MGMT Methylation and Differential Survival Impact by Sex in Glioblastoma.

Introduction: Sex differences in glioblastoma (GBM) have been observed in incidence, genetic and epigenetic alterations, and immune response. These differences have extended to the methylation of the MGMT promoter, which critically impacts temozolomide resistance. However, the association between sex, MGMT methylation, and survival is poorly understood, which this study sought to evaluate. Methods: A retrospective cohort study was conducted and reported following STROBE guidelines, based on adults with newly diagnosed GBM who received their first surgical intervention at Cleveland Clinic (Ohio, USA) between 2012 and 2018. Kaplan-Meier and multivariable Cox proportional hazards models were used to analyze the association between sex and MGMT promoter methylation status on overall survival (OS). MGMT was defined as methylated if the mean of CpG 1-5 ≥ 12. Propensity score matching was performed on a subset of patients to evaluate the effect of individual CpG site methylation. Results: A total of 464 patients had documented MGMT methylation status with a mean age of 63.4 (range 19-93) years. A total of 170 (36.6%) were female, and 133 (28.7%) received gross total resection as a first intervention. A total of 42.5% were MGMT methylated, with females more often having MGMT methylation than males (52.1% vs. 37.4%, p = 0.004). In univariable analysis, OS was significantly longer for MGMT promoter methylated than un-methylated groups for females (2 yr: 36.8% vs. 11.1%; median: 18.7 vs. 9.5 months; p = 0.001) but not for males (2 yr: 24.3% vs. 12.2%; median: 12.4 vs. 11.3 months; p = 0.22, p for MGMT-sex interaction = 0.02). In multivariable analysis, MGMT un-methylated versus methylated promoter females (2.07; 95% CI, 1.45-2.95; p < 0.0001) and males (1.51; 95% CI, 1.14-2.00; p = 0.004) had worse OS. Within the MGMT promoter methylated group, males had significantly worse OS than females (1.42; 95% CI: 1.01-1.99; p = 0.04). Amongst patients with data on MGMT CpG promoter site methylation values (n = 304), the median (IQR) of CpG mean methylation was 3.0% (2.0, 30.5). Females had greater mean CpG methylation than males (11.0 vs. 3.0, p < 0.002) and higher per-site CpG methylation with a significant difference at CPG 1, 2, and 4 (p < 0.008). After propensity score matching, females maintained a significant survival benefit (18.7 vs. 10.0 months, p = 0.004) compared to males (13.0 vs. 13.6 months, p = 0.76), and the pattern of difference was significant (P for CpG-sex interaction = 0.03). Conclusions: In this study, females had higher mean and individual CpG site methylation and received a greater PFS and OS benefit by MGMT methylation that was not seen in males despite equal degrees of CpG methylation.

Impact of KRAS mutation status on the efficacy of immunotherapy in lung cancer brain metastases.

Immune checkpoint inhibitors (ICIs) have resulted in improved outcomes in non-small cell lung cancer (NSCLC) patients. However, data demonstrating the efficacy of ICIs in NSCLC brain metastases (NSCLCBM) is limited. We analyzed overall survival (OS) in patients with NSCLCBM treated with ICIs within 90 days of NSCLCBM diagnosis (ICI-90) and compared them to patients who never received ICIs (no-ICI). We reviewed 800 patients with LCBM who were diagnosed between 2010 and 2019 at a major tertiary care institution, 97% of whom received stereotactic radiosurgery (SRS) for local treatment of BM. OS from BM was compared between the ICI-90 and no-ICI groups using the Log-Rank test and Cox proportional-hazards model. Additionally, the impact of KRAS mutational status on the efficacy of ICI was investigated. After accounting for known prognostic factors, ICI-90 in addition to SRS led to significantly improved OS compared to no-ICI (12.5 months vs 9.1, p < 0.001). In the 109 patients who had both a known PD-L1 expression and KRAS status, 80.4% of patients with KRAS mutation had PD-L1 expression vs 61.9% in wild-type KRAS patients (p = 0.04). In patients without a KRAS mutation, there was no difference in OS between the ICI-90 vs no-ICI cohort with a one-year survival of 60.2% vs 54.8% (p = 0.84). However, in patients with a KRAS mutation, ICI-90 led to a one-year survival of 60.4% vs 34.1% (p = 0.004). Patients with NSCLCBM who received ICI-90 had improved OS compared to no-ICI patients. Additionally, this benefit appears to be observed primarily in patients with KRAS mutations that may drive the overall benefit, which should be taken into account in the development of future trials.

Neutrophil to lymphocyte ratio influences impact of steroids on efficacy of immune checkpoint inhibitors in lung cancer brain metastases.

Steroids are often utilized to manage patients with non-small cell lung cancer brain metastases (NSCLCBM). Steroids and elevated neutrophil-to-lymphocyte ratio (NLR) have been associated with decreased overall survival (OS) in patients treated with immune checkpoint inhibitors (ICI). We retrospectively investigated patients treated with ICI after the diagnosis of NSCLCBM at a single tertiary care institution examing the impact of steroids and NLR. Overall survival (OS) and intracranial progression-free survival (PFS) were analyzed. 171 patients treated with ICI for NSCLCBM were included. Thirty-six received steroids within 30 days of the start of ICI, and 53 patients had an NLR ≥ 5 before the start of ICI. Upfront steroids was associated with decreased OS on multivariable analysis (median OS 10.5 vs. 17.9 months, p = .03) and intracranial PFS (5.0 vs. 8.7 months, p = .045). NLR ≥ 5 was indicative of worse OS (10.5 vs. 18.4 months, p = .04) but not intracranial PFS (7.2 vs. 7.7 months, p = .61). When NLR and upfront steroids are modeled together, there is a strong interaction (p = .0008) indicating that the impact of steroids depended on the patient's NLR. In a subgroup analysis, only in patients with NLR < 4 was there a significant difference in OS with upfront steroids (26.1 vs. 15.6 months, p = .032). The impact of steroids on the efficacy of ICI in patients with NSCLCBM is dependent on the patient's NLR underscoring its importance in these patients. Patients with a low NLR, steroid use decreases the efficacy of ICI. These results can inform clinicians about the impact of steroids in patients treated with ICI.

Sexually dimorphic radiogenomic models identify distinct imaging and biological pathways that are prognostic of overall survival in glioblastoma.

BACKGROUND: Recent epidemiological studies have suggested that sexual dimorphism influences treatment response and prognostic outcome in glioblastoma (GBM). To this end, we sought to (i) identify distinct sex-specific radiomic phenotypes-from tumor subcompartments (peritumoral edema, enhancing tumor, and necrotic core) using pretreatment MRI scans-that are prognostic of overall survival (OS) in GBMs, and (ii) investigate radiogenomic associations of the MRI-based phenotypes with corresponding transcriptomic data, to identify the signaling pathways that drive sex-specific tumor biology and treatment response in GBM. METHODS: In a retrospective setting, 313 GBM patients (male = 196, female = 117) were curated from multiple institutions for radiomic analysis, where 130 were used for training and independently validated on a cohort of 183 patients. For the radiogenomic analysis, 147 GBM patients (male = 94, female = 53) were used, with 125 patients in training and 22 cases for independent validation. RESULTS: Cox regression models of radiomic features from gadolinium T1-weighted MRI allowed for developing more precise prognostic models, when trained separately on male and female cohorts. Our radiogenomic analysis revealed higher expression of Laws energy features that capture spots and ripple-like patterns (representative of increased heterogeneity) from the enhancing tumor region, as well as aggressive biological processes of cell adhesion and angiogenesis to be more enriched in the "high-risk" group of poor OS in the male population. In contrast, higher expressions of Laws energy features (which detect levels and edges) from the necrotic core with significant involvement of immune related signaling pathways was observed in the "low-risk" group of the female population. CONCLUSIONS: Sexually dimorphic radiogenomic models could help risk-stratify GBM patients for personalized treatment decisions.

Outcomes of Sphincter Pharyngoplasty in the Cleft Population.

INTRODUCTION: Sphincter pharyngoplasty (SP) is becoming increasingly popular for correction of velopharyngeal insufficiency (VPI) after cleft palate repair because of high success rate, low incidence of postoperative obstructive sleep apnea (OSA), and ease of revision in case of failure. This study is a meta-analysis of SP outcomes, reasons for failure, and revision strategies. METHODS: A comprehensive review of the literature on SP outcomes was conducted. Sphincter pharyngoplasty failure was defined as persistent hypernasality, incomplete velopharyngeal port (VP) closure on instrumental evaluation with concomitant VPI, or nonresolving hyponasality and/or OSA persisting >3 months after surgery. Two-tailed paired Student t test was used to compare outcomes between syndromic versus nonsyndromic patients and preoperative versus postoperative OSA rates. RESULTS: Forty-four publications evaluating 2402 patients were included. Overall SP success rate was 78.4% (77.3% in nonsyndromic vs 84.8% in syndromic patients, P = 0.11). Overall primary revision rate was 17.8% (20% in nonsyndromic vs 15.4% in syndromic patients P = 0.97). Most failures (89.5%) manifested as persistent VPI with continued hypernasality requiring revision, whereas 10.5% of failures manifested as obstructive symptoms and/or severe hyponasality requiring revision. Causal factors of SP failure were the following: large central port (62.8%), dehiscence (15.5%), tight port (12.1%), and low-inset (9.7%). Primary revision success rate was 75.6%. Obstructive sleep apnea rates increased from 5.1% to 18.4% (P = 0.02). CONCLUSIONS: This study suggests that SP can resolve VPI in 78.4% of patients, which can be increased to 94.7% after one revision. Most failures are technique-dependent; therefore, there could be significant ground for improvement of outcomes.

Developing a protocol for normothermic ex-situ limb perfusion.

BACKGROUND: Ischemia time represents a significant limitation for successful extremity transplantation because of the rapid deterioration of ischemic muscle. Normothermic ex-situ preservation is an emergent method to prolong the organ viability following procurement, by replicating the physiologic conditions. The aim of this study was to develop an ex-situ normothermic limb perfusion system to preserve the viability and function of porcine limbs for 12 hours following procurement. METHODS: A total of 18 swine limbs were perfused. Thirteen limbs were used to develop the perfusion protocol. Five limbs were perfused according to the optimized protocol. These limbs were perfused at 39°C for twelve hours using an oxygenated colloid solution containing red blood cells. Glucose and electrolytes were kept within physiologic range by partial perfusate exchange. Limb specific perfusion quality was assessed by muscle contractility upon electrical nerve stimulation, compartment pressure, creatine kinase (CK) and myoglobin concentrations, tissue oxygen saturation (near infrared spectroscopy), indocyanine green angiography, and infrared radiation by thermographic imaging. RESULTS: The last five limbs reached the 12 hours' perfusion target maintaining normal compartment pressure (16.4 ± 8.20 mmHg), minimal weight increase (0.54 ± 7.35%), and mean muscle temperature of 33.6 ± 1.67°C. Myoglobin and CK concentrations were 875 ± 291.4 ng/mL, and 53344 ± 14850.34 U/L, respectively, at the end of perfusion. Muscle contraction was present in all limbs until cessation of perfusion. Differences in uniformity and quality of distal perfusion were identified with thermography and angiography imaging at 12 hours of perfusion. CONCLUSIONS: Ex-situ normothermic limb perfusion preserves swine limb physiology and function for at least 12 hours.

Lessons learned reconstructing complex scalp defects using free flaps and a cranioplasty in one stage.

BACKGROUND: The purpose of this study was to review our experience in single-stage reconstruction of skull and scalp defects, aiming to highlight pitfalls in our management. METHODS: We performed a retrospective chart review of all patients who had a single-stage cranioplasty and free-tissue transfer at our institution over the last 10 years. Thirteen patients (9 men and 4 women) with an average age of 66.5 years (range, 34-83 years) were identified. Etiology of the defects included malignancy (n = 7), osteoradionecrosis (n = 3), and infection (n = 3). The size of the bony defect averaged 103.1 cm(2) (range, 12-300 cm(2)). Cranioplasty procedures included reconstruction by methylmethacrylate and titanium mesh (n = 10), methylmethacrylate only (n = 1), or mesh only (n = 2). Free flaps used were anterolateral thigh (n = 10), latissimus dorsi (n = 2), or a rectus flap (n = 1). RESULTS: Five patients (38%) developed at least 1 complication. These included 2 anastomotic problems that were successfully salvaged, 5 cases of wound dehiscence, and 1 mortality due to a respiratory event. Four patients developed a recurrence, and 2 patients required flap contouring at a second stage. Two patients had further reconstruction using 1 (1 patient) or 2 (1 patient) additional free flaps. CONCLUSIONS: Given the complexity of these procedures, the high recurrence rate, and the likelihood of complications, methylmethacrylate is contraindicated in 1-stage cranioplasty and soft-tissue reconstruction in high-risk patients. For unfavorable local conditions (eg previous infection, radiotherapy), the surgeon can either postpone the cranioplasty until the soft-tissue reconstruction has healed, or use a nonanatomical titanium mesh alone. The soft-tissue flap should be harvested of larger dimensions than anticipated.