From the Guidelines
The percentage of malignancy in phylloides tumors is approximately 20-30% in malignant cases, as indicated by a metastatic rate of 20%–30% in malignant phyllodes tumors 1.
Key Points
- Most phylloides tumors are benign, but the exact percentage of malignancy can vary depending on the histological features of the tumor.
- Malignant phyllodes tumors have a higher risk of distant metastasis, primarily to the lungs and bones, occurring in approximately 10% of malignant cases.
- The risk of malignancy increases with age, with malignant phylloides tumors being more common in older women.
- Accurate diagnosis through core needle biopsy and proper histopathological examination is essential for appropriate management.
- Wide local excision with negative margins is the recommended treatment for all phylloides tumors regardless of classification, with adjuvant radiotherapy considered in high-risk cases of borderline phyllodes or malignant phyllodes tumors 1.
Treatment Considerations
- Standard surgical treatment remains wide excision with clear margins and either breast conservative surgery (BCS) or mastectomy can be undertaken.
- For large malignant phyllodes tumours, breast conservation may not be possible, and the role of immediate reconstruction needs careful discussion on an individual case basis.
- Adjuvant radiotherapy has been demonstrated to improve local control, but not survival, in breast sarcomas and neoadjuvant radiotherapy does not have a role in this anatomical site 1.
From the Research
Phyllodes Tumor Malignancy Percentage
- The exact percentage of malignancy in phyllodes tumors is not explicitly stated in the provided studies.
- However, the studies suggest that phyllodes tumors can be classified as benign, borderline, or malignant based on histopathologic analysis 2, 3, 4, 5, 6.
- A study published in 2022 recommends that borderline PTs should have a clear margin on excision due to their higher risk of recurrence, as well as the potential for a recurrence to progress to a malignant PT 6.
- Another study published in 2021 found that nearly one-third of malignant PTs recur locally, usually within a few years after initial diagnosis 2.
- A 2024 study reported that 26.7% of patients had their diagnosis upgraded to malignant phyllodes on completion excision, compared to initial biopsy 3.
- The 2021 study also reported that the five-year overall survival rate of malignant PTs is close to 80% 2.
Classification and Treatment
- Phyllodes tumors are rare fibroepithelial lesions of the breast that can be classified as benign, borderline, or malignant based on histopathologic analysis 2, 3, 4, 5, 6.
- The treatment of phyllodes tumors depends on the histological grade, with benign tumors typically being excised with a wide margin, and malignant tumors requiring more extensive surgery, such as mastectomy 3, 5, 6.
- Adjuvant radiation therapy may be considered for borderline and malignant phyllodes tumors, although its effectiveness is still being studied 4, 6.
- Chemotherapy may be discussed in malignant PT patients, although its role is not well established 6.