Molecular analyses of triple-negative breast cancer in the young and elderly.

BACKGROUND: Breast cancer in young adults has been implicated with a worse outcome. Analyses of genomic traits associated with age have been heterogenous, likely because of an incomplete accounting for underlying molecular subtypes. We aimed to resolve whether triple-negative breast cancer (TNBC) in younger versus older patients represent similar or different molecular diseases in the context of genetic and transcriptional subtypes and immune cell infiltration. PATIENTS AND METHODS: In total, 237 patients from a reported population-based south Swedish TNBC cohort profiled by RNA sequencing and whole-genome sequencing (WGS) were included. Patients were binned in 10-year intervals. Complimentary PD-L1 and CD20 immunohistochemistry and estimation of tumor-infiltrating lymphocytes (TILs) were performed. Cases were analyzed for differences in patient outcome, genomic, transcriptional, and immune landscape features versus age at diagnosis. Additionally, 560 public WGS breast cancer profiles were used for validation. RESULTS: Median age at diagnosis was 62 years (range 26-91). Age was not associated with invasive disease-free survival or overall survival after adjuvant chemotherapy. Among the BRCA1-deficient cases (82/237), 90% were diagnosed before the age of 70 and were predominantly of the basal-like subtype. In the full TNBC cohort, reported associations of patient age with changes in Ki67 expression, PIK3CA mutations, and a luminal androgen receptor subtype were confirmed. Within DNA repair deficiency or gene expression defined molecular subgroups, age-related alterations in, e.g., overall gene expression, immune cell marker gene expression, genetic mutational and rearrangement signatures, amount of copy number alterations, and tumor mutational burden did, however, not appear distinct. Similar non-significant associations for genetic alterations with age were obtained for other breast cancer subgroups in public WGS data. Consistent with age-related immunosenescence, TIL counts decreased linearly with patient age across different genetic TNBC subtypes. CONCLUSIONS: Age-related alterations in TNBC, as well as breast cancer in general, need to be viewed in the context of underlying genomic phenotypes. Based on this notion, age at diagnosis alone does not appear to provide an additional layer of biological complexity above that of proposed genetic and transcriptional phenotypes of TNBC. Consequently, treatment decisions should be less influenced by age and more driven by tumor biology.

The relationship between diverticula and low-grade mucinous neoplasm of the appendix. Does the diverticulum play a role in the development of periappendicular mucin deposition or pseudomyxoma peritonei?

Prevalences of diverticulum and low-grade mucinous neoplasm (LGMN) were reported as 0.04-2% and less than 1% in the appendix. In this study, the frequency of diverticulum in LGMN cases, the relationship between diverticula and periappendicular mucin, and the possible role of diverticula in pseudomyxoma peritonei pathogenesis were researched. Through systematic review and targeted search, 38 LGMN and 96 diverticula were identified, frequencies and relationship between diverticulum and LGMN were analysed. Diverticulum and LGMN were determined in 4.8% and 1.04%, respectively, of 1922 appendectomy materials specifically grossed by the same pathologist. The prevalence of diverticulum was higher in our study than literature. The difference may be due to detailed macroscopic examination. Diverticulum was detected in 60% of LGMN cases. The rate of diverticulum was found to be significantly higher in LGMNs than non-neoplastic diverticulum (p < 0.001). Periappendicular mucin deposition was significantly more frequent in LGMN cases with diverticulum than in other groups (p < 0.05). Follow-ups were available in 18 patients; none of them had mucin deposition in the peritoneal cavity. We detected that periappendicular mucin was highly associated with diverticula in LGMN cases. Periappendicular acellular mucin deposition may not give rise to pseudomyxoma peritonei. We may think that mucin could move out of the appendix through the diverticulum rather than neoplastic spread in some of these cases.

Comparing deep learning and pathologist quantification of cell-level PD-L1 expression in non-small cell lung cancer whole-slide images.

Programmed death-ligand 1 (PD-L1) expression is currently used in the clinic to assess eligibility for immune-checkpoint inhibitors via the tumor proportion score (TPS), but its efficacy is limited by high interobserver variability. Multiple papers have presented systems for the automatic quantification of TPS, but none report on the task of determining cell-level PD-L1 expression and often reserve their evaluation to a single PD-L1 monoclonal antibody or clinical center. In this paper, we report on a deep learning algorithm for detecting PD-L1 negative and positive tumor cells at a cellular level and evaluate it on a cell-level reference standard established by six readers on a multi-centric, multi PD-L1 assay dataset. This reference standard also provides for the first time a benchmark for computer vision algorithms. In addition, in line with other papers, we also evaluate our algorithm at slide-level by measuring the agreement between the algorithm and six pathologists on TPS quantification. We find a moderately low interobserver agreement at cell-level level (mean reader-reader F1 score = 0.68) which our algorithm sits slightly under (mean reader-AI F1 score = 0.55), especially for cases from the clinical center not included in the training set. Despite this, we find good AI-pathologist agreement on quantifying TPS compared to the interobserver agreement (mean reader-reader Cohen's kappa = 0.54, 95% CI 0.26-0.81, mean reader-AI kappa = 0.49, 95% CI 0.27-0.72). In conclusion, our deep learning algorithm demonstrates promise in detecting PD-L1 expression at a cellular level and exhibits favorable agreement with pathologists in quantifying the tumor proportion score (TPS). We publicly release our models for use via the Grand-Challenge platform.

Survival Outcomes, Digital TILs, and On-treatment PET/CT During Neoadjuvant Therapy for HER2-positive Breast Cancer: Results from the Randomized PREDIX HER2 Trial.

PURPOSE: PREDIX HER2 is a randomized Phase II trial that compared neoadjuvant docetaxel, trastuzumab, and pertuzumab (THP) with trastuzumab emtansine (T-DM1) for HER2-positive breast cancer. Rates of pathologic complete response (pCR) did not differ between the two groups. Here, we present the survival outcomes from PREDIX HER2 and investigate metabolic response and tumor-infiltrating lymphocytes (TIL) as prognostic factors. PATIENTS AND METHODS: In total, 202 patients with HER2-positive breast cancer were enrolled and 197 patients received six cycles of either THP or T-DM1. Secondary endpoints included event-free survival (EFS), recurrence-free survival (RFS), and overall survival (OS). Assessment with PET/CT was performed at baseline, after two and six treatment cycles. TILs were assessed manually at baseline biopsies, while image-based evaluation of TILs [digital TILs (DTIL)] was performed in digitized full-face sections. RESULTS: After a median follow-up of 5.21 years, there was no difference between the two treatment groups in terms of EFS [HR = 1.26; 95% confidence interval (CI), 0.54-2.91], RFS (HR = 0.69; 95% CI, 0.24-1.93), or OS (HR = 0.52; 95% CI, 0.09-2.82). Higher SUVmax at cycle 2 (C2) predicted lower pCR (ORadj = 0.65; 95% CI, 0.48-0.87; P = 0.005) and worse EFS (HRadj = 1.27; 95% CI, 1.12-1.41; P < 0.001). Baseline TILs and DTILs provided additional prognostic information to clinical parameters and C2 SUVmax. CONCLUSIONS: Long-term outcomes following neoadjuvant T-DM1 were similar to neoadjuvant THP. SUVmax after two cycles of neoadjuvant therapy for HER2-positive breast cancer may be an independent predictor of both short- and long-term outcomes. Combined assessment with TILs may facilitate early selection of poor responders for alternative treatment strategies.

Independent Clinical Validation of the Automated Ki67 Scoring Guideline from the International Ki67 in Breast Cancer Working Group.

Ki67 is an important biomarker with prognostic and potential predictive value in breast cancer. However, the lack of standardization hinders its clinical applicability. In this study, we aimed to investigate the reproducibility among pathologists following the guidelines of the International Ki67 in Breast Cancer Working Group (IKWG) for Ki67 scoring and to evaluate the prognostic potential of this platform in an independent cohort. Four algorithms were independently built by four pathologists based on our study cohort using an open-source digital image analysis (DIA) platform (QuPath) following the detailed guideline of the IKWG. The algorithms were applied on an ER+ breast cancer study cohort of 157 patients with 15 years of follow-up. The reference Ki67 score was obtained by a DIA algorithm trained on a subset of the study cohort. Intraclass correlation coefficient (ICC) was used to measure reproducibility. High interobserver reliability was reached with an ICC of 0.938 (CI: 0.920-0.952) among the algorithms and the reference standard. Comparing each machine-read score against relapse-free survival, the hazard ratios were similar (2.593-4.165) and showed independent prognostic potential (p ≤ 0.018, for all comparisons). In conclusion, we demonstrate high reproducibility and independent prognostic potential using the IKWG DIA instructions to score Ki67 in breast cancer. A prospective study is needed to assess the clinical utility of the IKWG DIA Ki67 instructions.

Interplay between copy number alterations and immune profiles in the early breast cancer Scandinavian Breast Group 2004-1 randomized phase II trial: results from a feasibility study.

Emerging data indicate that genomic alterations can shape immune cell composition in early breast cancer. However, there is a need for complementary imaging and sequencing methods for the quantitative assessment of combined somatic copy number alteration (SCNA) and immune profiling in pathological samples. Here, we tested the feasibility of three approaches-CUTseq, for high-throughput low-input SCNA profiling, multiplexed fluorescent immunohistochemistry (mfIHC) and digital-image analysis (DIA) for quantitative immuno-profiling- in archival formalin-fixed paraffin-embedded (FFPE) tissue samples from patients enrolled in the randomized SBG-2004-1 phase II trial. CUTseq was able to reproducibly identify amplification and deletion events with a resolution of 100 kb using only 6 ng of DNA extracted from FFPE tissue and pooling together 77 samples into the same sequencing library. In the same samples, mfIHC revealed that CD4 + T-cells and CD68 + macrophages were the most abundant immune cells and they mostly expressed PD-L1 and PD-1. Combined analysis showed that the SCNA burden was inversely associated with lymphocytic infiltration. Our results set the basis for further applications of CUTseq, mfIHC and DIA to larger cohorts of early breast cancer patients.

Diagnostic Value of Glucose Transporter 1 (GLUT-1) Expression in Nested Variant of Urothelial Carcinoma.

OBJECTIVE: Nested variant is bland-looking but aggressive subtype of urothelial carcinoma (UC). Cases having significant muscle invasion do not cause problems but small and superficial biopsies may be challenging due to morphological similarities between nested variant urothelial carcinoma and benign urothelial lesions. MATERIAL AND METHOD: We studied Glucose transporter 1 (GLUT-1), which is an integral membrane protein providing glucose pass through plasma membrane down its concentration gradient, to see if it is useful for the differential diagnosis. Twenty five cases of nested variant urothelial carcinoma and a control group consisting of 12 cases of cystitis glandularis, cystitis cystica and 4 cases of inverted papilloma were stained with GLUT-1 immunohistochemically. Membranous staining was scored on a scale of 0 to +3. RESULTS: Eleven of 25 nested variant UC cases showed a score of 2 and 14 of them showed a score of 3 on immunostaining with GLUT-1. Two cases showed a score of 1 and 10 cases did not show any staining in the control group. CONCLUSION: Our results showed that GLUT-1 may be a helpful marker when morphological separation cannot be made between nested variant UC and benign urothelial leisons. We also think that anti-GLUT-1 antibody treatment may be an option in the targeted treatment of nested variant.

Pseudoangiomatous Stromal Hyperplasia in Core Needle Biopsies of Breast Specimens.

BACKGROUND: Pseudoangiomatous stromal hyperplasia (PASH) is a benign lesion of myofibroblasts that is composed of a network of slit-like channels that resemble vascular spaces. The aims of this study were to document the frequency of PASH in core needle biopsy specimens (CNBS) of the breast, to describe which histopathologic findings coexist with PASH and to examine any endothelial cell differentiation. MATERIALS AND METHODS: We reevaluated hematoxylin and eosin-stained sections of all CNBS that were obtained during a 1-year period. First, we performed CD34 and CD31 immunostainings to highlight the areas of PASH, then performed D2-40/podoplanin (lymphatic endothelial marker) and Fli-1 (vascular endothelial cell marker) immunostains. RESULTS: The total number of CNBS was 412. Areas of PASH were noted in 37 of the 412 cases (9%), with a mean age of 38.5 years. The lesions that were described in association with PASH were "benign breast parenchyma with stromal fibrosis" (17/37; 46%), "fibroepithelial tumors" (17/37; 46%), "columnar cell changes (CCC)" (2/37; 5%), and "invasive carcinoma" (1/37; 3%). There were 2 cases of CCC within the foci of PASH (direct contact with PASH), and 8 additional cases of CCC that coexisted in the same specimen but were not in direct contact. There was no staining for D2-40 or Fli-1 within PASH foci. CONCLUSION: PASH lesions occurred with a frequency of 9% in CNBS and were mostly in association with benign breast lesions in premenopausal women. CCC was determined as an accompanying epithelial lesion within or near PASH areas. No obvious immunopositivity compatible with endothelial cell differentiation was revealed.

Malignant Phyllodes Tumor Including Aneurysmal Bone Cyst-Like Areas in Pregnancy - a Case Report and Review of the Literature.

BACKGROUND: Malignant phyllodes tumors of the breast are rare biphasic neoplasms. Only few cases related to pregnancy have been reported. CASE REPORT: A 37-year-old woman presented with swelling and pain in her left breast as well as hyperemia on the breast skin, 4 weeks after labor. In her family history, her aunt and maternal cousin had had a breast cancer diagnosis. Clinical evaluation of the patient was consistent with a breast abscess. Therefore, abscess drainage and biopsy from the cavity wall were performed. However, the biopsy was diagnosed as malignant phyllodes tumor. An evaluation by ultrasonography showed a well-defined hypoechoic mass with many cystic spaces covering the entire breast tissue. Therefore, a simple mastectomy was performed. Microscopic examination revealed a high-grade malignant phyllodes tumor. Additionally, bone cyst-like areas in the form of sponge-like blood-filled non-endothelialized spaces were observed. CONCLUSIONS: Since the breasts become larger due to the physiological changes during pregnancy, any underlying breast lesions may be obscured. Therefore, clinical breast examination in the first visit of pregnancy is important.

Benign mixed tumour of the breast and breast skin, two cases with diagnostic difficulties.

We present two cases of pleomorphic adenoma, one that developed in the breast parenchyma and the other in the breast skin, with their histopathological differential diagnosis.

Nodule-Forming Pseudoangiomatous Stromal Hyperplasia of the Breast: Report of Three Cases.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign proliferative entity of mammary stroma. It is generally found as an incidental finding. It may rarely present as a palpable nodule. Three patients, who were 29, 45, and 58 years of age, were referred to our clinic with nodule and pain in the breast. The physical examinations and ultrasound findings of all three patients were consistent with fibroadenoma. Core biopsies were performed and reported as "benign breast parenchyma including stromal fibrosis." PASH areas were noted in one case. The excision specimens were observed as solid nodular masses with smooth external surfaces and white in colour. Microscopically, well-demarcated hyalinized stroma, including slit-like pseudovascular spaces lined by bland spindle cells, was observed. Immunohistochemically, these cells showed positive staining for CD34 and negative staining for CD31. Nodule-forming PASH mostly confuses with fibroadenoma with respect to clinical examination and radiological findings. Definite diagnosis requires histopathological verification. Differential diagnosis should be made with low grade angiosarcoma, fibroepithelial tumors, and myofibroblastoma.

Matrix-Producing Carcinoma of the Breast: Case Report.

Matrix-producing carcinoma (MPC) is an uncommon variant of metaplastic carcinoma. It was first described by Wargotz and Norris in 1989 as invasive breast carcinoma with direct transition to cartilaginous stroma without intervening spindle cell component. Since then, several studies, mostly in the form of case reports or case series, have been reported and the origin of tumor cell, importance of appropriate terminology for the tumor, histopathological differential diagnosis, benign breast lesions that the tumor could correlate with, and prognosis and consequently the treatment modalities have been discussed. A 43-year-old woman referred to our clinic with a lump in her left breast. Physical examination and radiological findings were consistent with malignancy. Core biopsy of the lesion was reported as "invasive breast carcinoma" and then breast-conserving surgery with sentinel lymph node dissection were performed. The case was diagnosed as MPC of the breast. The literature findings imply epithelial cell (ductal and/or myoepithelial) nature of this tumor. The prognosis is still controversial. Histopathological evaluation of sufficiently sampled surgical excision material is important to recognize and make a correct diagnosis.

Mucinous urothelial carcinoma of the renal pelvis.

Urothelial carcinoma with abundant myxoid stroma is a newly-described and extremely rare entity. Since only very few cases have been reported, there is no consensus on its nomenclature. Microscopic examination revealed invasive urothelial carcinoma with widespread low-grade noninvasive areas. There were focal invasive areas in the neighborhood of the renal parenchyma. Malignant urothelial tumor/cell groups localized in the stroma had abundant myxoid/mucinous background in the invasive areas. The cytoplasm of the tumoral cells was more eosinophilic in these areas and the cells formed small groups and cords. Histochemically, PAS and Alcian Blue were positive in the cytoplasm of the tumoral cells and in the stroma while negative in the non-mucinous areas. Immunohistochemically, the tumoral cells of the mucinous invasive areas diffusely expressed MUC1 and MUC2. We discuss the origin of the mucinous/myxoid stroma, the tumor's nature and its nomenclature with histochemical and immunohistochemical features.