Final Results of Neoadjuvant Atezolizumab in Cisplatin-ineligible Patients with Muscle-invasive Urothelial Cancer of the Bladder.

BACKGROUND: Neoadjuvant immunotherapies hold promise in muscle-invasive bladder cancer (MIBC). OBJECTIVE: To report on 2-yr disease-free (DFS) and overall (OS) survival including novel tissue-based biomarkers and circulating tumor DNA (ctDNA) in the ABACUS trial. DESIGN, SETTING, AND PARTICIPANTS: ABACUS was a multicenter, single-arm, neoadjuvant, phase 2 trial, including patients with MIBC (T2-4aN0M0) who were ineligible for or refused neoadjuvant cisplatin-based chemotherapy. INTERVENTION: Two cycles of atezolizumab were given prior to radical cystectomy. Serial tissue and blood samples were collected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoints of pathological complete response (pCR) rate and dynamic changes to T-cell biomarkers were published previously. Secondary outcomes were 2-yr DFS and OS. A biomarker analysis correlated with relapse-free survival (RFS) was performed, which includes FOXP3, major histocompatibility complex class I, CD8/CD39, and sequential ctDNA measurements. RESULTS AND LIMITATIONS: The median follow-up time was 25 mo (95% confidence interval [CI] 25-26). Ninety-five patients received at least one cycle of atezolizumab. Eight patients did not undergo cystectomy (only one due to disease progression). The pCR rate was 31% (27/88; 95% CI 21-41). Two-year DFS and OS were 68% (95% CI 58-76) and 77% (95% CI 68-85), respectively. Two-year DFS in patients achieving a pCR was 85% (95% CI 65-94). Baseline PD-L1 and tumor mutational burden did not correlate with RFS (hazard ratio [HR] 0.60 [95% CI 0.24-1.5], p = 0.26, and 0.72 [95% CI 0.31-1.7], p = 0.46, respectively). RFS correlated with high baseline stromal CD8+ (HR 0.25 [95% CI 0.09-0.68], p = 0.007) and high post-treatment fibroblast activation protein (HR 4.1 [95% CI 1.3-13], p = 0.01). Circulating tumor DNA positivity values at baseline, after neoadjuvant therapy, and after surgery were 63% (25/40), 47% (14/30), and 14% (five/36), respectively. The ctDNA status was highly prognostic at all time points. No relapses were observed in ctDNA-negative patients at baseline and after neoadjuvant therapy. The lack of randomization and exploratory nature of the biomarker analysis are limitations of this work. CONCLUSIONS: Neoadjuvant atezolizumab in MIBC is associated with clinical responses and high DFS. CD8+ expression and serial ctDNA levels correlated with outcomes, and may contribute to personalized therapy in the future. PATIENT SUMMARY: We showed that bladder cancer patients receiving immunotherapy followed by cystectomy have good long-term outcomes. Furthermore, we found that certain biological features can predict patients who might have particular benefit from this therapy.

Stromal marker fibroblast activation protein drives outcome in T1 non-muscle invasive bladder cancer.

Fibroblast activation protein-α (FAP) is a transmembrane peptidase and a surrogate marker for cancer-associated fibroblasts (CAFs). FAP has been linked to worse prognosis and therapy resistance in several cancers. We hypothesised that FAP might have a prognostic 3biomarker potential to stratify patients with high-grade (HG) T1 non-muscle-invasive bladder cancer (NMIBC). We selected 30 patients with HG T1 NMIBC that progressed to ≥T2 disease which were pair-matched based on CUETO progression score variables with 90 patients that did not progress. After revision a final cohort of 86 patients was retained. Slides were stained for FAP, the luminal marker GATA3 and the basal marker CK5. All HG T1 tumour regions of interest (ROIs) within each patient were annotated, analysed and scored using image analysis software. FAP expression in HG T1 ROIs was significantly higher in progressors vs. non-progressors and was prognostic for recurrence-free survival, progression-free survival, cancer-specific survival, and overall survival. FAP expression in HG T1 ROIs remained strongly prognostic for these outcomes in a bivariable model corrected for adequate BCG per FDA definition. Expression of GATA3 and CK5 did not differ between progressors vs. non-progressors, and were not prognostic for these outcomes. FAP might serve as an easily applicable prognostic biomarker to risk-stratify patients with HG T1 NMIBC if these results are prospectively validated in a larger series.

Publisher Correction: Clinical efficacy and biomarker analysis of neoadjuvant atezolizumab in operable urothelial carcinoma in the ABACUS trial.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Kainic acid-induced status epilepticus decreases mGlu5 receptor and phase-specifically downregulates Homer1b/c expression.

Globally, over 50 million people are affected by epilepsy, which is characterized by the occurrence of spontaneous recurrent seizures. Almost one-third of the patients show resistance to current anti-epileptic drugs, making the exploration of new molecular targets necessary. An interesting target may be Homer1, due to its diverse roles in epileptogenesis and synaptic plasticity. Indeed, Homer1 regulates group I metabotropic glutamate (mGlu) receptors (i.e. mGlu1 and mGlu5) scaffolding and signaling in neurons. In the present work, using the systemic kainic acid (KA)-induced status epilepticus (SE) model in adult rats, we investigated the mRNA and protein expression patterns of the mGlu5 receptor, Homer1a and Homer1b/c at 10, 80 and 120 days post-SE (i.e. T10, T80 and T120). Epileptogenesis was validated by electrophysiological recordings of seizures via electroencephalography (EEG) monitoring and through upregulation of glial fibrillary acidic protein. At the protein level, the mGlu5 receptor was downregulated in the late latent phase (T10) and the early- and late exponential growth phase (T80 and T120, respectively), which was best observed in the hippocampal CA1 region. At mRNA level, significant downregulation of the mGlu5 receptor was only detected in the late exponential growth phase. Homer1a expression did not change at any investigated time point. Interestingly, Homer1b/c was only downregulated in the late latent phase, a period where spontaneous seizures are extremely rare. Thus, this phase-specific downregulation may be indicative of an endogenous neuroprotective mechanism. In conclusion, these results suggest that Homer1b/c may be an interesting molecular target to prevent epileptogenesis and/or control seizures.

Clinical efficacy and biomarker analysis of neoadjuvant atezolizumab in operable urothelial carcinoma in the ABACUS trial.

Antibodies targeting PD-1 or its ligand 1 PD-L1 such as atezolizumab, have great efficacy in a proportion of metastatic urothelial cancers1,2. Biomarkers may facilitate identification of these responding tumors3. Neoadjuvant use of these agents is associated with pathological complete response in a spectrum of tumors, including urothelial cancer4-7. Sequential tissue sampling from these studies allowed for detailed on-treatment biomarker analysis. Here, we present a single-arm phase 2 study, investigating two cycles of atezolizumab before cystectomy in 95 patients with muscle-invasive urothelial cancer (ClinicalTrials.gov identifier: NCT02662309). Pathological complete response was the primary endpoint. Secondary endpoints focused on safety, relapse-free survival and biomarker analysis. The pathological complete response rate was 31% (95% confidence interval: 21-41%), achieving the primary efficacy endpoint. Baseline biomarkers showed that the presence of preexisting activated T cells was more prominent than expected and correlated with outcome. Other established biomarkers, such as tumor mutational burden, did not predict outcome, differentiating this from the metastatic setting. Dynamic changes to gene expression signatures and protein biomarkers occurred with therapy, whereas changes in DNA alterations with treatment were uncommon. Responding tumors showed predominant expression of genes related to tissue repair after treatment, making tumor biomarker interpretation challenging in this group. Stromal factors such as transforming growth factor-ß and fibroblast activation protein were linked to resistance, as was high expression of cell cycle gene signatures after treatment.

Angiogenic desmoplastic histopathological growth pattern as a prognostic marker of good outcome in patients with colorectal liver metastases.

BACKGROUND: In patients with resectable colorectal liver metastases (CRLM), distinct histopathological growth patterns (HGPs) develop at the interface between the tumour and surrounding tissue. The desmoplastic (d) HGP is characterised by angiogenesis and a peripheral fibrotic rim, whereas non-angiogenic HGPs co-opt endogenous sinusoidal hepatic vasculature. Evidence from previous studies has suggested that patients with dHGP in their CRLM have improved prognosis as compared to patients with non-desmoplastic HGPs. However, these studies were relatively small and applied arbitrary cut-off values for the determination of the predominant HGP. We have now investigated the prognostic effect of dHGP in a large cohort of patients with CRLM resected either with or without neoadjuvant chemotherapy. METHODS: All consecutive patients undergoing a first partial hepatectomy for CRLM between 2000 and 2015 at a tertiary referral centre were considered for inclusion. HGPs were assessed in archival H&E stained slides according to recently published international consensus guidelines. The dHGP was defined as desmoplastic growth being present in 100% of the interface between the tumour and surrounding liver. RESULTS: In total, HGPs in CRLMs from 732 patients were assessed. In the chemo-naive patient cohort (n = 367), the dHGP was present in 19% (n = 68) and the non-dHGP was present in 81% (n = 299) of patients. This dHGP subgroup was independently associated with good overall survival (OS) (HR: 0.39, p < 0.001) and progression-free survival (PFS) (HR: 0.54, p = 0.001). All patients with any CRLM with a non-dHGP had significantly reduced OS compared to those patients with 100% dHGP, regardless of the proportion of non-dHGP (all p values ≤ 0.001). In the neoadjuvantly treated patient cohort (n = 365), more patients were found to express dHGP (n = 109, 30%) (adjusted odds ratio: 2.71, p < 0.001). On univariable analysis, dHGP was associated with better OS (HR 0.66, p = 0.009) and PFS (HR 0.67, p = 0.002). However, after correction for confounding by means of multivariable analysis no significant association of dHGP with OS (HR 0.92, p = 0.623) or PFS (HR 0.76, p = 0.065) was seen. CONCLUSIONS: The current study demonstrates that the angiogenic dHGP in CRLM resected from chemo-naive patients acts as a strong, positive prognostic marker, unmatched by any other prognosticator. This observation warrants the evaluation of the clinical utility of HGPs in prospective clinical trials.

The validation of Short Interspersed Nuclear Elements (SINEs) as a RT-qPCR normalization strategy in a rodent model for temporal lobe epilepsy.

BACKGROUND: In gene expression studies via RT-qPCR many conclusions are inferred by using reference genes. However, it is generally known that also reference genes could be differentially expressed between various tissue types, experimental conditions and animal models. An increasing amount of studies have been performed to validate the stability of reference genes. In this study, two rodent-specific Short Interspersed Nuclear Elements (SINEs), which are located throughout the transcriptome, were validated and assessed against nine reference genes in a model of Temporal Lobe Epilepsy (TLE). Two different brain regions (i.e. hippocampus and cortex) and two different disease stages (i.e. acute phase and chronic phase) of the systemic kainic acid rat model for TLE were analyzed by performing expression analyses with the geNorm and NormFinder algorithms. Finally, we performed a rank aggregation analysis and validated the reference genes and the rodent-specific SINEs (i.e. B elements) individually via Gfap gene expression. RESULTS: GeNorm ranked Hprt1, Pgk1 and Ywhaz as the most stable genes in the acute phase, while Gusb and B2m were ranked as the most unstable, being significantly upregulated. The two B elements were ranked as most stable for both brain regions in the chronic phase by geNorm. In contrast, NormFinder ranked the B1 element only once as second best in cortical tissue for the chronic phase. Interestingly, using only one of the two algorithms would have led to skewed conclusions. Finally, the rank aggregation method indicated the use of the B1 element as the best option to normalize target genes, independent of the disease progression and brain region. This result was supported by the expression profile of Gfap. CONCLUSION: In this study, we demonstrate the potential of implementing SINEs -notably the B1 element- as a stable normalization factor in a rodent model of TLE, independent of brain region or disease progression.

Replacement and desmoplastic histopathological growth patterns: A pilot study of prediction of outcome in patients with uveal melanoma liver metastases.

Up to 50% of uveal melanomas (UM) metastasise to the liver within 10 years of diagnosis, and these almost always prove rapidly fatal. As histopathological growth patterns (HGPs) of liver metastases of the replacement and desmoplastic type, particularly from colon and breast carcinoma, may import valuable biological and prognostic information, we have studied HGP in a series of 41 UM liver metastases originating from 41 patients from the period 2006-2017. Twenty patients underwent enucleation while 21 had radiation therapy. Analysis of UM by array comparative genomic hybridisation revealed: 25 (64%) patients with high risk (monosomy3/8q gain); 13 (33%) intermediate risk (M3/8normal or disomy3/8q gain); and 1 low risk (disomy3/8normal). The principal HGP was replacement in 30 (73%) cases and desmoplastic in 11 (27%) cases. Cases with replacement demonstrated striking vascular co-option/angiotropism. With the development of liver metastasis, only the replacement pattern, largest primary tumour diameter, and R2 (incomplete resection) status predicted diminished overall survival (OS; p < 0.041, p < 0.017, p < 0.047, respectively). On multivariate analysis, only HGP (hazard ratio; HR = 6.51, p = 0.008) and resection status remained significant. The genomic high-risk variable had no prognostic value at this stage of liver metastasis. Chi-square test showed no association of HGP with monosomy 3 or 8q gain. Eighteen of 41 (44%) patients are alive with disease and 23 (56%) patients died with follow-up ranging from 12 to 318 months (mean: 70 months, median: 47 months). In conclusion, we report for the first time the frequency of the replacement and desmoplastic HGPs in liver UM metastases resected from living patients, and their potential important prognostic value for UM patients, as in other solid cancers. These results may potentially be utilised to develop radiological correlates and therapeutic targets for following and treating patients with UM metastases.

Histopathological growth patterns as a candidate biomarker for immunomodulatory therapy.

The encroachment of a growing tumor upon the cells and structures of surrounding normal tissue results in a series of histopathological growth patterns (HGPs). These morphological changes can be assessed in hematoxylin-and-eosin (H&E) stained tissue sections from primary and metastatic tumors and have been characterized in a range of tissue types including liver, lung, lymph node and skin. HGPs in different tissues share certain general characteristics like the extent of angiogenesis, but also appropriate tissue-specific mechanisms which ultimately determine differences in the biology of HGP subtypes. For instance, in the well-characterized HGPs of liver metastases, the two main subtypes, replacement and desmoplastic, recapitulate two responses of the normal liver to injury: regeneration and fibrosis. HGP subtypes have distinct cytokine profiles and differing levels of lymphocytic infiltration which suggests that they are indicative of immune status in the tumor microenvironment. HGPs predict response to bevacizumab and are associated with overall survival (OS) after surgery for liver metastases in colorectal cancer (CRC). In addition, HGPs can change over time in response to therapy. With standard scoring methods being developed, HGPs represent an easily accessible, dynamic biomarker to consider when determining strategies for treatment using anti-VEGF and immunomodulatory drugs.

Clinical Vagus Nerve Stimulation Paradigms Induce Pronounced Brain and Body Hypothermia in Rats.

Vagus nerve stimulation (VNS) is a widely used neuromodulation technique that is currently used or being investigated as therapy for a wide array of human diseases such as epilepsy, depression, Alzheimer's disease, tinnitus, inflammatory diseases, pain, heart failure and many others. Here, we report a pronounced decrease in brain and core temperature during VNS in freely moving rats. Two hours of rapid cycle VNS (7s on/18s off) decreased brain temperature by around [Formula: see text]C, while standard cycle VNS (30[Formula: see text]s on/300[Formula: see text]s off) was associated with a decrease of around [Formula: see text]C. Rectal temperature similarly decreased by more than [Formula: see text]C during rapid cycle VNS. The hypothermic effect triggered by VNS was further associated with a vasodilation response in the tail, which reflects an active heat release mechanism. Despite previous evidence indicating an important role of the locus coeruleus-noradrenergic system in therapeutic effects of VNS, lesioning this system with the noradrenergic neurotoxin DSP-4 did not attenuate the hypothermic effect. Since body and brain temperature affect most physiological processes, this finding is of substantial importance for interpretation of several previously published VNS studies and for the future direction of research in the field.

Vagus Nerve Stimulation Applied with a Rapid Cycle Has More Profound Influence on Hippocampal Electrophysiology Than a Standard Cycle.

Although vagus nerve stimulation (VNS) is widely used, therapeutic mechanisms and optimal stimulation parameters remain elusive. In the present study, we investigated the effect of VNS on hippocampal field activity and compared the efficiency of different VNS paradigms. Hippocampal electroencephalography (EEG) and perforant path dentate field-evoked potentials were acquired before and during VNS in freely moving rats, using 2 VNS duty cycles: a rapid cycle (7 s on, 18 s off) and standard cycle (30 s on, 300 s off) and various output currents. VNS modulated the evoked potentials, reduced total power of the hippocampal EEG, and slowed the theta rhythm. In the hippocampal EEG, theta (4-8 Hz) and high gamma (75-150 Hz) activity displayed strong phase amplitude coupling that was reduced by VNS. Rapid-cycle VNS had a greater effect than standard-cycle VNS on all outcome measures. Using rapid cycle VNS, a maximal effect on EEG parameters was found at 300 µA, beyond which effects saturated. The findings suggest that rapid-cycle VNS produces a more robust outcome than standard cycle VNS and support already existing preclinical evidence that relatively low output currents are sufficient to produce changes in brain physiology and thus likely also therapeutic efficacy.