Significance of p53, Bcl-2, and HER-2/neu protein expression in Omani Arab females with breast cancer

Expression profile of tumour suppressor protein p53 and its regulator MDM2 in a cohort of breast cancer patients in a Tertiary Hospital in Ghana

BACKGROUND

Inactivation or mutation of the tumour suppressor gene p53 or its regulator mouse double minute 2 (MDM2) is the commonest event in breast cancer. These altered genes usually express abnormally high levels of their proteins in many carcinomas. The phenotypic expression of p53 and MDM2 in breast cancer cases in our setting is not known. This study investigated the expression of the tumour suppressor protein p53 and its regulator MDM2, using immunohistochemistry in a Ghana breast cancer cohort.

METHOD

A 9-year retrospective cross-sectional study on archived tissue blocks-formalin fixed paraffin embedded tissue (FFPE) was carried out. Demographic data were abstracted. Based on complete clinical data and availability of FFPE archived blocks 203 cases were selected for tissue micro array (TMA) construction. The TMA sections were subjected to immunohistochemistry (IHC) (ER, PR, HER2, p53, and MDM2). Expression of p53 and MDM2 were related to grade and molecular subtypes.

RESULTS

The age ranged from 17 to 92 years (mean = 49.34 ± 13.74). Most of the cases were high grade; grade II (34.9%) and grade III (55.7%). Fifty-four percent of the cases were triple negative. Invasive ductal carcinoma no special type was the commonest histotype (87.1%). Thirty-six percent (36%) of the cases expressed p53. Significant associations were found between p53 overexpression and histological grade (p = 0.034), triple negative (p = 0.0333) and luminal B (p<0.01) tumors. Most cases (93.1%) were negative for MDM2 expression. Significant association was found between MDM2 and HER2 over-expression as well as Ki-67. There was no significant positive correlation between MDM2 and p53 co-expression (p>0.05).

CONCLUSION

The elevated level of p53 expression in the aggressive breast cancer phenotypes (high histological grade and triple negative) in our cohort suggest that P53 elevation may be a poor prognostic marker in our setting. High expression of MDM2 in our cohort with high Ki67; also in cases with Her2/neu overexpression known with predictable poor prognosis in the absence of target therapy suggest MDM2 may be associated with aggressive biological behaviour in our breast cancer cases. The non-significant association of p53 and MDM2 expression in the same cases as also documented by previous studies suggest independent genetic pathway in tumourigenesis.

Correlation of Hormone Receptor and Human Epidermal Growth Factor Receptor-2/neu Expression in Breast Cancer with Various Clinicopathologic Factors

Background

A significant development in the breast carcinoma management is the correlation between the presence of hormone receptors in the tumor and response to hormonal therapy and chemotherapy. Human epidermal growth factor receptor-2/neu (Her-2/neu) overexpression also serves as a very useful parameter to predict response to herceptin.

Aim of Study

The study was conducted to correlate immunohistochemical expression of markers such as estrogen receptor (ER), progesterone receptor (PR), and Her-2/neu with various clinicopathologic parameters.

Materials and Methods

The study included 509 cases of breast carcinoma over a period of 5 years (from May 2009 to May 2014). Immunohistochemistry (IHC) for ER, PR, and her-2/neu was performed.

Results

ER positivity was observed in 42.8% (218/509) cases, PR positivity in 31.8% (194/509) cases whereas her-2 neu positivity was seen in 40.7% (203/509) cases. Triple marker (ER, PR, and Her-2/neu) negative cases were 23.6% (120/509) cases. ER and PR expression was found to have a statistically significant correlation with tumor grade. Statistically significant correlation was observed between tumor size and tumor grade and her-2/neu expression. Her-2/neu expression showed statistically significant association with tumor stage. As the tumor grade increased, the proportion of triple-negative cases went on increasing, which was statistically significant.

Conclusion

IHC has an increasingly important prognostic role in determination of factors that affect clinicopathologic features. Nevertheless, the results of this large series showed different patterns of findings with respect to clinicopathologic features.

High prevalence of HER-2/neu overexpression in female breast cancer among an Iraqi population exposed to depleted uranium

Background

This study aimed to estimate the rate of HER-2/neu (c-erbB2) immunohistochemical overexpression in different histological types of breast cancer found in the middle Euphrates region of Iraq, a region that was exposed to high levels of depleted uranium. HER-2/neu (c-erbB2) overexpression was correlated with common clinicopathological parameters such as age, grade, stage, tumor size and lymph node involvement to determine if any particular biomarker for exposure to depleted uranium could be found in the tumor samples from this region.

Materials and Methods

The present investigation was performed over a period starting from September 2007 to June 2008. Formalin-fixed, paraffin-embedded blocks from 90 patients with breast cancer were included in this study. A group of 25 patients with benign breast lesions (fibroadenoma) was included as a comparative group, and 20 breast tissue sections were used as controls. Labeled streptavidin-biotin (LSAB) complex method was employed for immunohistochemical detection of HER-2/neu.

Results

HER-2/neu immuno-expression was positive in 67.8% of breast cancer, while it was negative in all benign breast lesions (fibroadenoma) (P < 0.05). HER-2/neu immunostaining was significantly associated with histological type and recurrence of breast cancer (P < 0.05). It was positively correlated with tumor grade, but this finding was not significant (P > 0.05).

Conclusion

Based upon the findings of this study, it can be concluded that HER-2/neu overexpression plays an important role in the pathogenesis of breast cancer and is associated with a worse prognosis. The findings indicate that in regions exposed to high levels of depleted uranium, HER-2/neu overexpression is high, but its correlation with age, grade, stage, tumor size, and lymph node involvement is similar to studies that have been conducted on populations not exposed to depleted uranium.

Systematic review of breast cancer biology in developing countries (part 1): Africa, the middle East, eastern europe, Mexico, the Caribbean and South america

There has been no systematic appraisal of ethnicity-based variations in breast cancer (BC) biology amongst women from developing countries. A qualitative systematic review was conducted of breast cancer size, stage, grade, histological type, extra-mammary involvement, hormone receptor status as well as patient demographics. This review includes patients from Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America. BC in these regions present at an earlier age with large aggressive tumours. Distant metastases are frequently present at the time of diagnosis. African women have a higher frequency of triple negative tumours. Over half of Middle Eastern women have lymph node involvement at the time of diagnosis. Despite experiencing a lower incidence compared to the Ashkenazi Jewish population, Palestinian women have poorer five-year survival outcomes. The majority of women from Mexico and South America have stage two or three disease whilst over sixty percent of women from Eastern Europe have either stage one or stage two disease. The biological characteristics of BC in the Caribbean cannot be fully assessed due to a paucity of data from the region. BC amongst the developing world is characterised by an early peak age of onset with aggressive biological characteristics. Strategies that improve breast cancer awareness, address amenable risk factors and improve early detection are essential.

Serological levels of mutated p53 protein are highly detected at early stages in breast cancer patients

The aim of this study was to compare the sensitivity of the serological level of anti-p53 antibodies in breast cancer patients and to correlate its expression level with patient age, histological stage and grade of tumor differentiation. Total p53 protein expression (mutant and wild-type) was also determined in the breast cancer tissues using immunohistochemistry (IHC). The serological levels of mutant p53 expression were found to be age-dependent, reaching the highest level at 50 years of age. Faint or low detection was observed in patients ≤30 years of age. Anti-p53-antibodies were detected in patients ≤40 and ≥61 years of age. The serological levels of mutant p53 protein were highly detected in all stages of breast cancer, including the early stages. However, anti-p53 antibodies reached a high level of detection only in stage III breast carcinomas. No expression was found in patients with benign breast disease. The detection of p53 mutations was dependent on the grade of tumor differentiation, achieving the highest level in the poorly differentiated breast carcinomas. Results from IHC were highly correlated with serological p53 mutational analysis. Our findings indicate that mutant p53 in serum is a promising novel parameter for the evaluation of cellular biology and the prognosis of breast cancer from its early stages using blood samples. Anti-p53 antibodies were demonstrated to be less sensitive in this study. It is also possible to use the expression of mutant p53 protein as a molecular marker to differentiate benign breast disease from breast carcinoma prior to surgery.

Meta-analysis confirms BCL2 is an independent prognostic marker in breast cancer

Background

A number of protein markers have been investigated as prognostic adjuncts in breast cancer but their translation into clinical practice has been impeded by a lack of appropriate validation. Recently, we showed that BCL2 protein expression had prognostic power independent of current used standards. Here, we present the results of a meta-analysis of the association between BCL2 expression and both disease free survival (DFS) and overall survival (OS) in female breast cancer.

Methods

Reports published in 1994–2006 were selected for the meta-analysis using a search of PubMed. Studies that investigated the role of BCL2 expression by immunohistochemistry with a sample size greater than 100 were included. Seventeen papers reported the results of 18 different series including 5,892 cases with an average median follow-up of 92.1 months.

Results

Eight studies investigated DFS unadjusted for other variables in 2,285 cases. The relative hazard estimates ranged from 0.85 – 3.03 with a combined random effects estimate of 1.66 (95%CI 1.25 – 2.22). The effect of BCL2 on DFS adjusted for other prognostic factors was reported in 11 studies and the pooled random effects hazard ratio estimate was 1.58 (95%CI 1.29–1.94). OS was investigated unadjusted for other variables in eight studies incorporating 3,910 cases. The hazard estimates ranged from 0.99–4.31 with a pooled estimate of risk of 1.64 (95%CI 1.36–2.0). OS adjusted for other parameters was evaluated in nine series comprising 3,624 cases and the estimates for these studies ranged from 1.10 to 2.49 with a pooled estimate of 1.37 (95%CI 1.19–1.58).

Conclusion

The meta-analysis strongly supports the prognostic role of BCL2 as assessed by immunohistochemistry in breast cancer and shows that this effect is independent of lymph node status, tumour size and tumour grade as well as a range of other biological variables on multi-variate analysis. Large prospective studies are now needed to establish the clinical utility of BCL2 as an independent prognostic marker.

Differential expression of STAT5 and Bcl-xL, and high expression of Neu and STAT3 in non-small-cell lung carcinoma

Experimental evidence suggests that in lung cancer, development, progression and an increased proliferation rate can be linked to apoptosis-related factors. The objective of this study is to evaluate the status of Neu, signal transducer and activator of transcription (STAT)-3, STAT5 and Bcl-xL expression in non-small-cell lung cancer. We investigated the immunohistochemical expression of these proteins in 92 non-small-cell lung cancer specimens to establish their role in lung cancer pathogenesis. Neu was overexpressed in 65% of cases, and although STAT3 was overexpressed in 52.1% in cytoplasm, it was expressed in nucleus (activated) in 60.8%. Meanwhile, STAT5 was found overexpressed in 41.3% in cytoplasm and 32.6% in nucleus. Thus, Bcl-xL was overexpressed in cytoplasm in 81.5%. Interestingly, we found nuclear expression of Bcl-xL in 30.4% of cases. Finally, we found correlation among histological types of lung cancer and nuclear expression of both STAT5 (P=0.005) and nuclear Bcl-xL (P=0.003). Besides, nuclear expression of Bcl-xL was correlated with TNM stage IV (distant metastasis) (P=0.02). These results suggest for the first time, a relevant role for STAT5 and Bcl-xL as apoptosis-regulatory proteins in the pathogenesis of lung cancer, and overexpression of both Neu and activated STAT3, could be related with the proliferation rate in lung carcinoma cells.