Comparison of different approaches for assessment of HER2 expression on protein and mRNA level: prediction of chemotherapy response in the neoadjuvant GeparTrio trial (NCT00544765)

Human epidermal growth factor receptor 2 (HER2) testing is an essential part of pathological assessment in breast cancer patients, as HER2 provides not only prognostic but also predictive information on response to targeted therapy. So far, HER2 test accuracy of immunohistochemistry/in situ-hybridization techniques is still under debate, and more reliable and robust technologies are needed. To address this issue and to evaluate the predictive value of HER2 on chemotherapy, we investigated a cohort of 278 patients from the GeparTrio trial, a prospective neoadjuvant anthracycline/taxane-based multicenter study. In the GeparTrio trial, patients were not treated with any anti-HER2 therapy, as this was not standard therapy at this time. The HER2 status was analyzed by three different approaches: local and central evaluation using immunohistochemistry combined with in situ-hybridization as well as evaluation of HER2 mRNA expression using kinetic RT-PCR from formalin-fixed, paraffin-embedded (FFPE) tissue samples using a predefined cutoff. HER2 overexpression/amplification was observed in 37.3% (91/244) and 17.9% (41/229) of the informative samples in the local and central evaluations, respectively. Positive HER2 mRNA levels were found in 19.8% (55/278). We observed a highly significant correlation between central HER2 expression and HER2 status measured by kinetic RT-PCR (r = 0.856, P < 0.0001) and an overall agreement of 95.6% (κ statistic, 0.862, CI 0.77-0.94). Further, central HER2 as well as HER2 mRNA expression were predictors for a pathological complete response after neoadjuvant anthracycline/taxane-based primary chemotherapy in a univariate binary logistic regression analysis (OR 3.29, P = 0.002; OR 2.65, P = 0.004). The predictive value could be confirmed for the central HER2 status by multivariate analysis (OR 3.04, P = 0.027). The locally assessed HER2 status was not predictive of response to chemotherapy. Our results suggest that standardized methods are preferable for evaluation of HER2 status. The kinetic RT-PCR from FFPE tissue might be an additional approach for assessment of this important prognostic and predictive parameter but has to be confirmed by other studies.

Evaluation of tumor-associated lymphocytes as a predictor of response to neoadjuvant chemotherapy in breast cancer: Results from the GeparDuo and GeparTrio trial

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Background: Preclinical investigations suggest an involvement of the immune system in chemotherapy response; however, this contribution has not been validated in prospective clinical trials so far. Methods: We investigated the inflammatory infiltrate in a total of 1058 pretherapeutic breast cancer core biopsies from two neoadjuvant anthracycline-taxane-based studies. As a training cohort, we used 218 core biopsies from the GeparDuo study. The results were validated in a completely independent cohort of 840 samples from the GeparTrio study. In addition, molecular parameters of lymphocyte recruitment and activation in breast cancer tissue were evaluated by kinetic PCR. Results: While the overall rate of pathological complete response (pCR) in the GeparDuo cohort was 12.8%, it was significantly increased to 42.7% in the tumors with more than 60% intratumoral or stromal lymphocytes. In a multivariate regression analysis, the percentage of intratumoral lymphocytes (iTu-Ly) was an independent significant parameter for pCR (P = 0.013) in the GeparDuo cohort. In the validation set from the GeparTrio trial, the inflammatory infiltrate was a strong predictor of pCR in univariate (P < 0.0005) and multivariate logistic regression (P < 0.0005). For tumors with 60% iTu-Ly the pCR rate was 40% with an odds ratio (OR) of 8.5 (4.0–18.2) which were similar to those values in hormone receptor negative samples (pCR: 36%; OR: 6.0 [4.0–9.1]). The expression of inflammatory marker genes and chemokines related to B and T infiltration in tumor tissue was significantly linked to the presence of a lymphocytic infiltrate and mRNA expression data showed a significant association of T cell markers with a pCR (P < 0.003). Conclusions: An increased lymphocytic inflammatory infiltrate in breast cancer is a new independent predictor of response to anthracyclin-taxane neoadjuvant chemotherapy and might be helpful to identify patients with benefit from cytotoxic chemotherapy.

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[NF-kappaB subunit p65/RelA expression in ovarian carcinoma: prognostic impact and link to COX-2 overexpression]

AIMS

NF-kappaB has been demonstrated to activate proliferative, inflammatory, and angiogenic processes in ovarian cancer cells in vitro. To add translational information on the situation in vivo, we determined the expression pattern of p65, an important subunit of the classic NF-kappaB pathway, in ovarian carcinoma tissue, and investigated in vivo and in vitro whether this pathway is implicated in the known overexpression of cyclooxygenase-2 (COX-2).

METHODS

p65 siRNA, chemiluminescent NF-kappaB transcription factor assay, Taqman PCR, as well as immunoblotting were performed with OVCAR-3 ovarian cancer cells. 83 primary ovarian cancinomas as well as 17 cases of benign ovarian tissue were analyzed by p65 and COX-2 immunohistochemistry using a tissue microarray.

RESULTS

DNA-binding avtivity as well as COX-2 mRNA and protein expression were strongly inducible by IL-1beta treatment in OVCAR-3 cells, while p65 siRNA inhibited IL-1beta-dependent p65 activity (p = 0.037) as well as COX-2 expression on the mRNA (p < 0.03) and on the protein level. In human tumor tissue, p65 protein expression was significantly associated with COX-2 expression (p = 0.002) as well as tumor grading (p = 0.005). Furthermore, p65 expression was a significant prognostic indicator of a reduced patient survival both in univariate (p = 0.038) and in multivariate analysis (p = 0.014).

CONCLUSION

Our study indicates a deregulation of the classical NF-kappaB pathway in ovarian cancer, which results in the overexpression of the NF-kappaB target gene COX-2. Components of this pathway might constitute novel attractive targets for a specific therapy of advanced ovarian cancer.

Expression of lysophosphatidic acid acyltransferase beta (LPAAT-beta) in ovarian carcinoma: correlation with tumour grading and prognosis

Lysophosphatidic acid acyltransferase beta (LPAAT-β) is an enzyme involved in lipid biosynthesis whose role in tumour progression has been of emerging interest in the last few years. We investigated the expression of LPAAT-β by reverse transcriptase–polymerase chain reaction and immunohistochemistry in 10 ovarian cell lines as well as in a cohort of 106 ovarian tumours and normal ovaries. Lysophosphatidic acid acyltransferase beta mRNA was found in all cell lines and ovarian tumours examined. Expression of LPAAT-β protein was significantly increased in ovarian carcinomas compared to benign ovarian tissue (χ² test P-value=0.001, Kruskal–Wallis test P-value <0.0001). Furthermore, LPAAT-β expression was positively associated with higher tumour grade (P=0.044), higher mitotic index (P<0.0001) and tumour stage (P=0.032). Expression of LPAAT-β was significantly linked to reduced overall survival time (P=0.024) as well as to shorter progression-free survival time (P=0.012) in patients younger than 60 years. Our study shows that LPAAT-β is upregulated in ovarian cancer and is more prevalent in poorly differentiated tumours. In addition, LPAAT-β expression is a predictor of a worse prognosis in patients younger than 60 years. Further studies are needed to investigate if LPAAT-β may serve as a therapeutic target for certain subgroups of patients.

Duodenal calcium in chronic pancreatitis: is it of diagnostic value?

Chronic pancreatitis has been reported to be associated with an increased secretion of calcium in pancreatic juice. To determine whether estimation of duodenal calcium may be useful for diagnosing chronic pancreatitis, we compared duodenal calcium output in patients with chronic pancreatitis and in subjects without pancreatic disease, during intravenous infusion of secretion alone, with calcium, or with cholecystokinin-pancreozymin (CCK-PZ). Duodenal calcium output increased during infusion of both calcium and CCK-PZ to a similar extent in chronic pancreatitis and controls. Overall, duodenal output of chymotrypsin was markedly lower in chronic pancreatitis; however, chymotrypsin output increased in response to both intravenous calcium and CCK-PZ in both groups. Bilirubin output increased in both groups during calcium infusion, but this increase was significantly reduced in chronic pancreatitis; in contrast, CCK-PZ caused a similar increase in both groups. The high calcium output observed in hypercalcemia in the presence of low enzyme output suggests increased pancreatic secretion of enzyme-independent calcium in chronic pancreatitis. However, the difference is obscured by biliary calcium, which is secreted in much higher concentrations. Thus, duodenal calcium determination does not appear to be a useful diagnostic test in chronic pancreatitis.