Advances in diagnostic liquid-based cytology.

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Association between human epidermal growth factor receptor 2 status, namely low and zero expression, and prognosis in hormone receptor-positive breast cancer: a single-center retrospective study.

Background: The recently developed anti-human epidermal growth factor receptor 2 (HER2) therapy has substantially improved the prognosis of HER2-positive breast cancer. The DESTINY-Breast04 trial results showed that trastuzumab deruxtecan (T-DXd) significantly prolonged the survival of patients with HER2-low breast cancer, thus presenting a paradigm shift in anti-HER2 therapy. This may facilitate a change in the treatment strategy for HER2-low breast cancer. However, the implication of HER2-low in hormone receptor (HR)-positive breast cancer is unclear. In this retrospective study, we aimed to reveal the association between HER2 status, namely HER2-low and HER2-zero, and prognosis in HR-positive breast cancer. Methods: We collected the data of 247 patients with estrogen receptor (ER)-positive/HER2-negative breast cancer (159 with HER2-low and 88 with HER2-zero breast cancer) who underwent surgery. Patients were divided into HER2-low and HER2-zero groups. Univariate analysis was performed to evaluate the baseline characteristics using the Wilcoxon rank sum test and Fisher's exact test. Survival analysis of the HER2-low and HER2-zero groups was performed using the Kaplan-Meier method. Results: The median observation period was 2,706 days, and the median period until recurrence was 1,380 days; 25 patients (10%) had recurrences. Age (P=0.004) and menopausal status (P=0.04) were significant variables in the univariate analysis of baseline characteristics. In the subgroup analysis of luminal A- and B-like breast cancers, there was a significant difference in overall survival (OS) only in patients with luminal A-like breast cancer, but relapse-free survival (RFS) of the HER2-low luminal B-like cancer subgroups tended to be relatively short. Conclusions: We inferred that the HER2-low and HER2-zero statuses do not affect the RFS and OS of patients with ER-positive breast cancer. The prognostic significance of HER2-low or HER2-zero status in luminal A- and B-like breast cancers might differ, and a new treatment strategy is required for the HER2-low subgroup.

Trastuzumab deruxtecan for human epidermal growth factor receptor 2-low advanced or metastatic breast cancer: recommendations from the Japanese Breast Cancer Society Clinical Practice Guidelines.

The Japanese Breast Cancer Society Clinical Practice Guidelines are published as timely guidance on clinical issues in breast cancer treatment in Japan. In the recent edition of these guidelines, we addressed a new clinical question 34 (CQ 34, systemic treatment part) "Is trastuzumab deruxtecan recommended for patients with unresectable or metastatic HER2-low breast cancer?" and a new future research question 7 (FRQ 7, pathological diagnosis part) "How is HER2-low breast cancer diagnosed for the indication of trastuzumab deruxtecan?". These questions address use of trastuzumab deruxtecan in patients with unresectable or metastatic HER2-low breast cancer who have previously received chemotherapy for metastatic disease. The strengths of evidence and recommendation were determined through a quantitative and qualitative systematic review using multiple outcomes, including efficacy and safety. We conclude that trastuzumab deruxtecan is recommended for this patient population (strength of recommendation: 1; strength of evidence: moderate; CQ34) and that HER2-low expression for the indication of trastuzumab deruxtecan should be diagnosed using companion diagnostics based on appropriate criteria (FRQ7).

Using the DNA Integrity Number to Analyze DNA Quality in Specimens Collected from Liquid-Based Cytology after Fine-Needle Aspiration of Breast Tumors and Lesions.

INTRODUCTION: Cancer genome analysis using next-generation sequencing requires adequate and high-quality DNA samples. Genomic analyses were conventionally performed using formalin-fixed paraffin-embedded sections rather than cytology samples such as cell block or smear specimens. Specimens collected from liquid-based cytology (LBC) have the potential to be sources of high-quality DNA suitable for genetic analysis even after long-term storage. METHODS: We collected breast tumor/lesion fractions from 92 residual LBC specimens using fine-needle aspiration (FNA) biopsy, including breast carcinoma (1 invasive carcinoma and 4 ductal carcinomas in situ), papillomatous lesion (5 intraductal papillomas), and fibroepithelial lesion (19 phyllodes tumors and 53 fibroadenomas) samples, and others (1 ductal adenoma, 1 hamartoma, 1 fibrocystic disease, and 7 unknown). DNA was extracted from all samples and subjected to DNA integrity number (DIN) score analysis. RESULTS: Average DIN score collected from 92 LBC specimens was significantly higher score. In addition, high-quality DNA with high DIN values (7.39 ± 0.80) was successfully extracted more than 12 months after storage of residual LBC specimens. CONCLUSION: Residual LBC specimens collected from FNA of the breast were verified to carry high-quality DNA and could serve as an alternate source for genetic analysis.

Intraductal papilloma with atypical ductal hyperplasia and neuroendocrine differentiation as a possible precursor lesion of solid papillary carcinoma.

Breast papillary neoplasms include a wide range of tumor types, and their pathological diagnosis is sometimes difficult. Furthermore, the etiology of these lesions is still not fully understood. We report the case of a 72-years-old woman referred to our hospital with bloody discharge from the right nipple. An imaging study detected a cystic lesion, including a solid component contiguous with the mammary duct, in the subareolar region. The lesion was then removed by segmental mastectomy. Pathological examination of the resected specimen revealed an intraductal papilloma with atypical ductal hyperplasia. Moreover, the atypical ductal epithelial cells expressed neuroendocrine markers. The presence of an intraductal papillary lesion with neuroendocrine differentiation suggests solid papillary carcinoma. Thus, this case suggests that intraductal papilloma could be a precursor of solid papillary carcinoma.

Induction of SGK1 via glucocorticoid-influenced clinical outcome of triple-negative breast cancer patients.

PURPOSE: Triple-negative breast cancer (TNBC) is a highly heterogeneous and aggressive breast malignancy. Glucocorticoid (GC)-glucocorticoid receptor (GR) pathway plays a pivotal role in the cellular responses to various stresses including chemotherapy. Serum- and glucocorticoid-induced kinase-1 (SGK1) is known as an important downstream effector molecule in the GR signaling pathway, we attempted to explore its clinicopathological and functional significance in TNBC in which GR is expressed. METHODS: We first immunolocalized GR and SGK1 and correlated the results with clinicopathological variables and clinical outcome in 131 TNBC patients. We also evaluated the effects of SGK1 on the cell proliferation and migration in TNBC cell lines with administration of dexamethasone (DEX) to further clarify the significance of SGK1. RESULTS: The status of SGK1 in carcinoma cells was significantly associated with adverse clinical outcome in TNBC patients examined and was significantly associated with lymph node metastasis, pathological stage, and lymphatic invasion of the patients. In particular, SGK1 immunoreactivity was significantly associated with an increased risk of recurrence in GR-positive TNBC patients. Subsequent in vitro studies also demonstrated that DEX promoted TNBC cell migration and the silencing of gene expression did inhibit the cell proliferation and migration of TNBC cells under DEX treatment. CONCLUSIONS: To the best of our knowledge, this is the first study to explore an association between SGK1 and clinicopathological variables and clinical outcome of TNBC patients. SGK1 status was significantly positively correlated with adverse clinical outcome of TNBC patients and promoted carcinoma cell proliferation and migration of carcinoma cells.

Histopathology of non-mass-like breast lesions on ultrasound.

There have been several investigations of non-mass-like (NML) lesions on ultrasound (US) since Uematsu first described this approach, and it is a relatively new concept for breast examination. However, the results have varied, and there have been only a few studies related to the detailed histopathology of NML lesions on US. Here, we review the histopathology of NML lesions. NML lesions are pathologically benign, atypical, or malignant. There are two major findings of NML lesions on US: architectural distortion and calcifications. Architectural distortion pathologically indicates a fibrous change with ductal proliferation, invasive breast carcinoma, and carcinoma in situ. Histopathologically, microcalcifications are seen in both benign and malignant lesions, and it is important to distinguish between these lesions among NML lesions, particularly fibrocystic changes including adenosis and hyperplasia in the case of benign lesions and carcinoma in situ (ductal and lobular) in the case of malignant lesions. The differential major points may be whether NML lesions are associated with abundant hyperechoic foci, which indicate comedo necrosis on histology. They are usually high-grade carcinoma in situ that may be positive for HER2 or triple negativity. A recent report indicated that low-grade carcinoma in situ showed better survival than higher-grade carcinoma in situ, which is often accompanied by comedo necrosis on histology, reflecting visible microcalcification on US. NML lesions are considered to include a certain rate of low-grade carcinoma in situ. Therefore, more caution may be needed when detecting and managing NML lesions to avoid overdiagnosis and overtreatment as a result of this recent "low-risk ductal carcinoma in situ" concept.

Adenoid Cystic Carcinoma, Solid-Basaloid Subtype of the Breast: A Case Report.

We present a rare tumor of adenoid cystic carcinoma, solid-basaloid subtype of the breast. Solid-basaloid adenoid cystic carcinoma may have a worse prognosis than classical adenoid cystic carcinoma. A 70-year-old woman presented with a mass in her left breast. Malignancy was suspected on imaging and confirmed via core needle biopsy. Left breast partial mastectomy and sentinel lymph node biopsy were performed. Histologically, the tumor was composed of basaloid cells with hyperchromatic nuclei and frequent mitotic figures, as are small-cell neuroendocrine carcinomas. Immunohistochemical analysis of the tumor cells showed high expression of KIT and CD10 and focal expression of keratin 7. Synaptophysin, chromogranin A, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 were not expressed. This patient should be followed up carefully for distant metastases and recurrences.

Successful treatment of a patient with Takayasu's arteritis complicated with Crohn's disease with ustekinumab: A case report.

A 17-year-old woman was referred to our department with fever, general malaise, and weight loss. She was diagnosed with Takayasu arteritis (TAK) and Crohn's disease (CD) following positron emission tomography-computed tomography (PET-CT) and colonoscopy, respectively. Serological human leukocyte antigen (HLA) typing revealed HLA-B52 positivity. Initial treatment with prednisolone (PSL) (0.5 mg/kg) was insufficient; therefore, ustekinumab and 5-aminosalicylic acid were added. This treatment achieved PSL-free remission for both diseases, as confirmed by PET-CT and colonoscopy. Although treatment guidelines for TAK and CD have been previously established, treatment of patients with TAK with coexisting CD is controversial. Our case suggests that ustekinumab has the ability to achieve TAK remission in addition to its therapeutic effect on CD.

Reporting of Surgically Removed Lymph Nodes for Breast Tumors: Recommendations From the International Collaboration on Cancer Reporting.

CONTEXT.­: The International Collaboration on Cancer Reporting (ICCR), supported by major pathology and cancer organizations, aims at the standardization of evidence-based pathology reporting of different types of cancers, with the inclusion of all parameters deemed to be relevant for best patient care and future data collection. Lymph node metastasis is one of the most important prognostic factors in breast cancer. OBJECTIVE.­: To produce a histopathology reporting guide by a panel of recognized experts from the fields of pathology and surgery with elements deemed to be core (required) and noncore (recommended) to report when assessing regional lymph nodes of patients with breast cancer. DATA SOURCES.­: Published literature, previous guidelines/recommendations, and current cancer staging principles were the basis of the data set drafted by the expert panel. This was discussed in a series of teleconferences and email communications. The draft data set was then made available for public consultation through the ICCR Web site. After this consultation and ICCR ratification, the data set was finalized. CONCLUSIONS.­: The ICCR has published a data set for the reporting of surgically removed lymph nodes (including sentinel lymph node biopsy, axillary lymph node dissection, targeted axillary surgery, and lymph node sampling specimens) for breast tumors. This is part of a series of 4 ICCR breast cancer-related data sets. It includes 10 core elements along with 2 noncore elements. This should allow for synoptic reporting, which is more precise, uniform, and complete than nonsynoptic reporting, and leads to improved patient outcomes.

Development of an intraoperative breast cancer margin assessment method using quantitative fluorescence measurements.

Breast-conserving surgery has become the preferred treatment method for breast cancer. Surgical margin assessment is performed during surgery, as it can reduce local recurrence in the preserved breast. Development of reliable and lower-cost ex vivo cancer detection methods would offer several benefits for patient care. Here, a practical and quantitative evaluation method for the ex vivo fluorescent diagnosis of breast lesions was developed and confirmed through a three-step clinical study. Gamma-glutamyl-hydroxymethyl rhodamine green (gGlu-HMRG) has been reported to generate fluorescence in breast lesions. Using this probe, we constructed a reliable and reproducible procedure for the quantitative evaluation of fluorescence levels. We evaluated the reliability of the method by considering reproducibility, temperature sensitivity, and the effects of other clinicopathological factors. The results suggest that the fluorescence increase of gGlu-HMRG is a good indicator of the malignancy of breast lesions. However, the distributions overlapped. A 5 min reaction with this probe could be used to distinguish at least part of the normal breast tissue. This method did not affect the final pathological examination. In summary, our results indicate that the methods developed in this study may serve as a feasible intraoperative negative-margin assessment tool during breast-conserving surgery.

Surgical excision of a lactating adenoma with rapid enlargement: A case report.

INTRODUCTION AND IMPORTANCE: A lactating adenoma is a benign breast tumor occurring in young women during pregnancy or lactation. Its growth is usually slow but, occasionally, can become rapid, resulting in a giant mass. This case report outlines an example of the rapid growth of a lactating adenoma, which was surgically excised. In this case, malignancy could not be ruled out, and biopsy and surgical excision were considered. CASE PRESENTATION: We present the case of a 28-year-old woman referred to us owing to the presence of a left breast mass with progressive enlargement. She initially presented with a left breast mass of approximately 20-mm in size, which increased to an approximate size of 70 mm during pregnancy. The patient's mammogram showed an equal-density lobular mass in the left breast. Ultrasonography and magnetic resonance imaging revealed a circumscribed lobular mass with cystic regions in the upper lateral quadrant. The patient was diagnosed with adenosis using core needle biopsy. However, it did not shrink during follow-up, and resection was performed. Histologically, the proliferation of the cystic ducts containing eosinophilic secretions and dilated tubules consisting of cuboidal or hobnail-shaped cells were observed. CLINICAL DISCUSSION: Lactating adenoma, phyllodes tumor, and breast cancer are essential differential diagnoses when the size of breast masses increases rapidly. Ultrasonography is the first choice to examine lactating adenomas. Echogenic bands and pseudocapsules are characteristics of lactating adenomas. CONCLUSION: Surgical excision is a notable treatment option when a lactating adenoma exhibits rapid growth or increase in mass, as it could be malignant.

Tumor-infiltrating B cells and T cells correlate with postoperative prognosis in triple-negative carcinoma of the breast.

BACKGROUND: In this study, we investigated CD20+ TILs in triple-negative breast cancer (TNBC) and their relationship with T lymphocyte subsets (CD4+, CD8+, CD25+, and FOXP3+), including their combined prognostic value using an immunohistochemical staining method. METHODS: We investigated 107 patients with TNBC for whom a full-face section stained by hematoxylin and eosin between 2006 and 2018 at Dokkyo Medical University Hospital was available. RESULTS: The strongest association of infiltrating CD20+ TILs was with CD4+ TILs. There was a significant relationship between CD20+ and CD4+ TILs (r = 0.177; p < 0.001), CD8+ TILs (r = 0.085; p = 0.002), and FOXP3+ TILs (r = 0.0043; p = 0.032). No significant relationships were observed between the CD20+ and CD25+ TILs (r = 0.012; p = 0.264). Multivariate analysis revealed that only the CD20+/FOXP3 ratio was an independent factor for relapse-free survival (p < 0.001) and overall survival (p < 0.001). Patients with tumors highly infiltrated by CD4+, CD8+, and CD20+ TILs had a good prognosis. In contrast, those with tumors weakly infiltrated by CD20+ TILs but highly infiltrated by CD25+ and FOXP3+ TILs had a poor prognosis. CONCLUSIONS: CD20+ TILs may support an increase in CD4+ and CD8+ TILs, which altered the anti-tumor response, resulting in a positive prognosis. CD20+ TILs correlated with FOXP3+ Treg lymphocytes, which were reported to be correlated with a poor prognosis. Our study suggested that TIL-B cells have dual and conflicting roles in TIL-T immune reactions in TNBC.

Prognostic value of tumor-infiltrating B lymphocytes and plasma cells in triple-negative breast cancer.

BACKGROUND: Recent investigations have demonstrated that the tumor microenvironment, including tumor-infiltrating lymphocytes (TILs), is an important factor in tumor growth and development. While the prognostic correlation of tumor-infiltrating T cells has been widely studied in breast cancer, that of tumor-infiltrating B cells and plasma cells has not received so much attention, especially in triple-negative breast cancer (TNBC). METHODS: We investigated 114 patients with TNBC who had surgery between 2006 and 2019 at Dokkyo Medical University Hospital. Intratumoral (i) TILs were considered to be lymphocytes within cancer cell nests and directly infiltrating tumor cells. Similarly, stromal (s) TILs were considered to be lymphocytes within the tumor stroma, but not directly infiltrating tumor cells. CD20 + , CD38 + and CD138 + staining was determined by estimating the number of positive B cells. RESULTS: sCD20 + TILs had prognostic significance for relapse-free survival (RFS) (p = 0.043) and overall survival (OS) (p = 0.027). The sCD38 + TILs were significantly related to favorable RFS (p = 0.042). iCD38, iCD138, and sCD138 was not significantly correlated with RFS (p = 0.065, p = 0.719, p = 0.074) or OS (p = 0.071, p = 0.689, p = 0.082). CONCLUSIONS: The present study demonstrated that a high density of sCD20 + TILs was significantly related to favorable prognosis in both RFS and OS. Increased sCD38 + TILs in TNBC were correlated with a significantly favorable prognosis in RFS. These results indicate that TILs-B may have a profound influence on the clinical outcome of TNBC.

ER staining levels affect HER2 staining and heterogeneity.

PURPOSE: This study explored the relationship of ER expression levels with HER2 staining properties and heterogeneity and discussed the differences in HER2 assessment caused by the 2018 ASCO/CAP guideline updates from that of the 2013 version. METHODS: HER2-positive breast cancer was divided into three groups of the high hormone receptor expression (LH-high) group, low expression (LH-low) group, or negative (NLH) group to (1) compare differences in the percentage of the HER2 IHC test score of 2 + based on the 2013 ASCO/CAP guideline and in the intratumor heterogeneity of HER2 expression for breast cancer with an IHC score of 3 + among these groups, (2) compare the HER2/CEP17 ratio and the average HER2 copy number, and classified ISH groupings according to the 2018 ASCO/CAP guideline algorithm. RESULTS: (1) Of 244 HER2-positive breast cancers, the cases with a HER2 IHC score of 2 + (n = 54, 22.1%) were significantly more common in the LH-high group (n = 45, P < 0.001). The frequency of heterogeneity was low (n = 25, 10.2%) for the HER2 score of 3 + (n = 190, 77.9%), and significantly higher in the LH-high group (n = 19, 76%, P = 0.002). (2) In a HER2 IHC score of 2 + , Group 2 which is deemed HER2 negative according to the revised 2018 ASCO/CAP guideline was observed in 17 (39.5%) out of 43 cases, of which 16 cases (94.1%) were in the LH-high group. CONCLUSIONS: The LH-high group is a heterogeneous group largely consisting of heterogeneous cases with HER2 IHC scores of 2 + or 3 + . NLH, in contrast, is a homogenous group.

Relationship between MRI findings and invasive breast cancer with podoplanin-positive cancer-associated fibroblasts.

OBJECTIVE: Purpose of our study is to assess the relationship between MRI findings and invasive breast cancer (IBC) with cancer-associated fibroblasts (CAFs) that are positive for podoplanin. METHODS: We retrospectively analyzed the consecutive 109 IBCs. The IBCs were dichotomized as with (+) or without (-) podoplanin-positive CAFs. In MRI analyses, the dichotomized IBCs were compared the lesion to muscle ratio (L/M ratio) in STIR images, the ADC value, the distribution of kinetic parameters, and morphological findings. RESULTS: Of the 109 IBCs, 28 (26%) IBCs had podoplanin(+) CAFs. Compared to the podoplanin(-) group, the podoplanin(+) group tended to have a more malignant pathological status. In the STIR images, the podoplanin(+) group had significantly higher L/M ratio (7.59 vs. 6.55, p = 0.040). In a dynamic study, the podoplanin(+) group had a significantly higher percentage of the washout pattern (42.21% vs. 29.43%, p = 0.045). There were 23 mass lesions and 5 non-mass enhancement (NME) lesions in the podoplanin(+) group, and 69 mass lesions and 12 NME lesions in the podoplanin(-) group. The mass lesions of the podoplanin(-) group had a significantly higher likelihood of showing an irregular shape (n = 47 vs. 8, p = 0.035). The podoplanin(+) group's lesions had a significantly higher likelihood of showing a circumscribed margin (n = 14 vs. 6, p < 0.001) and a rim enhancement (n = 10 vs. 13, p = 0.047). In multivariate analyses, only high nuclear grade was significant predictive value of podoplanin(+) CAFs. CONCLUSION: Although not significant in multivariate analyses, MRI findings may be used to determine the podoplanin-positive CAF status of invasive breast cancer.

A case of acute diffuse large B cell lymphoma in an anti-human T-cell leukaemia virus type 1-positive rheumatoid arthritis patient treated with methotrexate, who died.

A 70-year-old woman was hospitalised due to jaundice and fever. She was diagnosed with rheumatoid arthritis (RA) at 54 years of age. Treatment with methotrexate (MTX) was successful, and her RA was in remission. Five weeks before the hospitalisation, she was diagnosed with optic neuritis due to a decline in the visual acuity of the right eye. She was treated with methylprednisolone pulse therapy, followed by prednisolone (PSL), before the hospitalisation, which were not effective. Blood tests showed increased C-reactive protein (CRP) levels, liver injury, and thrombocytopenia. Abdominal echo revealed numerous enlarged lymph nodes in the hepatic portal region. Malignant lymphoma was suspected due to high serum levels of soluble interleukin-2 receptor. None of the treatments were effective, and she died on the fifth hospital day. Diffuse large B cell lymphoma was diagnosed during the autopsy, which showed infiltration of CD20-positive atypical lymphocytes in almost all organs. Since she was taking MTX, she was diagnosed with immunosuppressive drug-associated lymphoproliferative disease (LPD). Anti-human T-cell leukaemia virus type 1 (HTLV-1) antibody was detected in her serum after her death; however, adult T cell leukaemia/lymphoma was not observed. LPD develops during the treatment of RA with disease modifying anti-rheumatic drugs; however, a rapid clinical course leading to death is rarely observed. Previous reports suggest that T cell dysregulation observed in HTLV-1 may contribute towards the development of B cell lymphoma. We have discussed the possible roles of HTLV-1 in LPD development in this case.

Metaplastic breast cancers frequently express immune checkpoint markers FOXP3 and PD-L1.

BACKGROUND: Metaplastic breast carcinoma encompasses a heterogeneous group of tumours with differentiation into squamous and/or spindle, chondroid, osseous or rhabdoid mesenchymal-looking elements. Emerging immunotherapies targeting Programmed Death Ligand 1 (PD-L1) and immune-suppressing T cells (Tregs) may benefit metaplastic breast cancer patients, which are typically chemo-resistant and do not express hormone therapy targets. METHODS: We evaluated the immunohistochemical expression of PD-L1 and FOXP3, and the extent of tumour infiltrating lymphocytes (TILs) in a large cohort of metaplastic breast cancers, with survival data. RESULTS: Metaplastic breast cancers were significantly enriched for PD-L1 positive tumour cells, compared to triple-negative ductal breast cancers (P < 0.0001), while there was no significant difference in PD-L1 positive TILs. Metaplastic breast cancers were also significantly enriched for TILs expressing FOXP3, with FOXP3 positive intra-tumoural TILs (iTILs) associated with an adverse prognostic outcome (P = 0.0226). Multivariate analysis identified FOXP3 iTILs expression status as an important independent prognostic factor for patient survival. CONCLUSIONS: Our findings indicate the clinical significance and prognostic value of FOXP3, PD-1/PD-L1 checkpoint and TILs in metaplastic breast cancer and confirm that a subset of metaplastics may benefit from immune-based therapies.

Androgen receptor expression is useful to predict the therapeutic effect in HER2-positive breast carcinoma.

PURPOSE: Although HER2-positive (HER2+) invasive breast carcinomas (BC) have a different clinical therapeutic responsiveness according to estrogen and progesterone receptor expression, the relationship with androgen receptors (AR), which are the same family of steroid hormones, is poorly understood. We investigated the relationship between AR expression in HER2 BCs and therapeutic responsiveness and prognosis in this study. METHODS: We evaluated patients with HER2 (H) + invasive BC undergoing surgery after neoadjuvant chemotherapy (± HER2-targeted therapies) from 2007-2017, classified as hormone receptor-positive (Allred score: 2-8) (luminal B: LH) and receptor-negative groups (Allred: score 0) (non-luminal: NLH). AR expression was assessed by immunostaining pre-neoadjuvant chemotherapy biopsy specimens, positive with Allred score ≥ 4. The pathological complete response, disease-free survival, and overall survival rates were compared between AR-positive and AR-negative groups. RESULTS: We classified 82 patients with HER2 + invasive BC into LH (n = 45, 54.9%) and NLH groups (n = 37, 45.1%), and AR + was observed in 43 patients (52.4%) (LH: 23, 51.1%; NLH: 20, 54.1%; p = 0.79). Quasi-pathological complete response was observed in 40 patients (48.8%) (LH: 18, 40%; NLH: 22, 59.5%; p = 0.08) overall, and in 31 AR + patients (72.1%) (LH: 15, 34.9%; NLH: 16, 37.2%), significantly higher than in the AR - group for both subgroups (p < 0.001). Regarding prognosis, disease-free survival was relatively better in the AR + group in all HER2 + BCs (p = 0.085), and overall survival was significantly better in the AR + group for NLH (p = 0.029). CONCLUSIONS: High AR expression may be a useful predictor of therapeutic effects and prognosis in both subgroups of HER2 + BCs.