Phyllodes tumors are rare breast tumors and represent fewer than 1.0% of all primary breast tumors. Most National Comprehensive Cancer Centers treat only about 5-10 phyllodes tumors annually, making collaborative research in this area vital. Dr. Rosenberger and her multi-disciplinary team treat approximately 20-30 women with phyllodes annually at Duke and focus on advancing our understanding of these tumors.

Phyllodes tumors are classified into three subtypes: (1) benign, (2) borderline, and (3) malignant grades, which have extremely diverse biological behavior, and are poorly understood at this time. Benign phyllodes tumors are similar to fibroadenomas, the most common benign breast mass in teenagers, whereas malignant phyllodes, on the other end of the spectrum, have overlapping features with aggressive breast sarcomas. Typically identified in younger women (average age of 40 years), all grades of phyllodes tumors are treated almost exclusively with surgery alone. Surgery remains the only effective therapy, as there is no known effective chemotherapy, immunotherapy, or hormonal therapy. When tumors are metastatic, few treatment options exist making prognosis poor. Because of the rarity of these tumors, there exists common misdiagnosis, inconsistent management, patient anxiety and significant surgical morbidity in these young women due to classically large tumors and no pre-surgical therapies.

Phyllodes Tumor Collaborative Network

The Duke Department of Surgery in collaboration with the Duke Cancer Institute is uniquely positioned to lead critical investigations into the genomic profiling of these rare tumors, development of early detection strategies, prevention, and even the potential development of a therapeutic target. Dr. Rosenberger is the founder and Principle Investigator of an 11-site multi-center collaborative network of Comprehensive Cancer Centers that research phyllodes tumors.  She also leads an open phyllodes tumor registry study, which collects biospecimens and stores live tumor/tissue for future research.

At Duke, Dr. Rosenberger collaborates with specialists from all areas of breast cancer diagnosis and treatment, including Dr. Juneko Grilley-Olson (Sarcoma Medical Oncology), Dr. Nicole Larrier (Sarcoma Radiation Oncology), Dr. Betty Tong (Thoracic Surgery), and Drs. Geoffroy Sisk and Brett Phillips (Plastic & Reconstructive Surgery). Importantly, these clinicians also collaborate with the scientists within Surgery, Pathology, Genetics, and within the Duke Cancer Institute. Together, these physicians and researchers are developing novel strategies directed at hereditary germline mutation identification, genomic profiling, and the potential to develop future therapeutic targets. 

Key Contributions

• Established a multi-institutional Phyllodes Tumor research network

• Developed the first Phyllodes Tumor Cancer Reporting Protocol for the College of American Pathologists (CAP)

• Established the first prospective Phyllodes Tumor registry study and tissue repository