Mixed Neuroendocrine-Non-Neuroendocrine Neoplasms of the Pancreas.

Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare neoplasms, composed of at least two components. The neuroendocrine part is always present. Histology is the most important tool for the diagnosis, but in the case of MiNEN, it is also important for the use of immunohistochemistry, which should include neuroendocrine but also ductal and acinar markers. Each component should be specifically described in the final pathology report, including the percentage on the entire tumor mass. The prognosis of MiNEN is very heterogeneous and depends on the different tumor components.

New insights in gastrointestinal "pediatric" neoplasms in adult patients: pancreatoblastoma, hepatoblastoma and embryonal sarcoma of the liver. A practical approach by GIPPI-GIPAD Groups.

Pediatric solid neoplasms are rare and very different from those observed in adults. The majority of them are referred to as embryonal because they arise as a result of alterations in the processes of organogenesis or normal growth and are characterized by proliferation of primitive cells, reproducing the corresponding tissue at various stages of embryonic development. This review will focus on embryonal gastrointestinal pediatric neoplasms in adult patients, including pancreatoblastoma, hepatoblastoma, and embryonal sarcoma of the liver. Although they are classically considered pediatric neoplasms, they may (rarely) occur in adult patients. Hepatoblastoma represents the most frequent liver neoplasm in the pediatric population, followed by hepatocellular carcinoma and embryonal sarcoma of the liver; while pancreatoblastoma is the most common malignant pancreatic tumor in childhood. Both in children and adults, the mainstay of treatment is complete surgical resection, either up front or following neoadjuvant chemotherapy. Unresectable and/or metastatic neoplasms may be amenable to complete delayed surgery after neoadjuvant chemotherapy. However, these neoplasms display a more aggressive behavior and overall poorer prognosis in adults than in children, probably because they are diagnosed in later stages of diseases.

Molecular Analysis of an Intestinal Neuroendocrine/Non-neuroendocrine Neoplasm (MiNEN) Reveals MLH1 Methylation-driven Microsatellite Instability and a Monoclonal Origin: Diagnostic and Clinical Implications.

Mixed neuroendocrine/non-neuroendocrine neoplasms (MiNEN) are rare mixed epithelial neoplasms in which a neuroendocrine component is combined with a non-neuroendocrine component. Here, we provide the clinical, pathologic, and molecular report of a 73-year-old-man presenting with an intestinal MiNEN. The lesion was composed of a well-differentiated G3 neuroendocrine tumor and a colloid adenocarcinoma. The molecular characterization was performed using a multigene next-generation sequencing panel. The neoplasm displayed microsatellite instability due to MLH1 promoter methylation. The extended molecular profile documented the same mutations affecting ARID1A, ASXL1, BLM, and RNF43 genes in both components, indicating a monoclonal origin of the tumor. Regarding component-specific gene mutations, BRCA2 was specifically altered in the neuroendocrine area. It may represent a new actionable target for precision oncology in MiNEN, but the lack of its alteration in the colloid component calls for further considerations on intratumor heterogeneity. The most important finding with potential immediate implications regards the presence of microsatellite instability: it indicates that this molecular alteration should become part of the diagnostic algorithm for these rare neoplasms.

Impact of estrogen receptor levels on outcome in non-metastatic triple negative breast cancer patients treated with neoadjuvant/adjuvant chemotherapy.

Although 1% is the recommended cut-off to define estrogen receptor (ER) positivity, a 10% cut-off is often used in clinical practice for therapeutic purposes. We here evaluate clinical outcomes according to ER levels in a monoinstitutional cohort of non-metastatic triple-negative breast cancer (BC) patients undergoing (neo)adjuvant chemotherapy. Clinicopathological data of 406 patients with ER < 10% HER2-negative BC treated with (neo)adjuvant chemotherapy between 01/2000 and 04/2019 were collected. Patients were categorized in ER-negative (ER < 1%; N = 364) and ER-low positive (1-9%, N = 42). At a median follow-up of 54 months, 88 patients had relapsed and 64 died. No significant difference was observed in invasive relapse-free survival (iRFS) and overall survival (OS) according to ER expression levels, both at univariate and multivariate analysis (5-years iRFS 74.0% versus 73.1% for ER-negative and ER-low positive BC, respectively, p = 0.6; 5-years OS 82.3% versus 76.7% for ER-negative and ER-low positive BC, respectively, p = 0.8). Among the 165 patients that received neoadjuvant chemotherapy, pathological complete response rate was similar in the two cohorts (38% in ER-negative, 44% in ER-low positive, p = 0.498). In conclusion, primary BC with ER1-9% shows similar clinical behavior to ER 1% BC. Our results suggest the use of a 10% cut-off, rather than <1%, to define triple-negative BC.

Ki67/MART1 and p63/SOX10 Dual Immunohistochemistry Allows a Correct Interpretation of the Melanocytic Component in the Diagnosis of Pigmented Pilomatricoma.

Pilomatricoma is a relatively common benign cutaneous adnexal tumor and a well-recognized entity, while its pigmented variant is far less common and less reported. Its estimated frequency ranges from 11 to 24%, according to a limited number of published case series. This article describes the case of a 42-year-old man presenting a firm subcutaneous nodule of the periareolar region. Histopathologic examination revealed a cystic lesion composed of matrical and supramatrical cells accompanied by a foreign body granulomatous cell reaction. Interestingly, a hyperpigmented area with numerous hyperplastic melanocytes and few mitoses was detectable. In order to assess the cell lineage of the mitotically active component in the hyperpigmented area, double immunohistochemistry with Ki67/Mart1 and p63/SOX10 was performed. Pigmented pilomatricoma is an underrecognized, underreported variant, and double immunohistochemistry stain is an effective tool in providing the correct interpretation of the proliferative activity in the different cellular populations.

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.

ERBB2 mRNA Expression and Response to Ado-Trastuzumab Emtansine (T-DM1) in HER2-Positive Breast Cancer.

Trastuzumab emtansine (T-DM1) is approved for the treatment of human epidermal growth factor receptor 2 (HER2)-positive (HER2+) metastatic breast cancer (BC) and for residual disease after neoadjuvant therapy; however, not all patients benefit. Here, we hypothesized that the heterogeneity in the response seen in patients is partly explained by the levels of human epidermal growth factor receptor 2 gene (ERBB2) mRNA. We analyzed ERBB2 expression using a clinically applicable assay in formalin-fixed paraffin-embedded (FFPE) tumors (primary or metastatic) from a retrospective series of 77 patients with advanced HER2+ BC treated with T-DM1. The association of ERBB2 levels and response was further validated in 161 baseline tumors from the West German Study (WGS) Group ADAPT phase II trial exploring neoadjuvant T-DM1 and 9 in vitro BC cell lines. Finally, ERBB2 expression was explored in 392 BCs from an in-house dataset, 368 primary BCs from The Cancer Genome Atlas (TCGA) dataset and 10,071 tumors representing 33 cancer types from the PanCancer TCGA dataset. High ERBB2 mRNA was found associated with better response and progression-free survival in the metastatic setting and higher rates of pathological complete response in the neoadjuvant setting. ERBB2 expression also correlated with in vitro response to T-DM1. Finally, our assay identified 0.20-8.41% of tumors across 15 cancer types as ERBB2-high, including gastric and esophagus adenocarcinomas, urothelial carcinoma, cervical squamous carcinoma and pancreatic cancer. In particular, we identified high ERBB2 mRNA in a patient with HER2+ advanced gastric cancer who achieved a long-lasting partial response to T-DM1. Our study demonstrates that the heterogeneity in response to T-DM1 is partly explained by ERBB2 levels and provides a clinically applicable assay to be tested in future clinical trials of breast cancer and other cancer types.

Integration of tumour infiltrating lymphocytes, programmed cell-death ligand-1, CD8 and FOXP3 in prognostic models for triple-negative breast cancer: Analysis of 244 stage I-III patients treated with standard therapy.

BACKGROUND: Tumour infiltrating lymphocytes (TILs) are an established prognostic biomarker for triple-negative breast cancer (TNBC). We evaluated the role of programmed cell-death ligand-1 (PD-L1), CD8 and FOXP3 expression in refining a prognostic model for non-metastatic TNBC beyond classic factors and TILs. METHODS: Primary tumour samples from 244 early patients with TNBC, all treated with surgery and chemotherapy, were collected. Stromal TILs were evaluated on haematoxylin-eosin slides according to guidelines. PD-L1, CD8 and FOXP3 were assessed by immunohistochemistry and evaluated by digital pathology. RESULTS: TILs, PD-L1, CD8 and FOXP3 were positively correlated with each other (P < 0.001). TILs were confirmed as an independent prognostic factor. When PD-L1, CD8 and FOXP3 were added to multivariable models including classic factors (age, stage, histologic grade) and TILs, PD-L1 provided the largest amount of additional prognostic information: likelihood ratio χ2 4.60, P = 0.032 (in a model including classic factors and TILs 10% increments) and likelihood ratio χ2 6.50, P = 0.011 (in a model including classic factors and TILs >30% versus <30%). In the subset of patients treated with neoadjuvant chemotherapy, FOXP3 provided further prognostic information beyond classic factors, TILs and pathological complete response (pCR) (likelihood ratio χ2 5.01, P = 0.025). For patients who did not achieve a pCR, the expression of CD8 and PD-L1 was significantly increased from baseline to residual disease. CONCLUSIONS: Beyond clinicopathological factors and TILs, other immune biomarkers may add prognostic information for early TNBC. The increased PD-L1 expression on residual disease after neoadjuvant chemotherapy strengthens the rationale of testing immune checkpoint inhibitors in the post-neoadjuvant setting.

Validation of Residual Proliferative Cancer Burden as a Predictor of Long-Term Outcome Following Neoadjuvant Chemotherapy in Patients with Hormone Receptor-Positive/Human Epidermal Growth Receptor 2-Negative Breast Cancer.

BACKGROUND: The integration of residual cancer burden (RCB) and post-treatment Ki67 as residual proliferative cancer burden (RPCB) has been proposed as a stronger predictor of long-term outcome in unselected patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT), as compared with RCB. However, no specific analysis in hormone-receptor-positive (HR+) human epidermal growth receptor 2-negative (HER2-) BC is available so far. MATERIALS AND METHODS: A cohort of 130 patients with HR+/HER2- BC who underwent NACT between 2000 and 2014 was included. Archival surgical specimens were evaluated for RCB. RPCB was calculated by combining RCB and Ki67 as previously described. Patients were categorized in four RCB and RPCB categories (pathological complete response and tertiles). Disease-free survival (DFS) and overall survival (OS) estimates were determined by Kaplan-Meier analysis and compared using the log-rank test. Overall change of χ2 and c-indexes were used to compare the performance of the prognostic models. RESULTS: RPCB was calculated for 85 patients. After a median follow up of 8.5 years, RCB was associated with OS (p = .048) but not with DFS (p = .152); RPCB was instead significantly associated with both DFS and OS (p = .034 and p < .001, respectively). In terms of OS, RPCB provided a significant amount of prognostic information beyond RCB (∆χ2 5.73, p < .001). In addition, c-index for OS prediction was significantly higher for RPCB as compared with RCB (0.79 vs. 0.61, p = .03). CONCLUSION: This is the first study evaluating RPCB in patients with HR+/HER2- BC treated with NACT. In this independent cohort, RPCB was a strong predictor of DFS and OS. The better performance of RPCB versus RCB was in part due to the ability of RPCB to discriminate a subgroup of patients with a particularly worse prognosis after NACT, who may be candidates for clinical trials evaluating novel adjuvant strategies. IMPLICATIONS FOR PRACTICE: The present work validated residual proliferative cancer burden (RPCB) as a strong predictor of long-term outcome in patients with hormone receptor-positive human epidermal growth receptor 2-negative (HR+/HER2-) breast cancer (BC) treated with neoadjuvant chemotherapy. In addition, results from the present study suggest RPCB as a promising tool to identify patients with HR+/HER2- BC who might potentially benefit from the inclusion in clinical trials evaluating novel or escalated postneoadjuvant treatment strategies because it allowed to discriminate a subgroup of patients with particularly poor prognosis despite having received subsequent endocrine therapy in the adjuvant setting.

Axillary Hibernoma in woman with Lobular breast cancer and MEN1 syndrome: A case report.

INTRODUCTION: The present study reports the case of an axillary hibernoma in a patient with lobular homolateral breast cancer and multiple endocrine neoplasia type1 (MEN-1). Hibernoma is a rare benign adipose tissue tumor, and usually manifests as a slowly growing and painless rubbery mass. These tumors can arise in various sites, but mammary hibernomas remain extraordinarily uncommon. Although hibernomas are metabolically active and therefore "glucose-avid" on fluorodeoxyglucose CT-positron emission tomography (FDG CT-PET), imaging alone is inadequate in providing a reliable diagnosis and definitive differential diagnosis from other malignancy. Only complete surgical excision is diagnostic and, in most cases, curative. PRESENTATION OF CASE: A 42-years-old woman was followed for MEN-1 syndrome associating with hyperparathyroidism, insulinoma, non-secretory adrenal adenoma and thyroid lump. A FDG CT-PET found high glucid hypermetabolism in thickened elongated area on the front axillary line. Hibernoma was diagnosed after realization of prophylactic left mastectomy, homolateral sentinel lymph node biopsy and exeresis of the known axillary lesion. DISCUSSION: Clinical importance lies in distinguishing hibernoma from other benign and malignant breast neoplasms, as well as inflammatory conditions that come into the histologic or radiologic differential. Hibernoma is not currently classified as a non-endocrine tumor related to MEN1, but this association could be not fortuitous for the linkage between modification of Menin protein function and pathogenesis of hibernomas. CONCLUSION: Our case deserves extraordinary attention because, not only it's a case of MEN1 syndrome associated with hibernoma, but in the context of this lesion there are multiple micro-foci of infiltrating lobular carcinoma.

Androgen Receptor Expression and Association With Distant Disease-Free Survival in Triple Negative Breast Cancer: Analysis of 263 Patients Treated With Standard Therapy for Stage I-III Disease.

Background: We evaluated immunohistochemical AR expression and correlation with prognosis in a large series of homogeneously treated patients with primary TNBC. Material and Methods: Patients diagnosed with stage I-III TNBC between 2000 and 2015 at Istituto Oncologico Veneto who received treatment with surgery and neoadjuvant and/or adjuvant chemotherapy were included. Whole tissue slides were stained for AR. AR-positive expression was defined as >1% of positively stained tumor cells. Distant-disease-free survival (DDFS) was calculated from diagnosis to distant relapse or death. Late-DDFS was calculated from the landmark of 3 years after diagnosis until distant relapse or death. Results: We included 263 primary TNBC patients. Mean AR expression was 14% (range 0-100%), and 29.7% (n = 78) of patients were AR+. AR+ vs. AR- cases presented more frequently older age (p < 0.001), non-ductal histology (p < 0.001), G1-G2 (p = 0.003), lower Ki67 (p < 0.001) and lower TILs (p = 0.008). At a median follow up of 81 months, 23.6% of patients experienced a DDFS event: 33.3% of AR+ and 19.5% of AR- patients (p = 0.015). 5 years DDFS rates were 67.2% and 80.6% for AR+ and AR- patients (HR = 1.82 95%CI 1.10-3.02, p = 0.020). AR maintained an independent prognostic role beyond stage, but when TILs were added to the model only stage and TILs were independent prognostic factors. AR was the only factor significantly associated with late-DDFS: 16.4% of AR+ and 3.4% of AR- patients experienced a DDFS after the landmark of 3 years after diagnosis (p = 0.001). Late-DDFS rates at 5 years from the 3-year landmark were 75.8% for AR+ and 95.2% for AR- patients (log-rank p < 0.001; HR = 5.67, 95%CI 1.90-16.94, p = 0.002). Conclusions: AR expression is associated with worse outcome for patients with TNBC. In particular, AR+ TNBC patients are at increased risk of late DDFS events. These results reinforce the rationale of AR targeting in AR+ TNBC.

Exceptional and Durable Responses to TDM-1 After Trastuzumab Failure for Breast Cancer Skin Metastases: Potential Implications of an Immunological Sanctuary.

Breast Cancer (BC) skin metastases represent a challenging clinical scenario. Although they usually arise when other distant metastases are already present, they may also represent a form of locoregional recurrence (LRR). Systemic therapy in this setting may have a role both in case a radical locoregional approach is unfeasible in order to achieve disease control, and as adjuvant strategy after radical removal of cutaneous lesions, in order to prevent or delay subsequent disease spread. Systemic therapy for HER2+ metastatic BC (MBC) currently relies on anti-HER2 targeted agents. In this context TDM1 is an option in trastuzumab-resistant patients.Here we present 2 cases of isolated skin metastases in patients with HER2+ BC progressing during or early after trastuzumab-based therapy, showing impressive responses to TDM1. We hypothesize that the unique properties of skin immune microenvironment may explain the failure of trastuzumab, which exerts its action also through immunological mechanisms, and the subsequent outlier responses to TDM1, that relies on a partially different mechanism of action.

Immune characterization of breast cancer metastases: prognostic implications.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) evaluated in primary breast cancer (BC) convey prognostic information. Limited data in the metastatic setting are available. METHODS: Secondary lesions from 94 BC patients, 43 triple-negative (TN) and 51 HER2-positive, were evaluated for TILs and expression of CD8, FOXP3, and PD-L1 by immunohistochemistry. RESULTS: TILs levels on metastasis were generally low (median 5%) and did not differ between TN and HER2+ tumors. Younger patients showed significantly lower TILs (p = 0.002). In HER2+ patients, TILs were higher in lung metastases as compared to other sites (p = 0.038). TILs composition was different across metastatic sites: skin metastases presented higher FOXP3 (p = 0.002) and lower CD8/FOXP3 ratio (p = 0.032). Patients treated for metastatic BC prior to biopsy had lower CD8 (overall: p = 0.005, HER2+: p = 0.011, TN: p = 0.075). In TN patients, median overall survival (OS) was 11.8 and 62.9 months for patients with low and high TILs, respectively (HR 0.29, 95%CI 0.11-0.76, log-rank p = 0.008). CD8/FOXP3 ratio was also prognostic in TN patients (median OS 8.0, 13.2, and 54.0 months in 1st, 2nd and 3th tertile, log-rank p = 0.019). Both TILs and CD8/FOXP3 ratio were independent factors at multivariate analysis. Counterintuitively, in HER2+ BC, low TILs tumors showed better prognosis (median OS 53.7 vs 39.9 months in TILs low and TILs high, not statistically significant). CONCLUSIONS: Our findings indicate the relevance of TILs as prognostic biomarker for TNBC even in the advanced setting and provide novel hypothesis-generating data on potential sources of immune heterogeneity of metastatic BC.