Current perspectives of KRAS in non-small cell lung cancer.

NSCLC has a diverse genomic background with mutations in key proto-oncogenic drivers including Kirsten rat sarcoma (KRAS) and epidermal growth factor receptor (EGFR). Roughly 40% of adenocarcinoma harbor Kras activating mutations regardless of smoking history. Most KRAS mutations are located at G12, which include G12C (roughly 40%), G12V (roughly 20%), and G12D (roughly 15%). KRAS mutated NSCLC have higher tumor mutational burden and some have increased PD-1 expression, which has resulted in better responses to immunotherapy than other oncogenes. While initial treatment for metastatic NSCLC still relies on chemo-immunotherapy, directly targeting KRAS has proven to be efficacious in treating patients with KRAS mutated metastatic NSCLC. To date, two G12C inhibitors have been FDA-approved, namely sotorasib and adagrasib. In this review, we summarize the different drug combinations used to target KRAS G12c, upcoming G12D inhibitors and novel therapies targeting KRAS.

Survival in metastatic microsatellite-stable colorectal cancer correlated with tumor mutation burden and mutations identified by next-generation sequencing.

Background: Next-generation sequencing (NGS) identifies mutations and molecular abnormalities within tumors, including tumor mutation burden (TMB). If a solid tumor has high TMB, immune checkpoint inhibitors (ICIs) are approved as an option for treatment. Studies have been inconclusive regarding how effective ICI are in treating patients with colorectal cancer (CRC), and it is unclear if high TMB is a good prognostic marker for CRC. We collected data from NGS of CRC and correlated survival to both TMB and mutations of interest, as well as investigated the efficacy of ICI. Methods: This was a retrospective cohort analysis at a single institution, collecting NGS data from January 2018 to December 2020 in patients with CRC who were microsatellite-stable (MSS), n=161. Demographics, clinical data, and results from NGS were collected, and a survival analysis looking at TMB and selected mutations of interest was performed. Patients who were treated with ICI were assessed in a descriptive subset analysis. Results: Patients with CRC who were MSS and had high TMB trended towards worse survival [hazard ratio (HR) =1.38] though the result was not significant (P=0.28). Survival was significantly worse in patients with a KRAS mutation (HR =1.71, P=0.04) and/or a CDKN2A mutation (HR =4.45, P<0.001). In this study population, 12 patients with high TMB had treatment with ICI, with nine of these patients having shorter progression-free survival (PFS) between 0.7 and 4.1 months, and three patients having longer PFS of 26.3, 24.7, and 13.2 months. Conclusions: High TMB in MSS CRC did not show statistical difference in outcome. Mutations in KRAS and/or CDKN2A correlated with worse prognosis. Some patients with MSS CRC and high TMB responded to ICI, though there is a need to identify a better biomarker to predict which patients will have a good response to ICI therapy.

TKI Type Switching Overcomes ROS1 L2086F in ROS1 Fusion-Positive Cancers.

Purpose: Despite the robust efficacy of ROS1 tyrosine kinase inhibitors (TKIs) in ROS1-positive non-small cell lung cancer, TKI resistance continues to hamper durability of the therapeutic response. The resistance liabilities of next-generation ROS1 TKI are sparsely characterized. Design: We compared the activity of type I TKIs (crizotinib, entrectinib, taletrectinib, lorlatinib, and repotrectinib) to the type II TKIs (cabozantinib and merestinib), and to the type I FLT3 inhibitor, gilteritinib, in CD74-ROS1 wildtype and F2004C, L2026M, G2032R, or L2086 mutant Ba/F3 cells. The findings from the Ba/F3 cell model were confirmed using NIH3T3 colony formation assays and in vivo tumor growth. CRISPR/Cas9 gene editing was used to generate isogenic wildtype and L2086F mutant TPM3-ROS1 expressing patient-derived cell lines. These lines were used to further evaluate TKI activity using cell viability and immunoblotting methods. Molecular modeling studies enabled the characterization of structural determinants of TKI sensitivity in wildtype and mutant ROS1 kinase domains. We also report clinical cases of ROS1 TKI resistance that were treated with cabozantinib. Results: ROS1 L2086F mutant kinase is resistant to type I TKI including crizotinib, entrectinib, lorlatinib, repotrectinib, taletrectinib, while the type II TKI cabozantinib and merestinib retain activity. Additionally, we found that gilteritinib, a type I FLT3 inhibitor, inhibited wildtype and L2086F mutant ROS1, however ROS1 G2032R solvent front mutation imposed resistance. The specific binding poses adopted by cabozantinib in the DFG-out kinase conformation and gilteritinib in the DFG-in kinase, provide rationale for their activity in the ROS1 mutants. Clinical cases demonstrated response to cabozantinib in tumors developing TKI resistance due to the ROS1 L2086F mutation. Conclusion: Cabozantinib and gilteritinib effectively inhibit ROS1 L2086F. Clinical activity of cabozantinib is confirmed in patients with TKI-resistant, ROS1 L2086F mutant NSCLC. Gilteritinib may offer an alternative with distinct off-target toxicities, however further studies are required. Since cabozantinib and gilteritinib are multi-kinase inhibitors, there is a persistent unmet need for more selective and better-tolerated TKI to overcome ROS1 L2086F kinase-intrinsic resistance. Translational relevance: ROS1 L2086F is an emerging recurrent resistance mutation to type I ROS1 TKIs, including later generation TKIs. Here, we show corroborating preclinical and clinical evidence for the activity of the quinolone-based type II TKI, cabozantinib, in ROS1 L2086F resistance setting. In addition, we show activity of the pyrazine carboxamide-based type I TKI, gilteritinib, in ROS1 L2086F resistance, suggesting that gilteritinib could be another option for ROS1 L2086F TKI-resistant patients. This study represents the first comprehensive report of ROS1 L2086F in the context of later-generation TKIs, including the macrocyclic inhibitors.

Estimating the Time Toxicity of Contemporary Systemic Treatment Regimens for Advanced Esophageal and Gastric Cancers.

(1) Background: The purpose of this study was to evaluate the time toxicity, or time spent in health care, of immunotherapy- versus chemotherapy-based regimens for metastatic esophageal and gastric cancers. (2) Methods: A literature search was conducted, and 18 phase III clinical trials of immune checkpoint inhibitors were selected for analysis. Health care days were calculated based on the number of days associated with receiving therapy and the adverse events reported in the clinical trials. Both the number of health care days and the median overall survival were compared among chemotherapy-only, immunotherapy-only, and chemo-immunotherapy regimens across this cohort of drug registration trials. (3) Results: The estimated median number of health care days was 37 (range of 7-52) days, or 1.2 (range of 0.2-1.7) months, compared to a median survival of 10.2 months across these 18 studies. For the chemotherapy-only regimens, the median number of health care days was 39 (range of 21-51) days, and for chemo-immunotherapy, it was 39 (range of 30-52) days. The immunotherapy-only regimens had fewer days, a median of 28 (range of 24-41), p < 0.05, compared to the other two arms. (4) Conclusions: The chemo-immunotherapy regimens did not add time toxicity compared to chemotherapy alone. The immunotherapy-only regimens had lower time toxicity compared to chemotherapy alone. In the setting of decreased time toxicity and improved overall survival, further development of immunotherapy-based regimens could improve outcomes in advanced esophageal and gastric cancers.

Risks of hypertension and thromboembolism in patients receiving bevacizumab with chemotherapy for colorectal cancer: A systematic review and meta-analysis.

BACKGROUND: Guidelines show that for metastatic colorectal cancer (mCRC), a combination of three-drug regimens, fluorouracil, leucovorin, and oxaliplatin and bevacizumab (BVZ), is one of the first-line standard therapies. BVZ is generally well tolerated; however, it is associated with infrequent, life-threatening side effects such as severe hypertension (HTN) (5%-18%), Grade ≥3 arterial thromboembolism (ATE) (2.6%), Grade ≥3 hemorrhagic events (1.2%-4.6%), and gastrointestinal perforation (0.3%-2.4%). This meta-analysis aims to evaluate the additive risk of BVZ-induced severe HTN and thromboembolism when BVZ is combined with a standard chemotherapy regime in patients with mCRC. METHODS: Our search was conducted from January 29, 2022, to February 22, 2022, through databases of PubMed, clinicaltrial.gov, EMBASE, Web of Science, and Cochrane Library. Data analysis from randomized controlled trials (RCTs) and clinical trials was conducted using Review Manager V.5.4, comparing BVZ-chemotherapy to chemotherapy only, focusing on cardiovascular AE such as HTN and arterial and venous thromboembolism. RESULTS: The analysis from 26 clinical trials and RCTs showed that the odds of HTN were about four times higher, and ATE subgroup analysis of 11 studies showed over two times higher odds of ATE in patients being treated with BVZ compared to the chemotherapy-only group. CONCLUSION: BVZ, when added to the standard chemotherapy regimen for mCRC, was associated with higher odds of developing HTN and thromboembolism, specifically ATE, than the chemotherapy-only group. Our findings are significant as they provide vital information in analyzing the risk-benefit ratio of adding BVZ to the standard chemotherapy regime in patients with mCRC, especially in patients with vascular comorbidities.

Combining Poly (ADP-Ribose) Polymerase (PARP) Inhibitors with Chemotherapeutic Agents: Promise and Challenges.

Better understanding of molecular drivers and dysregulated pathways has furthered the concept of precision oncology and rational drug development. The role of DNA damage response (DDR) pathways has been extensively studied in carcinogenesis and as potential therapeutic targets to improve response to chemotherapy or overcome resistance. Treatment with small molecule inhibitors of PARP has resulted in clinical response and conferred survival benefit to patients with ovarian cancer, BRCA-mutant breast cancer, HRD-deficient prostate cancer and BRCA-mutant pancreatic cancer, leading to US Food and Drug Administration (FDA) approvals. However, the observed clinical benefit with single agent PARP inhibitors is limited to few tumor types within the relevant genetic context. Since DDR pathways are essential for repair of damage caused by cytotoxic agents, PARP inhibitors have been evaluated in combination with various chemotherapeutic agents to broaden the therapeutic application of this class of drugs. In this chapter, we discuss the combination of PARP inhibitors with different chemotherapeutics agents, clinical experience to date, lessons learnt, and future directions for this approach.

Paraganglioma of the Head and Neck: A Review.

OBJECTIVE: To review the epidemiology, presentation, diagnosis, and management of head and neck paragangliomas. METHODS: A literature review of english language papers with focus on most current literature. RESULTS: Paragangliomas (PGLs) are a group of neuroendocrine tumors that arise in the parasympathetic or sympathetic ganglia. Head and neck PGLs (HNPGLs) comprise 65% to 70% of all PGLs and account for 0.6% of all head and neck cancers. The majority of HNPGLs are benign, and 6% to 19% of all HNPGLs develop metastasis outside the tumor site and significantly compromise survival. PGLs can have a familial etiology with germline sequence variations in different susceptibility genes, with the gene encoding succinate dehydrogenase being the most common sequence variation, or they can arise from somatic sequence variations or fusion genes. Workup includes biochemical testing to rule out secretory components, although it is rare in HNPGLs. In addition, imaging modalities, such as computed tomography and magnetic resonance imaging, help in monitoring in surgical planning. Functional imaging with DOTATATE-positron emission tomography, 18F-fluorodeoxyglucose, or 18F-fluorohydroxyphenylalanine may be necessary to rule out sites of metastases. The management of HNPGLs is complex depending on pathology, location, and aggressiveness of the tumor. Treatment ranges from observation to resection to systemic treatment. Similarly, the prognosis ranges from a normal life expectancy to a 5-year survival of 11.8% in patients with distant metastasis. CONCLUSION: Our review is a comprehensive summary of the incidence, mortality, pathogenesis, presentation, workup and management of HNPGLs.

Application of Value Framework to Phase III Trials of Immune Checkpoint Inhibitors in Esophageal and Gastric Cancer.

BACKGROUND: Recent trials testing immune-checkpoint inhibitors in esophago-gastric malignancies have shown mixed results. We aim to assess key subgroups using the ASCO Net Health Benefit Score (NHBS) and ESMO Magnitude of Clinical Benefit Scale (MCBS). MATERIALS AND METHODS: A search for phase III trials of FDA-approved anti-PD-1 or anti-PD-L1 drugs in esophago-gastric cancer trials was identified using www.clinicaltrials.gov. These published studies were scored using the ASCO NHBS and ESMO MCBS. The ASCO NHBS scores were compared by primary site of cancer (esophageal vs gastric) and PD-L1 expression using the Mann-Whitney test and the ESMO-MCBS grading, by Fisher's Exact test. RESULTS: Fifteen of 45 clinical trials were included. Of them, 6 were primarily esophageal cancer trials, and 9 were primarily gastric cancer trials. Ten stratified their analysis based on PD-L1 expression. The ASCO NHBS score was higher (mean 40, range 20 to 56.6 vs. mean 12, range -1.1 to 18.4, P < .01) for esophageal cancer than gastric cancer. No difference was observed in survival and response endpoints between the 2 groups. Similarly, the ESMO MCBS scored higher for esophageal cancer group than gastric cancer (P < .05). Additionally, the scores were higher in those with high PD-L1 expression vs. low PD-L1 (mean 36, range 11.2-66.6 vs. mean 14, range -19.5 to 43.6, P < .05). CONCLUSION: The ASCO NHB and ESMO scores were consistently higher among esophageal cancer trials than gastric cancer trials and in those with high PD-L1 expression than low expression. Histology and PD-L1 expression should be considered when discussing value of immunotherapy to patients.

The contemporary management of cancers of the sinonasal tract in adults.

Sinonasal malignancies make up <5% of all head and neck neoplasms, with an incidence of 0.5-1.0 per 100,000. The outcome of these rare malignancies has been poor, whereas significant progress has been made in the management of other cancers. The objective of the current review was to describe the incidence, causes, presentation, diagnosis, treatment, and recent developments of malignancies of the sinonasal tract. The diagnoses covered in this review included sinonasal undifferentiated carcinoma, sinonasal adenocarcinoma, sinonasal squamous cell carcinoma, and esthesioneuroblastoma, which are exclusive to the sinonasal tract. In addition, the authors covered malignances that are likely to be encountered in the sinonasal tract-primary mucosal melanoma, NUT (nuclear protein of the testis) carcinoma, and extranodal natural killer cell/T-cell lymphoma. For the purpose of keeping this review as concise and focused as possible, sarcomas and malignancies that can be classified as salivary gland neoplasms were excluded.

Gender and Patient Satisfaction in a Veterans Health Administration Outpatient Chemotherapy Unit.

Background: Our objective was to explore whether differences in patient satisfaction based on gender exist at the Veterans Affairs Portland Health Care System (VAPHCS) outpatient chemotherapy infusion unit. Methods: Veterans who received outpatient infusion treatments at the VAPHCS outpatient chemotherapy infusion unit from 2018 to 2020 were invited to take an anonymous survey. Response differences were analyzed using Fisher exact and Welch t tests. Male and female patient lists were first generated based on Computerized Patient Record System designation, then defined and results reported based on gender self-identification from survey responses. Results: The survey was conducted over a 2-week period during January and February of 2021. In total, 69 veterans were contacted: 21 (70%) of 30 female and 20 (51%) of 39 male veterans completed the survey. Most (62%) female patients were aged < 65 years, and 52% were treated for breast cancer. Most (90%) male patients were aged ≥ 65 years, and most commonly treated for prostate cancer (20%) or a hematologic malignancy (20%). Using our survey, patient satisfaction (SD) was 8.7 (2.2) on a 10-point scale among women, and 9.6 (0.6) among men (P = .11). History of sexual abuse or harassment was reported by 86% of women compared with 10% of men (P < .001). Women reported feeling uncomfortable around other patients in the infusion unit compared with men (29% vs 0%; P = .02) and discomfort in relaying uncomfortable feelings to a clinician (29% vs 0%; P = .02). Conclusions: Gender seems to be related to how veterans with cancer perceive their ambulatory cancer care. This may be due to the combination of a high history of sexual abuse and/or harassment among women who represent a minority of the total infusion unit population, the majority of whom receive treatment for a primarily gender-specific breast malignancy. Analysis was limited by the small sample size of women, many with advanced malignancy.

Quantitative DCE-MRI prediction of breast cancer recurrence following neoadjuvant chemotherapy: a preliminary study.

INTRODUCTION: Breast cancer patients treated with neoadjuvant chemotherapy (NACT) are at risk of recurrence depending on clinicopathological characteristics. This preliminary study aimed to investigate the predictive performances of quantitative dynamic contrast-enhanced (DCE) MRI parameters, alone and in combination with clinicopathological variables, for prediction of recurrence in patients treated with NACT. METHODS: Forty-seven patients underwent pre- and post-NACT MRI exams including high spatiotemporal resolution DCE-MRI. The Shutter-Speed model was employed to perform pharmacokinetic analysis of the DCE-MRI data and estimate the Ktrans, ve, kep, and τi parameters. Univariable logistic regression was used to assess predictive accuracy for recurrence for each MRI metric, while Firth logistic regression was used to evaluate predictive performances for models with multi-clinicopathological variables and in combination with a single MRI metric or the first principal components of all MRI metrics. RESULTS: Pre- and post-NACT DCE-MRI parameters performed better than tumor size measurement in prediction of recurrence, whether alone or in combination with clinicopathological variables. Combining post-NACT Ktrans with residual cancer burden and age showed the best improvement in predictive performance with ROC AUC = 0.965. CONCLUSION: Accurate prediction of recurrence pre- and/or post-NACT through integration of imaging markers and clinicopathological variables may help improve clinical decision making in adjusting NACT and/or adjuvant treatment regimens to reduce the risk of recurrence and improve survival outcome.

Comparison of neoadjuvant regimens for resectable gastroesophageal junction cancer: a systematic review of randomized clinical trials across three decades.

Background: The optimal perioperative treatment for adenocarcinoma of gastroesophageal junction (GEJ) tumor remains uncertain. The systematic review aims to assess the best neoadjuvant modality, namely chemotherapy (CT) versus chemoradiotherapy (CRT) based on randomized controlled trials (RCTs) for resectable gastric, esophageal and GEJ tumors. Methods: We performed a comprehensive PubMed database and Cochrane Library search to identify relevant RCTs related to neoadjuvant treatment for resectable GEJ adenocarcinoma. We included all published RCTs (phase 2 or 3) that tested specific neoadjuvant therapies (CT or CRT) if the patient population included GEJ tumors. We applied the Version 2 Cochrane risk-of-bias tool (RoB 2) to all the eligible studies. Outcomes examined included R0 resection and pathological response based on intention-to-treat (ITT) analysis, surgical outcomes, notable adverse events, and overall survival (OS). Each randomized group of every study was noted to be neoadjuvant CRT, CT, or surgery alone in order to compare the outcomes among these treatment approaches. Results: We identified 25 RCTs with 7,855 patients published from 1996 to 2019. Seven studies tested preoperative CT versus surgery alone, 7 tested preoperative radiotherapy (RT) or CRT versus surgery alone, 4 tested preoperative RT or CRT versus preoperative CT, and 7 tested other combinations. The R0 resection ranged 47-100% and the 3-year OS ranged 6-66.1% in all the study arms. In an exploratory analysis, CRT strategies showed a superior R0 resection rate [80.2%; 95% confidence interval (CI): 79.8-80.6%] to surgery alone (60.9%; 95% CI: 60.4-61.3%; P<0.01) and to preoperative CT (63.9%; 95% CI: 63.6-64.2%; P<0.01). When comparing 3- and 5-year OS, improvement was noted when comparing CRT to surgery alone (P<0.01), and perioperative CT to surgery alone (P<0.01), but no definite difference was noted between CRT versus CT. Discussion: Preoperative CRT showed improvement in R0 resection rate to surgery alone and preoperative CT. However, there is no significant difference in OS between CRT and CT. Both neoadjuvant strategies remain clinically meaningful options for patients with resectable GEJ tumors. Lack of patient-level data and inconsistent reporting of key outcomes across studies were the main limitations of our study.

Assessing the risk of thromboembolism in cancer patients receiving immunotherapy.

Malignancy has long been implicated with hypercoagulability, leading to an increased rate of both venous and arterial thromboembolic events (VTE and ATE). Immunotherapy has established itself as a cornerstone of modern cancer therapy by promoting antitumor immune responses, though there have been some suggestions that immune-related adverse events could include increased rates of VTE and ATE. In this review, we examine the available evidence regarding the use of immune checkpoint inhibitors (ICIs) and thrombosis. First, we describe the potential mechanisms by which ICIs might lead to thrombophilia given the overlap between the immune system, coagulation cascade, and platelet adhesion and activation. In addition, while there are some preclinical data evaluating immunotherapy-associated ATEs in animal models, there is a paucity of evidence exploring potential mechanism of VTEs in ICIs. Second, we review the incidence of ATE and VTE in patients receiving ICIs in the published literature. Finally, we discuss current limitations in understanding, areas of conflicting evidence, and approaches to further investigation.

Hypertension, diabetes, and corresponding annual clinical testing utilization: Comparison between Asian Indians and other races/ethnicities.

Asian Indians are at increased risk of developing cardiometabolic diseases. We sought to determine differences between Asian Indians and other races/ethnicities in hypertension and diabetes prevalence and associated annual blood pressure (BP) and fasting blood glucose (FBG) testing. A total of 257,652 adults ≥18 years from the 2011-2018 U.S. National Health Interview Surveys (NHIS) were included. BP and FBG testing in the past 12 months was defined dichotomously (yes/not yes). Racial/ethnic groups included non-Hispanic White (NHW), non-Hispanic Black (NHB), Asian Indian, Other Asians, and Hispanic/Multiracial. We used logistic regression, adjusting for covariates and the survey design. Analyses were completed from 08/2020-06/2021. Asian Indians (N = 3049) had 21% and 99% higher odds of hypertension and diabetes, respectively, than NHWs (aOR [95% CI]; hypertension: 1.21[1.04,1.40], diabetes: 1.99[1.64,2.41]). Accordingly, Asian Indians without diabetes had significantly higher odds of FBG screening than NHWs (Asian Indian: 1.41[1.25,1.59], NHB: 0.99 [0.95,1.04], Other Asian: 1.07[0.98, 1.18], Hispanic: 1.13[1.07,1.20]). Asian Indians without hypertension had a 14% insignificant increase in BP testing compared to NHWs (1.14[0.97,1.33]). Predictors of testing in Asian Indians included older age, doctor's visit, graduate-level education, insurance coverage, and history of hypertension or diabetes. NHBs with diabetes and Hispanics with hypertension had lower odds of FBG testing (0.75[0.66,0.84]) and BP testing (0.85[0.79,0.92]), respectively, than NHWs. Asian Indians have higher odds of diabetes and hypertension than NHWs and higher, but relatively lower, odds of FBG and BP testing. Increasing routine BP and FBG testing in Asian Indians in younger adults may allow for earlier detection of high-risk individuals.

Distinguishing granulomas from adenocarcinomas by integrating stable and discriminating radiomic features on non-contrast computed tomography scans.

OBJECTIVE: To identify stable and discriminating radiomic features on non-contrast CT scans to develop more generalisable radiomic classifiers for distinguishing granulomas from adenocarcinomas. METHODS: In total, 412 patients with adenocarcinomas and granulomas from three institutions were retrospectively included. Segmentations of the lung nodules were performed manually by an expert radiologist in a 2D axial view. Radiomic features were extracted from intra- and perinodular regions. A total of 145 patients were used as part of the training set (Str), whereas 205 patients were used as part of test set I (Ste1) and 62 patients were used as part of independent test set II (Ste2). To mitigate the variation of CT acquisition parameters, we defined 'stable' radiomic features as those for which the feature expression remains relatively unchanged between different sites, as assessed using a Wilcoxon rank-sum test. These stable features were used to develop more generalisable radiomic classifiers that were more resilient to variations in lung CT scans. Features were ranked based on two criteria, firstly based on discriminability (i.e. maximising AUC) alone and subsequently based on maximising both feature stability and discriminability. Different machine-learning classifiers (Linear discriminant analysis, Quadratic discriminant analysis, Support vector machines and random forest) were trained with features selected using the two different criteria and then compared on the two independent test sets for distinguishing granulomas from adenocarcinomas, in terms of area under the receiver operating characteristic curve. RESULTS: In the test sets, classifiers constructed using the criteria involving maximising feature stability and discriminability simultaneously achieved higher AUC compared with the discriminating alone criteria (Ste1 [n = 205]: maximum AUCs of 0.85versus . 0.80; p-value = 0.047 and Ste2 [n = 62]: maximum AUCs of 0.87 versus. 0.79; p-value = 0.021). These differences held for features extracted from scans with <3 mm slice thickness (AUC = 0.88 versus. 0.80; p-value = 0.039, n = 100) and for the ≥3 mm cases (AUC = 0.81 versus. 0.76; p-value = 0.034, n = 105). In both experiments, shape and peritumoural texture features had a higher stability compared with intratumoural texture features. CONCLUSIONS: Our study suggests that explicitly accounting for both stability and discriminability results in more generalisable radiomic classifiers to distinguish adenocarcinomas from granulomas on non-contrast CT scans. Our results also showed that peritumoural texture and shape features were less affected by the scanner parameters compared with intratumoural texture features; however, they were also less discriminating compared with intratumoural features.

Can Tumor Location on Pre-treatment MRI Predict Likelihood of Pseudo-Progression vs. Tumor Recurrence in Glioblastoma?-A Feasibility Study.

A significant challenge in Glioblastoma (GBM) management is identifying pseudo-progression (PsP), a benign radiation-induced effect, from tumor recurrence, on routine imaging following conventional treatment. Previous studies have linked tumor lobar presence and laterality to GBM outcomes, suggesting that disease etiology and progression in GBM may be impacted by tumor location. Hence, in this feasibility study, we seek to investigate the following question: Can tumor location on treatment-naïve MRI provide early cues regarding likelihood of a patient developing pseudo-progression vs. tumor recurrence? In this study, 74 pre-treatment Glioblastoma MRI scans with PsP (33) and tumor recurrence (41) were analyzed. First, enhancing lesion on Gd-T1w MRI and peri-lesional hyperintensities on T2w/FLAIR were segmented by experts and then registered to a brain atlas. Using patients from the two phenotypes, we construct two atlases by quantifying frequency of occurrence of enhancing lesion and peri-lesion hyperintensities, by averaging voxel intensities across the population. Analysis of differential involvement was then performed to compute voxel-wise significant differences (p-value < 0.05) across the atlases. Statistically significant clusters were finally mapped to a structural atlas to provide anatomic localization of their location. Our results demonstrate that patients with tumor recurrence showed prominence of their initial tumor in the parietal lobe, while patients with PsP showed a multi-focal distribution of the initial tumor in the frontal and temporal lobes, insula, and putamen. These preliminary results suggest that lateralization of pre-treatment lesions toward certain anatomical areas of the brain may allow to provide early cues regarding assessing likelihood of occurrence of pseudo-progression from tumor recurrence on MRI scans.