Faculty Bibliography

BACKGROUND:Colorectal carcinomas are one of the most commonly diagnosed malignancies. There are many prognostic factors relating to clinical course and disease progression, including tumor stage, metastasis, and tumor budding. In 2016, the International Tumor Budding Consensus Conference (ITBCC) created a system to uniformly assess tumor budding. This system includes a 3-tier system for the grading of tumor budding. In the past, there lacked uniform consensus, however the general grading practice was based on a 2-tiered system. Given that tumor budding is considered to have prognostic value, the accuracy and reproducibility of its assessment is vital. Our study aims to look at interobserver agreement in the scoring of tumor budding. DESIGN/METHODS:A total of 233 cases of colorectal carcinoma diagnosed in our health system were retrospectively analyzed and routine H&E stained slides of these cases were collected. A representative slide for tumor budding was selected per case. Four investigators with different levels of experience and expertise evaluated the selected slide of each case for tumor budding. Scoring was based on the ITBCC protocol. Clinico-pathological data was collected for each case and analyzed with tumor budding scores. Tumor budding scores per individual investigator and consensus tumor budding score were compared to patient and tumor characteristics including patient survival, tumor grade, tumor stage, and lymph node status. RESULTS:) and associated 95% confidence intervals was used to compare the ratings made by 4 pathologists. Overall, there was variation among pathologists in tumor budding score (Gwet's agreement coefficient = 0.25 and 0.326 for 3-tier and 2-tier grading system, respectively). Results show higher reliability with the 2-tier system compared to the 3-tier system. Tumor stage was significantly associated with budding score for all individual investigators and the consensus value (p value < 0.001). CONCLUSION/CONCLUSIONS:There is low inter-observer agreement in the assessment of tumor budding in colorectal carcinoma. This suggests that it is difficult to uniformly grade tumor budding and that our classification system needs improvement. We found that the older 2-tier system (Hase et al.) results in slightly higher inter-observer agreement than the recently proposed 3-tier grading system (ITBCC, 2016), though both systems lead to suboptimal agreement. Worth noting is that observers with subspecialty GI training and more work experience had higher inter-observer agreement. Our results showed that subspecialty training tends to increase agreement more than overall work experience. In addition, our exploratory results showed that there is an association of tumor budding score to tumor stage. While increasing refinement in classification, the 3-tiered system resulted in decreased agreement in tumor budding assessment. Clearly, there is more work to be done in the identification and quantification of tumor buds.

BACKGROUND:Uterine undifferentiated (UEAC)/dedifferentiated (DEAC) carcinomas are rare malignant neoplasms. They appear to pursue an aggressive clinical course with an advanced stage at presentation. Recently, it was discovered that the use of immunotherapeutic drugs targeting programmed cell death protein 1 (PD1)/programmed death ligand-1 (PD-L1) was associated with improved survival in several types of cancer (especially in patients with mismatch-repair (MMR) deficient patients). Whether these findings can be applied to UEAC/DEAC remains a question. Herein, the aim of this study is to evaluate the expression of PD-L1/PD-1 in UEAC/DEAC and its relationship to MMR status. This could offer useful therapeutic information. DESIGN/METHODS:Review of endometrial carcinoma (EC) diagnosed over the period of 2011 to 2017 in our institution identified 14 UEAC/DEAC cases (n=14). All cases had immunohistochemistry performed for MMR (MLH1, PMS2, MSH2 and MSH6), PD-L1 and PD-1. The protein expression was examined and in DEAC cases both the undifferentiated component and the low grade component were recorded separately. The expression of PD-L1 and PD-1 was scored in both the tumor and the peritumoral lymphocyte infiltration. RESULTS:Overall variable degrees of tumoral or immune stromal PD-L1 staining (from 1% to 5%), was present in 50.0% (7/14) of UC/DEACs. Seven cases (50%) were PD-1 positive (immune stromal). Five cases (35.7%) showed co-expression of PD-1 and PD-L1 (Figure 1). Worth noting is that PD-1 staining was exclusively present in peritumoral immune cells. Following this the 14 cases were further divided into MMR deficient and MMR proficient groups (Table 1). A total of 8 cases had MMR deficiency (57.1%). There was a statistically significant association for PD-L1 positivity in the MMR deficiency group (p=0.05). However there was no statistically significant differences regarding PD-1 positivity between MMR groups. CONCLUSIONS:PD-L1 and PD-1 were expressed in majority of MMR-deficient UEAC /DEAC cases. PD-L1 was not expressed in MMR-proficient carcinomas. These findings might help support potential immunotherapy trials in MMR-deficient UEAC /DEAC.

BACKGROUND:Death domain-associated protein 6 (DAXX) is involved in regulating apoptosis via subcellular localization. The presence of DAXX point mutations correlates well with loss of nuclear expression on immunohistochemistry (IHC). In this study, we sought to determine (1) whether DAXX expression pattern is the same across different uterine carcinoma subtypes, and (2) which uterine carcinomas show loss of nuclear DAXX IHC. DESIGN/METHODS:We studied 65 uterine carcinomas of the following histologic types: 30 endometrioid (12 FIGO [The International Federation of Gynecology and Obstetrics] grade 1, 12 FIGO grade 2, and 6 FIGO grade 3), 8 serous, 14 clear cell, and 13 undifferentiated/dedifferentiated type (UEC/DDEC). Nuclear DAXX IHC was assessed in each tumor and was graded semi-quantitatively as follows: 0% to 50%, 50% to 75%, and greater than 75% of lesional cells react. RESULTS: = .0001), where DAXX expression was cytoplasmic. In addition, in the 11 DDEC cases, all the differentiated components showed loss of nuclear DAXX compared with the undifferentiated components which retained nuclear DAXX expression. CONCLUSIONS:We demonstrate that loss of nuclear DAXX is present in low-grade endometrial carcinomas and the differentiated components in UEC/DDEC, but not in high-grade ones, suggesting DAXX's role in tumor progression and its potential as a therapeutic target in high-grade endometrial carcinomas.