Malignant and borderline phyllodes tumors of the breast: a multicenter study of 362 patients (KROG 16-08)
- 748 Downloads
To identify risk factors for local recurrence (LR) and investigate roles of adjuvant local therapy for malignant and borderline phyllodes tumors of the breast.
From 1981 to 2014, 362 patients with malignant (n = 235) and borderline (n = 127) phyllodes tumors were treated by breast-conserving surgery (BCS) or total mastectomy (TM) at 10 centers. Thirty-one patients received adjuvant radiation therapy (RT), and those who received adjuvant chemotherapy were excluded from the study.
Median follow-up was 5 years. LR developed in 60 (16.6%) patients. Regional recurrence occurred in 2 (0.6%) patients and distant metastasis (DM) developed in 19 (5.2%) patients. Patients receiving BCS (p = 0.025) and those not undergoing adjuvant RT (p = 0.041) showed higher LR rates. For malignant subtypes, local control (LC) rates at 5 years for BCS alone, BCS with adjuvant RT, TM alone, and TM with adjuvant RT were 80.7, 93.3, 92.4, and 100%, respectively (p = 0.033). Multivariate analyses revealed BCS alone, tumor size ≥ 5 cm, and positive margins as independent risk factors for LR. Margin-positive BCS alone showed poorest LC regardless of tumor size (62.5%, p = 0.007). For margin-negative BCS alone, 5-year LC rates for tumors ≥ 5 cm versus those < 5 cm were 71.8% versus 89.5% (p = 0.012). For borderline subtypes, only positive margins (p = 0.044) independently increased the risk of LR. DM developed exclusively in malignant subtypes and a prior LR event increased the risk of DM by sixfold (HR 6.2, 95% CI 1.6–16.1, p = 0.001).
Malignant and borderline phyllodes tumors with positive margins after surgery have high LR rates. After treatment by margin-negative BCS alone, patients with large malignant phyllodes tumors ≥ 5 cm also have heightened risk of LR. Thus, such patients should be considered for additional local therapy.
KeywordsMalignant phyllodes tumor Borderline phyllodes tumor Breast neoplasm Adjuvant therapy Recurrence Risk factor
Compliance with ethical standards
Conflict of interest
The authors have nothing to disclose.
Review of medical records was approved by the Korean Radiation Oncology Group (KROG) and the Institutional Review Board of each participating center in accord to the ethical standards of the Helsinki Declaration. Data pertaining to demographic, clinical, pathologic, and follow-up variables were collectively analyzed. Based on the retrospective design of analyses, requirement to obtain written informed consent from patients included in this study was exempted.
- 4.World Health Organization (1981) Histologic typing of breast tumors, 2nd edn. WHO, GenevaGoogle Scholar
- 5.Lakhani SREI., Schnitt SJ, Tan PH, van de Vijver MJ (2012) World Health Organization classification of tumours, 4th edn. IARC, LyonGoogle Scholar
- 9.National Comprehensive Cancer Network. Breast Cancer (Version 2. 2016). https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf. Accessed 1 Dec 2017
- 39.Fisher B, Anderson S, Bryant J, Margolese RG, Deutsch M, Fisher ER et al (2002) Twenty-year follow-up of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. New Engl J Med 347(16):1233–1241PubMedCrossRefGoogle Scholar