Snježana Tomić

Expression of androgen receptors in triple negative breast carcinomas.

Triple negative breast cancer (TNBC) consists of a group of tumors with poor prognosis, owing to aggressive tumor biology and lack of targeted therapy. The aim of this study was to assess the immunostaining for androgen receptors (ARs) in the group of TNBC, in addition to basal-like (BL) immunophenotype, BL morphology and conventional clinicopathological factors and to demonstrate its prognostic relevance in this group of tumors. The study included 83 patients. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER2, CK5/6, CK14, EGFR, Ki-67 and AR. Of the 83 TNBC samples, 32.5% showed positive immunostaining for AR, 66.3% had BL immunophenotype, and 48.2% had BL morphology. Positive AR immunostaining was inversely correlated with higher clinical stage, higher mitotic score, higher histological grade and higher proliferation index measured by Ki-67. Significantly more AR negative tumors were observed among the tumors with BL immunophenotype and BL morphology. There was no significant association between positive AR immunostaining and disease free survival or overall survival. More than one third of TNBC were AR-positive, and this represents a potential opportunity for novel targeted treatment in the group of breast tumors for which therapeutic options are currently limited.

The significance of immunohistochemical expression of merlin, Ki-67, and p53 in meningiomas.

Meningiomas are one of the most common CNS tumors whose appearance is closely linked to NF2 gene product merlin. Tumor markers Ki-67 and p53 play established role in tumor progression which should be analyzed in close association with merlin expression. The aim of this study was to investigate the immunohistochemical expression of merlin in meningiomas, correlation with Ki-67 and p53, and to determine the association of these results with histologic grade and subtype. The histologic sections of 170 patients with totally resected meningiomas, between January 2000 and December 2010, were classified according to WHO, immunohistochemically stained for Ki-67, p53, and merlin, and analyzed using light microscope. Ki-67 median was 5.6 times higher in group of patients with negative merlin than in those with positive merlin (P=0.05). Statistically significant correlation of merlin with p53 was found (P<0.001). Merlin expression between 2 combined groups (meningothelial/secretory and fibroblastic/transitional) was statistically significant (P=0.002). By comparing merlin expression and p53 levels, statistically significant difference was found (P=0.017). In the group with positive merlin and negative p53 as well as positive merlin and low p53, meningothelial/secretory subtypes of meningiomas were more common. In combination of negative merlin and negative p53 as well as negative merlin and high p53, there were more meningiomas of fibroblastic/transitional subtype. There was no statistically significant correlation between merlin and tumor grade (P=0.420). There is undeniable influence of merlin on the development and the proliferative ability of meningioma subtypes. Significant role of p53 pathway was confirmed.

Expression of topoisomerase II-α in triple negative breast cancer.

Triple negative breast cancer (TNBC)—defined by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 negativity is a group with poor prognosis, due to aggressive tumor biology and lack of targeted therapy. Topoisomerase II-&agr; (topoII&agr;) protein is one of the intracellular targets for anthracycline-based therapy, and high levels of topoII&agr; expression are recently observed in TNBC. The study included 83 patients who underwent surgery between January 2003 and December 2009. Paraffin blocks were stained immunohistochemically with CK5/6, CK14, EGFR, Ki-67, and topoII&agr;. Basal-like (BL) immunophenotype was defined by positivity for ≥1 basal cell markers: CK5/6, CK14, or EGFR. Of 83 TNBC, 66.26% were of the BL immunophenotype, which was significantly associated with higher mitotic count (P=0.023), BL morphology (P=0.005), higher histologic grade (P=0.022), and higher proliferation rate assessed by Ki-67 (P<0.001). TopoII&agr; expression was significantly correlated with invasive ductal carcinoma NOS (P=0.010), higher mitotic count (P=0.001), higher histologic grade (P=0.007), and higher Ki-67 (P<0.001). In conclusion, due to lack of expression of ER, PR, and human epidermal growth factor receptor 2 receptor in TNBC, specific targeted therapies are not effective, and chemotherapy is currently the only modality of available systemic therapy. Due to expression of topoII&agr;, anthracyclines may be effective in treatment of TNBC.

Prognostic value of Ki-67 proliferating index in triple negative breast carcinomas

The aim of this study was to assess Ki-67 in the triple negative breast cancer group (TNBC) in addition to basal like (BL) immunophenotype, BL morphology and conventional clinicopathologic factors, and to demonstrate their prognostic relevance in this group of tumors. Immunohistochemical staining for CK5/6, CK14, EGFR and Ki-67 was performed on 83 formalin-fixed, paraffin-embedded tumor sections. Correlations between categorical variables were studied using the chi-square and the Mann-Whitney U test. For survival analysis, the Kaplan-Meier method, the log-rank test and the Cox proportional hazard regression model were used. The optimal cut-off values for Ki-67 and mitotic count were selected using the ROC (receiver operating characteristic) method. Of the 83 TNBC, 55 (66.3%) had the BL immunophenotype, and 40 (48.2%) had BL morphology. Clinical stage and Ki-67 proliferation index were significantly associated with shorter disease-free survival (DFS) (p=0.002 and p<0.001) and overall survival (OS) (p=0.05 and p=0.025). An independent prognostic relevance regarding DFS and OS was found for clinical stage (p<0.001 and p<0.001), Ki-67 (p=0.008 and p=0.055) and BL morphology concerning DFS (p=0.011). Cellular proliferation measured by Ki-67 has prognostic relevance in TNBC, but further validation of its clinical significance, standardization of assessment and determination of optimal cut-off points is essential for this group of breast tumors.

The expression patterns of pro-apoptotic and anti-apoptotic factors in human fetal and adult ovary.

The influence of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins on the cell death (caspase-3, TUNEL) of different ovarian cell lineages was immunohistochemically analyzed in six fetal and five adult human ovaries in order to disclose possible mechanisms of cell number control. Mild to moderate expression of Bcl-2 characterized ovarian surface epithelium, follicular cells and oocytes of 15 and 22 week human ovaries, while expression of Bax and caspase-3 gradually increased in all ovarian cell populations, except caspase-3 in the ovarian surface epithelium. Different levels of Bax and Bcl-2 proteins co-expression characterized fetal ovarian cells, while TUNEL and caspase-3 co-expression was found only in some of them. In adult ovaries, Bcl-2 was moderately and Bax strongly expressed in the surface ovarian epithelium and stroma. Bcl-2 and Bax expression in granulosa and theca interna cells varied depending on the stage of follicular atresia. Caspase-3 apoptotic cells characterized granulosa cells of adult atretic follicles. Our results indicate that intracellular levels of Bcl-2 and Bax protein might regulate the final destiny of developing germ cells. Caspase-3 dependent apoptosis seems to be the most important, but not the only cell death pathway in ovaries. In adult ovaries, caspase-dependent cell death characterized granulosa cells, but not the germ cells.

Reproductive ability of pubertal male and female rats

Ten Fisher rats 50 to 55 days of age made up the pubertal group, and ten rats 90 to 95 days of age served as the controls. The testicular and epididymal weights and volumes of the pubertal males were lower than those of the controls (P<0.001). There was also a difference in relative epididymal weight (P<0.001). The sperm of pubertal males was morphologically abnormal in 58.2% of cases, as opposed to only 3.8% in the controls (P<0.001). The mean number of spermatozoa in the control group was 11.9 10(6)/ml and their viability was 99.6%, while these values could not be determined for pubertal rats. Serum testosterone was higher in the pubertal animals than in the controls (2.52 1.46 vs 0.92 0.34 nM, P<0.01). The ovaries of control females were heavier than those of pubertal females (P<0.001) but there was no difference in their relative weights. Serum estradiol was similar in both groups (75.5 12.8 vs 81.8 14.7 nM, P>0.05). At the beginning of gestation, the pubertal dams weighed less than the controls (P<0.001) but following uterectomy the body weights were equal. Pubertal dams delivered fewer pups than the controls (8.1 2.5 vs 10.4 1.3, P<0.05). There was no difference in the body weights of their offspring or in the weights of their placentas. The results suggest that, in contrast to their female counterparts, pubertal male rats are not fully mature and have not reached complete reproductive capacity at 50-55 days of age.

Her-2/neu assessment for gastric carcinoma: validation of scoring system.

BACKGROUND/AIMS Gastric cancer is the second leading cause of cancer mortality in the world. Amplification of HER-2/neu oncogene has become an important biomarker for identifying patients who respond to HER-2 targeting therapy. A number of studies have analyzed HER-2/neu overexpression in gastric carcinoma, and the rate of HER2 positivity is variable, ranging from 6% to 35%. METHODOLOGY In our study HER-2/neu expression was assessed on 73 samples of primary gastric cancer, using immunohistochemistry. For 19 patients preoperative biopsy samples and resected specimens were available. Additionally, internal ring study was performed to estimate intraobserver variability of IHC scoring among pathologists at our department. RESULTS HER-2/neu overexpression was found in 10 (13.6%) of the tested samples, and it was more common in intestinal (22.5%) than the diffuse type (3.7%). Not one of the 6 analyzed mixed type tumors showed HER-2/neu expression. For the paired samples (preoperative biopsy samples and resected specimens) the concordance rate for HER-2/neu expression was 94.7%. CONCLUSIONS According to high concordance rate in paired samples we consider it appropriate to evaluate HER2 expression on biopsy specimens, especially in unresectable cases, and to re-evaluate it on resected specimens if available, due to high heterogeneity of a gastric cancer.

Correlation Between E-cadherin Immunoexpression and Efficacy of First Line Platinum-Based Chemotherapy in Advanced High Grade Serous Ovarian Cancer

To analyze correlation between immunoexpression of E-cadherin and efficacy of first line platinum-based chemotherapy in patients with advanced-stage high-grade serous ovarian carcinoma. The expression of E-cadherin was analyzed immunohistochemically in formalin-fixed, paraffin-embedded samples from 98 patients with advanced-stage high-grade serous ovarian cancer and related to clinical features (stage according to the International Federation of Gynecology and Obstetrics (FIGO) and residual tumors after initial cytoreductive surgery), response to platinum-based chemotherapy (according to Response Evaluation Criteria in Solid tumors (RECIST 1.1 criteria)), platinum sensitivity (according to platinum free interval (PFI) as platinum-refractory, platinum-resistant and platinum-sensitive) and patients progression free survival (PFS) and overall survival (OS). E-cadherin immunostaining was positive in 74 and negative in 24 serous ovarian carcinomas. E-cadherin immunoreactivity was not associated with FIGO stage, residual tumor after initial cytoreductive surgery and number of chemotherapy cycles. Positive E-cadherin expression predict significantly better response to first line platinum-based chemotherapy (p < 0.001) and platinum sensitivity (p < 0.001). Moreover, positive E-cadherin expression predict significantly longer PFS (p < 0.001) and OS (p < 0.001). The multivariate analysis for OS showed that positive E-cadherin expression is predictor to platinum sensitivity (p < 0.001) and longer OS (p = 0.01). Positive E-cadherin expression seems to be a predictor of better response to first line platinum-based chemotherapy, platinum sensitivity and favorable clinical outcome in patients with advanced-stage serous ovarian cancer. Negative E-cadherin expression was shown to be significant, independent predictor of poorer PFS and OS. E-cadherin as a marker has predictive and prognostic value.

Mammographic screening has failed to improve pathohistological characteristics of breast cancers in Split region of Croatia

The national breast cancer screening program has been introduced in Croatia in the second half of 2006 with mammography as the screening method. We investigated the impact of screening mammography on the basic pathohistological characteristics of breast cancers retrieved from the database of large community hospital. The data were collected in the period following the initiation of national mamographic screening program (2007-2011), and compared with the data collected in the period before the program introduction (2002-2006) to explore the possible changing trends. In the screening period 1,320 breast cancers were diagnosed, while in the prescreening period 1,204 breast cancers were diagnosed (p=0.02). We found the reduction of mean tumor size (p=0.039), decrease of the diagnosed non-invasive cancers (p=0.001), and the higher percentage of the diagnosed ductal (p=0.0003) and grade 3 (p=0.038) invasive cancers in the screening period. We also noticed higher percentage of diagnosed advanced breast cancers with unknown tumor size in the screening period (p=0.027). We concluded that the implementation of national screening program did not improve the pathohistological features of breast cancers in our region probably due to low response rate to screening invitation.

Can we identify the group of small invasive (T1a,b) breast cancers with minimal risk of axillary lymph node involvement? A pathohistological and DNA flow cytometric study

The goal of this study was to identify a group of small (≤1cm) breast cancers (T1a,b) with a particularly low probability of axillary lymph node metastases, where routine axillary staging may be unnecessary. We retrospectively analyzed 152 T1a,b breast carcinomas with axillary dissection surgically removed at Clinical Hospital Center Split (Croatia) in the period from 1997 to 2006. The analysis included 40 T1a,b cancers with, and 112 T1a,b cancers without axillary lymph node metastases. The basic morphological features of cancers were investigated histologically, while hormone receptors and HER2/neu were investigated immunohistochemically with an additional CISH analysis of HER2/neu 2+ cases. The ploidy and S-phase fraction were determined by DNA flow cytometry. The association of the investigated features with the likelihood of axillary lymph node metastases was analyzed by univariate and multivariate analysis. The univariate analysis showed that lymph node metastases were associated with tumor size (T1a/T1b; p=0.026), histological type (ductal/non-ductal; p=0.014), lymphovascular invasion (p<0.001), HER2/neu expression (p=0.04), ploidy (p=0.027), and combined values of ploidy and S-phase fraction (p=0.025). The lymphovascular invasion was the only independent factor associated with axillary nodal metastases (p=0.01). In the group of T1a,b cancers without lymphovascular invasion, HER2/neu expression (p=0.021) and combined values of ploidy and S-phase fraction (p=0.016) were independent factors associated with axillary lymph node metastases. This study showed that diploid T1a,b cancers with low S-phase fraction, which are also without lymphovascular invasion and HER2/neu amplification, represented the group of cancers with a low probability of axillary lymph node metastases.