Integrative spatial omics reveals distinct tumor-promoting multicellular niches and immunosuppressive mechanisms in African American and European American patients with TNBC.

Racial disparities in triple-negative breast cancer (TNBC) outcomes have been reported. However, the biological mechanisms underlying these disparities remain unclear. We integrated imaging mass cytometry and spatial transcriptomics, to characterize the tumor microenvironment (TME) of African American (AA) and European American (EA) patients with TNBC. The TME in AA patients was characterized by interactions between endothelial cells, macrophages, and mesenchymal-like cells, which were associated with poor patient survival. In contrast, the EA TNBC-associated niche is enriched in T-cells and neutrophils suggestive of an exhaustion and suppression of otherwise active T cell responses. Ligand-receptor and pathway analyses of race-associated niches found AA TNBC to be immune cold and hence immunotherapy resistant tumors, and EA TNBC as inflamed tumors that evolved a distinctive immunosuppressive mechanism. Our study revealed the presence of racially distinct tumor-promoting and immunosuppressive microenvironments in AA and EA patients with TNBC, which may explain the poor clinical outcomes.

Improved Pathologic response to chemoradiation in MGMT methylated locally advanced rectal cancer.

Background and Purpose: With the growing interest in total neoadjuvant treatment for locally advanced rectal adenocarcinoma (LARC) there is an urgent unmet need to identify predictive markers of response to long-course neoadjuvant concurrent chemoradiotherapy (LCRT). O6-Methylguanine (O6-MG)-DNA-methyltransferase (MGMT) gene methylation has been associated in some malignancies with response to concurrent chemoradiotherapy. We attempted to find if pathologic response to LCRT was associated with MGMT promoter hypermethylation (MGMTh). Materials and Methods: Patients were identified with LARC, available pre-treatment biopsy specimens, and at least 1 year of follow-up who received LCRT followed by surgical resection within 6 months. Biopsies were tested for MGMTh using a Qiagen pyrosequencing kit (Catalog number 970061). The primary outcome of LCRT responsiveness was based on tumor regression grade (TRG), with grades of 0-1 considered to have excellent response and grades of 2-3 considered to be non-responders. Secondary outcomes included overall survival (OS) and recurrence free survival (RFS). Results: Of 96 patients who met inclusion criteria, 76 had samples which produced reliable assay results. MGMTh corresponded with higher grade and age of the biopsy specimen. The percentage of responders to LCRT was higher amongst the MGMTh patients than the MGMTn patients (60.0% vs 27.5%, p value = 0.0061). MGMTh was not significantly associated with improved OS (2-year OS of 96.0% vs 98.0%, p = 0.8102) but there was a trend for improved RFS (2-year RFS of 87.6% vs 74.2%, p = 0.0903). Conclusion: Significantly greater tumor regression following LCRT was seen in MGMTh LARC. Methylation status may help identify good candidates for close observation without surgery following LCRT.

Campylobacter coli bacteremia associated with diarrhea.

Campylobacter coli (C. coli) is a gram negative, non-spore forming, mobile, curved, or spiral-shaped rod organisms and one of the most common gastrointestinal human pathogens. Campylobacter very rarely causes bacteremia. However, there are reports of bloodstream infection of C. coli and most of the Campylobacterbacteremia have been found among immunocompromised patients. In this study, a case of C. coli blood stream infection that was associated with diarrhea in an immunocompetent patient.

Heterotopic Hepatic Tissue in the Placenta: A Case Report.

Heterotopic hepatic tissue in placenta or umbilical cord is rare. The exact mechanism by which this heterotopia occurs has not been fully understood but is thought to be related to yolk sac primordia. To date, a handful of such cases have been reported. We present a case of heterotopic liver tissue within a chorionic stem villus of a 37 week-growth restricted neonate and describe the tissue morphology and its immunohistochemistry workup.

Melanoma in the Breast: A Diagnostic Challenge.

Although rare, breast metastases can mimic primary tumors, both clinically, radiologically, and histopathologically. Melanoma is a highly metastasizing tumor, and it is known as a great mimicker of tumors. Metastatic melanoma in the breast can mimic primary breast cancer and pose a diagnostic challenge. In most cases, it is associated with disseminated disease and a poor prognosis, therefore, histologic, immunohistochemical and clinical correlation is crucial in diagnosing these cases. In this case report, we discuss a 63-year-old female who presented with clinical features of probable breast cancer, describe immunohistochemistry workup, and discuss pitfalls in interpretation.

Solitary Fibrous Tumor of Hard Palate: A Case Report and Literature Review.

Solitary fibrous tumor (SFT) is a mesenchymal tumor accounting for less than 2% of soft tissue tumors and has variable clinical behavior. It can arise in many anatomical locations of the body and in rare occasions in the oral cavity mostly in buccal mucosa and tongue. To date, a handful of such cases have been reported in the hard palate. We present a case of SFT in the hard palate of a 32-year-old man and describe the tissue morphology, immunohistochemistry workup, and follow-up together with literature review.