Predicting Prognosis of Phyllodes Tumors Using a Mammography- and Magnetic Resonance Imaging-Based Radiomics Model: A Preliminary Study.

PURPOSE: To investigate whether a radiomics model based on mammography (MG) and magnetic resonance imaging (MRI) can be used to predict disease-free survival (DFS) after phyllodes tumor (PT) surgery. METHOD: About 131 PT patients who underwent MG and MRI before surgery between January 2010 and December 2020 were retrospectively enrolled, including 15 patients with recurrence and metastasis and 116 without recurrence. 884 and 3138 radiomic features were extracted from MG and MR images, respectively. Then, multiple radiomics models were established to predict the recurrence risk of the patients by applying a support vector machine classifier. The area under the ROC curve (AUC) was calculated to evaluate model performance. After dividing the patients into high- and low-risk groups based on the predicted radiomics scores, survival analysis was conducted to compare differences between the groups. RESULTS: In total, 3 MG-related and 5 MRI-related radiomic models were established; the prediction performance of the T1WI feature fusion model was the best, with an AUC value of 0.93. After combining the features of MG and MRI, the AUC increased to 0.95. Furthermore, the MG, MRI and all-image radiomic models had statistically significant differences in survival between the high- and low-risk groups (P < .001). All-image radiomics model showed higher survival performance than the MG and MRI radiomics models alone. CONCLUSIONS: Radiomics features based on preoperative MG and MR images can predict DFS after PT surgery, and the prediction score of the image radiomics model can be used as a potential indicator of recurrence risk.

Effect of adjuvant radiotherapy on overall survival and breast cancer-specific survival of patients with malignant phyllodes tumor of the breast in different age groups: a retrospective observational study based on SEER.

PURPOSE: Malignant phyllodes tumor of the breast (MPTB) is a rare type of breast cancer, with an incidence of less than 1%. The value of adjuvant radiotherapy (RT) for MPTB has been controversial. The aim of the study was to explore the effect of radiotherapy on the long-term survival of female patients with MPTB at different ages. METHODS: Female MPTB patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2020. A Kaplan-Meier survival analysis was conducted to investigate the value of RT for the long-term survival of MPTB patients in different age groups. Additionally, univariate and multivariate Cox regression analyses were performed for overall survival (OS) and breast cancer-specific survival (BCSS) of MPTB patients. Furthermore, propensity score matching (PSM) was also performed to balance the differences in baseline characteristics. RESULTS: 2261 MPTB patients were included in this study, including 455 patients (20.12%) with RT and 1806 patients (79.88%) without RT. These patients were divided into four cohorts based on their ages: 18-45, 46-55, 56-65, and 65-80. Before adjustment, there was a statistically significant difference in long-term survival between RT-treated and non-RT-treated patients in the younger age groups (age group of 18-45 years: OS P = 0.019, BCSS P = 0.016; age group of 46-55 years: OS P < 0.001, BCSS P < 0.001). After PSM, no difference was found in long-term survival of patients in both younger and older groups regardless of whether they received RT (age group of 18-45 years: OS P = 0.473, BCSS P = 0.750; age group of 46-55 years: OS P = 0.380, BCSS P = 0.816, age group of 56-65 years: OS P = 0.484, BCSS P = 0.290; age group of 66-80 years: OS P = 0.997, BCSS P = 0.763). In multivariate COX regression analysis, RT did not affect long-term survival in patients with MPTB. CONCLUSION: There is no evidence that long-term survival of MPTB patients in specific age groups can benefit from RT.

Surgical margins and prognosis of borderline and malignant phyllodes tumors.

PURPOSE: To investigate the optimal surgical margin and prognostic risk factors for borderline and malignant phyllodes tumors (PTs). METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

Study of clinicopathological factors and their impact on survival in phyllodes tumour of breast at tertiary care cancer centre in India.

BACKGROUND: Phyllodes tumour is a rare breast neoplasm having three histological types i. e benign, borderline and malignant. Surgical excision is the mainstay of treatment, but quantification of adequate margin required during excision is still a matter of debate. Role of adjuvant radiotherapy also remains controversial. AIMS: Study of prognostic factors in patients with phyllodes tumour of breast and their effect on survival. SETTING AND DESIGN: A retrospective analysis. MATERIAL AND METHODS: From the year 2016 to 2019 we included 54 patients in this study and assessment of clinical and histopathological features, requirement of adjuvant radiotherapy and their effect on DFS (disease free survival) and OS (overall survival) was done. Log-rank test was used for univariate analysis and multivariate analysis was done by using Cox propotion hazard ratio method. STATISTICAL ANALYSIS: Descriptive statistics was used for calculating proportion and median value. Survival analysis was done by using Kaplan Meier method. P value of <0.05 was considered statistically significant. RESULTS: Mitotic count and presence of heterologous component had significant effect on overall survival (OS) and disease free survival (DFS) on multivariate analysis. No effect of adjuvant radiotherapy and the type of surgery (breast conservation surgery v/s mastectomy) was found on survival (OS, DFS). CONCLUSION: Surgery with adequate margins should be the treatment of choice for tumours with borderline and malignant histological type Histological features like high mitotic count and stromal overgrowth are known prognostic factors, however, heterologous component is also an important prognostic factor and should be studied in large randomized trials. Role of adjuvant radiotherapy remains controversial.

Clinicopathologic Characteristics and Patient Outcomes of Phyllodes Tumors: A Single Institution Experience.

Phyllodes tumors (PT) are rare fibroepithelial neoplasms that are classified as benign, borderline, or malignant. Patients with PT diagnosed between 2009 and 2019 were identified from a prospectively maintained single institutional database. 76 patients with PT were included; 47 (61.8%) were benign, 9 (11.8%) were borderline, and 20 (26.3%) were malignant. The mean age at diagnosis was 52. Surgical treatment of benign PT included excisional biopsy in 31 (66.0%) patients, segmental mastectomy in 15 (31.9%), and mastectomy in 1 (2.1%). Among patients with borderline PT, operative management was excisional biopsy in 4 (44.4%) and segmental mastectomy in 5 (55.6%). Of those with malignant PT, 7 (35.0%) were treated with excisional biopsy alone, 9 (45.0%) had lumpectomy (segmental mastectomy), and 4 (20.0%) underwent mastectomy. Malignant PT had a higher rate of necrosis compared to borderline or benign PT (25.0% vs 0% vs 4.3%, P = .016). Four patients had recurrent PT. Final positive margins were associated with recurrence (P = .044). The median overall follow-up time was 86.3 months (range 1.5-1414.1 months), and no deaths occurred among patients with malignant PT. Overall, recurrence rates of PT are low but may be increased by presence of positive margins.

The role of adjuvant radiotherapy in patients with malignant phyllodes tumor of the breast: a propensity-score matching analysis.

BACKGROUND AND OBJECTIVES: Malignant phyllodes tumor of the breast (MPTB) is a kind of rare tumor. Our objective was to investigate the role of adjuvant radiotherapy (RT) in MPTB patients. METHODS: MPTB patients were identified in the Surveillance, Epidemiology and End Results (SEER) database. Kaplan-Meier curves and multivariable Cox proportional hazards analyses were conducted to determine the effect of adjuvant RT on MPTB patients. Propensity-score matching (PSM) method was used to balance the clinicopathological characteristics. RESULTS: A total of 1353 MPTB patients were included in our study and the median follow-up time was 99 months (range: 0-331 months). 16.7% (226) MPTB patients received adjuvant RT, of which 49.1% (111) received mastectomy and 50.9% (115) underwent breast conservation surgery (BCS). Patients receiving adjuvant RT were more likely to be white, with better differentiation and larger tumors (p < 0.05). Multivariate analysis showed that poorer tumor differentiation grade, larger tumor size, and lymph node metastasis were associated with reduced survival while BCS was a protective factor of disease-specific survival (DSS) (HR 0.297; 95% CI 0.184-0.480) and overall survival (OS) (HR 0.445; 95% CI 0.321-0.616). After PSM, survival curves showed patients did not achieve an improved OS or DSS from adjuvant RT (p > 0.05). In subgroup analysis, no subgroup benefited from adjuvant RT. Exploratory analysis showed a survival benefit trend from adjuvant RT in patients with tumor larger than 50 mm and undergoing BCS. CONCLUSIONS: Among MPTB patients, adjuvant RT did not improve OS or DSS. In patients with tumor larger than 50 mm and receiving BCS, a survival benefit trend from adjuvant RT existed.

Prognostic Molecular and Biological Characteristics of Phyllodes Tumors of the Breast.

Prognosis for some histological variants of a rare breast disease, phyllodes tumors, is evaluated. The prognostic potential of some molecular biological factors significantly correlating with breast cancer prognosis is evaluated on a unique clinical material (244 cases with benign, intermediate, and malignant phyllodes tumors). The development of benign phyllodes tumor relapse directly correlated with the number of G0/1-phase cells and inversely correlated with the number of cells in the G2+M and S phases. The level of steroid hormone receptors in phyllodes tumors cannot serve as a prognostic marker predicting the disease course. The presence of somatic mutations of TP53 gene and loss of heterozygosity of specific intragenic loci in the tumor correlate with the development of disease relapse (p<0.05).

High expression of microRNA20b is associated with malignant clinicopathological features and poor prognosis in breast phyllodes tumor.

BACKGROUND: microRNAs, which expound the transcriptional regulation of gene expression, have been validated as prognostic markers in many tumors. The deregulated expression of microRNAs has been shown to aid classification of tumors and predict outcome in many tumors including breast PTs. The aim of our study is to investigate the clinical significance and prognostic value of microRNAs in PTs to identify a biomarker which has the potential for predicting prognosis and target therapy. METHODS: Quantitative real-time PCR (qRT-PCR) was used to detect the expression level of microRNA20b in 123 breast PTs patients. The correlations between the expression of microRNA20b and clinicopathological parameters were investigated. The prognostic significance of microRNA20b was investigated by the Kaplan-Meier survival and Cox proportional hazards regression model. RESULTS: The expression level of microRNA20b increased with the increase in the tumor grade (p < 0.05). High expression of microRNA20b correlated with stromal overgrowth, marked stromal cellularity, high atypia of stromal cells, infiltrative tumor margin, high mitotic activity, tumor grade, local recurrence and metastasis (p < 0.05). High expression of microRNA20b correlated with the shorter disease-free survival (DFS) (log-rank test, p < 0.001). Multivariate Cox regression analysis showed that microRNA20b was an independent prognostic indicator for breast PTs patients. CONCLUSION: The study demonstrated the promising potential of applying microRNA20b as a prognostic biomarker in PT patients.

The implications of neighborhood socioeconomic status on surgical management and mortality in malignant phyllodes patients in the Surveillance, Epidemiology, and End Results program.

BACKGROUND: Neighborhood socioeconomic status has been implicated in breast cancer incidence and mortality. However, there are no studies on the impact of neighborhood socioeconomic status on clinical outcomes or surgical management among patients with phyllodes tumors. The objective of this study is to understand the relationship between neighborhood socioeconomic status, surgical management and disease specific mortality in malignant phyllodes tumor patients in the Surveillance, Epidemiology, and End Results program. METHODS: Surveillance, Epidemiology, and End Results program was queried for malignant phyllodes tumor patients diagnosed between 2000 and 2016. Using the National Cancer Institute census tract-level index for neighborhood socioeconomic status the data were stratified into low neighborhood socioeconomic status, middle neighborhood socioeconomic status, and high neighborhood socioeconomic status. Bivariate intergroup analysis was conducted. Disease specific mortality was evaluated using a Cox proportional hazards model. RESULTS: Of the 651 patients with malignant phyllodes tumor in the sample, the disease specific mortality was 7.6% and 7.9% at 5 and 10 years, respectively. On bivariate analysis, there were no differences between the neighborhood socioeconomic status groups and surgery type (P = .794). On multivariable analysis, older age (≥71 years; hazard ratio 9.9; 95% confidence interval, 2.84-34.57; P < .001) and larger tumor size (≥40 mm; hazard ratio 2.20; 95% confidence interval, 1.09-4.44; P = .027) were associated with a higher disease specific mortality compared with younger age (≤ 40 years) and smaller tumor size (<40 mm). There was no association between neighborhood socioeconomic status and disease specific mortality (low neighborhood socioeconomic status-ref, middle neighborhood socioeconomic status hazard ratio 0.87 (95% confidence interval, 0.71-1.78; P = .71), high hazard ratio 0.91 (95% confidence interval, 0.44-1.90, P = .81). CONCLUSION: Among malignant phyllodes tumor patients in the Surveillance, Epidemiology, and End Results program, disease specific mortality and surgical management are mostly driven by tumor characteristics and not social determinants of health.

The Impact of Radiotherapy and Histological Risk Factors on Outcomes in Malignant Phyllodes Tumors.

PURPOSE: Breast phyllodes tumors (PT) are classified into benign, borderline, and malignant grades based on histopathologic characteristics. Specific to malignant PT (MPT), surgery is the mainstay yet relapse rates are high and knowledge gaps in the literature exist regarding adjuvant radiotherapy (RT). We aimed to investigate the outcomes of patients with MPT treated in a tertiary Asian institution. METHODS AND MATERIALS: Patients with nonmetastatic MPT treated from February 1992 to June 2019 were analyzed retrospectively. RT details and relapse fields were studied. Outcomes of patients with and without RT were compared and hazard ratios were calculated using Cox proportional hazard test. Multivariable analysis was performed. RESULTS: Twenty-two of 89 patients received adjuvant RT and the median dose was 60 Gy. In the no-RT group, 4 patients received RT on relapse and had no further recurrences; a further 2 received RT for fungating relapses with good symptomatic relief. RT was only increasingly prescribed after 2004. Median follow-up in the RT group was 3.31 years, compared with 6.17 years in the no-RT group. In the RT group, 15 patients (68.2%) underwent mastectomy, versus 39 (58.2%) in the no-RT group. One patient in the RT group developed an infield local relapse, compared with 21 of 67 patients in the no-RT group. Multivariate model showed that RT decreased risk of locoregional failure (hazard ratio 0.12, 95% confidence interval [CI] 0.02-0.92, P = .04). Three-year locoregional recurrence-free survival was higher in the RT group, 92.3% (95% CI, 78.9-100) versus 73.3% (95% CI, 63.1-85.1) in the no-RT group (P = .03). There were no differences in 3-year survival. CONCLUSIONS: We recommend that adjuvant radiotherapy be discussed for malignant PT for local control, even after mastectomy.

Expression of cancer stem cell markers in breast phyllodes tumor.

BACKGROUND: Phyllodes tumor (PT) is a rare tumor showing various malignant potential. The histological grade of PT is related to clinical outcome, but its relationship between gaining of malignant potential and underlying mechanism including cancer stem cell factor was not understood yet. OBJECTIVE: The main purpose of this study was to determine the expression pattern of cancer stem cell marker in PT and to understand its clinical and pathological implications. METHODS: CD44, CD166, ALDH1, and Ki-67 immunohistochemistry were performed on a tissue microarray from 185 cases of PT specimens (138 benign, 32 borderline, 15 malignant). The immunohistochemistry result and clinicopathological parameter of each cases were compared to analyze the implications of cancer stem cell markers on PT. RESULTS: Borderline/malignant PT showed higher CD44 expression of the stromal component than benign PT (p< 0.001). In lower histologic grade PT, CD166 showed increased expression in the epithelial component (p= 0.019), but decreased in the stromal component (p< 0.001). Stromal overgrowth was rarely observed as the number of positive cancer stem cell markers increased in the epithelial component (p< 0.001). In the stromal component, the number of positive cancer stem cell markers was related to higher histologic grade (p< 0.001), and increased stromal cellularity (p< 0.001), stromal atypia (p= 0.003), and stromal mitosis (p= 0.002). In benign PT, CD44 negativity (p= 0.013) and a decreased number of positive cancer stem cell markers (p= 0.012) in the epithelial component were related to poor prognosis. CONCLUSIONS: The cancer stem cell markers, CD44 and CD166, are expressed in both the epithelial and stromal components of phyllodes tumor. Besides, ALDH1 is only expressed in stromal component. In the stromal component, expression of cancer stem cell markers increases with higher PT histologic grade. In the epithelial component, the absence of cancer stem cell marker expression is related to poor clinical prognosis.

Impact of Metastasis Surgery and Alkylating-Agent-Based Chemotherapy on Outcomes of Metastatic Malignant Phyllodes Tumors: A Multicenter Retrospective Study.

BACKGROUND: Metastatic phyllodes tumors have poor prognosis with median overall survival of 11.5 months. The objective of this study is to identify prognostic factors and the best options for management of metastatic malignant phyllode tumors (MMPTs). PATIENTS AND METHODS: A multicentric retrospective study, including cases of MMPT from 10 sarcoma centers, was conducted. The primary end-point was overall survival (OS), and the secondary end-point was the clinical benefit of chemotherapy (CBCT) rate. RESULTS: 51 MMPT patients were included. Median time from diagnosis to metastatic recurrence was 13 months. Management of MMPT consisted in surgery of the metastatic disease for 16 patients (31.3%), radiation therapy of the metastatic disease for 15 patients (31.9%), and chemotherapy for 37 patients (72.5%). Median follow-up was 62.1 months [95% confidence interval (CI) 31-80 months]. Median OS was 11.5 months (95% CI 7.5-18.7 months). On multivariate analysis, two or more metastatic sites [hazard ratio (HR) 2.81, 95% CI 1.27-6.19; p = 0.01] and surgery of metastasis (HR 0.33, 95% CI 0.14-0.78; p = 0.01) were independently associated with OS. The CBCT rate was 31.4% and 16.7% for the first and second lines. Polychemotherapy was not superior to single-agent therapy. Alkylating-agent-based chemotherapy, possibly associated with anthracyclines, was associated with a better CBCT rate than anthracyclines alone (p = 0.049). CONCLUSIONS: The results of this study emphasize the impact of the number of metastatic sites on survival of MMPT patients and the leading role of metastasis surgery in MMPT management. If systemic therapy is used, it should include alkylating agents, which are associated with a better clinical benefit.

Predicting Outcome in Mammary Phyllodes Tumors: Relevance of Clinicopathological Features.

BACKGROUND: Phyllodes tumors (PTs) of the breast are uncommon fibroepithelial neoplasms. Most behave in a benign fashion but they also have the potential to recur locally or to metastasize. METHODS: In the current study involving 290 PTs (181 benign, 76 borderline, and 33 malignant) from three hospitals over an 11-year period, we assessed the relationship between histologic parameters (including histologic features affecting grade and surgical margin status), postoperative adjuvant treatment, and local recurrences and distant metastases. RESULTS: An involved surgical margin was the only factor associated with increased risk of local recurrences (hazard ratio [HR] 4.673, p = 0.003), but not for distant metastases. For local recurrences, a wider margin did not confer additional benefits. None of the histologic factors were predictive for local recurrences. In contrast, distant metastases were correlated with histologic parameters, particularly an infiltrative border (HR 10.935, p = 0.012) and the presence of necrosis (HR 15.311, p = 0.007). In this series, all local recurrences were found in patients without radiotherapy, regardless of surgical margin status. CONCLUSION: A negative surgical margin is mandatory for the effective local control of PT recurrence, and a minimal margin clearance may be sufficient. For distant metastases, the inherent characteristics of PTs are important, thus it may be prudent to evaluate additional histologic features, including necrosis, for patients' prognostication.

Adjuvant radiotherapy and chemotherapy for patients with breast phyllodes tumors: a systematic review and meta-analysis.

BACKGROUND: As the efficacy of radiotherapy and chemotherapy for treatment of phyllodes tumors (PTs) remains unclear, this study aimed to review all available data and evaluate the roles of radiotherapy and chemotherapy in PT treatment. METHODS: We performed a comprehensive search of databases, including PubMed, Web of Science and the Cochrane Library. The outcomes of interest included the local recurrence (LR) rate, metastasis rate, disease-free survival rate and overall survival rate. RESULTS: Seventeen studies enrolling 696 patients were included in this random effect meta-analysis. Subgroup analysis and meta-regression were also conducted to determine study heterogeneity. A pooled local recurrence rate of 8% (95% CI: 1-22%) was observed with a statistical heterogeneity of I2 = 86.6% (p < 0.01) for radiotherapy. This was lower than the recurrence rate of 12% for simple surgical treatment (95% CI: 7-18%). Meta-regression analysis found that surgical margin status was the main source of heterogeneity (p = 0.04). The metastasis rate of 4% (95% CI: 0-11%) for patients receiving radiotherapy without significant heterogeneity was also lower than the rate for the simple surgery group (8, 95% CI: 3-15%). The available data for chemotherapy were too limited to support meta-analysis. Accordingly, we offer a pure review of these data. CONCLUSION: Our findings suggest that radiotherapy is effective in achieving local disease control and preventing metastasis.

Breast Phyllodes Tumors Recruit and Repolarize Tumor-Associated Macrophages via Secreting CCL5 to Promote Malignant Progression, Which Can Be Inhibited by CCR5 Inhibition Therapy.

PURPOSE: Malignant phyllodes tumor (PT) is a fast-progression neoplasm derived from periductal stromal cells of the breast, which currently still lack effective treatment strategies. Our previous studies showed that the high density of tumor-associated macrophages (TAM) plays an important role in the malignant progression of PTs. TAMs secreted large amount of CCL18 to promote myofibroblast differentiation and invasion via binding to its receptor PIPTNM3 on myofibroblasts. Herein, we investigate the mechanism of how TAMs are recruited and repolarized by PTs to drive the malignant progression. EXPERIMENTAL DESIGN: The cytokines secreted by PTs were identified by the cytokine array. The clinical and pathologic correlations of the cytokine with PTs were estimated with IHC. The mechanisms of the cytokine that recruited and polarized the macrophage were explored with a coculture model of primary PT cells and macrophages in vitro and in vivo. The patient-derived xenografts (PDX) of malignant PTs were used to evaluate the therapeutic effect of CCR5 inhibitor. RESULTS: A high level of malignant PT-secreted CCL5 correlated with poor outcome of PTs and could be an independent prognostic factor of PTs. CCL5 bound to its receptor, CCR5, on macrophages thus activated AKT signaling to recruit and repolarize TAMs. Subsequently, the TAMs released CCL18 to further promote the aggressive phenotype of malignant PTs by enhancing and maintaining the myofibroblast differentiation and invasion in vitro and in vivo. In a murine PDX model of human malignant PTs, the CCL5-CCR5 axis blocked by maraviroc, an FDA-proved CCR5 inhibitor, prevented recruitment of monocytes to the tumor and dramatically suppressed tumor growth. CONCLUSIONS: Our findings indicate that malignant PTs recruit and repolarize TAMs through a CCL5-CCR5-driven signaling cascade. Thus, a positive feedback loop of CCL5-CCR5 and CCL18-PIPTNM3 between myofibroblast and TAMs is constituted to drive the malignant progression of PTs. Furthermore, targeting CCR5 with maraviroc represents a potential clinically available strategy to treat malignant PTs.

Malignant and borderline phyllodes tumors of the breast: a multicenter study of 362 patients (KROG 16-08).

PURPOSE: To identify risk factors for local recurrence (LR) and investigate roles of adjuvant local therapy for malignant and borderline phyllodes tumors of the breast. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Phyllodes tumors of the breast: The British Columbia Cancer Agency experience.

PURPOSE: Phyllodes tumors of the breast are uncommon fibroepithelial lesions for which optimal management remains unclear. This retrospective population-based study reports treatment and outcomes for patients with phyllodes tumors and evaluates characteristics that influence outcome. MATERIALS AND METHODS: Data were analysed on 183 patients with newly diagnosed phyllodes tumors from 1999 to 2014. Five-year Kaplan-Meier local recurrence and survival were compared between cohorts with benign (n=83), borderline (n=50) and malignant phyllodes tumor (n=49) histology. RESULTS: Median (range) follow-up was 65 (0.5-197) months. Local excision was performed in 163 and mastectomy in 19 patients. Eleven patients with malignant phyllodes tumors received radiation therapy. Overall, local recurrence occurred in 8.7%, distant metastases in 4.4%, and cause specific deaths in 3.8%. Five-year Kaplan-Meier outcomes among women with benign, borderline, and malignant phyllodes tumors were: local recurrence 6% vs 9% vs 21%, P=0.131; overall survival 96% vs 100% vs 82%, P=0.002; and disease-free survival 94% vs 91% vs 67%, P<0.001. Five-year Kaplan-Meier local recurrence among women with negative vs close vs positive margins were 8% vs 6% vs 37%, P<0.001. Corresponding rates for intermediate vs pushing vs infiltrative borders were 6% vs 6% vs 33%, P=0.006. Positive margins and infiltrative tumor borders were associated with increased local recurrence (all P≤0.006), and the latter remained significant in exploratory analyses after adjusting for margin status and phyllodes tumor classification. CONCLUSIONS: Five-year outcomes among women with phyllodes tumors were comparable to those reported in the literature. Exploratory analysis has suggested that infiltrative tumor borders may be used in conjunction with margin status to assess local recurrence risk.

Fibroepithelial lesions of the breast: a comprehensive morphological and outcome analysis of a large series.

Mammary fibroepithelial lesions encompass a wide spectrum of tumors ranging from an indolent fibroadenoma to potentially fatal malignant phyllodes tumor. The criteria used for their classification based on morphological assessment are often challenging to apply and there is no consensus as to what constitutes an adequate resection margin. We studied a retrospective cohort of 213 fibroepithelial lesions in 178 patients (80 fibroadenomas with unusual features and 133 phyllodes tumors: 63 benign, 41 borderline, and 29 malignant) in order to describe the spectrum of changes within each group, with special emphasis on margin evaluation. Outcome data were available for 153 fibroepithelial lesions in 139 patients (median 56 months, range 3-249 months). Positive final margin (tumor transected), age < 50 years and a predominantly myxoid stroma were statistically significant predictors of local recurrence, while age > 50, stromal overgrowth, diffuse marked atypia, necrosis and mitotic index of ≥ 10 per 10 HPF were predictive of distant metastases. Tumors with satellite/bulging nodules were at a significantly higher risk to have a final positive resection margin. Our findings highlight important aspects of the interpretation and reporting of fibroepithelial lesions: the amount of myxoid stroma and the presence of satellite nodules are clinically relevant and should be routinely assessed and reported; infiltrative border might not be a prerequisite for the diagnosis of malignant phyllodes tumor, while the presence of tumor necrosis, massive stromal overgrowth or mitotic index of ≥ 25 per 10 HPF is diagnostic of malignant phyllodes tumor. On the other hand, increased mitotic index outside of the range of the World Health Organization guidelines in the absence of other worrisome features should be treated with caution, as it can be found in benign tumors.

Prognostic factors in breast phyllodes tumors: a nomogram based on a retrospective cohort study of 404 patients.

The aim of this study was to explore the independent prognostic factors related to postoperative recurrence-free survival (RFS) in patients with breast phyllodes tumors (PTBs). A retrospective analysis was conducted in Fudan University Shanghai Cancer Center. According to histological type, patients with benign PTBs were classified as a low-risk group, while borderline and malignant PTBs were classified as a high-risk group. The Cox regression model was adopted to identify factors affecting postoperative RFS in the two groups, and a nomogram was generated to predict recurrence-free survival at 1, 3, and 5 years. Among the 404 patients, 168 (41.6%) patients had benign PTB, 184 (45.5%) had borderline PTB, and 52 (12.9%) had malignant PTB. Fifty-five patients experienced postoperative local recurrence, including six benign cases, 26 borderline cases, and 22 malignant cases; the three histological types of PTB had local recurrence rates of 3.6%, 14.1%, and 42.3%, respectively. Stromal cell atypia was an independent prognostic factor for RFS in the low-risk group, while the surgical approach and tumor border were independent prognostic factors for RFS in the high-risk group, and patients receiving simple excision with an infiltrative tumor border had a higher recurrence rate. A nomogram developed based on clinicopathologic features and surgical approaches could predict recurrence-free survival at 1, 3, and 5 years. For high-risk patients, this predictive nomogram based on tumor border, tumor residue, mitotic activity, degree of stromal cell hyperplasia, and atypia can be applied for patient counseling and clinical management. The efficacy of adjuvant radiotherapy remains uncertain.