Octavio Burgués

PI3K Pathway Mutations and PTEN Levels in Primary and Metastatic Breast Cancer

The purpose of this work was to determine whether there are differences in PIK3CA mutation status and PTEN protein expression between primary and matched metastatic breast tumors as this could influence patient management. Paraffin sections of 50 μm were used for DNA extraction and slides of 3 μm for immunohistochemistry (IHC) and FISH. Estrogen receptor, progesterone receptor, and HER2 IHC were repeated in a central laboratory for both primary tumors and metastases. PTEN levels were assessed by IHC and phosphoinositide 3-kinase (PI3K) pathway mutations were detected by a mass spectroscopy–based approach. Median age was 48 years (range: 30–83 years). Tumor subtype included 72% hormone receptor positive/HER2 negative, 20% HER2-positive, and less than 7.8% triple receptor negative. Tissues were available for PTEN IHC in 46 primary tumors and 52 metastases. PTEN was lost in 14 (30%) primary tumors and 13 (25%) metastases. There were five cases of PTEN loss and eight cases of PTEN gain from primary tumors to metastases (26% discordance). Adequate DNA was obtained from 46 primary tumors and from 50 metastases for PIK3CA analysis. PIK3CA mutations were detected in 19 (40%) of primary tumors and 21 (42%) of metastases. There were five cases of PIK3CA mutation loss and four cases of mutation gain (18% discordance). There was an increase of the level of PIK3CA mutations in four cases and decrease in one case from primary tumors to metastases. There is a high level of discordance in PTEN level, PIK3CA mutations, and receptor status between primary tumors and metastases that may influence patient selection and response to PI3K-targeted therapies. Mol Cancer Ther; 10(6); 1093–101. ©2011 AACR.

Concordance of Genomic Alterations between Primary and Recurrent Breast Cancer

There is growing interest in delivering genomically informed cancer therapy. Our aim was to determine the concordance of genomic alterations between primary and recurrent breast cancer. Targeted next-generation sequencing was performed on formalin-fixed paraffin-embedded (FFPE) samples, profiling 3,320 exons of 182 cancer-related genes plus 37 introns from 14 genes often rearranged in cancer. Point mutations, indels, copy-number alterations (CNA), and select rearrangements were assessed in 74 tumors from 43 patients (36 primary and 38 recurrence/metastases). Alterations potentially targetable with established or investigational therapeutics were considered “actionable.” Alterations were detected in 55 genes (mean 3.95 alterations/sample, range 1–12), including mutations in PIK3CA, TP53, ARID1A, PTEN, AKT1, NF1, FBXW7, and FGFR3 and amplifications in MCL1, CCND1, FGFR1, MYC, IGF1R, MDM2, MDM4, AKT3, CDK4, and AKT2. In 33 matched primary and recurrent tumors, 97 of 112 (86.6%) somatic mutations were concordant. Of identified CNAs, 136 of 159 (85.5%) were concordant: 37 (23.3%) were concordant, but below the reporting threshold in one of the matched samples, and 23 (14.5%) discordant. There was an increased frequency of CDK4/MDM2 amplifications in recurrences, as well as gains and losses of other actionable alterations. Forty of 43 (93%) patients had actionable alterations that could inform targeted treatment options. In conclusion, deep genomic profiling of cancer-related genes reveals potentially actionable alterations in most patients with breast cancer. Overall there was high concordance between primary and recurrent tumors. Analysis of recurrent tumors before treatment may provide additional insights, as both gains and losses of targets are observed. Mol Cancer Ther; 13(5); 1382–9. ©2014 AACR.

Cutaneous sclerosing Pacinian-like perineurioma

Cutaneous sclerosing Pacinian‐like perineurioma

Hepatoid adenocarcinoma of the urinary bladder

Abstract A new case of hepatoid adenocarcinoma was diagnosed in fragments obtained at transurethral resection (TUR) from a 71-year-old man who had complained of haematuria. The tumour was composed of trabeculae and small solid nests of polygonal atypical cells simulating hepatocarcinoma, together with glandular areas of an otherwise typical adenocarcinoma. Immunohistochemistry showed cytoplasmic reactivity to AFP, AAT, albumin and CAM 5.2. Membrane reactivity was seen in EMA immunostaining, and there was also positivity to polyclonal CEA following a canalicular pattern. Immunoperoxidase studies of hepatocyte growth factor (HGF) and its receptor, c-met, were positive. Their expression may be related to the aggressive behaviour of this tumour.

Patterns of HER2 Gene Amplification and Response to Anti-HER2 Therapies

A chromosomal region that includes the gene encoding HER2, a receptor tyrosine kinase (RTK), is amplified in 20% of breast cancers. Although these tumors tend to respond to drugs directed against HER2, they frequently become resistant and resume their malignant progression. Gene amplification in double minutes (DMs), which are extrachromosomal entities whose number can be dynamically regulated, has been suggested to facilitate the acquisition of resistance to therapies targeting RTKs. Here we show that ~30% of HER2-positive tumors show amplification in DMs. However, these tumors respond to trastuzumab in a similar fashion than those with amplification of the HER2 gene within chromosomes. Furthermore, in different models of resistance to anti-HER2 therapies, the number of DMs containing HER2 is maintained, even when the acquisition of resistance is concomitant with loss of HER2 protein expression. Thus, both clinical and preclinical data show that, despite expectations, loss of HER2 protein expression due to loss of DMs containing HER2 is not a likely mechanism of resistance to anti-HER2 therapies.

Determination of somatic oncogenic mutations linked to target-based therapies using MassARRAY technology

Somatic mutation analysis represents a useful tool in selecting personalized therapy. The aim of our study was to determine the presence of common genetic events affecting actionable oncogenes using a MassARRAY technology in patients with advanced solid tumors who were potential candidates for target-based therapies. The analysis of 238 mutations across 19 oncogenes was performed in 197 formalin-fixed paraffin-embedded samples of different tumors using the OncoCarta Panel v1.0 (Sequenom Hamburg, Germany). Of the 197 specimens, 97 (49.2%) presented at least one mutation. Forty-nine different oncogenic mutations in 16 genes were detected. Mutations in KRAS and PIK3CA were detected in 40/97 (41.2%) and 30/97 (30.9%) patients respectively. Thirty-one patients (32.0%) had mutations in two genes, 20 of them (64.5%) initially diagnosed with colorectal cancer. The co-occurrence of mutation involved mainly KRAS, PIK3CA, KIT and RET. Mutation profiles were validated using a customized panel and the Junior Next-Generation Sequencing technology (GS-Junior 454, Roche). Twenty-eight patients participated in early clinical trials or received specific treatments according to the molecular characterization (28.0%). MassARRAY technology is a rapid and effective method for identifying key cancer-driving mutations across a large number of samples, which allows for a more appropriate selection for personalized therapies.

Biphasic dermatofibrosarcoma protuberans with a labyrinthine plexiform high-grade fibrosarcomatous transformation

Several variants of dermatofibrosarcoma protuberans, a low‐grade superficial sarcoma, are well recognized. The most prognostically important is the fibrosarcomatous variant. We report a case of biphasic dermatofibrosarcoma protuberans in which the high‐grade component exhibited a previously undescribed plexiform pattern. A clinicopathological study complemented with immunohistochemical, ultrastructural, reverse transcription polymerase chain reaction and fluorescence in situ hybridization analyses of this unique case. Histopathologically, a conventional low‐grade dermatofibrosarcoma protuberans was admixed with intratumoral high‐grade areas showing a striking labyrinthine plexiform pattern characterized by a higher cellularity of larger and slightly atypical tumor cells. CD34 expression was present in both components, while Ki‐67 immunostaining was significantly higher in the plexiform high‐grade areas. Focal epithelial membrane antigen and claudin‐1 immunostaining was present at the interphase between high‐ and low‐grade areas. COL1A1‐PDGFB fusion transcripts, with breakpoints at exon 25 of COL1A1 and exon 2 of PDGFB, were present in both components, being more numerous, as the extra copies of both genes, in the high‐grade areas. A previously undescribed histopathologic pattern of high‐grade sarcomatous transformation of dermatofibrosarcoma protuberans is reported: a biphasic tumor with a labyrinthine plexiform high‐grade component.

The ever-evolving role of pathologists in the management of breast cancer with neoadjuvant treatment: recommendations based on the Spanish clinical experience

AbstractPurposeTo compare the current international standards for neoadjuvant systemic therapy (NAST) protocols, and establish consensus recommendations by Spanish breast pathologists; and to look into the Spanish reality of defining pathological complete response in daily practice. Materials and methodsA modified Delphi technique was used to gain consensus among a panel of 46 experts with regard to important issues about NAST specimens, with the objective of standardize handling and analysis of these breast cancer specimens. In addition, a survey was conducted among 174 pathologists to explore the Spanish reality of post-NAST breast cancer specimens handling. ResultsOur survey shows that pathologists in Spain follow the same guidelines as their international colleagues and face the same problems and controversies. Among the experts, 94.1% agreed on the recommendation for a pre-treatment evaluation with a core needle biopsy, and 100% of experts agreed on the need of having properly indicated information for the post-NAST surgical specimens. However, only 82.7% of them receive properly labelled specimens and even less receive specimens where markers are identified and the degree of clinical/radiological response is mentioned. Among participants 59.9% were familiar with the residual cancer burden system for post-NAST response quantification, but only 16.1% used it regularly. ConclusionsActive participation on breast cancer multidisciplinary teams, optimal usage of core needle biopsy for timely and standardized procedures for the diagnostic analysis, and accurate diagnosis of pathological complete response and complete evaluation of the response to NAST need to become the standard practice when handling breast cancer specimens in Spain.

Abstract P1-14-12: Validation of residual cancer burden index (RCB) as a prognostic tool in patients with early breast cancer (EBC) treated with neoadjuvant chemotherapy (NAC): Comparison of RCB and Miller & Payne system (M&P)

Pathological evaluation of response after NAC is a controversial issue. MP San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-14-12.

Abstract P1-14-13: Residual proliferative cancer burden (RPCB) is superior to RCB index as prognostic tool in early breast cancer patients (EBC) treated with neoadjuvant chemotherapy (NAC)

BACKGROUND: Many different scales have been developed in order to assess response to NAC. Apart from Miller and Payne and RCB systems, recently the addiction of post-NAC pathological Ki 67 (yp Ki67) to RCB, called RPCB system, has been considered as a more accurate prognostic tool. The aim of this study is to assess the prognosis value of RPCB in a routine practice cohort and to compare it to RCB index and ypKi67. METHODS: We performed a retrospective analysis of our database. Patients with stage I-III considered candidate for NAC from July 2008 and August 2011 were included. RPCB and RCB were calculated as previously published. Hormone receptor expression (HR), ypKi 67 and Her2 were assessed following international guidelines. The Harell c-index were used to compare the prognostic value of RPCB, RCB and ypKi 67. Clinical, therapeutic and pathological data were obtained from medical records. A correlation with disease-free survival (DFS) and overall survival (OS) was done using the Kaplan-Meier method and Cox regression model. RESULTS: From our database including 333 EBC patients treated with NAC 184 had data to calculate RPCB, RCB and ypKi 67, of whom 51.6% were HR+Her2- tumours, 21.7% HR+Her2+, 8.2% HR- Her2+ and 18.5% triple negative. Mean tumour size was 37.5 mm (25-45). The majority of the patients had histhological grade II-III tumours (84.2%) and N stage 0-1 (96.7%). 67.4% of the patients received anthracycline and taxane-based NAC, associated to trastuzumab in Her2+ patients (26.1%). Pathological complete response by subtypes were 6.3%, 17.5%, 60% and 26.5%, respectively. With a median follow-up of 49.9 months, DFS and OS at 36 months were 85.2% and 95.1%. In the multivariate analysis all three systems were prognostic for DFS (RPCB p CONCLUSION: RPCB, RCB and ypKi67 are prognostic for both DFS and OS in EBC patients treated with NAC. RPCB is a more accurate prognostic tool than ypKi67 and showed a trend towards superiority compared to RCB. Citation Format: Pons V, Perez-Fidalgo JA, Burgues O, Martin P, Cejalvo JM, Bermejo B, LLuch A. Residual proliferative cancer burden (RPCB) is superior to RCB index as prognostic tool in early breast cancer patients (EBC) treated with neoadjuvant chemotherapy (NAC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-14-13.