Background:Trastuzumab resistance hampers its well-known efficacy to control HER2-positive breast cancer. The involvement of PI3K/Akt pathway in this mechanism is still not definitively confirmed.Methods:We selected 155 patients treated with trastuzumab after development of metastasis or as adjuvant/neoadjuvant therapy. We performed immunohistochemistry for HER2, ER/PR, epidermal growth factor 1-receptor (EGFR), α-insulin-like growth factor 1-receptor (IGF1R), phosphatase and tensin homologue (PTEN), p110α, pAkt, pBad, pmTOR, pMAPK, MUC1, Ki67, p53 and p27; mutational analysis of PIK3CA and PTEN, and PTEN promoter hypermethylation.Results:We found 46% ER/PR-positive tumours, overexpression of EGFR (15%), α-IGF1R (25%), p110α (19%), pAkt (28%), pBad (22%), pmTOR (23%), pMAPK (24%), MUC1 (80%), PTEN loss (20%), and PTEN promoter hypermethylation (20%). PIK3CA and PTEN mutations were detected in 17% and 26% tumours, respectively. Patients receiving adjuvant trastuzumab with α-IGF1R or pBad overexpressing tumours presented shorter progression-free survival (PFS) (all P⩽0.043). Also, p110α and mTOR overexpression, liver and brain relapses implied poor overall survival (OS) (all P⩽0.041). In patients with metastatic disease, decreased PFS correlated with p110α expression (P=0.024), whereas for OS were the presence of vascular invasion and EGFR expression (P⩽0.019; Cox analysis).Conclusion:Our results support that trastuzumab resistance mechanisms are related with deregulation of PTEN/PI3K/Akt/mTOR pathway, and/or EGFR and IGF1R overexpression in a subset of HER2-positive breast carcinomas.

Some pituitary adenomas (PA) demonstrate aggressive behavior with local invasion and recurrences. Angiogenesis is regarded as an essential step in the formation of solid tumors. The aim of this study is to find out whether angiogenic factors may have information about the aggressiveness of PA that could be useful in determining the frequency of follow-up and whether adjuvant therapy is necessary. In this retrospective descriptive study, we evaluated vascular endothelial growth factors (VEGF) and VEGF receptor (KDR) mRNA expression by RT-PCR analysis on 46 human PA samples. Clinical data, histological subtype and radiologic characteristics were studied to determine the associations between the variables and the pre-operative behavior of the tumor. In addition, we monitored 12 patients without adjuvant post-operative therapies over 46 months after surgery, determining progression of tumor remnants and its association with these markers. VEGF expression correlates with KDR expression (r = 0.40, p = 0.006). VEGF demonstrates different expression between histological subtypes (p = 0.036). The extension at magnetic resonance imaging showed that VEGF expression was related to suprasellar extension (p = 0.007), being expressed more on tumors with extrasellar growth than intrasellar ones (p = 0.008). Our results demonstrate a 27.5 times increased risk of extrasellar growth when VEGF expression exceeds 0.222 normalized copy number (NCN) (p = 0.002). Likewise, tumors with KDR greater than 0.750 NCN had less recurrence-free survival time (p = 0.032). Our results suggest that the expression of VEGF and its receptor could be a marker for poor outcome after partial tumor resection. These data should be considered in future studies evaluating angiogenic factors as therapeutic targets in patients with PA.

The biology of breast carcinoma shows a great variation, reflected by the recent classification of phenotypes based on DNA microarrays or immunohistochemistry. The aim of this study was to determine the prevalence of insulin-like growth factor-1 receptor (IGF1R) in breast carcinoma subtypes and the impact on the outcome. We studied 197 consecutive breast carcinoma patients in stage I-II treated conservatively. Phenotypes were assessed on the basis of the expressions of ER/PR, HER2, Ki67, p53, Bcl2, CK5/6 and EGFR. Moreover, IGF1R expression (a-subunit and b-phosphorylated/active form) was evaluated by immunohistochemistry, IGF1R mRNA levels by quantitative RT-PCR and IGF1R mutations by direct DNA sequencing. Overall, 40% (78/197) of tumors were luminal A, 24% (48/197) luminal B, 19% (37/197) HER2-positive and 17% (34/197) basal/triplenegative. Luminal A tumors were predominantly of low grade, without necrosis, presenting in older patients as a r2-cm unilateral mass (all Pr0.046). a-IGF1R overexpression was observed more frequently in luminal A (49%) cases, followed by luminal B (20%), HER2-positive area under the curve (22%) and basal/triple-negative cases (9%) (P ¼ 0.01) with similar results for mRNA levels (53, 24, 13 and 10%, respectively) (P ¼ 0.038), but without differences for mutations (P ¼ NS). High IGF1R mRNA correlated with poor patient survival among subtypes (P ¼ 0.004) (Kaplan-Meier; log-rank test). For overall survival, only histological grade and IGF1R mRNA emerged as significant predictors (Pr0.034; Cox regression). Increased IGF1R mRNA implies poorer patient prognosis among the different subtypes, and that may be associated with the lack of responsiveness to tamoxifen in cases with a positive hormone receptor status. Our results highlight the biological and clinical relevance of IGF1R in early breast carcinoma subtypes, and provide knowledge to assist in treatment decision.

AimThe WHO Classification of Tumours of Endocrine Organs considers the inmunohistochemical characterization of pituitary adenomas (PA) as mandatory for patient diagnosis. Recent advances in the knowledge of the molecular patterns of these tumours could complement this classification with gene expression profiling.MethodsWithin the context of the Spanish Molecular Registry of Pituitary Adenomas (REMAH), a multicentre clinical-basic research project, we analysed the molecular phenotype of 142 PAs with complete IHC and clinical information. Gene expression levels of all pituitary hormones, type 1 corticotrophin-releasing hormone receptor, dopamine receptors and arginine vasopressin receptor 1b were measured by quantitative real-time polymerase chain reaction. In addition, we used three housekeeping genes for normalization and a pool of nine healthy pituitary glands from autopsies as calibration reference standard.ResultsBased on the clinically functioning PA (FPA: somatotroph, corticotroph, thyrotroph and lactotroph adenomas), we established the interquartile range of relative expression for all genes studied in each PA subtype. That allowed molecularly the different PA subtypes, including the clinically non-functioning PA (NFPA). Afterwards, we estimated the concordance of the molecular and immunohistochemical classification with clinical diagnosis in FPA and between them in NFPA. The kappa values were higher in molecular than in immunohistochemical classification in FPA and showed a bad concordance in all NFPA subtypes.ConclusionsAccording to these results, the molecular characterization of the PA complements the IHC analysis, allowing a better typification of the NFPA.

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