred Hutch Breast Cancer Program, shared her expertise in clinical research. Dr. Linden, who also holds the Athena Distinguished Professorship of Breast Cancer Research at UW Medicine, has been instrumental in bringing a new imaging tracer, FES-PET, to FDA approval. This tracer, which binds with estradiol instead of glucose, has been a game-changer for lobular patients, especially those interested in clinical trials.
Dr. Linden also addressed the issue of bone metastasis, which often excludes patients from clinical trials due to the lack of measurable disease. She explained how FDG-PETs can help monitor lytic lesions, allowing for the modification of criteria to include "PERCIST, or PET, measurable." This change would enable more patients with bone-dominant metastasis to participate in clinical trials.
Dr. Linden busted some myths about lobular cancer, emphasizing that it can be detected in the metastatic setting, with metastasis visible in various organs. However, she acknowledged the challenge of estimating the extent of the disease due to the unique spread pattern of ILC, especially in the peritoneal cavity.
Dr. Linden shared exciting news about new clinical trials relevant to ER+ lobular patients, including the Evangeline trial, a FFNP PET/CT trial, multiple KAT6 inhibitor trials, and the FAPI trial (LuMIERE), which focuses on fibroblast activation protein inhibition. She expressed particular enthusiasm for the FAPI trial, which uses a theranostic approach, combining a tracer with a radioactive payload, a potential game-changer in precision oncology.
A Call for Action and Further Research
The event concluded with a Q&A session, where Dr. Linden emphasized the risks of combined HRT for ER+ breast cancer patients and the harmful effects of alcohol. She also highlighted the importance of proper diagnostic workup for lobular patients, as many are underdiagnosed.
Stefanie LeJeunesse shared her hard-earned wisdom, emphasizing the importance of seeking care at an NCI-designated hospital, where the latest technology, expertise, and trials can make a significant difference in outcomes. Her story serves as a powerful reminder of the impact of early detection and specialized care.
This event at Fred Hutch Cancer Center not only brought awareness to invasive lobular breast cancer but also showcased the power of patient stories and scientific progress. By sharing experiences and insights, patients and experts are working together to improve detection, treatment, and ultimately, survival rates for this unique cancer subtype.
