Primary treatment of cystosarcoma phyllodes of the breast

Malignant phyllodes tumour of the breast with early recurrence in a young patient

A young woman in her 20s was found to have a left breast malignant phyllodes tumour by ultrasound-guided core needle biopsy, after identifying a palpable lump. She then underwent lumpectomy excision with >1 cm gross margins; however, final pathology demonstrated <1 cm margins at the superior margin. She then underwent re-excision of superior and medial margins to ensure at least a 1 cm margin. Biopsy tract was not excised at initial or re-excision surgery. Approximately 6 weeks after completion lumpectomy, the patient noted a new palpable mass near the previous biopsy site and underwent punch biopsy. Final pathology of this new mass was concordant with early recurrence. The patient then underwent lumpectomy of the new mass along with excision of the overlying skin and biopsy tract with >1 cm margins.

Surgical Management and System Therapy of the Most Giant Known Malignant Metastatic Breast Phyllodes Tumor: A Case Report and Review of the Literature

INTRODUCTION

Phyllodes tumors belong to uncommon fibroepithelial breast tumors with a range of biological behaviors. Phyllodes tumors are responsible for less than 1 percent of all neoplasms of the breast.

CASE PRESENTATION

A 66-year-old woman presented to our Breastcancer Unit in March 2021 because of a huge mass of her left breast with bleeding out of a tumor necrosis. Five years ago in 2016, a benign phyllodes tumor was diagnosed externally. When we started the treatment, the tumor had a weight of 18.6 kg.

CONCLUSION

We describe the surgical management and the systemic treatment of metastatic disease.

Multidisciplinary Management of Phyllodes Tumours and Breast Sarcoma: A Cross-sectional Survey of Clinical Practice across the UK and Ireland

AIMS

Phyllodes tumours and breast sarcomas are uncommon tumours and their rarity poses significant challenges in diagnosis and management. This cross-sectional study was conducted to evaluate the multidisciplinary clinical practice for these tumours across the UK and Ireland, with the aim of identifying gaps in knowledge and providing direction for establishing national guidelines.

MATERIALS AND METHODS

An international survey was adapted and circulated to breast and/or sarcoma surgeons and oncologists in the UK and Ireland through national organisations. Multidisciplinary team (MDT) responses were analysed anonymously.

RESULTS

Twenty-eight MDTs participated in this study, predominately from high-volume units (85.5%). Although only 43% of the surveyed units were part of a trust that holds a sarcoma MDT, 68% of units managed malignant phyllodes and angiosarcoma, whereas 64.5% managed soft-tissue sarcoma of the breast. Across all subtypes, axillary surgery was recommended by 14-21% of the MDTs and the most recommended resection margins for breast surgery were 'no tumour on ink' in benign phyllodes (39%) and 10 mm in the remaining subtypes (25-29%). Immediate breast reconstruction was supported by 11-18% of MDTs for breast sarcoma subtypes, whereas 36% and 32% advocated this approach in benign and borderline phyllodes tumours, respectively. Adjuvant radiotherapy and chemotherapy were recommended by up to 29% and 11% of the MDTs, respectively.

CONCLUSION

The results of this study demonstrate a wide variation in clinical practice across the surveyed MDTs. As only 28 MDTs participated in our study, with under-representation from low-volume units, our results might be an underestimation of the variability in practice across the UK and Ireland. This multi-institutional study sheds light on controversial aspects in the management of phyllodes tumours and breast sarcoma, identifies the need for national guidelines to inform best practice, and calls for the centralisation of the management of breast sarcoma within specialist centres.

Effect of radiation therapy on patients with stage T3 or T4 malignant phyllodes tumors: a retrospective observational study based on SEER

PURPOSE

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).

CONCLUSION

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.

Precise diagnosis of breast phyllodes tumors using Raman spectroscopy: Biochemical fingerprint, tumor metabolism and possible mechanism

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.

METHOD

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.

SIGNIFICANCE AND NOVELTY

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.

Comprehensive Clinical-Pathologic Assessment of Malignant Phyllodes Tumors: Proposing Refined Diagnostic Criteria

The latest World Health Organization classification of breast tumors recommends diagnosing malignant phyllodes tumors (MPTs) when all 5 morphologic features are present: permeative borders, marked stromal cellularity, marked stromal cytologic atypia, ≥10 mitoses per 10 high-power fields (HPF), and stromal overgrowth. We assessed the performance of this recommendation to capture MPTs and features predictive of distant metastasis in a multi-institutional retrospective study. Of 65 MPTs, most cases had at least focally permeative borders (58, 89%), with marked stromal cellularity in 40 (61.5%), marked atypia in 38 (58.5%), ≥10 mitoses per 10 HPF in 50 (77%), and stromal overgrowth in 56 (86%). Distant metastases were observed in 20 (31%) patients (median follow-up 24.5 mo, 1 to 204). Only 13 of 65 (20%) cases had all 5 morphologic features, while only 7 of 20 (35%) cases with distant metastases had all 5 features. In univariate analysis, only marked stromal atypia ( P =0.004) and cellularity ( P =0.017) were associated with decreased distant metastasis-free survival. In multivariate Cox regression, the combination of stromal overgrowth, marked stromal cellularity, and atypia (C-index 0.721, 95% CI: 0.578, 0.863) was associated with decreased distant metastasis-free survival. The current World Health Organization recommendation will miss a significant number of MPTs with distant metastases. We propose refined diagnostic criteria for MPTs: (1) stromal overgrowth combined with ≥1 feature(s) (marked cellularity, marked atypia, or ≥10 mitoses per 10 HPF), or (2) in the absence of stromal overgrowth, marked cellularity combined with ≥1 feature(s) (permeative borders, marked atypia, or ≥10 mitoses per 10 HPF).

CD146 promotes malignant progression of breast phyllodes tumor through suppressing DCBLD2 degradation and activating the AKT pathway

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Organoid models derived from patients with malignant phyllodes tumor of the breast

PURPOSE

Phyllodes tumor of the breast is a kind of rare neoplasm, which accounts for less than 1% of all breast tumors. Malignant phyllodes tumor (MPT) is the highest risk subtype of phyllodes tumor, and is characterized by the tendency of local recurrence and distant metastasis. The prediction of prognosis and the individual therapy for MPT is still challenging. It's urgent to develop a new reliable in vitro preclinical model in order to understand this disease better and to explore appropriate anticancer drugs for individual patients.

METHODS

Two surgically resected MPT specimens were processed for organoid establishment. MPT organoids were subsequently subjected to H&E staining, immunohistochemical analysis and drug screening, respectively.

RESULTS

We successfully established two organoid lines from different patients with MPT. The MPT organoids can well retain the histological features and capture the marker expression in original tumor tissues, including p63, vimentin, Bcl-2, CD34, c-Kit, and Ki-67, even after a long-term culture. The dose titration tests of eight typical chemotherapeutic drugs (paclitaxel, docetaxel, vincristine, doxorubicin, cisplatin, gemcitabine, cyclophosphamide, ifosfamide) on the two MPT organoid lines showed patient-specific drug responses and varying IC₅₀ values. Of all the drugs, doxorubicin and gemcitabine showed the best anti-tumor effect on the two organoid lines.

CONCLUSION

Organoids derived from MPT may be a novel preclinical model for testing personalized therapies for patients with MPT.

Clinical outcomes and biomarkers of phyllodes tumors of the breast: A single-center retrospective study

PURPOSE

Phyllodes tumors (PTs) are rare neoplasms with a certain risk of recurrence and/or metastasis. In clinical practice, there is a lack of high-quality clinical studies and unified guidelines to guide the treatment.

MATERIALS AND METHODS

All malignant and recurrence/metastasis PTs were retrospectively collected, which were diagnosed from 2008 to 2022.

RESULTS

A total of 82 patients were enrolled, including 69 malignant and 13 borderline tumors. 96.3% (79/82) received surgical treatment. During a median follow-up of 55.5 months, 20 patients (20/82, 24.4%) had distant metastasis (DM), while 32 (32/82, 39.0%) had local recurrence (LR). Univariate analysis showed the survival of PTs was associated with surgical methods (p < 0.001), tumor size (p = 0.026), and biological behavior (p = 0.017), but not age at diagnosis. In relapsed borderline PTs, we did not find deaths due to disease progression. Patients with DM were all malignant PTs, with disease-progression occurring within 3 years in more than 80% of patients. Among salvage treatments, the combination of antiangiogenic drugs improved the prognosis to some extent, with a significant increase in mPFS (2.77 vs. 1.53 months), but no significant statistical results were obtained (p = 0.168). Lactate dehydrogenase (LDH) was an independent predictor of the prognosis for malignant PTs (p = 0.001, HR = 1.203, 95%CI, 1.082-1.336).

CONCLUSION

Borderline PTs rarely metastasize, and even if LR occurs, surgical resection can lead to long-term survival. In metastatic phyllodes tumors (MPT), systemic therapy is not effective, but antiangiogenic drugs may prolong survival. LDH is an independent prognostic factor for malignant PTs to identify high-risk tumors.

Malignant phyllodes tumors of the breast: the malignancy grading and associations with prognosis

PURPOSE

This study aimed to correlate clinicopathological parameters with survival outcomes in a cohort of patients diagnosed with malignant phyllodes tumors (MPTs). We also analyzed the malignancy grade of MPTs and investigated the prognostic significance of the malignancy grading system.

METHODS

Clinicopathological parameters, malignancy grades, and clinical follow-up data of 188 women diagnosed with MPTs in a single-institution were analyzed. MPTs of the breast were grouped according to stromal atypia, stromal overgrowth, mitotic count, tumor differentiation, and necrosis. A Fleiss' kappa statistic was calculated to test the agreement between the pathologists for the grading of MPTs. Disease-free survival (DFS), distant metastasis-free survival (DMFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared between groups using the log-rank test. Cox regression was carried out to identify factors predictive of locoregional recurrence (LRR), distant metastasis (DM) and death.

RESULTS

A total of 188 MPTs were classified according to the malignancy grading system: 88 (46.8%) as low grade, 77 (41%) as an intermediate grade, and 23 (12.2%) as high grade. Excellent agreement between pathologists for the grading of MPTs (Fleiss' kappa 0.807). In our study population, the occurrence of DM and death were associated with the malignancy grade of MPTs (P < 0.001). Based on the DFS curves, the presence of heterologous elements (P = 0.025) and younger age (P = 0.014) were independent prognostic indicators. Additionally, the malignancy grade retained independent prognostic significance for predicting DMFS and OS (P < 0.001 and P = 0.009).

CONCLUSIONS

Higher malignancy grade, presence of heterologous elements, younger age, larger tumor size, and recent rapid tumor growth are poor prognostic factors for MPTs of the breast. The malignancy grading system may be generalized in the future.

Rethinking on the management strategy of malignant phyllodes tumor of the breast: An analysis based on the SEER database

Malignant phyllodes tumor of the breast (MPTB) is a rare breast neoplasm that has a high recurrence rate and its optimal treatment strategies remain controversial. Our study used the most up-to-date database to determine prognostic factors that predict cancer-specific survival (CSS) and to evaluate the effects of different treatment strategies for MPTB. We performed a retrospective cohort study using the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Women who were diagnosed with MPTB from 2000 to 2019 were included. Kaplan-Meier method and Cox proportional hazards regressions were used to evaluate the prognostic power of variables on CSS. A total of 1902 women with MPTB were included in the study, with a median follow-up duration of 87.5 months. Age was found not to independently predict CSS in patients with tumors larger than 10 cm (P = .235). Mastectomy was performed on a total of 898 (47.2%) patients including 210 women (23.4%) undergoing radiotherapy after surgery. Mastectomy showed worse CSS when compared with breast-conserving surgery in patients with tumors smaller than 10 cm. Patients undergoing radiotherapy were not inferior to non-radiotherapy patients on CSS when patients were stratified by tumor size. Breast-conserving surgery showed survival benefits for patients with small tumors (T1 and T2). Patients with radiotherapy were not inferior to non-radiotherapy patients on CSS. Treatment of patients with MPTB should be carefully selected based on different tumor sizes.

Bilateral metachronous breast malignancies: Malignant phylloides and invasive breast carcinoma-a case report

A 57-year-old Malay nullipara initially presented with a right breast lump that was increasing in size but defaulted follow-up. Two years later, she developed a contralateral breast lump. She only returned to the hospital when the right breast lump had become painful, 4 years from its onset. The biopsy of the right breast lump was a phylloides tumor and that of the left breast lump was a carcinoma. She had bilateral palpable axillary lymph nodes. She underwent bilateral mastectomy and axillary dissection. The pathology report confirmed the right breast lesion to be a malignant phylloides and the left breast lesion to be a carcinoma (pT3N2). She declined adjuvant treatment. A year after the surgical operation of the metachronous lesions, she had a right chest wall recurrence with widespread pulmonary metastases. She was given palliative chemotherapy but succumbed several months later.

Transformation of a Benign-Appearing Fibroepithelial Lesion to a Giant Malignant Phyllodes Tumor of the Breast

This is a case of a woman who presented with a left breast mass that was initially diagnosed as fibroadenoma on core biopsy and, after three years without any surgical intervention, was found to be a malignant phyllodes tumor. Initially, a core needle biopsy of the mass showed probable fibroadenoma. Because of the initial benign seeming diagnosis and the need to treat her tongue cancer, the patient did not recognize the need for a recommended surgical consultation and excision. Three years later, she presented after the mass had enlarged to encompass nearly the whole left breast. Core needle biopsy revealed spindle cell proliferation with scattered benign-looking tubules. Due to the large size of the mass, she underwent a total mastectomy, and the final pathology demonstrated a malignant phyllodes tumor. This case demonstrates a case of progression of a benign-appearing fibroepithelial lesion to a malignant phyllodes tumor three years later.

Management of phyllodes tumor: A systematic review and meta-analysis of real-world evidence

BACKGROUND

Phyllodes tumor is rare but has a high recurrence rate. Treatment modalities and clinicopathological prognostic factors for recurrence remain unclear. The synthesis of real-world data can enable the integration of sufficient evidence on optimal treatment for this population.

METHODS

We searched PubMed, Embase, and Cochrane Library databases for studies focusing on the management of phyllodes tumor including the surgical margin, different clinicopathological prognostic factors, and postoperative adjuvant radiotherapy versus no radiotherapy.

RESULTS

Fifty-two studies were retrieved. The pooled estimated recurrence rates of benign, borderline, and malignant tumors were 7.1%, 16.7%, and 25.1%, respectively. Surgical margins of 1 mm (odds ratio [OR]: 0.4, 95% confidence interval [CI]: 0.27-0.61) and 1 cm (OR: 0.45, 95% CI: 0.15-0.85) resulted in significantly higher recurrence rates. Postoperative adjuvant radiotherapy significantly reduced the recurrence rate of malignant tumors relative to no radiotherapy (P = 0.034) but did not significantly reduce the recurrence rates of overall and borderline tumors. Regarding clinicopathological features, moderate or severe stromal atypia and hypercellularity, stromal overgrowth, mitotic number of 5, tumor necrosis, tumor border, and margin status were determined as independent prognostic factors for recurrence, except a tumor size of 5 cm.

CONCLUSION

The ideal surgical margin for phyllodes tumor incision should be at least 1 cm in width. Adjuvant radiotherapy reduced the recurrence of malignant tumor. By identifying patients with poor clinicopathological risk factors, surgeons may reduce the recurrence rate of phyllodes tumor.

Local recurrence for phyllodes tumours of the breast: Systematic review and meta‑analysis

The objective of the present systematic review was the determination of methodologies preferable for treating phyllodes tumors (PTs) of the breast and whether the malignancy of the tumor is of significance to the selected treatment. In addition, to investigate if local recurrence (LR) within patients is different based on the therapeutic approach followed by the physician. All studies were gathered by utilization of the biggest online medical databases in the world including PubMed, Cochrane, Embase, Web of Science and Google Scholar. Due to the specificity of the study, the resultant set of studies included in the present analysis was not large. All included studies had to refer to patients diagnosed with PTs of the breast, include the malignancy of the tumor and the preferred treatment. Moreover, they included a reference to LR post-treatment, even if there wasn't any. The age range of patients was 20–55 years old and follow-ups should have been performed. As a result, from the initial 484 studies gathered and after proper and thorough evaluation, only 10 were of significance. The studies appeared heterogeneous in terms of population, topology, treatment methodology, additional therapeutic approaches, LR rate, age and follow-up periods. Overall, excisions were used for non-malignant tumors while mastectomy was preferable for tumors with malignancy. Radiotherapy was used both as an additional treatment for tumors and LR. Also, it was revealed that LR varied based on the malignancy and treatment methodology.

Re-Classification with Outcome Correlation of Previously Diagnosed Malignant Phyllodes Tumors Applying the 2016 Consensus Guidelines

Background. Classification of phyllodes tumors is challenging due unclear diagnostic criteria, recently addressed by consensus review criteria. Herein, we reviewed all malignant phyllodes tumor resections and reclassified them based on the consensus guidelines, correlating with outcome. We hypothesize that application of criteria would result in a significant proportion being "down-graded" to either borderline or benign phyllodes tumor. Methods. Primary resections of malignant phyllodes tumor were reviewed by four AP board-certified, breast fellowship-trained pathologists. Morphologic variables delineated in consensus guidelines (ie stromal cellularity, cellular atypia, tumor border, presence of heterologous elements, presence of stromal overgrowth) were evaluated. Following review, cases were reclassified as benign, borderline, or malignant. Results. Upon reclassification, 20% (5/20) cases were "down-graded" to borderline phyllodes tumor while 80% (15/20) remained malignant phyllodes tumor. Two morphologic features were statistically significant including broadly infiltrating tumor border in 80% (12/15) of malignant phyllodes tumors compared to none in borderline phyllodes tumor (0/5) (p = 0.004) and stromal overgrowth in 67% (10/15) of malignant phyllodes tumor compared to none in borderline phyllodes tumors (0/5) (p = 0.03). Upon review of the pathology reports, 30% (6/20) contained all 5 histomorphologic variables delineated in the consensus review criteria. Malignant phyllodes tumor resulted in five cases with recurrence (33.3%, 5/15) and three cases with metastases (20.0%, 3/15) and borderline phyllodes tumor resulted in one case with recurrence (20.0%, 1/5) and no metastases (0/5). Conclusion. The consensus guidelines for phyllodes tumor are useful for subclassification. We hypothesize that standardize reporting of the histomorphologic variables may lead to better consensus.

Therapeutic and immunomodulatory potential of pazopanib in malignant phyllodes tumor

Malignant phyllodes tumors (PT) are rare aggressive fibroepithelial neoplasms with high metastatic potential and lack effective therapy. We established a patient-derived xenograft (PDX) and cell line model (designated MPT-S1) of malignant PT which demonstrated clinical response to pazopanib. Whole exome sequencing identified somatic mutations in TP53, RB1, MED12, and KMT2D. Immunohistochemistry and genomic profiles of the tumor, PDX and cell line were concordant. In keeping with clinical observation, pazopanib reduced cell viability in a dose-dependent manner and evoked apoptosis, and led to significant abrogation of in vivo tumor growth. Whole transcriptomic analysis revealed that pazopanib decreased expression of genes involved in oncogenic and apoptosis signaling. We also observed decreased expression of ENPP1, with known roles in cancer invasion and metastasis, as well as STING pathway upregulation. Accordingly, pazopanib induced micronuclei formation, and evoked phospho-TBK1 and PD-L1 expression. In an additional cohort of malignant PT (n = 14), six (42.9%) showed comparable or higher levels of ENPP1 relative to MPT-S1, highlighting its potential role as a therapeutic target. In conclusion, we established MPT-S1, a new PDX and cell line model, and provided evidence for the clinical efficacy of pazopanib in malignant PT.

Surgical management in phyllodes tumors of the breast: a systematic review and meta-analysis

BACKGROUND

Information is still controversial in the studies regarding the current optimal surgical management of phyllodes tumors (PTs) of the breast. Local recurrence (LR) may occur with an upgraded in the pathological grade, influencing the prognosis of patients with PT. This systematic review and meta-analysis aimed to investigate the association of LR risk with margin status and margin width which could have significant implications on the surgical management of PT.

METHODS

Independent and comprehensive searches were performed by two authors through five databases including PubMed, Medline, Embase, ScienceDirect and Cochrane Library from January 1990 to October 2021. Studies investigating the association between margin width, margin status and LR rates were considered for inclusion. Study quality was evaluated using the Newcastle-Ottawa Scale (NOS). Meta-analysis was performed using RevMan5.3 software, and statistical heterogeneity was assessed using the Chi-square test and quantified using the I2 statistic. Visual inspection of funnel plots was used to judge publication bias.

RESULTS

A total of 34 articles were included in this article, all of which with NOS scores above 5. Regardless of the PT grade, positive margin significantly increased the risk of LR [odds ratio (OR) 3.64, 95% confidence interval (CI): 2.60-5.12]. No significant difference was found in the risk of LR between the margins <1 and ≥1 cm (OR 1.39, 95% CI: 0.67-2.92). For benign and borderline PTs, there were no significant differences of the LR risk between breast-conserving surgery (BCS) and mastectomy (benign OR 0.68, 95% CI: 0.12-3.78; borderline OR 1.14, 95% CI: 0.29-4.51). While the LR risk was significantly increased by BCS for malignant PT (OR 2.77, 95% CI: 1.33-5.74).

DISCUSSION

Different surgical management strategies should be considered for different PT grades. BCS was a feasible option and margins <1 cm was not significantly associated with LR risk for all grade of PT. After BCS, benign PT with positive margin could adopt the "wait and watch" strategy with regular follow-up, while borderline and malignant PTs were expected to underwent re-excision to ensure negative margins. More studies are still needed to clarify and update the existing conclusions and improve the prognosis of PT patients.

High-Grade Spindle Cell Lesions of the Breast: Key Pathologic and Clinical Updates

Most of the high-grade spindle cell lesions of the breast are malignant phyllodes tumors (MPTs), spindle cell carcinomas (SpCCs), and matrix-producing metaplastic breast carcinomas (MP-MBCs). MPTs have neoplastic spindle stromal cells and a classic leaf-like architecture with subepithelial stromal condensation. MPTs are often positive for CD34, CD117, and bcl-2 and are associated with MED12, TERT, and RARA mutations. SpCCs and MP-MBCs are high-grade metaplastic carcinomas, whereas neoplastic epithelial cells become spindled or show heterologous mesenchymal differentiation, respectively. The expression of epithelial markers must be evaluated to make a diagnosis. SAS, or rare metastatic spindle cell tumors, are seen in the breast, and clinical history is the best supporting evidence. Surgical resection is the standard of care.

Malignant phyllodes tumor and primary breast sarcoma; distinct rare tumors of the breast

BACKGROUND

Malignant phyllodes (MP) and primary breast sarcomas (PBS) are rare neoplasms with overlapping histopathologic features. We compared overall survival (OS) and estimated the association of surgery and therapies with OS.

METHODS

We utilized the National Cancer Database (2004-2016). Patients without surgery, unknown surgery, or margins, or Stage IV disease were excluded. Kaplan-Meier curves and Cox proportional hazards models were used to estimate unadjusted and adjusted OS, respectively.

RESULTS

A total of 3209 (59.5%) MP, and 2185 (40.5%) PBS were identified. Despite a larger median tumor size in MP (46 vs. 40 mm PBS, p < 0.001), lumpectomy rate was higher for MP (52.9% vs. 27.0% PBS, p < 0.001). Compared to MP, PBS patients more frequently received radiation (28.9% vs. 24%), and chemotherapy (28.1% vs. 4%), both p < 0.001. Unadjusted OS was lower for PBS (57% vs. 85% MP, log-rank p < 0.001). PBS (vs. MP) had persistently worse survival (hazard ratio [HR]: 1.98, 95% confidence interval [CI]: 1.69-2.31) after adjustment. Receipt of adjuvant therapies was not associated with OS (either neoplasm); however, lumpectomy was associated with improved OS (vs. mastectomy) for both PBS (HR: 0.59, 95% CI: 0.50-0.75) and MP (HR: 0.65, 95% CI: 0.53-0.81). Positive margins had no association with OS for MP (HR: 1.09, 95% CI: 0.75-1.60), but was associated with worse survival for PBS (HR: 2.35, 95% CI: 1.82-3.02).

DISCUSSION

We found significant survival differences between MP and PBS, with PBS having a consistently worse OS. Our findings support surgery as the mainstay of treatment for both tumor types and suggest that lumpectomy may be a reasonable option for select patients without compromising outcomes.

An integrative ultrasound-pathology approach to improve preoperative phyllodes tumor classification: A pilot study

OBJECTIVE

Preoperative diagnosis of phyllodes tumor (PT) is challenging, core-needle biopsy (CNB) has a significant rate of understaging, resulting in suboptimal surgical planification. We hypothesized that the association of imaging data to CNB would improve preoperative diagnostic accuracy compared to biopsy alone.

METHODS

In this retrospective pilot study, we included 59 phyllodes tumor with available preoperative imaging, CNB and surgical specimen pathology.

RESULTS

Two ultrasound features: tumor heterogeneity and tumor shape were associated with tumor grade, independently of CNB results. Using a machine learning classifier, the association of ultrasound features with CNB results improved accuracy of preoperative tumor classification up to 84%.

CONCLUSION

An integrative approach of preoperative diagnosis, associating ultrasound features and CNB, improves preoperative diagnosis and could thus optimize surgical planification.

Long-term Survival After Diverse Therapeutic Modalities in Malignant Phyllodes Tumors of the Breast

Background and Objects: Malignant phyllodes tumor of the breast (MPTB) is a rare tumor for which surgery or surgery combined with radiotherapy (RT) is the primary treatment method. However, recently, the therapeutic effect of RT on MPTB has been controversial. We aimed to explore the role of RT, chemotherapy (CT), and surgical modalities in patients with MPTB. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to select patients with MPTB who met the criteria between 2010 and 2018. Kaplan–Meier curves and Cox proportional risk regression models were used to analyze the effects of RT on MPTB patients. Based on this, we compared the effects of breast-conserving surgery (BSC) and mastectomy on the postoperative survival of MPTB. Results: A total of 298 patients with MPTB were included in this study. RT was received by 22.1% (n  =  66) of the patients while 77.9% (n  =  232) did not receive RT. CT was received by 4.7% (n  =  14) patients while 95.3% (n  =  284) did not receive CT. According to Kaplan–Meier curves, RT and CT combined resulted in a decrease in breast cancer-specific survival (BCSS) and overall survival (OS) compared to patients who did not receive RT. Mastectomy improved the OS and BCSS of the patients more than BCS). The findings of univariate and multivariate Cox regression analyses suggested that “distant metastasis”, “tumor grade” and “number of positive lymph node biopsies” affected OS of breast cancer, while “distant metastasis”, “tumor grade”, “surgery combined with radiotherapy/surgery”, and “radiotherapy/chemotherapy or not”, had a significant effect on BCSS. Conclusion: RT and CT did not significantly improve the long-term survival of MPTB patients. Mastectomy improved OS and BCSS of the patient more than BCS. RT in an early stage improved early prognosis moderately in MPTB patients with tumor diameter less than 50 mm.

Malignant Phyllodes Tumor of the Breast and Pregnancy: A Rare Case Report and Literature Review

Phyllodes Tumor (PT) is a rare fibroepithelial breast tumor that can behave differently depending on its biologic features. Traditionally, PTs are classified by their histologic features into benign, borderline, and malignant. In most cases that were reported, all PTs may recur, but only the borderline and malignant PT can metastasize. PT usually occurs as a breast lump or accidental finding on ultrasound (US) examination. The clinical features include a well-defined breast mass, regular or lobulated. The diagnosis is based on the integration of morphology features, but remains challenging, particularly in the distinction from fibroadenomas. We report a case of a 36-year-old patient who presented for a voluminous breast mass, rapidly growing in the past 3–4 months. At presentation, the patient was 19 weeks pregnant. The breast tumor had the clinical and US aspect of PT. A core needle biopsy was obtained, confirming a benign PT, and local excision was performed with no postoperative complications. The final pathology report showed a borderline PT with close resection margins of 1 mm. Immunohistochemistry (IHC) established the diagnosis of malignant PT with heterologous sarcomatous differentiation. The case was discussed in the multidisciplinary tumor board (MDT) and mastectomy was recommended. The patient fully consented but refused surgery at 25 weeks’ gestation, fearing premature delivery. The right breast was closely monitored by US, and at 9 weeks after the first surgery, signs of local recurrence were detected. At 35 weeks’ gestation, right mastectomy was performed, with no perioperative complications. The pregnancy was closely followed up and no complication were found. The final pathology report describes multiples PT recurrences with heterologous sarcomatous differentiation. The pregnancy outcome was uneventful, and the patient delivered a healthy child vaginally at term with no peripartum complication. Postpartum, a computer tomography (CT) examination of the head, thorax, abdomen and pelvis was performed, with no evidence of metastases. Adjuvant chemotherapy and radiotherapy completed the treatment. The follow-up and CT scan showed no metastases or further recurrence 4 years after diagnosis. In conclusion, diagnosis of PT can be difficult, especially because of the easy confusion with fibroadenoma of the breast. There are rare cases when a pathology exam needs further assessment and IHC is recommended for accurate diagnosis. Although malignant PT is rare and accounts for <1% of all breast cancers, the diagnosis and treatment that are recommended are based on the reported cases. Moreover, when complete surgical excision is achieved, the rates of recurrence and distant metastases are low, and adjuvant therapy might not be necessary.

Periductal Stromal Tumor of the Breast: One Institution's Review of 6 Tumors Over a 22 Year Period With Immunohistochemical Analysis

Introduction. Periductal stromal tumor (PST) of the breast is a rare fibroepithelial neoplasm with controversial pathogenesis. Methods. A retrospective search of our Pathology database from 2000 to 2021 identified 6 PST, all evaluated according to the Armed Forces Institute of Pathology (AFIP) criteria. Immunohistochemistry for CD10, CD34, CD117, GATA3, p63, SOX10, ER, PR, HER2, smooth muscle actin (SMA), beta-catenin, and myogenin was performed as well. Results. All 6 patients were female and age ranged from 29 to 55 years (mean 40 years). Tumor size ranged from 2.9 to 5.9 cm (mean 3.0 cm). Data showed absence of leaf-like architecture (0/6), at least moderate hypercellularity (6/6), lack of a circumscribed border (5/6), coalescing nodules with intermixed adipose tissue (4/6), at least moderate stromal atypia (4/6), and an elevated mitotic activity ≥3mitotic figures/10 HPF (6/6). The stromal cells were positive for CD10 (4/4), CD34 (4/4), CD117 (3/4), and SMA (3/4), and negative for GATA3 (0/6), p63 (0/6), SOX10 (0/6), ER (0/4), PR (0/4), HER2 (0/4), nuclear beta-catenin (0/5), and myogenin (0/4). No patient had a PST recurrence or metastasis (average follow-up of 91 months). Conclusion. We confirm that PST shares morphologic and immunophenotypic similarities with phyllodes tumor (PT). However, PST can be reliably differentiated from PT using the AFIP criteria. Additionally, PST's immunoprofile of positive CD117 and CD34 stromal expression alongside the negative GATA3, p63, and SOX10 reactivity can aid the pathologist in excluding metaplastic carcinoma. All 6 of our PST behaved as benign neoplasms akin to benign PT.

A leafy surprise: Case report of male breast malignant phyllodes

INTRODUCTION AND IMPORTANCE

Phyllodes tumor is a biphasic fibroepithelial tumor which accounts for less than 1% of all breast neoplasms. We aim to raise awareness among clinicians that a male breast lump may be indicative of underlying sinister pathology and therefore, should be investigated thoroughly.

CASE PRESENTATION

A 62 year old male presented in clinic with right beast lump for the last 6 weeks. A preoperative diagnosis of spindle cell tumor was made on core needle biopsy. Neoadjuvant chemotherapy was administered in order to downsize the tumor as it was inseparable from underlying muscle. A post-operative diagnosis of malignant phyllodes was made following mastectomy. As the tumor was 1 mm from the deep margin, adjuvant radiotherapy was administered.

CLINICAL DISCUSSION

Differential diagnoses of malignant phyllodes include metaplastic carcinomas metastatic/primary sarcomas and fibroadenomas. Metaplastic carcinomas are morphologically heterogeneous and include adenosquamous carcinoma, squamous cell carcinoma and spindle cell carcinoma. In some malignant phyllodes, extensive stromal proliferation can make detection of epithelial component very difficult. This highlights the limitation of core biopsy in establishing an accurate preoperative diagnosis. The standard treatment for phyllodes treatment is surgical resection with margins of 1 cm or more. Adjuvant radiotherapy is used in cases with threatened margins.

CONCLUSION

Malignant phyllodes tumor of breast can exist in men, and its accurate pre-operative diagnosis is difficult given the limitations of core biopsy. This case report draws attention to the challenges associated with the diagnosis of this rare condition and highlights the role of different treatment modalities in its management.

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.

Aggressive malignant phyllodes tumor of breast with omental metastases - A case report

Distant metastasis from malignant Phyllodes tumour (PT) is rare. They generally metastasize to the lung, bone, pleura, and liver. We present a very rare case of a 25-year-old woman with intraabdominal metastases from malignant phyllodes tumour of the breast. She presented with left breast lump and the biopsy was Phyllodes tumour. She underwent a two staged surgery; left modified radical mastectomy followed by left latissimus dorsi musculocutaneous flap cover. She received adjuvant radiation therapy to left chest wall. Following which she developed intrabdominal mass which was proven to be metastasis from Phyllodes tumour. She was then advised palliative chemotherapy. Malignant Phyllodes with distant metastases has a dismal prognosis. We propose it is preferable to have a CT Thorax and Abdomen as a staging workup for patients with malignant PT to identify those with poor prognosis.

Phyllodes Tumors: A Scoping Review of the Literature

PURPOSE

Phyllodes tumors are rare tumors of the breast, with most literature being retrospective with limited guidelines on the management of these patients. Scoping review was performed to highlight themes and gaps in the available literature.

METHODS

A scoping review of the literature was performed as per PRISMA-ScR guidelines with titles, abstracts, and full texts reviewed in duplicate. Data were abstracted and summarized in categories of diagnostics, surgical management, adjuvant therapies, treatment of recurrence, and surveillance. Quality assessment was performed for each paper.

RESULTS

The search identified 4498 references, 434 full-text papers were reviewed, and 183 papers were included. Ultrasound, magnetic resonance imaging, and core needle biopsy are valuable preoperative diagnostics tools. Pathology reporting should include stromal overgrowth, stromal cellularity, nuclear atypia, mitotic rate, borders, and presence of heterologous elements. Ki67 may have a role in grading and prognosticating. Breast conservation is safe in all grades of phyllodes but may be associated with increased local recurrence in malignant phyllodes. Surgical margins should depend on grade. Axillary node positivity rate is very low, even with clinically enlarged lymph nodes. Adjuvant radiation is a useful tool to decrease local recurrence in malignant phyllodes tumors, tumors > 5 cm, age < 45 years, close margins, and breast conservation. There is no evidence supporting adjuvant chemotherapy. Recurrence can be managed with repeat wide excision; however, mastectomy is associated with lower re-recurrence. Surveillance protocols are variable in the literature.

CONCLUSIONS

There is heterogeneity in the literature on phyllodes tumors. Consensus guidelines based on the literature will help provide evidence-based care.

Management and outcomes of phyllodes tumours - 10 year experience

INTRODUCTION

Phyllodes tumours represent 0.3-1% of breast tumours, typically presenting in women aged 35-55 years. They are classified into benign, borderline and malignant grades and exhibit a spectrum of features. There is significant debate surrounding the optimal management of phyllodes tumour, particularly regarding appropriate margins.

METHODS

This is a retrospective review of a prospectively maintained database of patients who underwent surgical management for phyllodes tumours in a single tertiary referral centre from 2007-2017. Patient demographics, tumour characteristics, surgical treatment and follow-up data were analysed. Tumour margins were classified as positive (0 mm), close (≤2 mm) and clear (>2 mm).

RESULTS

A total of 57 patients underwent surgical excision of a phyllodes tumour. The Mean age was 37.7 years (range: ages 14-91) with mean follow-up of 38.5 months (range: 0.5-133 months). There were 44 (77%) benign, 4 (7%) borderline and 9 (16%) malignant phyllodes cases. 54 patients had breast conserving surgery (BCS) and 3 underwent mastectomy. 30 (53%) patients underwent re-excision of margins. The final margin status was clear in 32 (56%), close in 13 (23%) and positive in 12 (21%). During follow-up, 4 patients were diagnosed with local recurrence (2 malignant, 1 borderline and 1 benign pathology on recurrence samples).

CONCLUSION

There are no clear guidelines for the surgical management and follow-up of phyllodes tumours. This study suggests that patients with malignant phyllodes and positive margins are more likely to develop local recurrence. There is a need for large prospective studies to guide the development of future guidelines.

Genetic differences between benign phyllodes tumors and fibroadenomas revealed through targeted next generation sequencing

Breast fibroepithelial lesions are biphasic tumors which comprise the common benign fibroadenomas (FAs) and the rarer phyllodes tumors (PTs). This study analyzed 262 (42%) conventional FAs, 45 (7%) cellular FAs, and 321 (51%) benign PTs contributed by the International Fibroepithelial Consortium, using a previously curated 16 gene panel. Benign PTs were found to possess a higher number of mutations, and higher rates of cancer driver gene alterations than both groups of FAs, in particular MED12, TERT promoter, RARA, FLNA, SETD2, RB1, and EGFR. Cases with MED12 mutations were also more likely to have TERT promoter, RARA, SETD2, and EGFR. There were no significant differences detected between conventional FAs and cellular FAs, except for PIK3CA and MAP3K1. TERT promoter alterations were most optimal in discriminating between FAs and benign PTs. Our study affirms the role of sequencing and key mutations that may assist in refining diagnoses of these lesions.

Apatinib treatment is effective for metastatic malignant phyllodes tumors of the breast: a case report

Background

We report a rare case of malignant phyllodes tumors (MPT) with partial response to apatinib.

Case presentation

A 26-year-old woman had a palpable mass in her right breast for over a year. After resection, pathology indicated malignant phyllodes tumor. Eleven months after surgery, she underwent reoperation for a lung nodule, which demonstrated lung metastasis. She refused chemotherapy and was rehospitalized six months later due to leg pain. Pelvic mass biopsy revealed metastatic malignant phyllodes tumor. After concurrent chemoradiotherapy of the pelvic mass, multiple lung metastases emerged. Subsequent treatment with apatinib 500 mg/day resulted in a reduction in mass size and partial response. She survived for more than 8 months.

Conclusion

The present case showed the potential therapeutic effects of apatinib in patients with MPT.

Phyllodes tumors of the breast: Adjuvant radiation therapy revisited

Background

Phyllodes tumors (PT) are rare entity and surgical resection is the cornerstone of treatment. No standard of care exists regarding adjuvant treatment especially radiation therapy (RT).

Patients and methods

We analyzed all patients with non-metastatic, resected phyllodes tumors who presented to our institution from January 2005 through December 2019. Primary study endpoints included local recurrence free survival (LRFS) and overall survival (OS).

Results

One hundred and eight patients were analyzed (patients with incomplete treatment and follow up data were excluded). Fifty patients had benign phyllodes, 26 patients had borderline and 32 patients had malignant phyllodes. In the benign group, no significant difference in LRFS was observed between patients who received adjuvant RT (n = 3) and those who did not (5-year LRFS 100% vs. 85% respectively, p = 0.49). The 5 year OS for patients who received RT was 60% vs. 89% for those who did not (p 0.40). In the borderline/malignant group, adjuvant RT significantly improved five year LRFS (90% in the RT group vs. 42% in the no RT group, p = 0.005). The 5 year LRFS in patients treated with margin negative breast conserving surgery and RT was 100% vs. 34.3% in patients who did not receive RT (p 0.022). Patients treated with mastectomy and RT had a 5 year LRFS of 100% vs. 83% for patients who did not receive RT (p 0.24). On multivariate analysis, radiation therapy was independently associated with decreased hazard of local failure (HR 0.21, CI 0.05–0.89, p = 0.03). No difference in OS was found between the RT and no RT groups (5-year OS was 52% vs. 45% respectively, p 0.54).

Conclusion

The results of the current study confirm the excellent prognosis of benign phyllodes tumors; warranting no further adjuvant treatment after margin-negative surgical resection. For patients with borderline/malignant phyllodes tumors, adjuvant radiation therapy significantly improved LRFS after margin negative wide local excision; however, patients treated with mastectomy did not attain the same benefit from adjuvant irradiation.

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Benign phyllodes tumors have excellent prognosis with high local control rates.

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Adjuvant radiation therapy does not improve local recurrence free survival or overall survival in benign phyllodes tumors.

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Borderline/malignant phyllodes tumors have high local recurrence and distant metastases rate.

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Radiation improves local control after margin negative lumpectomy but not after mastectomy in borderline/malignant phyllodes.

Malignant Phyllodes Tumor of the Breast: A Practice Review

Introduction: Phyllodes tumor (PT) of the breast, particularly malignant phyllodes tumor (mPT), is a rare fibroepithelial neoplasm. A complex diagnosis is based on pathologic, radiologic, and clinical findings, with controversies about what is the best therapeutic strategy. Objective: Our objective was to provide an overview of the clinical, pathologic, and therapeutic aspects of this rare tumor. Conclusions: mPT is a rare presentation of breast cancer and a challenge in clinical practice. A multidisciplinary approach should take into account some aspects like pathogenic mutations and hereditary syndromes. Oncologic surgery is the fundamental approach, and the use of adjuvant therapies is still controversial due to the lack of clinical trials. Treatment recommendations should be individualized according to patient risk and preferences. Prospective studies are fundamental to clarifying the best treatment for these tumors.

Outcomes of systemic therapy in metastatic phyllodes tumor of the breast

PURPOSE

Metastatic phyllodes tumors of the breast (MPT) are rare breast neoplasms, limiting development of standardized treatment approaches. We sought to characterize the largest group of MPT thus far reported, evaluating systemic therapy outcomes.

METHODS

Adult patients diagnosed with MPT between 1993 and 2015 and followed at MD Anderson Cancer Center were selected for retrospective chart review. Systemic therapy was sorted into: adriamycin/ifosfamide (AI), other anthracycline regimens, other ifosfamide regimens, gemcitabine-based regimens, and other. Given one patient may have received more than one regimen, we assumed that the effects of each regimen were independent from previous therapy. Median overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Log-rank test was performed to evaluate the difference in OS between patient characteristics groups, and the differences in PFS between the five chemotherapy regimens.

RESULTS

We identified 50 MPT patients, with 31 patients receiving 61 systemic regimens. Median OS was 10.7 months (95% CI: 8.67, 16.5). AI had a PFS of 9.10 months (95% CI: 5.03, 14.2), other ifosfamide regimens had a PFS of 5.10 months (95% CI: 0.67, 12.1), other anthracycline regimens had a PFS of 3.65 months (95% CI: 1.17, 7.90), gemcitabine-based regimens had a PFS of 2.80 months (95% CI: 1.83, 4.60), and other regimens had a PFS of 1.67 months (95% CI: 1.13, 7.77).

CONCLUSION

MPT patients are a unique population with limited characterization to date. Our study demonstrates activity of multiple sarcoma-directed chemotherapy regimens, with ifosfamide-containing regimens having the longest PFS.

Correlations of morphological features and surgical management with clinical outcome in a multicentre study of 241 phyllodes tumours of the breast

AIMS

Phyllodes tumours (PTs) represent an unusual but complex group of breast lesions with a tendency to recur locally and, less commonly, metastasise. On core biopsies, their appearances can be difficult to discriminate from those of other fibroepithelial lesions, which may compromise their surgical management. The aims of this study were to assess the preoperative diagnosis of PTs and to evaluate the impacts of surgical management and morphological features on their behaviour.

METHODS AND RESULTS

We combined datasets from three centres over two decades, including core biopsies, excision specimens, and follow-up. Core biopsy results were compared with final excision specimens. The relationships of surgical procedure and morphological features with local recurrence (LR) and metastasis were assessed. Two hundred and forty-one PTs were studied. Core biopsy resulted in a diagnosis of possible or definite PT in 76% of cases. Malignant tumours were more likely to be larger, occurred at an older age, and were surgically more challenging, with difficulties being encountered in achieving negative margins. There were 12 cases (5%) that showed LR alone, and another six cases (2.5%) that had distant metastases. Morphological features associated with adverse outcome were grade of PT, increased mitotic counts, necrosis, infiltrative margins, stromal atypia, and heterologous components. Both LR and metastatic behaviour correlated with larger size and distance to margins.

CONCLUSIONS

Our results suggest that excision margins have a significant impact on LR of PT, whereas metastatic behaviour is influenced by tumour biology. We add to the evidence base on histological features of tumours that contribute to long-term outcomes of PT patients.

Retrospective study of malignant phyllodes tumors of the breast: Younger age, prior fibroadenoma surgery, malignant heterologous elements and surgical margins may predict recurrence

Purpose

The potential recurrence rate of malignant phyllodes tumors (MPTs) of the breast is high, and the prognostic factors are still unclear. We therefore aim to study the factors affecting the outcome of MPTs.

Methods

A retrospective review of MPT patients treated from 2006 to 2020 at our institution was conducted. Univariate and multivariate Cox proportional hazard models were used to examine the influence of different variables on RFS. Moreover, significant prognostic factors were combined to construct the nomogram to predict the probability of relapse occurring in MPT patients. The 5-year and 10-year RFS rates were estimated using the Kaplan–Meier method.

Results

During the study period, 188 MPT patients were identified. The presence of malignant heterologous elements was observed in 23 (12.2%) patients with MPT, and the patients with malignant heterologous elements who received chemotherapy had longer RFS, which could reduce the risk of recurrence (p = 0.022). Recurrence occurred in 56/188 (29.8%) patients, of whom 47 experienced local recurrence and 11 experienced distant metastases. The 5-year and 10-year cumulative RFS rates were 77.5% and 70.1%, respectively. Age (p = 0.041), fibroadenoma surgery history (p = 0.004), surgical margins (p = 0.001) and malignant heterologous elements (p < 0.001) were independent risk factors for postoperative RFS. Subsequently, a nomogram was built, with a C-index of 0.64 (95% CI: 0.629–0.661), to predict the risk of recurrence.

Conclusion

The results of this study showed that younger age, fibroadenoma surgery history, malignant heterologous elements and surgical margins <1 cm predict a higher incidence of recurrence in MPT patients. Patients with malignant heterologous elements treated with chemotherapy could have a reduced risk of recurrence.

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This is the largest cohort of malignant phyllodes tumors in China.

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Age, fibroadenoma surgery history, surgical margins and malignant heterologous elements predict the risk of recurrence.

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Patients with malignant heterologous elements treated with chemotherapy could reduce the risk of recurrence.

Breast Sarcomas, Phyllodes Tumors, and Desmoid Tumors: Epidemiology, Diagnosis, Staging, and Histology-Specific Management Considerations

Breast sarcomas arise from connective tissues of the breast and account for fewer than 1% of all breast malignancies. They can be subclassified as primary breast sarcomas, which arise de novo and are histologically diverse, and secondary breast sarcomas, which arise as a result of radiation or lymphedema and are most commonly angiosarcomas. Two other connective tissue neoplasms that occur within the breast include phyllodes tumors and desmoid tumors, which exhibit a spectrum of behaviors. Malignant phyllodes tumors are biologically similar to primary breast sarcomas, whereas desmoid tumors are technically benign but often locally aggressive. Patients with breast sarcomas often present with a rapidly growing mass or, in cases of radiation-associated angiosarcoma, violaceous cutaneous lesions. Core needle biopsy is generally required to confirm the diagnosis of sarcomas. Staging workup includes MRI and chest imaging, although these are not required in the case of benign phyllodes or desmoid tumors. In general, localized breast sarcomas should be resected, with the extent of resection tailored to histologic subtype. Radiation and chemotherapy can be used in the neoadjuvant or adjuvant setting, but data are limited, so treatment decisions should be made on an individualized basis. Systemic therapy options for metastatic disease and refractory breast desmoids mimic those used for the same histologies when present in other sites. Given the rarity and heterogeneity of breast sarcoma, as well as limited literature describing these entities, expert multidisciplinary evaluation is crucial for optimal decision making.

Giant Benign Mammary Phyllodes Tumor: Report of a Case and Review of the Literature

Phyllodes tumor of the breast is an infrequently encountered fibroepithelial neoplasm, which accounts for 0.3–1% of all tumors. Few case reports have described the occurrence of giant phyllodes tumor. To our knowledge, about 20% of phyllodes tumors would be considered giant benign. Complete surgical excision is the standard of care for giant benign phyllodes tumors; axillary lymph node metastasis is rare, and dissection should be limited to patients with pathologic evidence of tumor in the lymph nodes. We report the case of a 40-year-old Mexican woman with giant mammary tumor who underwent a right total mastectomy. The pathology results showed a benign phyllodes tumor 4,857 g in weight and 40.2 × 36.3 × 15 cm in size. We do not suggest adjuvant radiation therapy for patients with benign phyllodes tumors that are widely excised. A review of the pertinent literature was performed.

Malignant Phyllodes of Breast

Phyllodes tumors of breast (PTB) have been known to an uncommon and particular disease to handle owing to diagnostic ambiguity and unpredictable clinical outcome. Malignant phyllodes tumors (MPT) are diagnosed when there are marked stromal hypercellularity, atypia, increased mitoses of ≥10/10 HPFs, permeative tumor borders, and stromal overgrowth. The presence of a malignant heterologous element (MHE) places the tumor into the malignant category regardless of other histological features. Excision with negative margins should be achieved for recurrent and malignant phyllodes tumor. An ideal margin width remains to be determined, and may need to be considered in relation to factors such as tumor size and cosmesis. Without the convincing evidence of survival benefit, adjuvant RT has revealed more favorable local control rate compared with observation group. Stromal expression of Twist and Foxc2, epithelial-mesenchymal transition marker, was associated with high tumor grade and poor prognosis. Tumor-associated macrophage drives myoblast differentiation and malignant progression of PTB through a CCL18-driven signaling cascade amenable to antibody disruption. Recent targeted sequencing on PTBs provided insights into the molecular pathogenesis and genetic characterization with potential clinical implications.

Phyllodes Tumours Will Only Get Bigger During Pandemic Restrictions

Phyllodes tumours of the breast are rare fibroepithelial stromal tumours which are morphologically very different from epithelial breast cancer. Its diagnosis and management has always been challenging till the World Health Organization (WHO) divided it into two-three subtypes in 2003, only then it was found that incidence and management and follow-up of these three subtypes need to be completely different to reach the optimum outcome.

We are presenting a case of a 47-year-old female who presented relatively late (due to pandemic restrictions) with a large phyllodes tumour requiring mastectomy as well as adjuvant treatment.

Contemporary Multi-Institutional Cohort of 550 Cases of Phyllodes Tumors (2007-2017) Demonstrates a Need for More Individualized Margin Guidelines

PURPOSE

Phyllodes tumors (PTs) are rare breast neoplasms, which have little granular data on margins. Current guidelines recommend ≥ 1 cm margins; however, recent data suggest narrower margins are sufficient, and for benign PT, a negative margin may not be necessary.

METHODS

We performed an 11-institution contemporary (2007-2017) review of PT practices. Demographics, surgical, and histopathologic data were captured. Logistic regression was used to estimate the association of select covariates with local recurrence (LR).

RESULTS

Of 550 PT patients, the majority underwent excisional biopsy (55.3%, n = 302/546) or lumpectomy (wide excision) (38.5%, n = 210/546). Median tumor size was 30 mm, 68.9% (n = 379) were benign, 19.6% (n = 108) borderline, and 10.5% (n = 58) malignant. Surgical margins were positive in 42% (n = 231) and negative in 57.3% (n = 311). A second operation was performed in 38.0% (n = 209) of the total cohort, including 51 patients with an initial negative margin (82.4% with < 2 mm), and 157 with an initial positive margin, with residual disease only found in six (2.9%). Notably, 32.0% (n = 74) of those with an initial positive margin did not undergo a second operation, among whom only 2.7% (n = 2) recurred. Recurrence occurred in 3.3% (n = 18) of the total cohort (n = 15 LR, n = 3 distant), at median follow-up of 36.7 months. LR (all PT grades) was not reduced with wider negative margin width (≥ 2 mm v < 2 mm: odds ratio [OR] = 0.39; 95% CI, 0.07 to 2.10; P = .27) or final margin status (positive v negative: OR = 0.96; 95% CI, 0.26 to 3.52; P = .96).

CONCLUSION

In current practice, many patients are managed outside of current guidelines. For the entire cohort, a wider margin width was not associated with a reduced risk of LR. We do not recommend re-excision of a negative margin for benign PT, regardless of margin width, as a progressively wider surgical margin is unlikely to reduce LR.

Pancreatic metastases and first reported gallbladder metastasis from phyllodes tumor of the breast

Distant metastases from breast phyllodes tumor (PT) are very rare. They usually occur in lung and bones. We report a case of a 51-year-old woman who was hospitalized in the digestive surgical department for atypical epigastric pain. Her medical history started 2 years ago when she underwent a curative left mastectomy for a malignant PT of the breast. Radical surgery was indicated to her resectable pancreatic tumor diagnosed on computed tomography. Histological exam confirmed that it was pancreatic metastases of her breast PT. Adjuvant chemotherapy was indicated. Three months after the surgery, the patient developed gallbladder and brain metastases. She died 5 weeks later. With this case, we enrich the literature with another example of pancreatic metastasis from PT and we report, for the first time, gallbladder metastasis. The very high aggressiveness of this tumor suggests that markers of tumor malignancy need to be sought after by subsequent studies.