Surgical margins and prognosis of borderline and malignant phyllodes tumors

To investigate the optimal surgical margin and prognostic risk factors for borderline and malignant phyllodes tumors (PTs).

A retrospective analysis was conducted on patients with borderline and malignant PTs at our hospital from 2011 to 2022. Univariate and multivariate Cox proportional hazard models were employed to analyze the effects of various variables on local recurrence-free survival (LRFS) and disease-free survival (DFS).

This study comprised 150 patients, 85 classified as borderline and 65 as malignant. During a median follow-up of 66 months (range: 3-146 months), 34 cases (22.7%) experienced local recurrence, 9 cases (6.0%) exhibited distant metastasis, and 7 cases (4.7%) resulted in death. Irrespective of the histological subtypes, patients with surgical margins ≥ 1 cm exhibit significantly higher 5-year LRFS and 5-year DFS rates compared to those with margins < 1 cm. Among patients with initial margins < 1 cm, LRFS (P = 0.004) and DFS (P = 0.003) were improved in patients reoperated to achieve margins ≥ 1 cm. Surgical margin < 1 cm (HR = 2.567, 95%CI 1.137-5.793, P = 0.023) and age < 45 years (HR = 2.079, 95%CI 1.033-4.184, P = 0.040) were identified as independent risk factors for LRFS. Additionally, surgical margin < 1 cm (HR = 3.074, 95%CI 1.622-5.826, P = 0.001) and tumor size > 5 cm (HR = 2.719, 95%CI 1.307-5.656, P = 0.007) were determined to be independent risk factors for DFS.

A negative surgical margin of at least 1 cm (with secondary resection if necessary) should be achieved for borderline and malignant PTs. Tumor size > 5 cm and age < 45 years were predictive of recurrence, suggesting multiple therapy modalities may be considered for these high-risk patients.