Approximately 20–30% of endometrial carcinomas (EC) are characterized by mismatch repair (MMR) deficiency (dMMR) or microsatellite instability (MSI), and their testing has become part of the routine diagnosis. The aim of this study was to establish and compare the MMR status using various approaches. Immunohistochemistry (IHC), PCR-based MSI, and the detection of defects in the four key MMR genes (MLH1, PMS2, MSH2, and MSH6) via methylation-specific multiplex ligation-dependent probe amplification (MLPA) and targeted next-generation sequencing (NGS) were performed. MSH3 expression was also evaluated. A set of 126 early-stage EC samples were analyzed, 53.2% of which were dMMR and 46.8% of which were proficient MMR (pMMR) as determined using IHC, whereas 69.3% were classified as microsatellite stable, while 8.8% and 21.9% were classified MSI-low (MSI-L) and MSI-high (MSI-H), respectively. In total, 44.3% of the samples showed genetic or epigenetic alterations in one or more genes; MLH1 promoter methylation was the most common event. Although acceptable concordance was observed, there were overall discrepancies between the three testing approaches, mainly associated with the dMMR group. IHC had a better correlation with MMR genomic status than the MSI status determined using PCR. Further studies are needed to establish solid conclusions regarding the best MMR assessment technique for EC.
To compare the concordance in risk classification between the EndoPredict and the MammaPrint scores obtained for the same cancer samples on 40 estrogen-receptor positive/HER2-negative breast carcinomas.Formalin-fixed, paraffin-embedded invasive breast carcinoma tissues that were previously analyzed with MammaPrint as part of routine care of the patients, and were classified as high-risk (20 patients) and low-risk (20 patients), were selected to be analyzed by the EndoPredict assay, a second generation gene expression test that combines expression of 8 genes (EP score) with two clinicopathological variables (tumor size and nodal status, EPclin score).The EP score classified 15 patients as low-risk and 25 patients as high-risk. EPclin re-classified 5 of the 25 EP high-risk patients into low-risk, resulting in a total of 20 high-risk and 20 low-risk tumors. EP score and MammaPrint score were significantly correlated (p = 0.008). Twelve of 20 samples classified as low-risk by MammaPrint were also low-risk by EP score (60%). 17 of 20 MammaPrint high-risk tumors were also high-risk by EP score. The overall concordance between EP score and MammaPrint was 72.5% (κ = 0.45, (95% CI, 0.182 to 0.718)). EPclin score also correlated with MammaPrint results (p = 0.004). Discrepancies between both tests occurred in 10 cases: 5 MammaPrint low-risk patients were classified as EPclin high-risk and 5 high-risk MammaPrint were classified as low-risk by EPclin and overall concordance of 75% (κ = 0.5, (95% CI, 0.232 to 0.768)).This pilot study demonstrates a limited concordance between MammaPrint and EndoPredict. Differences in results could be explained by the inclusion of different gene sets in each platform, the use of different methodology, and the inclusion of clinicopathological parameters, such as tumor size and nodal status, in the EndoPredict test.
Abstract Purpose of the Study: Marine sponges have developed mechanisms to protect themselves from a hostile marine microenvironment. One of these mechanisms is the use of biologically active metabolites, explored nowadays for their anticancer properties. PM060184 is one of these compounds, isolated from the Madagascan sponge Lithoplocamia lithistoides. This polyketide is currently under evaluation on clinical trials, and its antitumor activity was previously reported in the preclinical setting in a panel of cell lines and subcutaneous tumor xenografts of different origin. The purpose of the study is to explore the effect of PM060184 in a panel of ovarian high-grade serous (HGS) carcinoma cell lines with different sensitivity to cisplatin and paclitaxel. Experimental Procedures: Cell growth inhibition was analyzed by exposure of increasing concentrations of PM060184 in 96 multiwell plates for 72h, by subsequent confluence evaluation and sulphorhodamine (SRB) staining. Cell cycle experiments were done by propidium iodide (PI) staining after treatment of cell lines at their IC50 value for 72h. Three independent experiments with 6 replicates per condition were performed for both approaches. Celigo Image Cytometer platform was employed for phase contrast and viable cells discrimination with a triple staining (Hoechst, PI and calcein AM), as well as for cell cycle analyses. Results: We have focused on the effect of this drug on a panel of HGS ovarian carcinoma cell lines, previously characterized by their response to cisplatin and paclitaxel. We have observed antiproliferative activity in a concentration-dependent manner, with IC50 values at subnanomolar concentrations in all the cell lines tested. This effect was observed in platinum-sensitive and -resistant cell lines and all of them were also more sensitive to PM060184 than paclitaxel, another tubulin-binding agent usually used for the treatment of ovarian cancer. We have evaluated cell cycle and apoptosis at the IC50 values for each cell line. We have seen that this agent disrupts the cell cycle at different phases, as DNA synthesis and mitosis, depending on the cell line. Additionally, an increase in apoptotic cell death is detected as a sub G1 peak by flow cytometry in most of the cell lines tested. Conclusions: PM060184 is a new tubulin-binding agent with a potent antitumor activity in a panel of HGS ovarian cancer cell lines, with different ranges of sensitivity to cisplatin and paclitaxel. Additionally, this effect is more potent than that exerted by other tubulin-binding compounds, such as paclitaxel. However, the underlying mechanism of PM060184 action on ovarian HGS cell lines will need to be further elucidated. Citation Format: Victoria Heredia-Soto, Andrés Redondo, Alejandro Gallego, María Miguel-Martín, Roberto Crespo, Alicia Hernández, David Hardisson, Jaime Feliu, Carlos Galmarini, Marta Mendiola. Exploratory testing of PM060184 compound in high-grade serous ovarian carcinoma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5876.
Abstract Background The results of the Grupo Español Multidisciplinar en Cáncer Digestivo (GEMCAD)-1402 phase II randomized trial suggested that adding aflibercept to modified fluorouracil, oxaliplatin, and leucovorin (mFOLFOX6) induction, followed by chemoradiation and surgery, could increase the pathological complete response (pCR) rate in patients with high-risk, locally advanced rectal cancer. Here we update results up to 3 years of follow-up and evaluate the predictive value of consensus molecular subtypes identified with immunohistochemistry (IHC). Methods Patients with magnetic resonance imaging–defined T3c-d and/or T4 and/or N2 rectal adenocarcinoma in the middle or distal third were randomly assigned to mFOLFOX6 induction, with aflibercept (mF+A; n = 115) or without aflibercept (mF; n = 65), followed by capecitabine plus radiotherapy and surgery. The risk local relapse, distant metastases, disease-free survival (DFS), and overall survival (OS) were estimated at 3 years. Selected samples were classified via IHC into immune-infiltrate, epithelial, or mesenchymal subtypes. Results mF+A and mF had 3-year DFS of 75.2% (95% confidence interval [CI] = 66.1% to 82.2%) and 81.5% (95% CI = 69.8% to 89.1%), respectively; 3-year OS of 89.3% (95% CI = 82.0% to 93.8%) and 90.7% (95% CI = 80.6% to 95.7%), respectively; 3-year cumulative local relapse incidences of 5.2% (95% CI = 1.9% to 11.0%) and 6.1% (95% CI = 1.7% to 15.0%), respectively; and 3-year cumulative distant metastases rates of 17.3% (95% CI = 10.9% to 25.5%) and 16.9% (95% CI = 8.7% to 28.2%), respectively. pCRs were achieved in 27.5% (n = 22 of 80) and 0% (n = 0 of 10) of patients with epithelial and mesenchymal subtypes, respectively. Conclusion Adding aflibercept to mFOLFOX6 induction was not associated with improved DFS or OS. Our findings suggested that consensus molecular subtypes identified with IHC subtypes could be predictive of pCR with this treatment.
Low-grade and early-stage endometrioid endometrial carcinomas (EECs) have an overall good prognosis but biomarkers identifying patients at risk of relapse are still lacking. Recently, CTNNB1 exon 3 mutation has been identified as a potential risk factor of recurrence in these patients. We evaluate the prognostic value of CTNNB1 mutation in a single-centre cohort of 218 low-grade, early-stage EECs, and the correlation with beta-catenin and LEF1 immunohistochemistry as candidate surrogate markers. CTNNB1 exon 3 hotspot mutations were evaluated by Sanger sequencing. Immunohistochemical staining of mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6), p53, beta-catenin, and LEF1 was performed in representative tissue microarrays. Tumours were also reviewed for mucinous and squamous differentiation, and MELF pattern. Nineteen (8.7%) tumours harboured a mutation in CTNNB1 exon 3. Nuclear beta-catenin and LEF1 were significantly associated with CTNNB1 mutation, showing nuclear beta-catenin a better specificity and positive predictive value for CTNNB1 mutation. Tumours with CTNNB1 exon 3 mutation were associated with reduced disease-free survival (p = 0.010), but no impact on overall survival was found (p = 0.807). The risk of relapse in tumours with CTNNB1 exon 3 mutation was independent of FIGO stage, tumour grade, mismatch repair protein expression, or the presence of lymphovascular space invasion. CTNNB1 exon 3 mutation has a negative impact on disease-free survival in low-grade, early-stage EECs. Nuclear beta-catenin shows a higher positive predictive value than LEF1 for CTNNB1 exon 3 mutation in these tumours.
564 Background: The combination of Bev-Pac significantly improved progression-free survival (PFS), compared with Pac alone in first-line treatment of HER2-negative MBC. To date only a few biomarkers relating to bevacizumab efficacy have been published, and none of them have been validated in prospective studies. The aim of this study is to build a profile predicting PFS in patients treated with Bev-Pac. Methods: 60 patients with Her2-negative MBC treated with Bev-Pac were included. RNAs were collected from formalin-fixed paraffin-embedded primary breast samples. Expression levels of 170 angiogenesis related genes were measured using quantitative real time PCR. Predictive models, genetic (G) and combined genetic-clinical (GC), were fitted by Lasso-penalized multivariate Cox proportional hazards modeling and validated by Leave One Out Cross Validation (LOOCV). Cross-validated Kaplan-Meier (KM) curves and time-dependent ROC curves were generated to estimate the predictive accuracy of the PFS models, and a log-rank permutation test was used to evaluate the statistical significance. Results: 49 patients had estrogen positive, and 11 had triple negative tumors. 60% received Bev-Pac in first line, and 40% in second or subsequent lines. Median PFS was 11.4 months. The multivariate clinical model generated with 5 variables (number of previous lines, disease free interval, estrogen receptor status, previous chemotherapy and metastatic locations) showed the last one (< 3 vs > 3 locations or liver metastasis) as the only clinical variable significantly correlated with PFS. An 11-gene profile (G model) was correlated with PFS. The G model and the GC model identified two groups of patients with different PFS, although the GC model was statistically more consistent across different time points (median PFS 17.9 months in favorable group vs. 7.4 months in the other). Conclusions: A molecular signature of 11 genes correlated with PFS in a series of patients treated with Bev-Pac. Better predictive accuracy was obtained by a combination of genetic and clinical variables.
Eribulin has shown antitumour activity in some soft tissue sarcomas (STSs), but it has only been approved for advanced liposarcoma (LPS).In this study, we evaluated the effect of eribulin on proliferation, migration and invasion capabilities in LPS, leiomyosarcoma (LMS) and fibrosarcoma (FS) models, using both monolayer (2D) and three-dimensional (3D) spheroid cell cultures. Additionally, we explored combinations of eribulin with other drugs commonly used in the treatment of STS with the aim of increasing its antitumour activity.Eribulin showed activity inhibiting proliferation, 2D and 3D migration and invasion in most of the cell line models. Furthermore, we provide data that suggest, for the first time, a synergistic effect with ifosfamide in all models, and with pazopanib in LMS as well as in myxoid and pleomorphic LPS.Our results support the effect of eribulin on LPS, LMS and FS cell line models. The combination of eribulin with ifosfamide or pazopanib has shown in vitro synergy, which warrants further clinical research.
e17504 Background: PARP inhibitors (PARPi), as Olaparib (OLA), have changed the therapeutic landscape in HGSOC and TNBC. However, most patients will develop resistance to PARPi. Although resistance mechanisms are poorly understood, it is suggested that BRCA mutations reversions or cell cycle alterations could be involved. APR-246 is a new targeted agent that restores p53 in TP53-mutated cells. The aim of our study was to assess the potential synergism of the combination of carboplatin (carbo) plus APR-246 in both OLA-sensitive and OLA-resistant HGSOC and TNBC cell lines. Methods: We selected two HGSOC (PEO1-S and Kuramochi-S) and one TNBC TP53 mutant cell lines (MDA-MB-231-S). Resistance to OLA was generated by pulse doses with IC75 OLA for 24 hours and recovered for two weeks during a period of 6 months (PEO1-R) and to increased concentrations of OLA for 72 hours during a period of 1 year (Kuramochi-R, MDA-MB-231-R). Next-generation sequencing was performed in order to assess mutations. IC50 of APR-246 and Carbo and the combination of both (combo) were calculated for Kura-S/R, PEO1-S/R and 231-S/R cell lines. Synergism between both drugs was assessed with Chou-Talalay method for combination index (CI) at Fa50. DNA damage was assessed by gamma-H2AX expression by western-blot (WB). Results: 231-S harboured a TP53 mutation (mut) (missense R280K) and BRCA wildtype (wt), in PEO1-S BRCA2 mut p.Y1655* and TP53 mut was detectable. Kuramochi-S was TP53 mut (missense D816Y) and BRCA2 mut. BRCA and p53 mutation remained unchanged in the resistant lines generated.The mutation profile of each line and the IC50 of APR-246, carbo and combo are shown in the table. IC50 of carboplatin is superior in all 3 resistant cell lines when compared to their sensitive parental line, suggesting a potential cross-resistance to platinum in OLA-resistance. The combination of carbo and APR-246 is synergistic even in OLA-resistant cell lines, in fact in those cross-resistant lines values of synergism by Chou-Talalay are improved by the combo suggesting a potential role of this combination in PARPi resistant cell lines. WB showed an increased DNA damage with the combo when compared to either single agent, with an increase in H2AX in all lines either sensitive or resistant. Conclusions: The combination of APR246 and carboplatin is synergistic in all 3 studied cell lines but also in the OLA resistant ones. The combo increased its synergistic effect suggesting a potential role of combo in OLA-resistant tumors. [Table: see text]