LBCA Scientific Advisory Board (SAB) Chair, Dr. Jason Mouabbi and Dr. Sherry Shen, co-lead of the ILC program Memorial Sloan Kettering Cancer Center recently presented their important ILC research in poster presentations at the American Society of Clinical Oncology (ASCO) conference last May 29- June 2nd in Chicago. ASCO’s annual conference convenes oncology professionals worldwide to share the latest cancer research and shape cancer care. In discussing their studies, Dr. Mouabbi noted that his latest research provides a scientific roadmap for developing more personalized therapies specifically designed for ILC patients’’ and Dr. Shen explained how her study results “highlight the importance of genomic testing —either through a tumor biopsy or a blood test that detects tumor DNA in the bloodstream” to help guide treatment for patients with ILC.
Patient Advocate Gitte Joergensen provided lay summaries of both research abstracts below.
P5-10-14: Macroscale Genomic Alterations in Histomolecular Invasive Lobular Carcinoma Compared to Other Breast Cancer Subtypes
Author(s): Jason A. Mouabbi, Vladimir Kushnarev, Daria Goncharova, Oleg Baranov, Konstantin Chernyshov, Nikita Kotlov, Francesca Paradiso, Michael Hensley, Rachel M. Layman, Debasish Tripathy, Paula R. Pohlmann, Funda Meric-Bernstam
This study explored the genetic features of a type of breast cancer called invasive lobular carcinoma (ILC), using a new classification method called “histomolecular ILC” (hmILC). Researchers compared 617 breast cancer samples, including both hmILC and other types. They found that hmILC tumors had distinct genetic patterns, including more frequent deletions of the CDH1 gene, higher mutation rates, and unique mutational processes (like APOBEC). While many other breast cancers showed signs of DNA repair problems (called homologous recombination deficiency, or HRD), hmILC tumors were less likely to have these repair issues, yet some still had high mutation rates. These differences suggest that hmILC may need different, more personalized treatment strategies, especially therapies that target DNA damage and repair pathways.
What This Means for Patients with ILC::
- If you have invasive lobular breast cancer, your tumor may have unique genetic characteristics that differ from other breast cancers.
- Standard treatments may not always work the same way, especially if your tumor doesn’t show the usual signs of DNA repair problems like other types do.
- Personalized genetic testing may help guide your treatment by identifying which repair pathways or mutation patterns are most relevant.
- This research supports the need for clinical trials and tailored therapies designed specifically for lobular breast cancer patients.
Dr. Mouabbi shared, “This study reveals that invasive lobular carcinoma (ILC) has fundamentally different genetic patterns compared to invasive ductal carcinoma (IDC), including unique DNA damage and repair mechanisms that aren’t captured by current treatment approaches. By identifying these distinct molecular fingerprints (particularly the different ways ILC tumors accumulate mutations and repair DNA) this research provides a scientific roadmap for developing more personalized therapies specifically designed for ILC patients, rather than treating them with the same one-size-fits-all approach used for IDC.“
P5-10-14: Treatment Patterns, Genomic Characteristics, and Outcomes Among Patients with Metastatic Lobular Breast Cancer
This study looked at over 650 patients with metastatic invasive lobular carcinoma (ILC), a type of breast cancer that behaves differently from more common types. Researchers analyzed treatment patterns, gene mutations, and survival outcomes using genetic data from the MSK-IMPACT sequencing test. They found that most patients had hormone receptor-positive disease and had received multiple lines of treatment. Certain gene mutations were common, such as CDH1 (79%), PIK3CA (48%), and PTEN (11%). While survival did not vary by ILC subtype, it did vary depending on the genetic profile: patients with mutations in CDH1, PIK3CA, or PTEN had significantly shorter survival times. This shows that the genetic features of metastatic ILC can affect outcomes and may help guide treatment.
What This Means for patients with ILC:
- If you have metastatic lobular breast cancer, genetic testing (like next-generation sequencing) can reveal important information about your tumor.
- Some mutations, like in CDH1, PIK3CA, or PTEN, may be linked to shorter survival, which could influence how your doctors manage your care.Understanding your tumor’s genetics may help identify clinical trials or targeted therapies that are more likely to work for you.
- This study highlights the value of personalized cancer care based on tumor biology, not just subtype.
Dr. Sherry Shen shared, “Our data highlight the importance of genomic testing—either through a tumor biopsy or a blood test that detects tumor DNA in the bloodstream—as certain mutations can help predict how the cancer will behave and which treatments may work best.”
