Haris Zahoor

Brain and Peripheral Atypical Inflammatory Mediators Potentiate Neuroinflammation and Neurodegeneration

Neuroinflammatory response is primarily a protective mechanism in the brain. However, excessive and chronic inflammatory responses can lead to deleterious effects involving immune cells, brain cells and signaling molecules. Neuroinflammation induces and accelerates pathogenesis of Parkinson’s disease (PD), Alzheimer’s disease (AD) and Multiple sclerosis (MS). Neuroinflammatory pathways are indicated as novel therapeutic targets for these diseases. Mast cells are immune cells of hematopoietic origin that regulate inflammation and upon activation release many proinflammatory mediators in systemic and central nervous system (CNS) inflammatory conditions. In addition, inflammatory mediators released from activated glial cells induce neurodegeneration in the brain. Systemic inflammation-derived proinflammatory cytokines/chemokines and other factors cause a breach in the blood brain-barrier (BBB) thereby allowing for the entry of immune/inflammatory cells including mast cell progenitors, mast cells and proinflammatory cytokines and chemokines into the brain. These peripheral-derived factors and intrinsically generated cytokines/chemokines, α-synuclein, corticotropin-releasing hormone (CRH), substance P (SP), beta amyloid 1–42 (Aβ1–42) peptide and amyloid precursor proteins can activate glial cells, T-cells and mast cells in the brain can induce additional release of inflammatory and neurotoxic molecules contributing to chronic neuroinflammation and neuronal death. The glia maturation factor (GMF), a proinflammatory protein discovered in our laboratory released from glia, activates mast cells to release inflammatory cytokines and chemokines. Chronic increase in the proinflammatory mediators induces neurotoxic Aβ and plaque formation in AD brains and neurodegeneration in PD brains. Glial cells, mast cells and T-cells can reactivate each other in neuroinflammatory conditions in the brain and augment neuroinflammation. Further, inflammatory mediators from the brain can also enter into the peripheral system through defective BBB, recruit immune cells into the brain, and exacerbate neuroinflammation. We suggest that mast cell-associated inflammatory mediators from systemic inflammation and brain could augment neuroinflammation and neurodegeneration in the brain. This review article addresses the role of some atypical inflammatory mediators that are associated with mast cell inflammation and their activation of glial cells to induce neurodegeneration.

Smoothened Inhibition Leads to Decreased Proliferation and Induces Apoptosis in Esophageal Adenocarcinoma Cells

The Hedgehog (Hh) pathway is known to be active in Barretts carcinogenesis. Therefore, we evaluated the efficacy and underlying mechanisms of inhibition of cancer cell growth by the smoothened (Smo) antagonist BMS-833923 in esophageal adenocarcinoma (EAC) cell lines. Cell proliferation and apoptosis were evaluated by flow cytometry, Western blotting, immunofluorescence, and quantitative reverse transcription polymerase chain reactions. Results showed that the Smo antagonist led to reduced Hh pathway activity, resulting in decreased cell proliferation and induction of apoptosis via the intrinsic pathway in the esophageal cancer cells. In conclusion, the Smo antagonist may have application as an EAC chemotherapeutic agent.

A propensity-matched analysis comparing survival after primary minimally invasive esophagectomy followed by adjuvant therapy to neoadjuvant therapy for esophagogastric adenocarcinoma.

OBJECTIVES Prognosis for patients with locally advanced esophagogastric adenocarcinoma (EAC) is poor with surgery alone, and adjuvant therapy after open esophagectomy is frequently not tolerated. After minimally invasive esophagectomy (MIE); however, earlier return to normal function may render patients better able to receive adjuvant therapy. We examined whether primary MIE followed by adjuvant chemotherapy influenced survival compared with propensity-matched patients treated with neoadjuvant therapy. METHODS Patients with stage II or higher EAC treated with MIE (N = 375) were identified. Using 30 pretreatment covariates, propensity for assignment to either neoadjuvant followed by MIE (n = 183; 54%) or MIE as primary therapy (n = 156; 46%) was calculated, generating 97 closely matched pairs. Hazard ratios were adjusted for age, sex, body mass index, smoking, comorbidity, and final pathologic stage. RESULTS In propensity-matched pairs, adjusted hazard ratio for death did not differ significantly for primary MIE compared with neoadjuvant (hazard ratio, 0.83; 95% confidence interval, 0.60-1.16). Recurrence patterns were similar between groups and 65% of patients with IIb or greater pathologic stage received adjuvant therapy. Clinical staging was inaccurate in 37 out of 105 patients (35%) who underwent primary MIE (n = 18 upstaged and n = 19 downstaged). CONCLUSIONS Primary MIE followed by adjuvant chemotherapy guided by pathologic findings did not negatively influence survival and allowed for accurate staging compared with clinical staging. Our data suggest that primary MIE in patients with resectable EAC may be a reasonable approach, improving stage-based prognostication and potentially minimizing overtreatment in patients with early stage disease through accurate stage assignments. A randomized controlled trial testing this hypothesis is needed.

The revised American Joint Committee on Cancer staging system (7th edition) improves prognostic stratification after minimally invasive esophagectomy for esophagogastric adenocarcinoma

BACKGROUND Staging for esophagogastric adenocarcinoma lacked sufficient prognostic accuracy and was revised. We compared survival prognostication between American Joint Committee on Cancer (AJCC) 6th and 7th editions. METHODS We abstracted data for 836 patients who underwent minimally invasive esophagectomy for esophagogastric adenocarcinoma (n = 256 neoadjuvant). Monotonicity and strength of survival trends, by stage, were assessed (log-rank test of trend chi-square statistic) and compared using permutation testing. Overall survival (Cox regression) and model fit (Akaike Information Criterion) were determined. RESULTS A greater log-rank test of trend statistic indicated stronger survival trends by stage in AJCC 7th (152.872 vs 167.623; permutation test P < .001) edition. Greater Cox likelihood chi-square value (162.957 vs 173.951) and lower Akaike Information Criterion (4,831.011 vs 4,820.016) indicated better model fit. Superior performance was also shown after neoadjuvant therapy. CONCLUSION AJCC 7th edition staging for esophagogastric adenocarcinoma provides superior prognostic stratification after minimally invasive esophagectomy, overall and after neoadjuvant therapy compared with AJCC 6th edition.

Emerging growth factor receptor antagonists for the treatment of renal cell carcinoma

ABSTRACT Introduction: The landscape of systemic treatment for metastatic renal cell carcinoma (RCC) has dramatically changed with the introduction of targeted agents including vascular endothelial growth factor (VEGF) inhibitors. Recently, multiple new agents including growth factor receptor antagonists and a checkpoint inhibitor were approved for the treatment of refractory metastatic RCC based on encouraging benefit shown in clinical trials. Areas covered: The background and biological rationale of existing treatment options including a brief discussion of clinical trials which led to their approval, is presented. This is followed by reviewing the limitations of these therapeutic options, medical need to develop new treatments and major goals of ongoing research. We then discuss two recently approved growth factor receptor antagonists i.e. cabozantinib and lenvatinib, and a recently approved checkpoint inhibitor, nivolumab, and issues pertaining to drug development, and future directions in treatment of metastatic RCC. Expert opinion: Recently approved growth factor receptor antagonists have shown encouraging survival benefit but associated drug toxicity is a major issue. Nivolumab, a programmed death 1 (PD-1) checkpoint inhibitor, has similarly shown survival benefit and is well tolerated. With multiple options now available in this patient population, the right sequence of these agents remains to be determined.

Pro-Inflammatory Cytokines Predict Relapse-Free Survival after One Month of Interferon-α but Not Observation in Intermediate Risk Melanoma Patients

Background E1697 was a phase III trial of adjuvant interferon (IFN)-α2b for one month (Arm B) versus observation (Arm A) in patients with resected melanoma at intermediate risk. We evaluated the levels of candidate serum cytokines, the HLA genotype, polymorphisms of CTLA4 and FOXP3 genes and the development of autoantibodies for their association with relapse free survival (RFS) in Arm A and Arm B among 268 patients with banked biospecimens. Methods ELISA was used to test 5 autoantibodies. Luminex/One Lambda LABTypeRSSO was used for HLA Genotyping. Selected CTLA4 and FOXP3 Single nucleotide polymorphisms (SNPs) and microsatellites were tested for by polymerase chain reaction (PCR). Sixteen serum cytokines were tested at baseline and one month by Luminex xMAP multiplex technology. Cox Proportional Hazards model was applied and the Wald test was used to test the marginal association of each individual marker and RFS. We used the Lasso approach to select the markers to be included in a multi-marker Cox Proportional Hazards model. The ability of the resulting models to predict one year RFS was evaluated by the time-dependent ROC curve. The leave-one-out method of cross validation (LOOCV) was used to avoid over-fitting of the data. Results In the multi-marker modeling analysis conducted in Arm B, one month serum IL2Rα, IL-12p40 and IFNα levels predicted one year RFS with LOOCV AUC = 82%. Among the three markers selected, IL2Rα and IFNα were the most stable (selected in all the cross validation cycles). The risk score (linear combination of the 3 markers) separated the RFS curves of low and high risk groups well (p = 0.05). This model did not hold for Arm A, indicating a differential marker profile in Arm B linked to the intervention (adjuvant therapy). Conclusions Early on-treatment proinflammatory serum markers (IL2Rα, IL-12p40, IFNα) significantly predict RFS in our cohort of patients treated with adjuvant IFN-α2b and warrant further study.

Mast Cell Proteases Activate Astrocytes and Glia-Neurons and Release Interleukin-33 by Activating p38 and ERK1/2 MAPKs and NF-κB

Inflammatory mediators released from activated microglia, astrocytes, neurons, and mast cells mediate neuroinflammation. Parkinson’s disease (PD) is characterized by inflammation-dependent dopaminergic neurodegeneration in substantia nigra. 1-Methyl-4-phenylpyridinium (MPP+), a metabolite of parkinsonian neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), induces inflammatory mediators’ release from brain cells and mast cells. Brain cells’ interaction with mast cells is implicated in neuroinflammation. However, the exact mechanisms involved are not yet clearly understood. Mouse fetal brain-derived cultured primary astrocytes and glia-neurons were incubated with mouse mast cell protease-6 (MMCP-6) and MMCP-7, and mouse bone marrow-derived mast cells (BMMCs) were incubated with MPP+ and brain protein glia maturation factor (GMF). Interleukin-33 (IL-33) released from these cells was quantitated by enzyme-linked immunosorbent assay. Both MMCP-6 and MMCP-7 induced IL-33 release from astrocytes and glia-neurons. MPP+ and GMF were used as a positive control-induced IL-33 and reactive oxygen species expression in mast cells. Mast cell proteases and MPP+ activate p38 and extracellular signal-regulated kinases 1/2 (ERK1/2), mitogen-activated protein kinases (MAPKs), and transcription factor nuclear factor-kappa B (NF-κB) in astrocytes, glia-neurons, or mast cells. Addition of BMMCs from wt mice and transduction with adeno-GMF show higher chemokine (C-C motif) ligand 2 (CCL2) release. MPP+ activated glial cells and reduced microtubule-associated protein 2 (MAP-2) expression indicating neurodegeneration. IL-33 expression increased in the midbrain and striatum of PD brains as compared with age- and sex-matched control subjects. Glial cells and neurons interact with mast cells and accelerate neuroinflammation and these interactions can be explored as a new therapeutic target to treat PD.

Feasibility of Cisplatin-Based Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer Patients With Diminished Renal Function

Micro‐Abstract A retrospective analysis assessed chemotherapy tolerability and outcomes of patients with glomerular filtration rate (GFR) < 60 mL/min who received cisplatin‐based neoadjuvant chemotherapy for muscle‐invasive bladder cancer. Patients with impaired GFR had more treatment discontinuations and modifications relative to normal GFR patients, but most completed intended treatment cycles. For carefully selected patients with impaired GFR, cisplatin‐based chemotherapy remains a treatment option. Background: Cisplatin‐based neoadjuvant chemotherapy (NAC) before radical cystectomy is the standard of care in muscle‐invasive bladder cancer. There are limited data regarding chemotherapy tolerability and outcomes for patients with low glomerular filtration rate (GFR) who receive cisplatin‐based NAC. Patients and Methods: A retrospective analysis of patients who received cisplatin‐based NAC at Cleveland Clinic (2005‐2016) was undertaken. Patients with pre‐NAC GFR < 60 mL/min by either Cockcroft‐Gault (CG) or Modification of Diet in Renal Disease (MDRD) formula were compared to patients with GFR ≥ 60 mL/min for NAC tolerability, pathologic complete and partial response (pPR), and the ability to undergo radical cystectomy. Results: Thirty patients with low GFR (34‐59 mL/min) and 94 patients with normal GFR (≥ 60 mL/min) were identified. Low GFR patients were older (median, 71 vs. 65 years), but other demographic and transurethral resection of bladder tumor characteristics were comparable. Low GFR patients more frequently had early NAC discontinuation (30% vs. 13%), NAC modifications (delays, dose reduction, or discontinuation, 66% vs. 40%), and cisplatin‐based NAC administered in split doses (37% vs. 16%). No differences in NAC tolerability or outcomes were noted among low GFR patients receiving split‐dose versus standard regimens. No differences were noted between low and normal GFR patients in NAC cycles (median, 3 for each), cystectomy rates (93% for each), time to cystectomy, and GFR change from baseline to after NAC. Pathologic complete response was higher among normal GFR patients (24% vs. 14%). Conclusion: Patients with low GFR had more NAC discontinuations and modifications, but most completed planned NAC cycles. For carefully selected patients with GFR < 60 mL/min, cisplatin‐based NAC remains a treatment option.

Patient Characteristics, Treatment Patterns and Prognostic Factors in Squamous Cell Bladder Cancer

Background Squamous cell carcinoma (SCC) is an uncommon histologic subtype of bladder cancer with limited data on treatment patterns, outcomes, and prognostic factors. “Real world” information might inform decision‐making, prognostic estimates, and clinical trial designs. Patients and Methods A retrospective review of patients with tissue‐confirmed bladder SCC treated at Cleveland Clinic from 2007 to 2016 was performed. Data on patient characteristics, treatment patterns, and clinical follow‐up were extracted. Univariate analysis was used to identify predictors of overall survival (OS), recurrence‐free survival (RFS) and time to recurrence. Results Of 58 identified patients, 42 had complete data available. Median age at diagnosis was 67 years (range, 37‐90). Hematuria was the most common (71%) presenting symptom; 32 patients had pure SCC and 10 predominant/extensive squamous differentiation without major differences noted in clinicopathologic variables or outcomes among those 2 groups. Overall, 35 patients underwent cystectomy with 5 receiving neoadjuvant and 1 adjuvant chemotherapy, whereas 3 had chemotherapy for recurrent disease. Of patients with cystectomy, most had locally advanced disease (75% pT3/4, 35% pN+). Overall, 10 patients progressed and 14 died; median OS was not reached. The 2‐year estimated OS, RFS, and cumulative incidence of recurrence were 61% ± 9%, 50% ± 9%, and 32% ± 9%, respectively. Hydronephrosis, older age (70 years or older), lymphovascular invasion, nodal metastases, and advanced T stage were associated with 1 or more poor outcomes. Conclusion In patients with resectable bladder SCC, radical cystectomy remains the main treatment modality. The role of perioperative chemotherapy remains unclear. The identified prognostic factors might be helpful for prognostication, treatment discussion, and trial eligibility/stratification. Micro‐Abstract Bladder squamous cell carcinoma (SCC) is rare with limited data on prognosis and treatment patterns. Herein we present a retrospective review of patients with bladder SCC treated at our institution. Radical cystectomy was the main treatment for resectable disease. The identified prognostic factors might help prognostication, treatment decision, and trial eligibility/stratification.

Extended therapy breaks from VEGFR TKI therapy in renal cell carcinoma: Sometimes less is more

The treatment landscape of metastatic renal cell carcinoma (mRCC) dramatically changed with the introduction of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI) [1]. Despite major advances in the field of immunotherapy, TKIs remain a fundamental therapy in mRCC. Novel methods to optimize VEGFR TKI delivery are thus critical to improve clinical outcomes while minimizing toxicity. A primary challenge with TKIs is the balance of clinical efficacy and associated toxicities of longterm therapy. Treatment breaks were incorporated into the development of VEGFR TKIs to limit toxicities, suggesting that continuous treatment is not always necessary and that extended periods off treatment might be feasible without compromising clinical outcomes. Retrospective and prospective data support the feasibility of intermittent TKI dosing with extended breaks. A retrospective analysis investigated whether patients with mRCC treated with TKI (sunitinib or sorafenib) who achieve complete response (CR) on treatment, can take a treatment break until relapse [2]. Of 53 patients who stopped treatment, 29 (55%) remained without recurrent disease at a median follow up of 8.5 months. The majority of the remaining 24 patients who relapsed were able to reinitiate the same TKI and maintained antitumor response, indicating that TKIs can be stopped and restarted in select patients. Similarly, the impact of treatment breaks of 3 months or longer for reasons other than progressive disease (PD) in mRCC patients receiving VEGFR TKI was evaluated in a retrospective study of 112 patients [3]. The median duration of the initial break was 16.8 months with a range of 12.5-26.4 months off therapy. Achievement of CR prior to the initial treatment break (n = 15) was associated with a longer surveillance period (p = .0004). These retrospective data further indicate that TKI treatment breaks are feasible in some patients. The concept of prolonged treatment breaks was prospectively investigated in a randomized discontinuation trial of sorafenib, in which mRCC patients with stable disease after 12 weeks of sorafenib were randomly assigned to receive placebo or to continue sorafenib. The progression free survival (PFS) in patients who were assigned to placebo but then crossed over at progression to restart sorafenib, was similar to patients who were continued on sorafenib. Patients who were in the placebo arm had more tumor growth but the antitumor effect of sorafenib was maintained upon reinitiating treatment, further highlighting that extended breaks from therapy do not necessarily compromise clinical outcomes [4]. Additional prospective data supporting the feasibility of intermittent TKI dosing with extended breaks in patients with mRCC was recently published [5]. Patients with treatment-naïve mRCC were treated with 4 cycles of sunitinib and then restaged. Patients who had >10% reduction in tumor burden (TB) were taken off therapy. These patients then underwent imaging every two cycles and resumed therapy only if there was an increase in TB >10%. Following treatment reinitiation, treatment would again be held for >10% TB reduction. This intermittent treatment schedule was continued until progressive disease (PD) or unacceptable toxicities. Of 37 patients, 20 patients had >10% TB decrease and all patients (100%) entered the intermittent phase. The median duration of the treatment breaks was 8.3 weeks (range, 4.7 to 192.1 weeks) with seven patients having prolonged treatment breaks lasting 3.2 to 43.6 months. The clinical efficacy in this intermittent treatment trial (objective response rate (ORR) of 46% and median PFS of 22.4 months) was no worse than previously reported data in first line treatment with sunitinib [6, 7], thus suggesting that intermittent treatment with sunitinib is feasible and doesn’t compromise clinical activity in carefully selected patients. A phase II/III clinical trial in UK is ongoing with a goal of randomizing 1000 mRCC patients to standard dosing or intermittent dosing of sunitinib [8]. The overall aim of the trial is to determine whether intermittent dosing schedule is non-inferior to standard dosing in terms overall survival and quality of life. Results of this trial will further solidify the existing data to support intermittent dosing schedule of sunitinib. In summary, TKIs have changed the treatment landscape of RCC and will continue to play an important role in the treatment of RCC in the future. Challenges in TKI delivery include mitigating long-term toxicities while maintaining clinical efficacy, and strategies like prolonged treatment breaks are critical to optimize the delivery of TKIs.