Neuroendocrine Cancer of the Breast: A Rare Entity

Non-metastatic primary neuroendocrine neoplasms of the breast: a reference cancer center's experience of a heterogenous entity

Background

Primary neuroendocrine neoplasms of the breast (Br-NENs) are rare. The classification has been updated in recent years making interpretation of the data published challenging. It is unclear whether neuroendocrine differentiation is associated with poorer prognosis and what treatment approaches should be applied.

Methods

The database for breast cancer patients treated between 2009 and 2022 at the Maria Sklodowska-Curie National Research Institute of Oncology Branch Krakow was explored to search for Br-NENs. Patients' medical and pathological data were collected and analyzed.

Results

We included 22 females with Br-NEN without metastases at the time of diagnosis. The median age was 64 years (range: 28-88), Of the cases, 18 were hormone receptor positive, all were HER-2 negative, the median Ki67 was 27% (10-100%). The median tumor size at the time of diagnosis was 29.5mm (7-75mm), 9 patients were N-positive. DCIS was present in 5 cases. Only one case was negative for chromogranin and synaptophysin staining, but data were missing for 4 cases. Nine patients received adjuvant chemotherapy, mainly based on anthracyclines and taxanes, while 16 received adjuvant hormonal therapy and 15 received postoperative radiotherapy. Radical surgery was performed in all patients, but two underwent suboptimal tumorectomy. One patient had local recurrence, three experienced metastatic disease, all involving the lungs, but these patients are still alive. The median follow-up was 96 months (8-153). Two patients died, with a follow up time of no recurrence >4 years. Our results were compared to twelve case series collecting clinical data on Br-NENs, with median patient number of 10.5 (range: 3-142).

Conclusion

Br-NENs represent a heterogenous group of diseases, lacking data from prospective studies or clinical trials. There are no established treatment standards tailored for Br-NENs. Our patients' cohort exhibited a favorable prognosis, potentially attributed to lower tumor stage and Ki67 index compared to other reported case series. We suggest that radical surgery and postoperative radiotherapy be administered akin to standard treatment for breast cancer of no special type. ESMO also advocates for this approach in systemic treatment, although we recommend considering platinum-based chemotherapy for patients with poorly differentiated Br-NENs exhibiting high Ki67.

Virus-associated neuroendocrine cancers: Pathogenesis and current therapeutics

Neuroendocrine neoplasms (NENs) comprise malignancies involving neuroendocrine cells that often lead to fatal pathological conditions. Despite escalating global incidences, NENs still have poor prognoses. Interestingly, research indicates an intricate association of tumor viruses with NENs. However, there is a dearth of comprehension of the complete scenario of NEN pathophysiology and its precise connections with the tumor viruses. Interestingly, several cutting-edge experiments became helpful for further screening of NET for the presence of polyomavirus, Human papillomavirus (HPV), Kaposi sarcoma-associated herpesvirus (KSHV), Epstein Barr virus (EBV), etc. Current research on the neuroendocrine tumor (NET) pathogenesis provides new information concerning their molecular mechanisms and therapeutic interventions. Of note, scientists observed that metastatic neuroendocrine tumors still have a poor prognosis with a palliative situation. Different oncolytic vector has already demonstrated excellent efficacies in clinical studies. Therefore, oncolytic virotherapy or virus-based immunotherapy could be an emerging and novel therapeutic intervention. In-depth understanding of all such various aspects will aid in managing, developing early detection assays, and establishing targeted therapeutic interventions for NENs concerning tumor viruses. Hence, this review takes a novel approach to discuss the dual role of tumor viruses in association with NENs' pathophysiology as well as its potential therapeutic interventions.

Rare subtypes of triple negative breast cancer: Current understanding and future directions

Rare subtypes of triple-negative breast cancers (TNBC) are a heterogenous group of tumors, comprising 5-10% of all TNBCs. Despite accounting for an absolute number of cases in aggregate approaching that of other less common, but well studied solid tumors, rare subtypes of triple-negative disease remain understudied. Low prevalence, diagnostic challenges and overlapping diagnoses have hindered consistent categorization of these breast cancers. Here we review epidemiology, histology and clinical and molecular characteristics of metaplastic, triple-negative lobular, apocrine, adenoid cystic, secretory and high-grade neuroendocrine TNBCs. Medullary pattern invasive ductal carcinoma no special type, which until recently was a considered a distinct subtype, is also discussed. With this background, we review how applying biological principals often applied to study TNBC no special type could improve our understanding of rare TNBCs. These could include the utilization of targeted molecular approaches or disease agnostic tools such as tumor mutational burden or germline mutation-directed treatments. Burgeoning data also suggest that pathologic response to neoadjuvant therapy and circulating tumor DNA have value in understanding rare subtypes of TNBC. Finally, we discuss a framework for advancing disease-specific knowledge in this space. While the conduct of randomized trials in rare TNBC subtypes has been challenging, re-envisioning trial design and technologic tools may offer new opportunities. These include embedding rare TNBC subtypes in umbrella studies of rare tumors, retrospective review of contemporary trials, prospective identification of patients with rare TNBC subtypes entering on clinical trials and querying big data for outcomes of patients with rare breast tumors.

Breast neuroendocrine tumor arising in the axilla of a man: a case report

BACKGROUND

Accessory breast carcinomas of the axilla of males are rare, and primary breast neuroendocrine tumors (BNETs) are rare as well. We present a case of a BNET arising in the axilla of a man.

CASE PRESENTATION

A 64-year-old Japanese man presented with a hard 15-mm mass in the axilla and axillary lymph node swelling. Histopathological examination of the incisional biopsy specimen revealed a neuroendocrine carcinoma. Therefore, wide radical excision of the axillary tumor and axillary lymph node dissection were performed. Hematoxylin and eosin staining showed that the solid tumor was mainly located in the subcutaneous adipose tissues and appeared to invade the skin. The tumor phenotypes were positive for CAM 5.2, synaptophysin, estrogen receptor, progesterone receptor, and GATA-binding protein 3; they were negative for human epidermal growth receptor 2. The neuroendocrine component comprised more than 90% of the tumor, and the Ki-67 index was 21%. These results indicated that the tumor was a BNET. This patient underwent adjuvant chemotherapy, endocrine therapy, and radiotherapy.

CONCLUSIONS

BNET cases in males are rare. The clinical and histological criteria as well as treatment for these rare cases are discussed.

HER-2-positive primary neuroendocrine neoplasms of the breast with signet ring feature: A case report and review of literature

Background

Primary neuroendocrine neoplasm of the breast (BNEN) is an uncommon breast neoplasm, and in most cases, it presents as hormone receptors positive and HER-2 negative. Moreover, in neuroendocrine neoplasms (NENs), the signet ring feature is a rare morphological subtype, and only a few cases have been reported. Here, we report the case of a primary breast neuroendocrine neoplasm with an unusual signet ring cell appearance in this paper. The documentation of this case, combined with a review of the literature, may add to existing knowledge about the outcome and management of this rare tumor.

Methods

In the present review, we describe a unique case of HER-2-positive primary BNEN with a signet ring feature that has not been reported in English. Additionally, we performed a literature search of the PubMed and Web of Science databases and calculated statistics for clinical data and follow-up.

Results

Our literature search, excluding non-English literature, identified 15 articles with data from 24 cases, including ours. The mean age was 51.25 years (range, 30-79 years), and there were 13 male patients (54%) and 11 female patients (46%). Of the 24 cases, some cases (11/24) were associated with lymph node metastases, a few cases (6/24) had distant metastasis, and the vast majority of cases (23/24) occurred in the digestive system. Primary hepatic signet ring cell neuroendocrine tumor showed slow progression and good prognosis. Lymph node involvement was identified in one of eight (12.5%) documented cases, and one of eight (12.5%) reported cases presented with distant metastatic disease. However, the prognosis of neuroendocrine tumors with signet ring cells in the pancreas and stomach was poor. Lymph node involvement was identified in 9 of 15 (60%) documented cases, and 5 of 15 (33.3%) reported cases presented with distant metastatic disease.

Conclusion

NENs with a signet ring feature is uncommon, and this is the first case report of its occurrence in the breast. Current knowledge is limited to anecdotal experience based on case reports and small case series. We provide a literature review to summarize knowledge about this rare entity.

Primary Breast Neuroendocrine Tumors: An Analysis of the National Cancer Database

BACKGROUND

Primary breast neuroendocrine tumors (BNETs) represent < 1% of breast cancers. Diagnosing BNETs can be challenging, and a limited amount of cohort data currently exists in literature. We aimed to describe primary BNET characteristics, treatment modalities, and survival outcomes through the National Cancer Database (NCDB).

METHODS

A retrospective cohort analysis was performed using the NCDB from 2004 to 2017. BNET cases were compared with patients with invasive ductal carcinoma (IDC). A matched IDC cohort was created by matching patient age, race, and disease stage. Kaplan-Meier analysis was performed, and hazard ratios (HR) were calculated through the bootstrap sampling method.

RESULTS

A total of 1389 BNET and 1,967,401 IDC cases were identified. When compared with IDC patients, BNET patients were older, had more comorbidities, and were more often male (p < 0.01). BNETs were larger, higher grade, and more frequently hormone receptor negative (p < 0.01). While BNET patients were treated with surgery and radiotherapy (p < 0.01) less often compared with IDC patients, they presented at later disease stage (p < 0.001) and received systemic treatment more frequently (53.5% vs. 40%, p < 0.01). Patients with BNET had increased mortality compared with the matched IDC cohort: stage 1 HR 1.8, stage 2 HR 2.0, stage 3 HR 1.8, and stage 4 HR 1.5 (p < 0.001 for all).

CONCLUSION

Patients with BNET tend to present at higher clinical stages, are more frequently hormone receptor negative, and have inferior overall survival compared with patients with IDC. Further treatment strategies and studies are needed to elucidate optimal therapies to maximize patient outcomes.

Primary neuroendocrine carcinoma of the breast with leptomeninges metastasis: A case report and literature review

Primary neuroendocrine carcinoma of the breast (NECB) is a rare tumour with an incident rate of 0.3-0.5%. The most common metastatic sites of NECB are liver, bones, lung, pancreas, soft tissues and brain, while leptomeninges metastasis (LM) is reported rarely. This current case report describes a 50-year-old female patient with NECB and LM whose overall survival was 2 months. The report also presents the current literature regarding the knowledge of this unusual tumour and metastatic type. The current patient was diagnosed with NECB with right cerebellar metastasis, followed by LM. She underwent modified radical mastectomy of the left breast, left whole breast radiation therapy and incomplete adjuvant chemotherapy until the metastasis occurred. Whole-brain radiation therapy and a first-line salvage regimen of etoposide and cis-platinum were then undertaken. The patient died 2 months after their LM diagnosis. Primary NECB with LM is sporadic, devoid of effective treatment and associated with a poor prognosis. Consequently, it is vitally important to identify LM in order to achieve longer patient survival.

Invasive ductal carcinoma of breast with neuroendocrine differentiation: A case report

Primary invasive breast carcinoma with neuroendocrine differentiation is an uncommon presentation. We hereby report a case diagnosed as invasive ductal carcinoma with neuroendocrine differentiation in a 52‐year‐old female patient who presented with a painless right breast lump.

Primary invasive breast carcinoma with neuroendocrine differentiation is an uncommon presentation. We hereby report a case of invasive ductal carcinoma with neuroendocrine differentiation who presented with a painless right breast lump. The patient was evaluated with mammography, ultrasound‐guided tru‐cut biopsy, and CT scan of the chest. Later right mastectomy with frozen section examination of right axillary sentinel lymph node was performed. Finally, a diagnosis of invasive ductal carcinoma with neuroendocrine differentiation was made with the help of the histomorphological evaluation and immunohistochemical study using neuroendocrine markers like CD56 and INSM1. To the best of our knowledge, this is the first case of invasive breast carcinoma with neuroendocrine differentiation reported from Nepal and can help better understand the clinical entity, diagnosis, treatment, and prognosis of this rare tumor.

Small-cell breast carcinoma with response to atezolizumab: a case report

Background: Small-cell carcinoma of the breast is a rare disease with little research outlining molecular targets or optimal therapeutic management. We summarize a young female patient with poorly differentiated high-grade carcinoma with neuroendocrine features/small-cell carcinoma. Case presentation: A 31-year-old female presented with a large left breast mass. Initial biopsy revealed small-cell, triple-negative breast carcinoma. Treatment consisted of cisplatin and etoposide but was poorly tolerated and discontinued after one cycle. Combination abraxane/atezolizumab resulted in transient partial response in tumor size with 7 months of progression-free stability. Worsening metastatic disease was found 8 months after initial biopsy on radiologic studies and the patient expired 10 months after initial biopsy. Conclusion: Transient benefit in response to combination abraxane/atezolizumab was demonstrated.

Head to head: Do neuroendocrine tumours in the breast truly exist?

Breast cancer (BC) is a heterogeneous disease with a spectrum of morphological features. Concepts of histogenesis and differentiation in BC remain controversial. Recent evidence supports differentiation rather than histogenesis as the underlying mechanism for the myriad morphological appearances of BC. Prognosis and response to therapy are determined by a combination of factors including tumour grade, stage and receptor status whereas tumour histological types play an independent role in only limited examples. Neuroendocrine tumours (NETs) comprise one of the most debated entities in the breast since their first description. Apart from the rare small cell NE carcinoma (NEC) which has well-characterised features similar to their counterparts in other organs, the true existence, diagnostic criteria and clinical significance of NE neoplasms (NENs) in the breast are shrouded in controversy. At the core of this discussion is whether normal NE cells exist in the breast, and if breast NETs have distinct morphology and clinical behaviour. When NETs are encountered in the breast, metastatic origin has to be excluded. The more frequent situation in which NE differentiation is observed in breast cancers is in the context of recognisable, morphologically well described special type neoplasms like the hypercellular mucinous carcinoma and solid papillary carcinoma. In this review, arguments for and against maintaining the category of NENs in the breast are articulated in relation to existing literature on this group of unusual tumours.

Biomarker Landscape in Neuroendocrine Tumors With High-Grade Features: Current Knowledge and Future Perspective

Neuroendocrine tumors (NETs) are classified based on morphology and are graded based on their proliferation rate as either well-differentiated low-grade (G1) to intermediate (G2–G3) or poorly differentiated high-grade neuroendocrine carcinomas (NEC G3). Recently, in gastroenteropancreatic (GEP) NETs, a new subgroup of well-differentiated high-grade tumors (NET G3) has been divided from NEC by WHO due to its different clinical–pathologic features. Although several mutational analyses have been performed, a molecular classification of NET is an unmet need in particular for G3, which tends to be more aggressive and have less benefit to the available therapies. Specifically, new possible prognostic and, above all, predictive factors are highly awaited, giving the basis for new treatments. Alteration of KRAS, TP53, and RB1 is mainly reported, but also druggable alterations, including BRAF and high microsatellite instability (MSI-H), have been documented in subsets of patients. In addition, PD-L1 demonstrated to be highly expressed in G3 NETs, probably becoming a new biomarker for G3 neuroendocrine neoplasm (NEN) discrimination and a predictive one for immunotherapy response. In this review, we describe the current knowledge available on a high-grade NET molecular landscape with a specific focus on those harboring potentially therapeutic targets in the advanced setting.

Non-conventional and Investigational PET Radiotracers for Breast Cancer: A Systematic Review

Breast cancer is one of the most common malignancies in women, with high morbidity and mortality rates. In breast cancer, the use of novel radiopharmaceuticals in nuclear medicine can improve the accuracy of diagnosis and staging, refine surveillance strategies and accuracy in choosing personalized treatment approaches, including radioligand therapy. Nuclear medicine thus shows great promise for improving the quality of life of breast cancer patients by allowing non-invasive assessment of the diverse and complex biological processes underlying the development of breast cancer and its evolution under therapy. This review aims to describe molecular probes currently in clinical use as well as those under investigation holding great promise for personalized medicine and precision oncology in breast cancer.

The classification of neuroendocrine neoplasms of the breast and its clinical relevance

Neuroendocrine neoplasms of the breast (Br-NENs) are rare tumors of the mammary gland. Their definition and classification have been a matter of discussion for more than half a century, as they present some degree of overlap with other malignancies in the mammary gland. The recent evolutions in the understanding of the pathogenesis of neuroendocrine neoplasms (NENs) as well as the novel tools in the diagnostic arsenal of the pathologists, and a better correlation with clinical data, have led to improved classification schemes for these entities, beginning from those arising in digestive and thoracic organs. These new classification concepts have been recently expanded to NENs arising in every anatomical site, with the proposal of a common classification framework that has been applied in the 5th edition of the WHO classification of tumors. These concepts include the recognition of two distinct families of NENs (neuroendocrine tumors, NETs, and neuroendocrine carcinomas, NECs), the identification of mixed neuroendocrine/non-neuroendocrine neoplasms, and the application of definite morphological and immunohistochemical criteria for the diagnosis of NENs. The last WHO classification of Br-NENs, however, still seems to leave several unanswered questions and unmet needs in the understanding of diagnostic and clinical features of these entities. This review will critically revise the current classification of Br-NENs, underlining its lights and shadows and focusing on the identification of diagnostic histopathological criteria that can help the univocal recognition of Br-NET, Br-NEC, and Br-MiNEN.

The VES-13 and G-8 tools as predictors of toxicity associated with aromatase inhibitors in the adjuvant treatment of breast cancer in elderly patients: A single-center study

Background

Adjuvant hormone treatment of postmenopausal breast cancer is mainly based on aromatase inhibitors. Adverse events associated with such class of drugs are particularly severe in elderly patients. Therefore, we investigated the possibility of ab initio predict which elderly patients could encounter toxicity.

Methods

In light of national and international oncological guidelines recommending the use of screening tests for multidimensional geriatric assessment in elderly patients aged ≥70 years and eligible for active cancer treatment, we assessed whether the Vulnerable Elder Survey (VES)-13 and the Geriatric (G)-8 could be predictors of toxicity associated with aromatase inhibitors. Seventy-seven consecutive patients aged ≥70 diagnosed with non-metastatic hormone-responsive breast cancer and therefore eligible for adjuvant hormone therapy with aromatase inhibitors, were screened with the VES-13 and the G-8, and underwent a six-monthly clinical and instrumental follow-up in our medical oncology unit, from September 2016 to March 2019 (30 months). Said patients were identified as vulnerable (VES-13 score ≥3 or G-8 score ≤14) and fit (VES-13 score <3 or G-8 score >14). The likelihood of experiencing toxicity is greater among vulnerable patients.

Results

The correlation between the VES-13 or the G-8 tools and the presence of adverse events is equal to 85.7% (p = 0.03). The VES-13 demonstrated 76.9% sensitivity, 90.2% specificity, 80.0% positive predictive value, 88.5% negative predictive value. The G-8 demonstrated 79.2% sensitivity, 88.7% specificity, 76% positive predictive value, 90.4% negative predictive value.

Conclusion

The VES-13 and the G-8 tools could be valuable predictors of the onset of toxicity associated with aromatase inhibitors in the adjuvant treatment of breast cancer in elderly patients aged ≥70.

Invasive Ductal Breast Cancer with Osteoclast-Like Giant Cells: A Case Report Based on the Gene Expression Profile for Changes in Management

We report the case of a 49-year-old woman diagnosed with a rare histotype of early breast cancer (BC), invasive ductal carcinoma with osteoclast-like giant cells (OGCs), from the perspective of gene profile analysis tests. The patient underwent a quadrantectomy of the right breast with removal of 2 cm neoplastic nodule and three ipsilateral sentinel lymph nodes. The Oncotype Dx gave a recurrence score (RS) of 23, and taking into account the patient's age, an RS of 23 corresponds to a chemotherapy benefit of 6.5%. After a multidisciplinary collegial discussion, and in consideration of the patient's age, the absence of comorbidity, the premenopausal state, the rare histotype and the Oncotype Dx report, the patient was offered adjuvant chemotherapy treatment followed by hormone therapy. This case may be an example of the utility of integrating gene expression profiling tests into clinical practice in the adjuvant treatment decision of a rare histotype BC. The Oncotype Dx test required to supplement the histological examination made us opt for the proposal of a combined treatment of adjuvant chemotherapy followed by adjuvant hormone therapy. It demonstrates the importance of considering molecular tests and, in particular, the Oncotype Dx, in estimating the risk of disease recovery at 10 years in order to identify patients who benefit from hormone therapy alone versus those who benefit from the addition of chemotherapy, all with a view toward patient-centered oncology. Here, we discuss the possible validity and limitations of the Oncotype Dx in a rare luminal A-like histotype with high infiltrate of stromal/inflammatory cells.

Sex and Gender Influences on Cancer Immunotherapy Response

The global burden of cancer is growing and a wide disparity in the incidence, malignancy and mortality of different types of cancer between each sex has been demonstrated. The sex specificity of cancer appears to be a relevant issue in the management of the disease, and studies investigating the role of sex and gender are becoming extremely urgent. Sex hormones are presumably the leading actors of sex differences in cancer, especially estrogens. They modulate gene expression, alter molecules and generate disparities in effectiveness and side effects of anticancer therapies. Recently immunotherapy aims to improve anticancer treatment strategies reducing off-target effects of chemotherapy and direct cancer cells killing. It is recognized as a fruitful strategy to treat and possible to cure cancer. Immunotherapeutic agents are used to activate or boost the activation of the immune system to fight cancer cells through physiological mechanisms often evaded in the offensive march of the disease. These therapeutic strategies have allowed new successes, but also have serious adverse effects including non-specific inflammation and autoimmunity. Sex and gender issues are of primary importance in this field, due to their recognized role in inflammation, immunity and cancer, and the clarification and understanding of these aspects is a necessary step to increase the responses and to diminish the adverse effects of immunotherapy. This review describes the available knowledge on the role of sex and gender in cancer immunotherapy, and will offer insights to stimulate the attention and practice of clinicians and researchers in a gender perspective of new cancer treatment strategies.