Prognostic factors and treatment insights for metastatic malignant phyllode tumors

The aim of this study is to contribute a better understanding of metastatic malignant phyllode tumors (MMPTs) by exploring its prognostic factors, describing treatment landscape, and providing optimal treatment choices.

This retrospective multicentric study was included 43 patients with MMPTs who received treatment from 2009 to 2023 in four centers. The primary endpoint of the study was overall survival (OS).

The median overall survival of these patients was 7.27 months (range: 0.63-118.53) and the median follow-up time was 16.8 months (range: 2-188). The median age of these patients were 49 years. The median metastasis-free survival (MFS, it is the time between initial diagnosis and diagnosis of metastatic disease) was 7.27 months, and the most common site of metastasis was lung (35/43, 81.4 %). Treatment for MMPTs primarily consisted of systemic chemotherapy and metastasectomy. Multivariate analysis revealed that chemotherapy after metastasis (HR = 0.250, 95 % CI 0.109-0.571; P = 0.001) and MFS >6 months (HR = 0.407, 95 % CI 0.198-0.836; P = 0.014) were independently associated with OS. The most common chemotherapy regimen was anthracyclines along with ifosfamide (AI), with the median progression-free survival of 5.5 months. Metastasectomy did not significantly improve OS.

The study findings highlight the significance of systemic treatment (chemotherapy) and the impact of MFS on prognosis of MMPTs. For these patients, systemic treatment may improve survival outcomes. And patients with MFS <6 months appear to have a poorer prognosis.