B. Asselain

Outcome impact of PIK3CA mutations in HER2-positive breast cancer patients treated with trastuzumab

Background:Phosphatidylinositol 3-kinase (PI3K) pathway activation has been suggested to negatively influence response to anti-HER2 therapy in breast cancer patients. The present study focused on mutations of the PIK3CA gene, encoding one of the two PI3K subunits.Methods:PIK3CA mutations were assessed by direct sequencing in 80 HER2-positive patients treated with 1 year of trastuzumab. All patients preoperatively received four cycles of anthracycline-based chemotherapy, followed by four cycles of docetaxel and 1 year of trastuzumab, starting either before surgery with the first cycle of docetaxel and continuing after surgery (neoadjuvant trastuzumab arm, n=43), or only after surgery (adjuvant trastuzumab arm, n=37).Results:PIK3CA mutations were found in 17 tumours (21.3%). Better disease-free survival (DFS) was observed in patients with PIK3CA wild-type compared with mutated tumours (P=0.0063). By combining PIK3CA status and treatment arms, four separate prognostic groups with significantly different DFS (P=0.0013) were identified.Conclusion:These results confirm that the outcome of HER2-positive patients treated with trastuzumab is significantly worse in patients with PIK3CA-mutated compared with wild-type tumours.

Circulating tumor cell detection and transcriptomic profiles in early breast cancer patients

In the early 2000s, studies using high-throughput transcriptomic analyses revealed different aspects of breast cancer biology. Several outcome-based predictors and biologybased classifiers have been proposed: invasiveness gene signature (IGS), intrinsic molecular subtype, wound-response signature, etc. Recently, circulating tumor cell (CTC) cytological detection has been associated with metastasis-free and overall survival in the REMAGUS02 neoadjuvant trial [1]. In this article, we report, for the first time, the transcriptomic analysis of 60 nonmetastatic breast cancers according to CTC detection. The REMAGUS02 trial included breast cancer patients with locally advanced or large breast cancer. CTC detection was carried out at baseline and at the end of chemotherapy using the CellSearch system (Veridex, Raritan, NJ). Total RNA extracted from the pretreatment cancer biopsy was hybridized on the GeneChip Human Genome U1331 2.0 Array (Affymetrix, Santa Clara, CA). Conditions of the sampling procedures and RNA quality control are detailed elsewhere [2]. The genechip robust multi-array average procedure [3] was used to normalize the gene expression data. A hierarchical clustering was then carried out using the 10 000 probe sets that showed the highest values in the interquartile range (IQR). We applied the intrinsic gene set on the complete dataset of 60 samples to define the molecular subtypes and the IGS. We used the defined and validated centroids of 306 genes to discriminate between previously identified molecular breast cancer subtypes. We matched the probe list UniGene ID (Build#204) to the GeneChip Human Genome U133A 2.0 Array, resulting in a list of 294 unique probe sets. Each sample was assigned to the nearest subtype/centroid as determined by the highest Spearman rank order correlation between the gene expression values of the 294 probe sets and the 5 subtype centroids. The IGS score was determined by calculating the Pearson correlation between the probe set expression values of each sample and the 110 reference expression levels of the same genes defining the IGS signature. Single probe set analyses were carried out using the Wilcoxon rank sum test. Finally, because half of the probe sets showed the highest IQR values, a significance analysis of microarray (SAM) was proposed to detect differentially associated genes (DEG) between CTCpositive and -negative patients. At first, unsupervised clustering revealed three major tumor clusters; they unsurprisingly corresponded to triplenegative, human epithelial growth factor receptor 2(HER2)positive/estrogen receptor (ER)-negative, and ER-positive breast cancer immunohistological phenotypes. CTC detection was not statistically different among these three clusters (Figure 1). Breast cancers were then classified according to selected biology-based signatures: the intrinsic subtype classifier and IGS, which is stemness related. CTC detection was not statistically different among subgroups: basal, n = 6/18 (33%); HER2, n = 3/10 (33%); luminal A, n = 2/15 (13%); luminal B, n = 2/10 (20%); normal like, n = 2/7 (29%); low-risk IGS, n = 9/27 (33%); and high-risk IGS, n = 6/33 (18%). Single probe set analyses were then carried out on candidate genes that are directly involved in CTC detection by the CellSearch system (cytokeratin 8, 18, 19, and EpCAM) or that are surrogate markers for breast cancer stem cells (CD24, CD44, ALDH1A1): messenger RNA levels were not correlated with CTC positivity. In addition, at the high false discovery rate of 30%, only 18 DEG were found using a SAM procedure. This is the first study, to date, to correlate CTC detection in nonmetastatic breast cancer with the gene expression profile of the primary tumor. We did not confirm previously published in vitro experiments that suggested that normal-like

Prognostic Biomarkers Used for Localised Prostate Cancer Management: A Systematic Review

CONTEXT Prostate cancer stratification is based on tumour size, pretreatment PSA level, and Gleason score, but it remains imperfect. Current research focuses on the discovery and validation of novel prognostic biomarkers to improve the identification of patients at risk of aggressive cancer or of tumour relapse. OBJECTIVE This systematic review by the Intergroupe Coopérateur Francophone de Recherche en Onco-urologie (ICFuro) analysed new evidence on the analytical validity and clinical validity and utility of six prognostic biomarkers (PHI, 4Kscore, MiPS, GPS, Prolaris, Decipher). EVIDENCE ACQUISITION All available data for the six biomarkers published between January 2002 and April 2015 were systematically searched and reviewed. The main endpoints were aggressive prostate cancer prediction, additional value compared to classical prognostic parameters, and clinical benefit for patients with localised prostate cancer. EVIDENCE SYNTHESIS The preanalytical and analytical validations were heterogeneous for all tests and often not adequate for the molecular signatures. Each biomarker was studied for specific indications (candidates for a first or second biopsy, and potential candidates for active surveillance, radical prostatectomy, or adjuvant treatment) for which the level of evidence (LOE) was variable. PHI and 4Kscore were the biomarkers with the highest LOE for discriminating aggressive and indolent tumours in different indications. CONCLUSIONS Blood biomarkers (PHI and 4Kscore) have the highest LOE for the prediction of more aggressive prostate cancer and could help clinicians to manage patients with localised prostate cancer. The other biomarkers show a potential prognostic value; however, they should be evaluated in additional studies to confirm their clinical validity. PATIENT SUMMARY We reviewed studies assessing the value of six prognostic biomarkers for prostate cancer. On the basis of the available evidence, some biomarkers could help in discriminating between aggressive and non-aggressive tumours with an additional value compared to the prognostic parameters currently used by clinicians.

Abstract P1-14-03: Overall survival results of a multicenter randomized phase II study in locally advanced breast cancer patients treated with or without neoadjuvant Trastuzumab for HER2 positive tumor (Remagus 02 trial)

Background: Trastuzumab is indicated in neoadjuvant setting in locally advanced HER2 positive breast cancer patients (Gianni L. Lancet 2010). There is no data on the impact of the use of neoadjuvant Trastuzumab (T) compared to adjuvant T on survival. Patients and methods: From May 2004 to October 2007, 341 stage II-III breast cancer patients were included in a phase II randomized trial and received 4 cycles (c) of epirubicin (75 mg/m2 d1)–cyclophosphamide (750 mg/m2 d1) q 3 w followed by 4 (c) of docetaxel (100 mg/m2 d1) q 3 w. Pts with HER2+++ tumor (120 pts) were randomized to receive or not neoadjuvant T combined with docetaxel. From September 2005, all pts with HER2+cancer received adjuvant T for a total of 18 c (106 pts). All pts with hormone receptors positive tumor received hormonal treatment according to menopausal status (Pierga et al BCRT 2010). We report here overall survival (OS) and disease free survival (DFS) data at 5 year and associated prognostic factors. Results: At a median follow up of 49 months, the median DFS was not reached for the whole population and was statistically superior for the HER2 positive cancer patients treated with chemotherapy plus neoadjuvant T compared to the other groups, p = 0.018. The median OS is not reached for the whole population and is statistically higher in HER2 positive tumor group compared to HER2 negative group (p = 0.00077). For 106 HER2 positive breast cancer patients who had received one year of complete trastuzumab treatment, there was no significant difference in OS and DFS between pts who started T in neoadjuvant setting versus in adjuvant setting. DFS and OS were not significantly influenced by pathological Complete Response rate (pCR) (respectively, p = 0.22 and p = 0.56). At multivariate analysis including 6 factors (age, tumor size, clinical lymph node, ER, PgR), factors which influenced OS were tumor size (p = 0.03) and ER expression (p = 0.06) and for DFS, clinical lymph node status (p = 0.049) and PgR expression (p = 0.046). Conclusion: pCR is not a surrogate of survival in the HER2+subgroup. HER2 positive breast cancer pts receiving trastuzumab have a significant higher OS than those with HER2 negative tumors. OS and DFS do not seem to differ between the neoadjuvant T group and the T adjuvant group. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-03.