Potential predictors for CDX2 expression loss and mismatch repair deficiency in colorectal cancer.

CDX2 expression loss is commonly associated with mismatch repair deficiency (dMMR) in colorectal cancer (CRC). However, there are only a few studies that have attempted to correlate CDX2 expression loss with specific MMR genes (MLH1, MSH2, MSH6, PMS2). This is a retrospective study of 327 patients who underwent surgery due to CRC. Nine patients (2.9%) had two synchronous CRCs, making the total sample 336 CRC. Histopathological data such as tumor type, tumor grade, perineural, lymphatic, and vascular invasion, pT stage, pN stage, peritumoral and intratumoral lymphocytic infiltration were collected and recorded in the database. After immunohistochemical analysis, CDX2 expression, MLH1, MSH2, MSH6, and PMS2 deficiency were also recorded. CDX2 expression loss was detected in 19 out of 336 CRCs (5.9%) and was associated with ascending colon CRC, partially mucinous adenocarcinoma, poorly differentiated carcinoma, and dMMR. Forty-four (13.1%) of CRCs were dMMR. We found a statistically significant association between CDX2 expression loss and MLH1 and PMS2 deficiency. Considering that most expression phenotypes include pairs of MMR genes, we analyzed MLH1/PMS2 and MSH2/MSH6 as heterodimers. Analysis of heterodimers showed a similar result, namely, that MLH1/PMS2 heterodimer deficiency was significantly associated with CDX2 expression loss. We also constructed a regression model for CDX2 expression loss and for dMMR. Poor tumor differentiation and MLH1/PMS2 heterodimer deficiency have been identified as potential predictors for CDX2 expression loss. CRC in the ascending colon and CDX2 expression loss have been identified as positive potential predictors of dMMR with rectal cancer as negative potential predictor of dMMR. Our study showed a significant association between CDX2 expression loss and MLH1 and PMS2 deficiency in CRC. We also managed to produce a regression model for CDX2 expression and showed that poor tumor differentiation and MLH1/PMS2 heterodimer deficiency are independent factors for CDX2 expression loss. We were the first to include CDX2 expression in a regression model for dMMR and showed that CDX2 expression loss can be used as a predictive factor for dMMR, which should be confirmed by further studies.

Angiodysplasia of the Gallbladder: An Unknown Risk Factor for Cholecystolithiasis.

Angiodysplasia is a common type of lesion characterized by malformed submucosal and mucosal blood vessels. Angiodysplasia of the gallbladder is extremely rare, usually an incidental finding, with only two cases reported. Laparoscopic cholecystectomy is a curative treatment for angiodysplasia of the gallbladder. Our report describes a case of angiodysplasia of the gallbladder in a patient who underwent elective laparoscopic cholecystectomy for biliary colic because of gallstones, and a systematic literature review. We surmise that angiodysplasia of the gallbladder could be a risk factor for gallstones in younger female patients.

Inter-laboratory comparison of Ki-67 proliferating index detected by visual assessment and automated digital image analysis.

BACKGROUND: Proliferation rate is a major determinant of the biologic behavior of the tumor and provides information that can be used to guide treatment decisions. METHODS: This ring study included 27 pathologists from 14 Institutions, in order to assess inter-observer concordance between pathologists in Croatia. We analyzed Ki-67 proliferative index on ten randomly selected breast cancer samples comparing consistency between visual assessment using light microscopy compared to digital image analyses results from one central laboratory as a referral value. RESULTS: When we analyzed Ki-67 as numeric value high concordance rate was found between Ki-67 score visually assessed in all participating Institutions compared to referral value assessed by digital image analysis (ICC 0.76, 95% CI 0.58-0.91), and Krippendorff's alpha was 0.79 (95% CI 0.58-1.00). Concordance was better in slides with higher Ki-67 values. When we categorized Ki-67 values according to generally accepted 20% cut-off value we noticed the lower concordance rate among participants in our study. CONCLUSION: Proliferation remains one of the most important parameters for tumor characterization helpful in making clinical decisions, but it should be used with great caution. Standardization of the Ki-67 assessment is essential and proliferating index should be expressed as exact numeric value. For patients with proliferative index near the cut-off value, other factors must be considered in making clinical decisions.

Superoxide dismutases in chronic gastritis.

Human gastric diseases have shown significant changes in the activity and expression of superoxide dismutase (SOD) isoforms. The aim of this study was to detect Mn-SOD activity and expression in the tissue of gastric mucosa, primarily in chronic gastritis (immunohistochemical Helicobacter pylori-negative gastritis, without other pathohistological changes) and to evaluate their possible connection with pathohistological diagnosis. We examined 51 consecutive outpatients undergoing endoscopy for upper gastrointestinal symptoms. Patients were classified based on their histopathological examinations and divided into three groups: 51 patients (archive samples between 2004-2009) with chronic immunohistochemical Helicobacter pylori-negative gastritis (mononuclear cells infiltration were graded as absent, moderate, severe) divided into three groups. Severity of gastritis was graded according to the updated Sydney system. Gastric tissue samples were used to determine the expression of Mn-SOD with anti-Mn-SOD Ab immunohistochemically. The Mn-SOD expression was more frequently present in specimens with severe and moderate inflammation of gastric mucosa than in those with normal mucosa. In patients with normal histological finding, positive immunoreactivity of Mn-SOD was not found. Our results determine the changes in Mn-SOD expression occurring in the normal gastric mucosa that had undergone changes in the intensity of chronic inflammatory infiltrates in the lamina propria.

INTERLABORATORY CONCORDANCE IN HER-2 POSITIVE BREAST CANCER.

Accurate assessment of HER-2 status is essential for identifying patients who will benefit from HER-2 targeted therapy. The aim of the present study was to show results on the concordance between local and central laboratory testing results in HER-2 positive breast cancer patients. In cases with discordant findings, the immunohistochemical (IHC) and/or in situ hybridization (FISH/SISH) analysis was performed in central laboratories. A total of 104 out of 143 (72.72%) breast carcinoma cases were HER-2 positive (score 3+), while nearly 14% of tumors (20/43) showed weak (score 2+) and 12% (19/143) negative IHC staining (score 0 and 1+). After repeated IHC and ISH, 88% (126/143) were classified as HER-2 positive and 12% (17/143) as HER-2 negative cases. The results obtained are in agreement with many studies that confirmed similar discordance in HER-2 testing by IHC and/or FISH between local and central laboratory. Thus, our findings as well as those from other studies support the importance of regular quality assessment of the staining procedures performed and consistency of interpretation of HER-2 test results.

Malignant potential of dysplastic endocervical epithelium assessed by ploidy status, S-phase fraction and C-myc expression.

The aim of this study was to determine if dysplastic endocervical cells (EC) posses a neoplastic potential as precursor lesions to adenocarcinoma in situ (AIS). The malignant potential was determined by assessing the ploidy status and proliferative activity by flow cytometry and c-myc expression by immunohistochemistry. The studied parameters were assessed separately in morphologically normal, dysplastic and malignant EC. The chi 2 test showed significant association of malignant EC with aneuploidy (p = 0.008) and high proliferative activity (p = 0.042). Since one third of the dysplastic EC are also aneuploid and show high mitotic activity, they probably have malignant potential as well. The dysplastic EC showed a significant association with c-myc oncogene expression (p = 0.028). Our results indicate the existence of pre-malignant glandular lesions, while the immunohistochemical detection of c-myc protooncogene could be helpful in detection of EC with malignant potential, even without any dysplastic morphological changes.