Laboratory Investigation最新文献

p53 Immunohistochemistry (IHC) is a reliable surrogate for determining TP53 mutation status in endometrial carcinomas (ECs). However, the correlation of p53 IHC patterns and TP53 mutation characteristics in mismatch repair deficiency (MMRd) and/or POLE-mutant ECs was not comprehensively investigated. In this study, we identified 4 p53 expression patterns in 40 MMRd and/or POLE-mutant ECs with TP53 mutations. Thirteen cases (33%) displayed a wild-type pattern. Nine cases (23%) showed atypical pattern, characterized by the presence of eye-catching clustered cells with strong nuclear staining or weak-to-moderate cytoplasmic staining, which were patchily distributed with blurred boundaries. Fourteen cases (35%) demonstrated subclonal pattern with distinct regions of wild-type and mutation-type staining, of which 3 cases were originally misdiagnosed as "mixed EC." Only 4 (10%) cases exhibited typical aberrant pattern. Tumors with wild-type and atypical patterns were predominantly associated with MMRd and POLE mutations, respectively. Among 52 TP53 mutations identified, 75% were missense and 25% were truncating, predominantly in DNA-binding domain. Gain-of-function missense mutations were more frequent in cases with subclonal patterns, whereas non-gain-of-function missense mutations predominated in wild-type or atypical patterns. Concurrent mutations were present in 25% of cases and were more common in aberrant or atypical patterns. Interestingly, 2 POLE wild-type cases with subclonal MMR expression showed p53 overexpression across the entire tumor, complicating molecular subtyping. These findings highlight the prevalence of atypical and subclonal p53 expression patterns in MMRd and/or POLE-mutant ECs with TP53 mutations, aiding in accurate IHC interpretation and thus more precise EC histological and molecular classification.

High immune cell infiltration is generally associated with better survival in colorectal cancer (CRC). Recently, a prognostic score called CD8^IE-FOXP3^IS, which integrates the densities of tumor intraepithelial CD8⁺ and intrastromal FOXP3⁺ cells, was introduced using multiplex immunofluorescence. In this study, we developed a triple chromogenic immunohistochemistry assay to evaluate the CD8^IE-FOXP3^IS score and assessed its prognostic value in comparison with the CD3-CD8 T-cell density score (based on the principles of the Immunoscore) and conventional prognostic parameters. Multiplex immunohistochemistry combined with machine learning-assisted image analysis was used to quantify CD8^IE and FOXP3^IS densities in 2 independent cohorts comprising 1724 CRC patients. Multivariable Cox regression models were used to evaluate the prognostic value of the CD8^IE-FOXP3^IS score. We found that a low CD8^IE-FOXP3^IS score was associated with higher disease stage, more frequent lymphovascular invasion, and mismatch repair proficient status. In addition, a low CD8^IE-FOXP3^IS score was associated with higher CRC-specific mortality independent of the CD3-CD8 T-cell density score and other tumor and patient characteristics (cohort 1: hazard ratio [HR] for low vs high CD8^IE-FOXP3^IS score, 3.08; 95% CI, 1.54-6.15; P_trend = 6.0E-4; cohort 2: HR, 4.30; 95% CI, 2.58-7.17; P_trend = 3.2E-9). These findings indicate that triple chromogenic immunohistochemistry combined with digital pathology is an applicable method for quantifying tumor intraepithelial CD8⁺ and stromal FOXP3⁺ cell densities, allowing for the determination of the CD8^IE-FOXP3^IS score. The CD8^IE-FOXP3^IS score shows a strong prognostic value, which appears superior to overall CD3⁺ and CD8⁺ T-cell density measurement.