Breast phyllodes tumor (PT) is a rare fibroepithelial neoplasm with potential malignant behavior. Long non-coding RNAs (lncRNAs) play multifaceted roles in various cancers, but their involvement in breast PT remains largely unexplored. In this study, microarray was leveraged for the first time to investigate the role of lncRNA in PT. We identified lncRNA ZFPM2-AS1 was significantly upregulated in malignant PT, and its overexpression endowed PT with high tumor grade and adverse prognosis. Furthermore, we elucidated that ZFPM2-AS1 promotes the proliferation, migration, and invasion of malignant PT in vitro. Targeting ZFPM2-AS1 through nanomaterial-mediated siRNA delivery in patient-derived xenograft (PDX) model could effectively inhibit tumor progression in vivo. Mechanistically, our findings showed that ZFPM2-AS1 is competitively bound to CDC42, inhibiting ACK1 and STAT1 activation, thereby launching the transcription of TNFRSF19. In conclusion, our study provides evidence that ZFPM2-AS1 plays a pivotal role in the pathogenesis of breast PT, and suggests that ZFPM2-AS1 could serve as a prognostic indicator for patients with PT as well as a promising novel therapeutic target.

OBJECTIVE: 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.
CONCLUSIONS: There is no evidence that long-term survival of MPTB patients in specific age groups can benefit from RT.

Breast phyllodes tumours (PTs) are a unique type of fibroepithelial neoplasms with metastatic potential and recurrence tendency. However, the precise nature of heterogeneity in breast PTs remains poorly understood. This study aimed to elucidate the cell subpopulations composition and spatial structure and investigate diagnostic markers in the pathogenesis of PTs.
We applied single-cell RNA sequencing and spatial transcriptomes on tumours and adjacent normal tissues for integration analysis. Immunofluorescence experiments were conducted to verify the tissue distribution of cells. Tumour cells from patients with PTs were cultured to validate the function of genes. To validate the heterogeneity, the epithelial and stromal components of tumour tissues were separated using laser capture microdissection, and microproteomics data were obtained using data-independent acquisition mass spectrometry. The diagnostic value of genes was assessed using immunohistochemistry staining.
Tumour stromal cells harboured seven subpopulations. Among them, a population of widely distributed cancer-associated fibroblast-like stroma cells exhibited strong communications with epithelial progenitors which underwent a mesenchymal transition. We identified two stromal subpopulations sharing epithelial progenitors and mesenchymal markers. They were inferred to further differentiate into transcriptionally active stromal subpopulations continuously expressing COL4A1/2. The binding of COL4A1/2 with ITGA1/B1 facilitated a growth pattern from the stroma towards the surrounding glands. Furthermore, we found consistent transcriptional changes between intratumoural heterogeneity and inter-patient heterogeneity by performing microproteomics studies on 30 samples from 11 PTs. The immunohistochemical assessment of 97 independent cohorts identified that COL4A1/2 and CSRP1 could aid in accurate diagnosis and grading.
Our study demonstrates that COL4A1/2 shapes the spatial structure of stromal cell differentiation and has important clinical implications for accurate diagnosis of breast PTs.

OBJECTIVE: 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.

OBJECTIVE: Among all primary breast tumors, malignant phyllodes tumor of the breast (MPTB) make up less than 1%. In the treatment of phyllode tumors, surgical procedures such as mastectomy and breast-conserving surgery are the mainstay. MPTB has, however, been controversial when it comes to treating it with RT. We aimed to explore the prognostic impact of RT and other clinicopathologic factors on long-term survival for patients with stage T3 or T4 malignant phyllodes tumors.
METHODS: We select patients with stage T3 or T4 MPTB who qualified for the criteria between 2000 and 2018 via the Surveillance, Epidemiology, and End Results (SEER) database. We performed 1:1 propensity score matching (PSM) and Kaplan-Meier analysis to explore the role of RT in long-term survival of patients with stage T3 or T4 MPTB. A univariate and multivariate analysis of breast cancer-specific survival (BCSS) and overall survival (OS) risk factors was carried out using a Cox proportional hazards model. In addition, the nomogram graph of OS and BCSS was constructed.
RESULTS: A total of 583 patients with stage T3 or T4 malignant phyllodes tumors were included in this study, of whom 154 (26.4%) received RT, and 429 (73.6%) were treated without RT. Before adjustment, between groups with and without RT, BCSS (p = 0.1) and OS (p = 0.212) indicated no significant difference respectively. Using of PSM, the two groups still did not differ significantly in BCSS (p = 0.552) and OS (p = 0.172). In multivariate analysis, age (p < 0.001), surgery of primary site (p < 0.001) and distant metastatic status (p < 0.001) were related to prognosis, while RT still did not affect BCSS (p = 0.877) and OS (p = 0.554).
CONCLUSIONS: Based on the SEER database analysis, the study suggests that the patients with stage T3 or T4 MPTB treated with RT after surgery didn\'t have significant differences in BCSS or OS compared to those not treated with RT.

Phyllodes tumors (PTs) are rare breast tumors characterized by varying biological behavior and heterogeneous clinical findings. As a result, accurately diagnosing PTs preoperatively is challenging, often leading to misdiagnosis. A 49-year-old patient presented with a steadily growing right breast mass that had persisted over a 10-year period. Breast mammography and ultrasonography results indicated the presence of a PT. Following a lumpectomy, the patient was diagnosed with a borderline PT. However, nearly 1 year later, she was readmitted due to the recurrence of a palpable mass at the site. Consequently, 1 year and 8 months after the initial operation, she underwent thoracoscopic lobectomy to address solitary lung metastases. Subsequently, the patient experienced brain metastasis and massive hemorrhage 14 months later. Long-term follow-up was recommended. This case study presents an instance of borderline PT with clinical and imaging features that are crucial for guiding clinical operations and evaluating patient prognosis.

BACKGROUND: Breast malignant phyllodes tumors (MPT) are quite uncommon. It is rarely reported that they occur in conjunction with breast cancer. We detailed a case in which an MPT and ductal carcinoma in situ carcinoma occurred simultaneously in 2 different breasts.
METHODS: A 79-year-old female patient was seen for a rapidly growing lump in the upper left quadrant of her breast. The lump was described as huge, hard, irregular, and palpable. MRI of the breasts revealed a big mass in the left breast and a smaller lump in the right.
METHODS: Ductal carcinoma in situ with breast MPT.
METHODS: We performed a double mastectomy. Post-operative endocrine treatment was suggested.
RESULTS: During the 18-month follow-up period, no signs of recurrence or metastasis were seen. The ultrasound examination of the chest wall showed no abnormality. Bilateral axillary and supraclavicular ultrasonography showed no lymphadenectasis and a CT scan of the lungs showed no suspicious cancer nodules.
CONCLUSIONS: It is possible for MPT and ductal carcinoma in situ to occur simultaneously in different breasts. Surgeons need to integrate clinical observations, imaging tools, and patient history to make an early diagnosis. Before undergoing surgery, a thorough examination of both breasts is required.

BACKGROUND: Breast fibroadenomas and phyllodes tumors are both fibroepithelial tumors with comparable histological characteristics. However, rapid and precise differential diagnosis is a tough point in clinical pathology. Given the tendency of phyllodes tumors to recur, the difficulty in differential diagnosis with fibroadenomas leads to the difficulty in optimal management for these patients.
METHODS: In this study, we used Raman spectroscopy to differentiate phyllodes tumors from breast fibroadenomas based on the biochemical and metabolic composition and develop a classification model. The model was validated by 5-fold cross-validation in the training set and tested in an independent test set. The potential metabolic differences between the two types of tumors observed in Raman spectroscopy were confirmed by targeted metabolomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
RESULTS: A total of 204 patients with formalin-fixed paraffin-embedded (FFPE) tissue samples, including 100 fibroadenomas and 104 phyllodes tumors were recruited from April 2014 to August 2021. All patients were randomly divided into the training cohort (n = 153) and the test cohort (n = 51). The Raman classification model could differentiate phyllodes tumor versus fibroadenoma with cross-validation accuracy, sensitivity, precision, and area under curve (AUC) of 85.58 % ± 1.77 %, 83.82 % ± 1.01 %, 87.65 % ± 4.22 %, and 93.18 % ± 1.98 %, respectively. When tested in the independent test set, it performed well with the test accuracy, sensitivity, specificity, and AUC of 83.50 %, 86.54 %, 80.39 %, and 90.71 %. Furthermore, the AUC was significantly higher for the Raman model than that for ultrasound (P = 0.0017) and frozen section diagnosis (P < 0.0001). When it came to much more difficult diagnosis between fibroadenoma and benign or small-size phyllodes tumor for pathological examination, the Raman model was capable of differentiating with AUC up to 97.45 % and 95.61 %, respectively. On the other hand, targeted metabolomic analysis, based on fresh-frozen tissue samples, confirmed the differential metabolites (including thymine, dihydrothymine, trans-4-hydroxy-l-proline, etc.) identified from Raman spectra between phyllodes tumor and fibroadenoma.
UNASSIGNED: In this study, we obtained the molecular information map of breast phyllodes tumors provided by Raman spectroscopy for the first time. We identified a novel Raman fingerprint signature with the potential to precisely characterize and distinguish phyllodes tumors from fibroadenoma as a quick and accurate diagnostic tool. Raman spectroscopy is expected to further guide the precise diagnosis and optimal treatment of breast fibroepithelial tumors in the future.

The present study aimed to explore the association between immunohistochemical markers and phyllodes tumor (PT). The retrospective case control study included biopsies from patients with PT who underwent surgical treatment, and patients with fibronenoma (FA), diagnosed in our hospital from October 2014 to May 2021. Differences in microscopic histopathological characteristics and expressions of common immunohistochemical markers (CD10, cluster of differentiation 117 marker, cluster of differentiation 34 marker, tumor protein P53, cell proliferation antigen) for different grades of PT and FA were analyzed. A total of 69 patients were enrolled, of them 34 with PT (12 with benign PT, 13 with borderline PT, and 9 with malignant PT) and 35 with FA. With the increase of tumor malignancy, significant enlargement trend was noted; for FA, most tumor boundaries were well-defined, the stromal distribution was homogeneous, the stromal cellularity was small. In contrast for PT, as the degree of malignancy increased, tumor boundary gradually became ill-defined and the stromal distribution was heterogeneous; stromal cellularity and stromal overgrowth had increased significantly (All P < .05). Multivariate analysis showed that among other markers only CD10 expression (OR = 0.67, 95%CI: -0.88, 2.22, P < .05) was independently associated with PT. The study showed that in addition to histological features, CD10 expression was independently associated with PT and has a potential to be used as a differentiation marker.

As a rapid-progressing tumor, breast malignant phyllodes tumors (PTs) are challenged by the lack of effective therapeutic strategies and suitable prognostic markers. This study aimed to clarify the role and mechanism of CD146 on promoting PTs malignant progression, and to identify a novel prognosis marker and treatment target of breast malignant PTs.
The expression and prognostic significance of CD146 in PTs was detected through single-cell RNA-sequencing (scRNA-seq), immunostaining, real-time PCR and other methodologies. Functional experiments including proliferation assay, colony formation assay, transwell assay, and collagen contraction assay were conducted to validate the role of CD146 in malignant progression of PTs. The efficacy of anti-CD146 monoclonal antibody AA98 against malignant PTs was corroborated by a malignant PT organoid model and a PT patient-derived xenograft (PDX) model. Transcriptome sequencing, proteomic analysis, co-immunoprecipitation, and pull-down assay was employed to identify the modulating pathway and additional molecular mechanism.
In this study, the scRNA-seq analysis of PTs disclosed a CD146-positive characteristic in the α-SMA+ fibroblast subset. Furthermore, a progressive elevation in the level of CD146 was observed with the malignant progression of PTs. More importantly, CD146 was found to serve as an independent predictor for recurrence in PT patients. Furthermore, CD146 was found to augment the viability and invasion of PTs. Mechanistically, CD146 acted as a protective \"shield\" to prevent the degradation of Discoidin, CUB, and LCCL domain-containing protein 2 (DCBLD2), thereby activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and enhancing malignant behaviors of PT cells. In the malignant PT organoid and PDX model, a significant suppression of malignant PT growth was observed after the application of AA98.
These findings suggested that CD146 served as an efficacious marker for predicting PT malignant progression and showed promise as a prognosis marker and treatment target of breast malignant PTs. The study further unveiled the essential role of the CD146-DCBLD2/PI3K/AKT axis in the malignant progression of PTs.