BACKGROUND: It is well established that most colorectal carcinomas arise from conventional adenomas through the adenoma-carcinoma sequence (ACS) model. mitogen-activated protein kinases (MAPKs) pathway has been reported as a crucial player in tumorigenesis. The MAPK signaling pathway is activated by different extracellular signals involving the “mitogen-activated/extracellular signal-regulated kinase 1 (MEK1)”, and this induces the expression of genes involved in proliferation and cellular transformation. Diaphanous-related formin-3 (DIAPH3) acts as a potential metastasis regulator through inhibiting the cellular transition to amoeboid behavior in different cancer types. OBJECTIVE: The aim of the study was to investigate the pattern of immunohistochemical expression of MEK1 and DIAPH3 in colorectal adenoma (CRA) and corresponding colorectal carcinoma (CRC) specimens. METHODS: The immunohistochemical expression of DIAPH3 and MEK1 was examined in 43 cases of CRC and their associated adenomas using tissue microarray technique. RESULTS: MEK1 was overexpressed in 23 CRC cases (53.5%) and in 20 CRA cases (46.5%). DIAPH3 was overexpressed in 11 CRA cases (about 29%) which were significantly lower than CRC (22 cases; 58%) (P = 0.011). Both MEK1 and DIAPH3 overexpression were significantly correlated in CRC (P = 0.009) and CRA cases (P = 0.002). Tumors with MEK1 overexpression had a significantly higher tumor grade (P = 0.050) and perineural invasion (P = 0.017). CONCLUSIONS: Both MEK1 and DIAPH3 are overexpressed across colorectal ACS with strong correlation between them. This co- expression suggests a possible synergistic effect of MEK1 and DIAPH-3 in colorectal ACS. Further large-scale studies are required to investigate the potential functional aspects of MEK1 and DIAPH3 in ACS and their involvement in tumor initiation and the metastatic process.

BackgroundThe prevalence of colorectal cancer (CRC) is widespread and associated with significant morbidity and deaths. In CRC, hormone receptors, such as androgen receptors (AR), are pathologically modified. Additional research is required to understand better its function and predictive and therapeutic value in CRC metastatic potential.ObjectiveTo assess the AR status in CRC primary tumors and metastatic lymph nodes.MethodsTissue microarray and immunohistochemical techniques were applied to 75 CRC cases with lymph node (LN) metastases. We correlate the results with all relevant clinicopathological indicators of prognostic relevance.Results and conclusionOut of the 75 cases that were analyzed, 16% of CRC primaries and 12% of LN metastases had nuclear AR that was focally positive. AR expression was significantly correlated with advanced age, conventional non-mucinous histology, lower grade, and arousal on top of adenoma. A deeper invasion was likewise linked to AR expression; however, this association was not statistically significant. AR expression has a positive prognostic influence since the median overall and disease-free survival of cases with positive AR expression in either primary carcinomas or LN metastases were significantly higher than that of cases with negative expression in both primary and LN metastases. We assume that AR expression in CRC has a positive prognostic influence.

BACKGROUND:Investigation of new molecular markers expressed in colorectal carcinoma can help to select patients getting benefits from new target therapeutic modalities. AIM:Investigation of expression of GLUT1 and ASCT2 in colorectal carcinoma. MATERIALS AND METHODS:Sixty three colorectal resection specimens for cases diagnosed with colorectal carcinoma were included in the study. Full sections were examined for histopathological data including tumor type, grade, stage, and lymphovascular invasion were recorded. TMA blocks were constructed and immunostained with polyclonal antibodies for both GLUT1 and ASCT2. RESULTS:GLUT1 was expressed in 82% of cases while ASCT2 was expressed in 76% of cases. Statistically significant correlation was found between both GLUT1 and ASCT2. A statistically significant correlation was found between either marker with both disease stage and lymph node metastases. No significant correlation was found between either GLUT1 or ASCT2 and any of the clinical parameters as well as with disease-free survival. CONCLUSION:GLUT1 and ASCT2 are more prevalent in poorly differentiated and advanced stage colorectal carcinoma. Their expression in high percentage of cases can suggest the possible role of their target therapies in colorectal carcinoma.

Patients with colorectal cancer in different stages show variable outcomes/therapeutic responses due to their distinct tumoral biomarkers and biological features. In this sense, this study aimed to explore the prognostic utility of BRAF, programmed death-1 (PD1), and its ligand (PDL1) protein signatures in colon adenocarcinoma. The selected protein markers were explored in 64 archived primary colon adenocarcinomas in relation to clinicopathological features. BRAF overexpression was found in 39% of the cases and was significantly associated with grade 3, N1, advanced Dukes stage, presence of relapse, and shorter overall survival (OS). PD1 expression in the infiltrating immune cells (IICs) exhibited significant association with T2/T3, N0/M0, early Dukes stage, and absence of relapse. PDL1 expression in IICs is significantly associated with advanced nodal stage/distant metastasis, advanced Dukes stage, and shorter OS. Meanwhile, PDL1 expression in neoplastic cells (NC) was associated with the advanced lymph node/Dukes stage. A positive combined expression pattern of PDL1 in NC/IICs was associated with poor prognostic indices. Tumor PDL1 expression can be an independent predictor of OS and DFS. The multivariate analyses revealed that short OS was independently associated with the RT side location of the tumor, PD1 expression in stromal IICs, and PDL1 expression in NC. In conclusion, overexpression of BRAF in colon adenocarcinoma is considered a poor prognostic pathological marker. In addition, PDL1 expression in NC is considered an independent prognostic factor for DFS/OS. Combined immunohistochemical assessment for BRAF and PD1/PDL1 protein expressions in colon adenocarcinoma might be beneficial for selecting patients for future targeted therapy.

e13053 Background: In patients with metastatic hormonal receptors (HR)-positive, HER2-negative breast cancer, CDK 4/6 inhibitors with hormonal therapy is the current standard first line therapy in patients without visceral crisis. Limited data is available about the outcome of second line therapy after CDK 4/6 inhibitors. In this study, we reported the survival outcome of second line systemic therapy after CDK 4/6 inhibitors in a single institute in Saudi Arabia. Methods: We retrospectively checked patients with metastatic HR-positive, HER2-negative breast cancer who received first line therapy with palbociclib in addition to an aromatase inhibitor in King Abdullah Medical City, Saudi Arabia. Patients who received second line systemic therapy were recruited. Different clinicopathological data were checked in addition to type of second line therapy, dates of starting 1 st and second lines therapy and dates of progression. We check progression-free survival (PFS) with second line therapy in relation to the type of second line therapy, duration of 1 st line therapy and other potential prognostic factors. Results: We recruited 59 eligible patients. Median PFS of the study group was 4 months (95% CI 2.9-5.1). No significant difference in PFS according to type of second line systemic therapy (chemotherapy: 4 months, everolimus with hormonal therapy: 6 months, hormonal monotherapy: 3 months, p=0.17). In addition, there was no significance difference in second line therapy PFS according to duration of 1 st line palbociclib-hormonal therapy (≤ 12 months: 4 months vs. >12 months: 5 months, HR 0.97, 95% CI: 0.55-1.7, p=0.92). Similarly, taking 6 months as a cutoff, no significant difference in PFS (≤ 6 months: 4 months, >6 months: 6 months, HR 0.73, 95% CI: 0.43-1.24, p=0.25). Similarly, no difference in second line PFS according to menopausal status, age at diagnosis (≤ 50 vs >50) or ER-Allred score (≤ 6 vs >6). Conclusions: Outcome of 2 nd line systemic therapy following first line palbociclib with hormonal therapy was poor in the study cohort. No significant difference in PFS according to type of systemic therapy, duration of first line therapy, or other clinicopathological factors.

Background CDK 4/6 inhibitors with hormonal therapy are the standard first-line therapy in metastatic hormonal receptors (HR)-positive and HER2-negative breast cancer. This study aims to assess the impact of neutropenia with 1st cycle, dose reduction, HER2-low status, and other clinicopathological factors on survival outcomes with the first-line palbociclib and hormonal therapy. Patients and Methods. In this retrospective study, we recruited patients with metastatic HR-positive and HER2-negative breast cancer. Neutropenia with 1st cycle, palbociclib dose reduction in addition to different clinicopathological and survival data were checked in patients' medical records. Survival outcomes were compared according to the abovementioned factors. Results We recruited 150 patients who received first-line palbociclib with hormonal therapy. 86% of patients developed 1st cycle neutropenia which was more common in patients with high Ki67. Dose reduction was recorded in 46.7% of patients and it was more common in patients with higher Allred scores (scores 7–8). The median progression-free survival (PFS) of the study group was 22 months. No significant difference was observed in PFS according to the 1st cycle of neutropenia or grade of neutropenia. Similarly, no difference in PFS according to palbociclib dose reduction and HER2 low status was observed. Only the Allred score and having a single site of metastasis had an independent significant relation with PFS. The median overall survival (OS) of the study group was 39 months. No significant difference was observed in OS according to the 1st cycle neutropenia, grade of neutropenia, palbociclib dose reduction, and HER2-low status. Only the Allred score and having a single site of metastasis had an independent significant relation with OS. In addition, no difference was observed in PFS and OS according to ECOG PS (2 vs. 0-1) or menopausal status. Conclusion No significant impact of the 1st cycle neutropenia, dose reduction, having ECOG PS2, menopausal status, or HER2 low status on survival outcome was observed. Survival outcome was significantly better in patients with single metastatic sites and higher ER-Allred scores.

Background: Some epithelial tumors express the carbohydrate antigen 125 (Cancer antigen-125, CA-125) and CA 19-9, especially ovarian and pancreatic tumors. Patients with non-Hodgkin lymphoma (NHL) were reported to have a close association between serum CA-125 levels and adverse prognostic factors with worse survival. We aimed to investigate CA-125 and 19-9 expression in nodal diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS) tissues using immunohistochemistry (IHC) and their relations to clinicopathological manifestations and patients' survival. Methods: 65 cases of DLBCL NOS were examined. A modified mechanical pencil tip was used to construct Manual Tissue Micro-array (TMA) blocks. Immunohistochemical staining for CA-125 and CA 19-9 was performed and scored semi-quantitatively. All relations were analyzed using established statistical methodologies. Results: Aberrant expression of CA 19-9 was detected in 12% of cases without any expression of CA-125. Moreover, 75% of the CA 19-9 positive cases were statistically significantly associated with anemia and performance status 1. Also, 75% of the CA 19-9 positive cases were females. Conclusions: CA 19-9 was aberrantly expressed in 12% of nodal DLBCL NOS cases and significantly related to anaemia and performance status but not to survival. In cases of DLBCL NOS, CA 19-9 expression cannot be considered an independent prognostic factor. CA-125 was not expressed in nodal DLBCL NOS tissues, necessitating re-evaluation studies. Therefore, it is advised to conduct more research to clarify the potential correlation between serum and tissue CA 19-9 levels and other clinic-pathological characteristics of nodal and extranodal DLBCL NOS patients.

Background: Lymphovascular invasion (LVI) is known to be associated with a poor outcome in breast cancer patients. It indicates a highly proliferative cancer. Few studies examined the value of LVI as a predictor for outcome after neoadjuvant chemotherapy (NAC). The aim of this study to look for an association between survival outcomes and clinicopathological features in locally advanced breast cancer patients treated with NAC and to identify the predictors of nodal pathologic complete response (PCR). Methods:This study is a retrospective analysis of 224 women with locally advanced breast cancer who underwent NAC between 2011-2020. Kaplan-Meier analyses were used to assess the associations between disease-free survival (DFS) and overall survival (OS) and all clinicopathological variables including LVI in breast surgical specimens following NAC. Associations between nodal PCR and all clinicopathologic variables were assessed Results:Median follow-up was 29.9 months. Absence of nodal PCR (p.000), positive family history (p .027), clinical T4 (p.049), pathological TNM staging (p.016), high tumor grade (p .020),triple negative disease(p .016) and absence of tumor PCR (p.001) were associated with worse disease free survival. Absence of nodal PCR (p.002), high BMI (p.039), multicentric disease (p.026), high tumor grade, triple negative disease (p.018), and absence of tumor PCR (p.005) were associated with worse overall survival. LVI was found in 53 of surgical specimens (23.7%). It was associated with worse DFS (HR) (2.967) 95% CI (1.7-4.9), p.000 and overall survival (HR) (3.05) 95% CI (1.525-6.09), p.002). Nodal PCR significantly correlated with T stage (p .013), LVI (p.000), ER status (p.004), PR status (p.003), Her2neu status and IHC score (p.000), tumor subtype (p.000), tumor PCR (p.000), DFS (p.000), and OS (p.000). Conclusion:LVI is significantly associated with worse DFS and OS in locally advanced breast cancer patients treated with NAC. This data confirmed the previously published recommendation to add LVI to the pathological staging system. LVI may be further explored as a guide for adjuvant treatment options in clinical trials. Nodal PCR is another significant predictor of outcome and is associated significantly with tumor PCR and LVI. Both tumor PCR and LVI can be used as criteria for axillary surgery omission in future trials. Citation Format: Omima Elemam, Khaled Elnaghi, Ziad Emarah, Hossam Alghanami, Seham Abdelkhalek. Residual lymphovascular invasion: Predicts the outcome of neoadjuvant chemotherapy in locally advanced breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-07-30.

Background: There are several DNA repair pathways that protect cellular DNA from injury, such as nucleotide excision repair (NER) and mismatch repair (MMR). The protein product of the excision repair cross-complementation group 1 (ERCC1) gene plays a pivotal role in NER. The exact relationship between MMR proteins and ERCC1 is not well known in colorectal carcinoma (CRC). Aim of the Study: To investigate expression of ERCC1 and MMR proteins in colorectal mucinous carcinoma (MA) and non-mucinous carcinoma (NMA) using tissue microarray technique. Material and Methods: We studied tumor tissue specimens from 150 patients with colorectal mucinous (MA) and non-mucinous adenocarcinoma (NMA). Tissue microarrays were constructed using modified mechanical pencil tips technique and immunohistochemistry for ERCC1, MLH1, MSH2, MSH6, and PMS2. Results: NMA showed a significantly more frequent aberrant cytoplasmic expression than MA while MA showed a more frequent intact nuclear expression than NMA. There were no significant differences between the NMA and MA groups in the expression of MMR proteins. In NMA cases, ERCC1 expression was significantly related to MMR status while was not significantly related in MA cases. ERCC1 expression was not significantly related to overall and disease-free survival in both NMA and MA groups. Conclusion: this study is the first to investigate the relation between MMR status and ERCC1 expression in colorectal MA and NMA. ERCC1 expression was significantly related to MMR status only in NMA cases. Hence, the current study emphasizes that further research about the relation between various DNA repair pathways is needed.

Background: Expression of PD-L1 detected by immunohistochemistry can represent a new hope for cancer management. The role of PD L1 in breast cancer is still unclear. Similarly, is the role of tumor-infiltrating FOXP3 +ve regulatory T (Treg) cells where literature data are conflicting. Our study aimed to evaluate the immunohistochemical expression of PD L1 and FOXP3 in breast cancer, correlate them with clinicopathological parameters as well as evaluating their relation.Methods: This is a retrospective study carried out on 136 breast cancer specimens. Only cases with proved pathological diagnosis of infiltrating duct carcinoma of no special type (NST) were included. Tissue microarray blocks were constructed and immunostained with the polyclonal antibody for PDL1 and monoclonal antibody for FOXP3.Results: Statistically significant correlation was found between high FOXP3 and nearly all adverse prognostic factors including; grade III tumors (p = .003), basal-like subtype(p = .001), high Ki67(p = .001), negative ER status(p = .001), negative PR(p = .028), HER2 expression(p = .04), advanced stage (p = .001), and LN metastases(p = .001). For PDL1, only statistically significant correlation with high Ki67 (p = .018) and advanced stage(p = .03) was found. A statistically significant positive correlation was found between PD L1 and FOXP3(p= .001). No statistically significant correlation was found between both PDL1 and FOXP3 in relation to disease-free survival (DFS) (p = .054). PDL1, age (≥ 50 years), nodal metastases were significant predictors of relapse in breast cancer.Conclusion: The current study supports PDL1 as a predictor of relapse in breast cancer. Additionally, it highlights the synergistic role between PDL1 and FOXP3 in breast cancer microenvironment. Each can be considered as a poor prognostic marker in breast cancer. This raises a concern about the benefit of breast cancer patients from blocking of PDL1 pathway.

BACKGROUND: E-cadherin and Fascin are adhesive proteins that are expressed in many tumors. It was supposed that loss of expression of these proteins is associated with increased aggressiveness of the tumor. Whether spinal and intracranial meningiomas express adhesion proteins in different rates is not yet known. OBJECTIVE: We aimed to investigate the expression of E-cadherin and Fascin in a large number of meningioma specimens and determine if clinical and prognostic significance exists METHODS: One hundred and thirty-four spinal and intracranial meningioma samples were collected. Manual TMA blocks were constructed and immunohistochemistry for E-cadherin and Fascin was done. Focal or diffuse staining was considered positive. RESULTS: Intracranial meningioma occurred in significantly younger age than spinal ones. Most of spinal meningiomas were of transitional histology. E-cadherin was expressed in 38.8% of cases. Spinal meningiomas showed statistically significant negative expression of E-cadherin than intracranial tumors. All atypical meningiomas showed negative E-cadherin expression. Fascin was expressed in 9% of cases with significant expression in atypical cases. CONCLUSIONS: Aggressive behavior of meningioma could be explained in part by loss of E-cadherin and overexpression of Fascin especially in spinal meningiomas. Further studies are suggested to explore the biological aspects of spinal and intracranial meningiomas for constructing tailored targeted therapies.