A retrospective review of phyllodes tumours of the breast: A single institution experience

Fibroepithelial Lesions of the Breast: Update on Molecular Profile With Focus on Pediatric Population

CONTEXT.—

This review article derives from the breast pathology lecture at the Eighth Princeton Integrated Pathology Symposium (PIPS VIII).

OBJECTIVE.—

To provide a literature review and update on fibroepithelial lesions of the breast with molecular findings and findings regarding the pediatric population.

DATA SOURCES.—

The sources include extensive literature review, personal research, and experience.

CONCLUSIONS.—

Given significant differences in prognosis and management of fibroepithelial lesions, we aim to provide readers with pertinent definitions, pathomorphology, molecular findings, and management for each diagnosis, with insights on the pediatric population.

Diagnosis and management of phyllodes tumours for the surgeon: An algorithm

A Phyllodes Tumour (PT) is an uncommon fibroepithelial lesion, with three histological grades - benign, borderline and malignant. PTs cause significant challenges in diagnosis, management and prognostication. Recent publications have clarified the definitions and prognostication of PTs. Contemporary data currently challenge international guidelines on PT management. We performed an in-depth literature review to develop a best-practice management algorithm for PTs. Diagnostic recommendations are that neither current imaging techniques, nor fine-needle biopsies, can reliably diagnose a PT. Core needle biopsy is the optimal diagnostic technique. Indeterminate or suspicious lesions are recommended to undergo an excisional biopsy due to the inherently heterogeneous nature of PTs. Management guidelines are that benign PTs should be completely excised, although an involved margin is acceptable in select situations. Borderline PTs should have a clear margin on excision due to their higher risk of recurrence, as well as the potential for a recurrence to progress to a malignant PT. In malignant PTs, a margin of 3 mm is acceptable as there is no reduction in recurrence risk if margins are >3 mm. Routine axillary surgery is not indicated in PTs, with axillary surgery only indicated in a histologically-confirmed positive axilla. Adjuvant treatment recommendations are that borderline and malignant PTs should be discussed at MDT, with radiotherapy considered in both. Chemotherapy should be discussed in malignant PT patients. In summary, we have developed an up-to-date simple algorithm to guide the surgeon's management of patients diagnosed with PTs and reduce excessive surgery.

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.

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.

Prognostic factors in phyllodes tumours of the breast: retrospective study on 166 consecutive cases

BACKGROUND

Phyllodes tumours (PTs) are rare fibroepithelial tumours accounting for <1% of all breast tumours. We assessed clinicopathological features and their prognostic effect in a single-institution patients' cohort.

METHODS

Patients diagnosed with PT between 2001 and 2018 at our institution were identified. Clinical, surgical and pathological features were collected. Phyllodes-related relapse was defined as locoregional or distant recurrence (contralateral excluded), whichever first.

RESULTS

A total of 166 patients were included: 115 with benign, 30 with borderline and 21 with malignant PTs. Features associated with malignant PT were younger age, larger T size, higher mitotic count, marked cytological atypia, stromal overgrowth, stromal hypercellularity, necrosis and heterologous differentiation (all p<0.01). The majority of patients with malignant PT underwent mastectomy (63.2% vs 3% of benign/borderline, p<0.001) and had negative surgical margins (83.3%). 4-year cumulative phyllodes-related relapse incidence was 7% for benign/borderline PT and 21.3% for malignant PT (p=0.107). In the entire cohort, marked cellular atypia and heterologous differentiation were associated with worse phyllodes-related relapse-free survival (HR 14.10, p=0.036 for marked vs mild atypia; HR 4.21, p=0.031 for heterologous differentiation present vs absent). For patients with benign PT, larger tumour size was associated with worse phyllodes-related relapse-free survival (HR 9.67, p=0.013 for T>5 cm vs T≤2 cm). Higher tumour-infiltrating lymphocytes (TILs) were associated with borderline and malignant PT (p=0.023); TILs were not associated with phyllodes-related relapse-free survival (HR 0.58, p=0.361 for TILs>2% vs≤2%). Overall, four patients died because of PT: three patients with malignant and one with borderline PT.

CONCLUSIONS

Patients with malignant PT had increased rates of phyllodes-related relapse and phyllodes-related death. Cellular atypia and heterologous differentiation were poor prognostic factors in the entire cohort; large tumour size was associated with an increased risk of phyllodes-related relapse in benign PT.

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.

A retrospective review of phyllodes tumors of the breast from a single institution

BACKGROUND

Phyllodes tumors (PTs) are rare fibroepithelial breast tumors with diverse biological behavior.

OBJECTIVE

This study aimed to analyze the characteristics, management, and outcome of phyllodes tumors.

METHODS

Patients diagnosed with PTs in our institution from January 2013 to December 2017 were identified retrospectively by the ICD-10 code. Data were collected from medical records. The diagnosis of this tumor was based on histopathological results. Variables analyzed included age, tumor site, surgical option, axillary lymph nodes, chemotherapy and radiotherapy, metastases, disease-free survival (DFS), and overall survival (OS) rate.

RESULTS

Sixty-nine cases of PTs were diagnosed during the period, of which 31 were benign, 38 were malignant, and 1 was a case of bilateral metachronous tumors. We did not find any borderline pathologic cases. The patient's ages ranged from 20 to 71 years, with the highest number of cases (28) from the 40-49-year-old age group. The majority of patients (42) had PT on the right side. Simple mastectomy was the most performed treatment, with 53 such cases, including both benign and malignant. The axillary staging was carried out in 16 cases, of which none had nodal metastasis. Ten cases received chemotherapy, and 16 cases of malignant phyllodes received postoperative radiotherapy. We found 4 cases with distant metastases and 5 cases that developed local recurrence. The DFS rate reached 92.75%, and the overall 5-year survival rate was 84.21%.

CONCLUSIONS

The incidence of PTs is highest in women in the 3rd and fourth decades of age. Simple mastectomy and wide excision are the treatments of choice, with a low recurrence rate in both benign and malignant PTs cases.

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.

Heterogeneity of enhancement kinetics in dynamic contrast-enhanced MRI and implication of distant metastasis in invasive breast cancer

AIM

To investigate the heterogeneity of enhancement kinetics for breast tumour in order to demonstrate the predictive power of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) features for distant metastasis (DM) in invasive breast cancer.

MATERIALS AND METHODS

Time-signal intensity curve (TIC) patterns from 128 patients with invasive breast cancer were analysed by a pixel-based DCE-MRI analysis. This MRI technique enabled pixels with varying TIC patterns (persistent, plateau, washout and non-enhancement) to be categorised semi-automatically and the percentage of different TIC patterns in each breast tumour to be calculated. The percentage of TIC patterns was compared between the DM and non-DM groups. DM-free survival was estimated using Kaplan-Meier survival analysis.

RESULTS

This study demonstrated a larger percentage of persistent TIC and non-enhancement TIC was associated with DM in invasive breast cancer. The cut-off values of persistent TIC and non-enhancement TIC were 22.5% and 2.5%. Combining TIC patterns and traditional predictors (tumour size and axillary lymph node status) can improve the prediction efficiency. The multivariable model yielded an area under the receiver operating characteristic curve (AUC) of 0.87 with 0.70 sensitivity and 0.87 specificity in leave-one-out cross-validation (LOOCV). These predictors showed significant differences in DM-free survival by Kaplan-Meier analysis.

CONCLUSION

This study shows that breast tumours with higher heterogeneity are more likely to metastasise, and pixel-based TIC analysis has utility in predicting distant metastasis of invasive breast cancer.

Surgical margins for borderline and malignant phyllodes tumours

BACKGROUND

Phyllodes tumours represent less than 1% of all UK breast neoplasms. Histological features allow classification into benign, borderline or malignant, which has a significant impact on prognosis and recurrence. Currently, there is no consensus for the optimal surgical excision margin. This systematic review aims to provide a comparative summary of outcomes (local recurrence, metastasis and survival) for borderline and malignant phyllodes tumours resected with either ≥1cm or <1cm margins.

METHODS

MEDLINE and Embase were systematically searched (1990 to July 2019), in line with PRISMA guidelines. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Ten retrospective studies were included (Newcastle-Ottawa scale mean score: 5.6, range: 8-4). Nine reported local recurrence rates, four reported distant metastasis and four reported survival. Meta-analysis pooling demonstrated no statistically significant difference between <1cm and ≥1cm margins in terms of local recurrence rates (relative risk [RR] 1.43, 95% confidence interval [95% CI] 0.70 - 2.93; p=0.33, n=456), distant metastasis (RR 1.93, 95% CI 0.35 - 10.63; p=0.45, n=72) or mortality (RR 1.93, 95% CI 0.42 - 8.77; p=0.40, n=58) for borderline and malignant tumours. Additionally, two studies demonstrated no significant difference in local recurrence for borderline tumours excised with <0.1cm margins compared to ≥1cm.

CONCLUSION

Current evidence suggests that margins <1cm may provide adequate tumour excision. This could enable breast conservation in patients with smaller breast-to-tumour volume ratios, with improved cosmetic outcomes and patient satisfaction. A prospective, multi-institutional trial would be appropriate to further elucidate the safety of smaller margins.

The Characteristics of Local Recurrence After Breast-Conserving Surgery Alone for Malignant and Borderline Phyllodes Tumors of the Breast (KROG 16-08)

BACKGROUND

Despite margin-negative breast-conserving surgery (BCS), phyllodes tumors (PT) of the breast show high local recurrence (LR) rates. In this study we aimed to assess the site and grade of LR to identify high-risk patients after initial treatment of malignant and borderline PT using BCS alone.

PATIENTS AND METHODS

From 1981 to 2014, 312 patients with malignant (n = 164) and borderline (n = 148) PT were treated using BCS alone at 10 centers. LR was defined as true recurrence (TR) if < 2 cm from the primary tumor bed and as elsewhere failure (EF) if otherwise.

RESULTS

At a median of 21 months, LR occurred in 17.6% (55 of 312), 18.9% (31 of 164) among malignant and 16.2% (24 of 148) among borderline PT (P = .636). Only 1.9% (6 of 312) had EF. Five-year cumulative LR rates were 14.7% and 35.9% after margin-negative and -positive BCS, respectively (P < .001). Positive margin was an independent risk factor for TR (P = .002) and EF (P = .002). In multivariable competing risk regression of patients with negative margins < 1 cm (n = 115), age < 35 years (P = .001), and tumor size ≥ 5 cm (P = .008) independently increased LR risk. Of patients who experienced a LR, 30.9% (17 of 55) had a second or third repeated event. Borderline-to-malignant transformation rates increased at each LR event: 4.1% (6 of 148), 12.5% (3 of 24), and 77.8% (7 of 9) at first, second, and third LR, respectively (P = .006).

CONCLUSION

LRs almost always develop near the primary tumor bed. Many patients experience multiple events, with heightened risk of borderline-to-malignant transformation at each subsequent event. For patients with negative margins < 1 cm, younger age and larger tumor size are independent risk factors for increased LR.

Local Recurrence of Benign, Borderline, and Malignant Phyllodes Tumors of the Breast: A Systematic Review and Meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to investigate local recurrence (LR) rates among the three grades (benign, borderline, and malignant) of phyllodes tumors (PTs). The study also assessed various risk factors for LR.

METHODS

Electronic articles published between 1 January 1995 and 31 May 2018, were searched and critically appraised. The authors independently reviewed the abstracts and extracted data for LR rates and LR risk factors.

RESULTS

The review incorporated 54 studies with 9234 individual cases. The pooled LR rates were 8% for benign, 13% for borderline, and 18% for malignant PTs. The risk of LR was significantly increased by borderline versus benign PTs (odds ratio [OR] 2.00; 95% confidence interval [CI] 1.68-2.38) and malignant versus borderline PTs (OR 1.28; 95% CI 1.05-1.55). The significant risk factors for LR were mitoses, tumor border (infiltrating vs. pushing), stromal cellularity (moderate/severe vs. mild), stromal atypia (severe vs. mild/absent), stromal overgrowth (severe vs. mild/absent), and tumor necrosis (positive vs. negative). Age and tumor size were not associated with LR risk. The subgroup analysis showed that breast-conserving surgery versus mastectomy and positive versus negative surgical margins were significantly associated with an increased LR risk only in malignant PTs.

CONCLUSIONS

The risk of LR was significantly increased from benign to borderline to malignant PTs. Mitoses, tumor border, stromal cellularity, stromal atypia, stromal overgrowth, tumor necrosis, type of surgery, and surgical margin status may be risk factors for LR. Different management strategies could be considered for different PT grades.

Phyllodes tumors of the breast. The treatment results for 340 patients from a single cancer centre

PURPOSE

The primary treatment of choice for patients with phyllodes tumor of the breast (PTB) is surgery. Two major problems regarding the treatment of such patients remain unclear: what is the appropriate surgical margin and what role is played by adjuvant radiotherapy (ART).

METHODS

The study provides a retrospective review of all patients with PTB treated between 1952 and 2013 at a single institute. The histology slides were re-examined based on WHO criteria. The clinical characteristics and therapy outcomes were obtained. The five-year survival with no evidence of disease (NED) was used as the end point.

RESULTS

The study population comprised 340 women with PTB. Fifty-five percent of the patients were diagnosed with the benign, 11.8% with borderline and 33.2% with malignant PTB. All the patients received primary treatment with surgery (mastectomy-27.1%, and BCS- 72.9%). Local recurrence (LR) was found in 28 (9.1%) of these patients. Four patients with borderline and 8 with malignant PTB who were treated with BCS and had tumor-free margins < 1 cm received ART. None of these patients had LR and all survived 5 years NED. Of the 340 patients from our group, 294 (86.4%) survived five-years NED.

CONCLUSION

The prognosis for benign PTB is excellent and can be cured with surgery alone. A sufficient margin would be 0.1 cm (data from the literature) or 0.2-0.4 cm (our study). We recommend application of ART for such patients but the role of ART in patients with borderline and malignant PTB treated with BCS and with surgical margin < 1 cm remains uncertain.