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.

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.

A meta-analysis of bevacizumab’s cardiovascular risks in patients treated for colorectal cancer

113

Background: Bevacizumab (BVZ), a recombinant humanized monoclonal IgG antibody, is commonly used as first- and second-line adjuvant therapy in metastatic colorectal cancer. Recent guidelines have shown that a combination of three cytotoxic drug regimens FOLFOX (fluorouracil, leucovorin and oxaliplatin) along with BVZ is regarded as one of the first-line options. As we see an upward trend in using BVZ; it is crucial to analyze the side effects and potential toxicities. A frequent adverse effect with BVZ is hypertension. The prevailing hypothesis for the mechanism of BVZ induced hypertension is an increase in vascular tone due to the inhibition of VEGF-mediated vasodilation. A persistent elevation of arterial blood pressure is generally asymptomatic, but unmanaged hypertension can lead to cardiovascular complications, encephalopathy, and subarachnoid hemorrhage. Therefore, this meta-analysis aims to evaluate and assess the risk of BVZ induced hypertension. Methods: Our search included articles from PubMed, EMBASE, Web of Science, and Cochrane Library from 1980 to March 2022. Randomized controlled trials and clinical trials with BVZ as an add-on therapy mentioning cardiovascular side effects were included. Full analysis control group included various guideline directed chemotherapies and the subgroup analysis control group focused on FOLFOX therapy. A random-effects model was used with Review Manager, and a P value < 0.05 was considered significant. Results: We included a total of 17,807 patients in our study with an average age of 65 years. Analysis pooled from 19 RCTs showed that the odds of hypertension (Grade 3 or more) in patients treated with BVZ were about four times higher than the control group (OR 3.82, 95% CI 3.35-4.36, p-value < 0.00001, I2 = 78%). In a subgroup analysis, BVZ was compared with FOLFOX group, with odds of hypertension (Grade 3 or more) in BVZ group being about five times higher than in FOLFOX group (OR 5.24, 95% CI 4.06-6.77, p-value < 0.00001, I2 = 58%). Conclusions: Our meta-analysis demonstrates a significant cardiovascular risk of Bevacizumab when added to the standard regime for advanced colorectal cancer treatment. When BVZ was used as an add-on therapy to FOLFOX regimens for colorectal cancer, it was associated with about five times higher odds of developing hypertension (Grade 3 or more) in the treatment group with BVZ. Previous RCTs have demonstrated that BVZ add-on therapy to the standard regime is safe and without significant risk of toxicity. Our findings are important as they give vital information in assessing the risk-benefit ratio of adding BVZ, especially in a population with vascular comorbidities. Now that we have established the statistical significance of hypertensive risk with BVZ, it will be interesting to see how these events can be prevented in patients treated for metastatic colorectal cancer. Dedicated RCTs are needed to confirm these findings.

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.

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.

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.

Immunotherapy in head and neck squamous cell carcinoma: An updated review

Squamous cell cancer of the head and neck (HNSCC) is the sixth most common cancer and is associated with significant morbidity and mortality. The tumor microenvironment for HNSCC is a complex interplay of immune cells, stromal cells, and cytokines amongst others. Immunotherapy acts as an effective antineoplastic agent by influencing this complex environment and includes immune checkpoint inhibitors (ICI). ICI have been approved in the frontline setting for recurrent and metastatic (R/M) HNSCC as well as platinum-refractory (second line) R/M HNSCC. However, recent clinical studies highlight that the response to immunotherapy varies, and different ICI, as well as different combination strategies play a crucial role in augmenting the efficacy of immunotherapy. An in-depth analysis and focused study of the immune contexture in patients with HNSCC receiving ICI remains critical. Many novel immunotherapies including CAR-T cell therapy, oncolytic virus therapy, and vaccines are underway. Ongoing trials are testing ICI in the neoadjuvant and adjuvant settings. Furthermore, identifying better biomarkers to target population that benefits from immunotherapy is of paramount importance. Pioneering the optimal combination regimen utilizing new novel immunotherapy has recently become a paradigm shift in the HNSCC treatment landscape. Herein, we summarize the clinical development with all ongoing clinical trials of immunotherapy in HNSCC.

Improving patient satisfaction and care delivery for female veteran patients with cancer receiving outpatient infusion therapies

279

Background: Our objective was to explore if differences in patient satisfaction based on gender exist in a Veterans Health Administration (VHA) outpatient chemotherapy infusion unit. Methods: Veterans who received outpatient infusion treatments from 2018 to 2020 were contacted by phone and agreed to partake in an anonymous 25 question online survey. Response differences were analyzed using Fisher’s exact and Welch's t-tests. Results: 69 veterans were contacted. 70% (21/30) of women and 51% (20/39) of male veterans completed the survey. Most women were < 65 years (62%), and 52% treated for breast cancer. 90% of men were > 65 years old, majority treated for prostate cancer (20%) or a hematological cancer (20%). Using our survey, patient satisfaction was 8.71/10 points (± 0.60) in women vs. 9.55 (± 2.24) in men (p = 0.113). 86% of women endorsed hx of sexual abuse or harassment vs 10% of men (p < 0.001). More women vs men felt uncomfortable around other patients and unable to voice uncomfortable experiences to a provider in the infusion unit (p < 0.05). Not statistically significant but potential clinical importance was more women felt uncomfortable around the offending gender (29% vs 0%), more women felt greater emotional support and importance with access to a tx room with the same gender (29% vs 0%), and more women preferred access to a gender specific restroom (30% vs 20%). Conclusions: Gender appears related to how veterans with cancer perceive their ambulatory cancer care. This may be due to the combination of high sexual abuse and/or harassment hx amongst women who are a minority of the total infusion unit population, the majority of whom receive tx for a primarily gender specific breast malignancy. Analysis was limited by the small sample size of women, many with advanced malignancy. Ongoing initiatives based on these survey results are underway and may be applicable to other outpatient cancer center facilities where patient demographic and infusion unit design may be similar.[Table: see text]

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.

Application of value framework to phase III trials of immune checkpoint inhibitors in esophageal and gastric cancer

e18817

Background: Recent clinical trials testing use of immune-checkpoint inhibitors in esophageal and gastric carcinomas have shown both positive and negative results. Given these mixed signals, we aimed to assess outcomes and tolerability of key subgroups using the ASCO Net Health Benefit Score (NHBS) and ESMO Magnitude of Clinical Benefit Scale (MCBS). Methods: A detailed search for phase III trials investigating use of FDA-approved anti PD-1 or anti PD-L1 drugs in esophageal and gastric cancer trials was completed using www.clinicaltrials.gov followed by primary literature identification on PubMed. These studies were then independently selected, reviewed, and scored using the ASCO NHBS and ESMO MCBS by two investigators, and any discrepancy was mutually resolved. The ASCO NGBS scores were compared by primary site of cancer (esophageal vs gastric) and PD-L1 expression using the Mann-Whitney test. The ESMO-MCBS grading were compared using Fisher's Exact test. Results: Of the 45 records identified, 15 clinical trials were included. Of them, six were primarily esophageal cancer trials, and nine were primarily gastric cancer trials. Of all 15, 10 stratified their analysis based on PD-L1 expression. The ASCO NHBS score was significantly higher for esophageal cancer than gastric cancer (mean 40, range 20 – 56.6 vs. mean 12, range -1.1 – 18.4, p < .01). No difference, however, was observed in survival and response rate outcome endpoints between the two groups. Similarly, the ESMO MCBS was also higher for esophageal cancer group than gastric cancer (p < .05). Additionally, the median scores were higher in the patients with high PD-L1 expression vs low PD-L1 expression (mean 37, range 11.2 – 66.6 vs. mean 14, range -19.5 – 43.6, p < .05). Conclusions: In this cohort of drug registration trials of immune checkpoint inhibitors for upper GI cancers, we showed the ASCO NHB scores and ESMO scores were consistently higher among esophageal cancer trials than gastric cancer trials and in those with high PD-L1 expression than those with low PD-L1 expression. Oncologists should carefully discuss overall clinical value and expectations of immunotherapy benefit with their patients per cancer histology and PDL1 expression, exercising caution in cases of gastric adenocarcinoma with low PD-L1 expression.[Table: see text]

Duration of treatment in oncology clinical trials: does the duration change when the same drug moves from the experimental arm to the control arm?

Background

When a new drug comes to the market, the incentive for the sponsoring company is to maximize the treatment duration in order for the patient to reap the full therapeutic benefit of the product and achieve a positive trial result. We sought to enumerate instances when an already-approved oncology drug was used as a comparator for a newer drug seeking approval and compare the duration of treatment when it is used in the intervention arm to when it is used as a comparator.

Patients and methods

In a cross-sectional analysis, we searched drug approval announcements for advanced, metastatic, or unresectable cancers between 2009 and 2020. We included studies reporting on an approved drug and studies reporting on when the same drug was used as a comparator for other drugs seeking Food and Drug Administration (FDA) approval. We examined median progression-free survival and duration of treatment for when the drug was initially approved and for when the drug was used as a comparator for other drugs that were seeking approval.

Results

Of the 23 instances when an approved drug was later used as a comparator against a newer drug seeking FDA approval, we found 11 instances (47.8%) where the drug, when used as a comparator arm, had a shorter duration of treatment than when it was used in the intervention arm. The median duration of treatment in the study initially testing the drug was 6.0 months (range: 2.2-12.7 months), whereas the median duration of treatment when the same drug was used as a comparator was 4.9 months (range: 1.7-12.0 months).

Conclusions

These results suggest that there is bias in how long a patient receives a given therapy, and this bias favors the newer therapy. Clinical trialists should seek to utilize methodology that reduces bias so that the relative efficacy of newer drugs can be objectively assessed.

•

We found 23 instances when an approved drug was later used as a comparator against a newer drug seeking FDA approval.

•

Drugs, as a comparator, had a shorter duration of treatment than when used in the intervention arm in 48% of instances.

•

The median durations of treatment for drugs seeking approval and then as comparators were 6 and 5 months, respectively.

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.

Pilot trial of physical and cognitive changes related to fall risk in enzalutamide patients with castration-resistant prostate cancer (CRPC)

e17018

Background: Advanced prostate cancer disproportionally affects older men (age ≥ 75 years). Despite representing only 26% of diagnoses, older men represent half of those diagnosed with metastatic disease and half of all prostate cancer deaths. Treatment options for CRPC include enzalutamide (enza), a competitive inhibitor of the androgen receptor, which shows improved overall survival and other cancer-specific responses in older men. However, enza is also reportedly associated with increased fall frequency of unclear pathophysiology. This pilot study examines strength, balance, and cognition in men before and 12 weeks after starting enza therapy for CRPC. Methods: This prospective single-arm study included men about to begin enza for CRPC, ≥ 65 years, able to ambulate independently. The following tests were administered at baseline and 12 weeks after initiation of enza: Sit-to-stand test (STS), Timed-Up-and-Go test, proprioception assessment, computerized dynamic posturography including sensory organization test (SOT), motor control test (MCT), and limits of stability; Functional Assessment of Cancer Therapy-Prostate, BPI-SF, Activities-specific Balance Confidence (ABC), Montreal Cognitive Assessment (MoCA), International Physical Activity Questionnaire (IPAQ), and the Godin leisure-time exercise questionnaire (GLTEQ). Falls were assessed with self-report fall diaries and calls from study team to participants over the course of 12 months. Results: Twenty-five participants enrolled. Median age was 75 years. There were 23 (92%) with both baseline and 12-week assessments, and 21 (84%) participants had complete falls data. From baseline to the 12-week follow up, ABC scale scores decreased (median 90.4 to 85.2), GLTEQ scale scores decreased (median 31.4 to 28.0), and time sitting per day from IPAQ increased (4 hours to 5 hours). Of those evaluable for falls, 15 (71%) did not fall during the 12 months and 6 (29%) fell at least once. The fallers and non-fallers did not differ with respect to age or MoCA scores at baseline and on re-assessment. Those who fell performed more poorly on the STS test, the ABC and the dynamic posturography evaluations. Those who fell also had a higher level of activity by GLTEQ. Conclusions: This pilot study does not clearly elucidate the pathophysiology of falls in older men with CRPC taking enza but does provide useful and important guidance for the design of future studies in this area. Baseline and 12-week testing should be repeated at the 24-week time-point to allow for sufficient exposure to enza. To avoid confounding by practice effects, physical tests, particularly dynamic posturography, should be performed at least once prior to baseline assessment. Further research is needed to understand the mechanisms underlying the increased risk of falls previously observed in older men with CPRC taking enza.

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 thromboembolism (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 is 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.

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 (S_tr), whereas 205 patients were used as part of test set I (S_te¹) and 62 patients were used as part of independent test set II (S_te²). 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 (S_te¹ [n = 205]: maximum AUCs of 0.85versus . 0.80; p-value = 0.047 and S_te² [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-T_1w MRI and peri-lesional hyperintensities on T_2w/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.

Cause of mortality in patients with lung cancer and brain metastasis

e21743

Background: Lung cancer is the most common cause of cancer-related mortality and most deaths are associated with metastatic disease, with brain being a common site. Historically, whole brain radiation therapy was the treatment of choice and resulted in median survivals in the range of 6 months. There is no consensus in management of patients who have brain metastasis with systemic disease.We aim to evaluate patients with brain metastasis from lung cancer for cause of death, to investigate whether patients died from central nervous system (CNS) progression or systemic disease or other/undetermined causes. Our hypothesis is that most deaths in contemporary patients with brain metastasis in lung cancer are due to systemic disease, and less commonly due to CNS progression. Methods: In this retrospective observational study, we did a chart review of all adult patients with non-small cell lung cancer and brain metastasis or leptomeningeal disease, who received treatment at Maimonides Cancer Center between 2010 and 2017. Patients with unavailable or incomplete medical records were excluded. Baseline characteristics, pathological factors of the tumor and cause of death was collected from the chart. The cause of death was categorized into systemic and brain causes, and difference in characteristics of patients and tumor were studied. Results: A total of 132 patients were included and their charts were reviewed. Out of 132, 96 could have a clear cause of death categorized into systemic or brain causes, the rest were either mixed or uncategorized. We found that 33% patients died of brain metastasis, and related causes, whereas 67% died of systemic disease progression. There were no different in the two groups in terms of gender, smoking status, histology, size of lung lesion, or number and size of brain lesion. The patients who died of brain metastasis had a significantly higher age, and worse Eastern Cooperative Oncology Group status. Interestingly, the patients who died of systemic causes more commonly had adrenal metastasis (12 vs 0) which was statistically significant, and liver (14 vs 3) metastasis which was not statistically significant. Conclusions: Two-thirds of patients with brain metastases died of systemic disease rather than CNS progression. This may reflect improvements in systemic and local therapies to forestall cancer progression in the CNS. This finding suggests that delaying systemic therapy for CNS treatment may negatively impact overall cancer control. More research needs to be done to answer this question with certainty, including prospective clinical trials.

Stable and discriminating radiomic predictor of recurrence in early stage non-small cell lung cancer: Multi-site study

OBJECTIVES

To evaluate whether combining stability and discriminability criteria in building radiomic classifiers will improve the prognosis of cancer recurrence in early stage non-small cell lung cancer on non-contrast computer tomography (CT).

MATERIALS AND METHODS

CT scans of 610 patients with early stage (IA, IB, IIA) NSCLC from four independent cohorts were evaluated. A total of 350 patients from Cleveland Clinic Foundation and University of Pennsylvania were divided into two equal sets for training (D₁) and validation set (D₂). 80 patients from The Cancer Genome Atlas Lung Adenocarcinoma and Squamous Cell Carcinoma and 195 patients from The Cancer Imaging Archive, were used as independent second (D₃) and third (D₄) validation sets. A linear discriminant analysis (LDA) classifier was built based on the most stable and discriminate features. In addition, a radiomic risk score (RRS) was generated by using least absolute shrinkage and selection operator, Cox regression model to predict time to progression (TTP) following surgery.

RESULTS

A feature selection strategy focusing on both feature discriminability and stability resulted in the classifier having a higher discriminability on validation datasets compared to the discriminability alone criteria in discriminating cancer recurrence (D₂, AUC of 0.75 vs. 0.65; D₃, 0.74 vs. 0.62; D₄, 0.76 vs. 0.63). The RRS generated by most stable-discriminating features was significantly associated with TTP compared to discriminating alone criteria (HR = 1.66, C-index of 0.72 vs. HR = 1.04, C-index of 0.62).

CONCLUSION

Accounting for both stability and discriminability yielded a more generalizable classifier for predicting cancer recurrence and TTP in early stage NSCLC.

Prediction of Heparin Induced Thrombocytopenia (HIT) Using a Combination of 4Ts Score and Screening Immune Assays

Clinical assessment (4Ts) followed by testing for Heparin/platelet factor 4 (HPF4) antibody in intermediate and high risk patients is the standard algorithm of pretest for Heparin induced thrombocytopenia (HIT), and the diagnosis is confirmed by serotonin releasing assay (SRA) in those who have positive antibodies. We conducted a retrospective analysis in a cohort of patients treated in a community hospital who had HIT antibody test by either ELISA or a rapid Particle Immunofiltration Assay (PIFA), regardless of their 4Ts scores. Among 224 patients, 17 had HIT. The PPV for those with a 4 T score ≥4 was 10.4%, which misdianosed 3 patients with HIT who tested positive for antibodies. Combining 4 T score ≥4 AND positive HIT antibody showed a PPV of 20.3% and a sensitivity of 70.6%, misdiagnosing 5 HIT patients. Using 4Ts ≥4 OR positive HIT antibody showed 100% sensitivity and 100% negative predictive value (NPV). The ELISA test had 100% sensitivity and 100% NPV, while the PIFA test missed 2 HIT patients, with sensitivity of 60% and NPV of 96.7%. Our results suggest that SRA testing should be conducted if a patient presents with a 4 T score ≥4 OR a positive HIT antibody, and antibody tests should be conducted for every patient suspected of HIT.

Changes in CT Radiomic Features Associated with Lymphocyte Distribution Predict Overall Survival and Response to Immunotherapy in Non-Small Cell Lung Cancer

No predictive biomarkers can robustly identify patients with non-small cell lung cancer (NSCLC) who will benefit from immune checkpoint inhibitor (ICI) therapies. Here, in a machine learning setting, we compared changes ("delta") in the radiomic texture (DelRADx) of CT patterns both within and outside tumor nodules before and after two to three cycles of ICI therapy. We found that DelRADx patterns could predict response to ICI therapy and overall survival (OS) for patients with NSCLC. We retrospectively analyzed data acquired from 139 patients with NSCLC at two institutions, who were divided into a discovery set (D1 = 50) and two independent validation sets (D2 = 62, D3 = 27). Intranodular and perinodular texture descriptors were extracted, and the relative differences were computed. A linear discriminant analysis (LDA) classifier was trained with 8 DelRADx features to predict RECIST-derived response. Association of delta-radiomic risk score (DRS) with OS was determined. The association of DelRADx features with tumor-infiltrating lymphocyte (TIL) density on the diagnostic biopsies (n = 36) was also evaluated. The LDA classifier yielded an AUC of 0.88 ± 0.08 in distinguishing responders from nonresponders in D1, and 0.85 and 0.81 in D2 and D3 DRS was associated with OS [HR: 1.64; 95% confidence interval (CI), 1.22-2.21; P = 0.0011; C-index = 0.72). Peritumoral Gabor features were associated with the density of TILs on diagnostic biopsy samples. Our results show that DelRADx could be used to identify early functional responses in patients with NSCLC.

Predicting pathologic response to neoadjuvant chemoradiation in resectable stage III non-small cell lung cancer patients using computed tomography radiomic features

OBJECTIVE

The use of a neoadjuvant chemoradiation followed by surgery in patients with stage IIIA NSCLC is controversial and the benefit of surgery is limited. There are currently no clinically validated biomarkers to select patients for such an approach. In this study we evaluate computed tomography (CT) derived intratumoral and peritumoral texture and nodule shape features in their ability to predict major pathological response (MPR). MPR being defined as ≤10% of residual viable tumor, assessed at the time of surgery.

MATERIAL AND METHODS

Ninety patients with stage III NSCLC treated with chemoradiation prior to surgical resection were selected. The patients were divided randomly into two equal sets, one for training and one for independent testing. The radiomic texture and shape features were extracted from within the nodule (intra) and from the parenchymal regions immediately surrounding the nodule (peritumoral). A univariate regression analysis was performed on the image and clinicopathologic variables and then included into a multivariable logistic regression (MLR) for binary outcome prediction of MPR. The radiomic signature risk-score was generated by using a multivariate Cox regression model and association of the signature with OS and DFS was also evaluated.

RESULTS

Thirteen stable and predictive intratumoral and peritumoral radiomic texture features were found to be predictive of MPR. The MLR classifier yielded an AUC of 0.90 ± 0.025 within the training set and a corresponding AUC = 0.86 in prediction of MPR within the test set. The radiomic signature was also significantly associated with OS (HR = 11.18, 95% CI = 3.17, 44.1; p-value = 0.008) and DFS (HR = 2.78, 95% CI = 1.11, 4.12; p-value = 0.0042) in the testing set.

CONCLUSION

Texture features extracted within and around the lung tumor on CT images appears to be associated with the likelihood of MPR, OS and DFS to chemoradiation.

Combination of Peri- and Intratumoral Radiomic Features on Baseline CT Scans Predicts Response to Chemotherapy in Lung Adenocarcinoma

Purpose

To identify the role of radiomics texture features both within and outside the nodule in predicting (a) time to progression (TTP) and overall survival (OS) as well as (b) response to chemotherapy in patients with non-small cell lung cancer (NSCLC).

Materials and Methods

Data in a total of 125 patients who had been treated with pemetrexed-based platinum doublet chemotherapy at Cleveland Clinic were retrospectively analyzed. The patients were divided randomly into two sets with the constraint that there were an equal number of responders and nonresponders in the training set. The training set comprised 53 patients with NSCLC, and the validation set comprised 72 patients. A machine learning classifier trained with radiomic texture features extracted from intra- and peritumoral regions of non-contrast-enhanced CT images was used to predict response to chemotherapy. The radiomic risk-score signature was generated by using least absolute shrinkage and selection operator with the Cox regression model; association of the radiomic signature with TTP and OS was also evaluated.

Results

A combination of radiomic features in conjunction with a quadratic discriminant analysis classifier yielded a mean maximum area under the receiver operating characteristic curve (AUC) of 0.82 ± 0.09 (standard deviation) in the training set and a corresponding AUC of 0.77 in the independent testing set. The radiomics signature was also significantly associated with TTP (hazard ratio [HR], 2.8; 95% confidence interval [CI]: 1.95, 4.00; P < .0001) and OS (HR, 2.35; 95% CI: 1.41, 3.94; P = .0011). Additionally, decision curve analysis demonstrated that in terms of clinical usefulness, the radiomics signature had a higher overall net benefit in prediction of high-risk patients to receive treatment than the clinicopathologic measurements.

Conclusion

This study suggests that radiomic texture features extracted from within and around the nodule on baseline CT scans are (a) predictive of response to chemotherapy and (b) associated with TTP and OS for patients with NSCLC.© RSNA, 2019Supplemental material is available for this article.

Perinodular and Intranodular Radiomic Features on Lung CT Images Distinguish Adenocarcinomas from Granulomas

Purpose To evaluate ability of radiomic (computer-extracted imaging) features to distinguish non-small cell lung cancer adenocarcinomas from granulomas at noncontrast CT. Materials and Methods For this retrospective study, screening or standard diagnostic noncontrast CT images were collected for 290 patients (mean age, 68 years; range, 18-92 years; 125 men [mean age, 67 years; range, 18-90 years] and 165 women [mean age, 68 years; range, 33-92 years]) from two institutions between 2007 and 2013. Histopathologic analysis was available for one nodule per patient. Corresponding nodule of interest was identified on axial CT images by a radiologist with manual annotation. Nodule shape, wavelet (Gabor), and texture-based (Haralick and Laws energy) features were extracted from intra- and perinodular regions. Features were pruned to train machine learning classifiers with 145 patients. In a test set of 145 patients, classifier results were compared against a convolutional neural network (CNN) and diagnostic readings of two radiologists. Results Support vector machine classifier with intranodular radiomic features achieved an area under the receiver operating characteristic curve (AUC) of 0.75 on the test set. Combining radiomics of intranodular with perinodular regions improved the AUC to 0.80. On the same test set, CNN resulted in an AUC of 0.76. Radiologist readers achieved AUCs of 0.61 and 0.60, respectively. Conclusion Radiomic features from intranodular and perinodular regions of nodules can distinguish non-small cell lung cancer adenocarcinomas from benign granulomas at noncontrast CT. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Nishino in this issue.

Isolated Pulmonic Valve Endocarditis

BACKGROUND Infective endocarditis (IE) has a high mortality rate, even when treated with appropriate antibiotic therapy and surgical intervention. Right-sided endocarditis is in itself rare, with some studies reporting an incidence of 5-10%. The majority of these cases involve the tricuspid valve, and isolated pulmonary valve endocarditis (PVE) is an extremely rare entity affecting less than 2% of patients with infective endocarditis. Identification and early management are crucial to prevent long-term complications and reduce mortality. CASE REPORT We present a patient with a history of essential hypertension and no underlying valvular disease, who underwent dental cleaning and subsequently developed low-grade fever, myalgia, and malaise. This occurred during the flu season, and was initially diagnosed and treated as flu, without any improvement. The patient was later found to be bacteremic with S. mitis, with no identifiable source, and a normal transthoracic echocardiogram (TTE). He was later hospitalized, had a transesophageal echocardiogram, and was found to have a large pulmonic valve vegetation. CONCLUSIONS This case presents an interesting and rare finding of endocarditis, isolated to the pulmonic valve, in an otherwise healthy individual with no predisposing risk factors. The lack of peripheral stigmata, as well as an unremarkable initial outpatient TTE, made the diagnosis more difficult. It should also be noted that current guidelines do not specifically address right-sided endocarditis, and do not specify the role of surgical intervention.

Mass Effect Deformation Heterogeneity (MEDH) on Gadolinium-contrast T1-weighted MRI is associated with decreased survival in patients with right cerebral hemisphere Glioblastoma: A feasibility study

Subtle tissue deformations caused by mass-effect in Glioblastoma (GBM) are often not visually evident, and may cause neurological deficits, impacting survival. Radiomic features provide sub-visual quantitative measures to uncover disease characteristics. We present a new radiomic feature to capture mass effect-induced deformations in the brain on Gadolinium-contrast (Gd-C) T1w-MRI, and their impact on survival. Our rationale is that larger variations in deformation within functionally eloquent areas of the contralateral hemisphere are likely related to decreased survival. Displacements in the cortical and subcortical structures were measured by aligning the Gd-C T1w-MRI to a healthy atlas. The variance of deformation magnitudes was measured and defined as Mass Effect Deformation Heterogeneity (MEDH) within the brain structures. MEDH values were then correlated with overall-survival of 89 subjects on the discovery cohort, with tumors on the right (n = 41) and left (n = 48) cerebral hemispheres, and evaluated on a hold-out cohort (n = 49 subjects). On both cohorts, decreased survival time was found to be associated with increased MEDH in areas of language comprehension, social cognition, visual perception, emotion, somato-sensory, cognitive and motor-control functions, particularly in the memory areas in the left-hemisphere. Our results suggest that higher MEDH in functionally eloquent areas of the left-hemisphere due to GBM in the right-hemisphere may be associated with poor-survival.

Shape Features of the Lesion Habitat to Differentiate Brain Tumor Progression from Pseudoprogression on Routine Multiparametric MRI: A Multisite Study

BACKGROUND AND PURPOSE

Differentiating pseudoprogression, a radiation-induced treatment effect, from tumor progression on imaging is a substantial challenge in glioblastoma management. Unfortunately, guidelines set by the Response Assessment in Neuro-Oncology criteria are based solely on bidirectional diametric measurements of enhancement observed on T1WI and T2WI/FLAIR scans. We hypothesized that quantitative 3D shape features of the enhancing lesion on T1WI, and T2WI/FLAIR hyperintensities (together called the lesion habitat) can more comprehensively capture pathophysiologic differences across pseudoprogression and tumor recurrence, not appreciable on diametric measurements alone.

MATERIALS AND METHODS

A total of 105 glioblastoma studies from 2 institutions were analyzed, consisting of a training (n = 59) and an independent test (n = 46) cohort. For every study, expert delineation of the lesion habitat (T1WI enhancing lesion and T2WI/FLAIR hyperintense perilesional region) was obtained, followed by extraction of 30 shape features capturing 14 "global" contour characteristics and 16 "local" curvature measures for every habitat region. Feature selection was used to identify most discriminative features on the training cohort, which were evaluated on the test cohort using a support vector machine classifier.

RESULTS

The top 2 most discriminative features were identified as local features capturing total curvature of the enhancing lesion and curvedness of the T2WI/FLAIR hyperintense perilesional region. Using top features from the training cohort (training accuracy = 91.5%), we obtained an accuracy of 90.2% on the test set in distinguishing pseudoprogression from tumor progression.

CONCLUSIONS

Our preliminary results suggest that 3D shape attributes from the lesion habitat can differentially express across pseudoprogression and tumor progression and could be used to distinguish these radiographically similar pathologies.

Tracheomediastinal Fistula: Rare Complication of Treatment with Bevacizumab

Tracheomediastinal fistula is a rare condition caused by multiple etiologies. We present a case of a patient of lung carcinoma receiving chemotherapy. A 63-year-old woman presented to the emergency room with a two-month history of worsening cough and shortness of breath. She was being treated with pemetrexed and bevacizumab for Stage IV non-small cell lung carcinoma. Chest X-ray showed a mass in the lung with mediastinal adenopathy. Computed tomography (CT) scan showed a perforation, confirmed with bronchoscopy. She had a secondary infection and she was started on intravenous antibiotics. The patient decided to continue care in a hospice. We present a rare complication of bevacizumab which has been only reported once in literature. Bevacizumab is known to cause tracheal fistulas when coupled with like invasive procedures. In our case, the patient developed a fistula without any invasive interventions. We advise that physicians using bevacizumab should be aware of the possibility of having such fistulas.

Combination of computer extracted shape and texture features enables discrimination of granulomas from adenocarcinoma on chest computed tomography

Differentiation between benign and malignant nodules is a problem encountered by radiologists when visualizing computed tomography (CT) scans. Adenocarcinomas and granulomas have a characteristic spiculated appearance and may be fluorodeoxyglucose avid, making them difficult to distinguish for human readers. In this retrospective study, we aimed to evaluate whether a combination of radiomic texture and shape features from noncontrast CT scans can enable discrimination between granulomas and adenocarcinomas. Our study is composed of CT scans of 195 patients from two institutions, one cohort for training ([Formula: see text]) and the other ([Formula: see text]) for independent validation. A set of 645 three-dimensional texture and 24 shape features were extracted from CT scans in the training cohort. Feature selection was employed to identify the most informative features using this set. The top ranked features were also assessed in terms of their stability and reproducibility across the training and testing cohorts and between scans of different slice thickness. Three different classifiers were constructed using the top ranked features identified from the training set. These classifiers were then validated on the test set and the best classifier (support vector machine) yielded an area under the receiver operating characteristic curve of 77.8%.

Abstract P4-09-12: Quantitative image features of nuclear and tubule architecture distinguish high and low oncotype DX risk categories of ductal carcinoma in situ from H&E tissue images

Background: Ductal Carcinoma in Situ (DCIS) is a pre-invasive stage of breast cancer, where malignant cells line the duct but have not spread into other parts of the breast. Oncotype DX (ODX) is a genomic test, which divide patients into three risk of recurrence categories (Low, Intermediate, and High) to help physicians determine if patients require adjuvant therapy. However, ODX is expensive, tissue destructive, and has a turnaround time of 7-10 days. There has been an interest in the use of image analysis of routine H&E histopathology slides to predict the course of the disease; the rationale being that the analytics are able to unearth subtle sub-visual cues regarding disease morphology that may escape visual examination. In this work, we evaluate the role of computer extracted features of nuclear morphology and the necrotic regions from surgically resected specimens to predict ODX categories in patients with DCIS.

Methods: H&E slides from breast tissue of 37 patients who were diagnosed with DCIS and underwent a lumpectomy were acquired. Nine of the 37 had high ODX score (higher than 54), while the rest had a low score (lower than 39). All the slides were digitized on a Philips slide scanner. For each image, a watershed algorithm segmented the individual nuclei, which were used to generate 230 nuclei features including nuclear architecture, nuclear shape and nuclear texture features within each candidate breast duct. In addition, we captured the area of necrosis and empty lumen region inside breast ducts to generate features pertaining to tubule packing.

The average feature values for each patient were calculated across all the breast ducts in each slide. A 3-fold cross validation scheme with 50 repetitions was used with the Support Vector Machine (SVM) classifier to predict the ODX risk category for each patient. We used a covariance algorithm to select the top 4 features that were independent of each other but relevant to the ODX class label.

Results: The top ranked features included features from three categories: nuclei architectural features (standard deviation of triangle area in Delaunay graph, skewness of edge length in Cell Cluster Graph), nuclear texture (standard deviation of Haralick matrix intensity) possibly reflecting chromatin patterns in the cell, and the Tubule Packing Ratio, a measure of the ratio of necrosis area and empty lumen area inside the breast ducts compared to the whole breast duct area. The SVM in conjunction with these 4 features yielded a mean area under receive operator characteristic curve (AUC) of 0.95 in correctly predicting high and low ODX risk categories.

Conclusion: We found that our histomorphometry features pertaining to nuclear arrangement, nuclear texture and necrosis could differentiate between DCIS patients with high and low ODX risk categories. Additional independent validation of the approach is needed to confirm the preliminary findings presented here.

Citation Format: Li H, Whitney J, Thawani R, Gilmore H, Badve S, Madabhushi A. Quantitative image features of nuclear and tubule architecture distinguish high and low oncotype DX risk categories of ductal carcinoma in situ from H&E tissue images [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-09-12.

Prediction of recurrence in early stage non-small cell lung cancer using computer extracted nuclear features from digital H&E images

Identification of patients with early stage non-small cell lung cancer (NSCLC) with high risk of recurrence could help identify patients who would receive additional benefit from adjuvant therapy. In this work, we present a computational histomorphometric image classifier using nuclear orientation, texture, shape, and tumor architecture to predict disease recurrence in early stage NSCLC from digitized H&E tissue microarray (TMA) slides. Using a retrospective cohort of early stage NSCLC patients (Cohort #1, n = 70), we constructed a supervised classification model involving the most predictive features associated with disease recurrence. This model was then validated on two independent sets of early stage NSCLC patients, Cohort #2 (n = 119) and Cohort #3 (n = 116). The model yielded an accuracy of 81% for prediction of recurrence in the training Cohort #1, 82% and 75% in the validation Cohorts #2 and #3 respectively. A multivariable Cox proportional hazard model of Cohort #2, incorporating gender and traditional prognostic variables such as nodal status and stage indicated that the computer extracted histomorphometric score was an independent prognostic factor (hazard ratio = 20.81, 95% CI: 6.42–67.52, P < 0.001).

Changes in computer extracted features of vessel tortuosity on CT scans post-treatment in responders compared to non-responders for non-small cell lung cancer on immunotherapy

11518

Background: Immune-checkpoint blockade treatments demonstrate promising clinical efficacy in patients with non-small cell lung cancer (NSCLC). Nivolumab is a PD-1 inhibitor that is FDA approved for treatment of patients with chemotherapy refractory advanced NSCLC. The current standard clinical approach to evaluating tumor response is sub-optimal in defining clinical benefit from immunotherapy drugs. We sought to evaluate whether computer extracted measurements of vessel tortuosity significantly and differentially change post treatment between NSCLC patients who do and do not respond to immunotherapy. Methods: A total of 50 NSCLC patients including pre- and post- treatment CT scans were included in this study. The patients were either responders or non-responders to Nivolumab. Patients who did not receive Nivolumab after 2 cycles due to lack of response or progression as per RECIST were classified as ‘non-responders’. A total of 35 tortuosity features of the vessels around the lung nodules were investigated. In the training cohort (N = 25), the features were ranked based on the degree of change between pre- and post- treatment CT. The top 4 features were used for training a Support Vector Machine (SVM) classifier to identify which patients did and did not respond to immunotherapy on a validation cohort of N = 25 patients. Results: The top features identified were the ones associated with the curvature of the vessel branches. The AUC for the SVM classifier was 0.75 for the training and 0.79 for the test set. Conclusions: Changes in specific vessel tortuosity features between baseline and post-treatment CT scans following nivolumab were different between NSCLC patients who did and did not respond. Multi-site validation of the vessel tortuosity features is needed to establish it as a predictive biomarker for NSCLC patients treated with immunotherapy.

Evolution of radiomic features on serial CT scans as an imaging based biomarker for evaluating response in patients with non-small cell lung cancer treated with nivolumab

e14534

Background: Nivolumab is a PD-1 inhibitor that is FDA approved for treatment of chemotherapy refractory advanced NSCLC. The current standard clinical approach to evaluating tumor response is sub-optimal in evaluating clinical benefit from immunotherapy drugs. Our study aims to explore whether changes in radiomic features of the tumor between baseline and 2-week post-treatment CT scans can predict treatment response. Methods: 41 NSCLC patients treated with nivolumab were included in this study. 22 patients with pre- and post-nivolumab CT scans were used as a learning set and the remaining 19 for independent testing. Patients who did not receive nivolumab after 2 cycles due to lack of response or progression as per RECIST were classified as ‘non-responders’, and patients who had radiological response as per RECIST, or stable disease as per RECIST and clinical improvement were classified as ‘responders’. Lung nodules on pre-treatment CT scans were annotated with 3D SLICER software by a radiologist. 312 texture features of lung nodules were extracted and investigated in the study. The percent difference of each extracted feature was calculated based on the baseline and 2 week post-therapy CT scan. In the learning set, the six features that most significantly changed between baseline and post-treatment scans and also maximally differentially expressed between responders and non-responders were identified. Unsupervised clustering was applied on the set of 6 features for the 19 patients in the test set to predict which patients did and did not respond. Results: The top 6 features predictive of response corresponded to the Haralick, Gabor and Laws texture families. Unsupervised clustering yielded an accuracy of 78.95%. Conclusions: Our results suggest that changes in certain radiomic texture features between baseline and post-treatment CT scans following nivolumab could identify early clinical response to treatment. Additional validation of these novel quantitative imaging based approaches is warranted to accurately define clinical benefit from immunotherapy.

Computer extracted measurements of intra-tumoral heterogeneity on H&E stained tissue images to distinguish short term and long term survivors in patients with non-small cell lung carcinoma

e20052

Background: Molecular and morphologic heterogeneity is an important characteristic of cancer. This spatial and temporal tumor heterogeneity has important implications on tumor behavior and response to therapies. This study aims to evaluate the role of computer extracted features of intra-tumoral heterogeneity (ITH) from digitized whole slide H&E stained images of early stage NSCLC patients treated with surgery as a prognostic marker for survival. Methods: A cohort of 89 early stage NSCLC patients treated with surgery with long term survival data were identified. 28 patients had OS> 3 years from the date of definitive surgery and were defined as long term survivors and 61 patients had OS < 3 years, and were defined as short term survivors. Corresponding H&E stained whole mounted lung tissue images was digitally scanned and a thoracic pathologist marked the primary tumor margins on these images. Our computational approach involved determining the variance in measurements relating to nuclear size, shape, and texture across the tissue section; Each feature was then assigned a morphologic diversity score (MDS) based off the variance; the top predictive MDS features were identified via Wilcoxon Rank Sum Test and then evaluated via a quadratic classifier using 3-fold cross validation. Kaplan-Meier (KM) survival analysis was performed for the ITH features, as well as T- and N-stage. Results: The top ranked MDS features yielded a mean area under the receiver operating characteristic curve (AUC) of 0.66 in discriminating short term from long term survivors. A p=0.00657 (see Table) was obtained for KM-analysis of the ITH features. Conclusions: Computer extracted image features of ITH enabled differentiation of NSCLC patients with short and longer term survival. Large scale multi-site validation will need to be done to establish ITH measurements as a prognostic biomarker for NSCLC patients. [Table: see text]

Computer extracted features of gland morphology on H&E surgically resected tissue images as predictive of biochemical recurrence and rate of expression in African American compared to Caucasian American men

e16559

Background: Prostate cancer (PCa) is 1.7 times more prevalent and 2.3 times more lethal in African American (AA) men than in Caucasian American (CA) men. Additionally there is a higher incidence (when controlling for relative population size) of more aggressive PCa in the AA compared to the CA population which has led a number of groups to investigate whether there are molecular differences in the disease phenotype between the two groups. In this work we investigate whether computer extracted features of glandular morphology from digitized pathology images of surgical specimens identified as predictive of biochemical recurrence are also differentially expressed between AA and CA patients. Methods: Two cohorts were gathered. Cohort 1 (C1) contained digitized whole mount Gleason 7 radical prostatectomy specimens (RPS) from 72 patients (46 CA, 26 AA). Cohort 2 (C2) comprising quarter and whole mount RPS from 145 patients (135 CA, 10 AA), who either had biochemical recurrence in 5 years (47) or did not (98). A pathologist annotated each image in both cohorts for a representative cancerous region. Glands were automatically segmented and 216 features describing gland arrangement, shape, and disorder were extracted from every image. Features were tested for significance by Wilcoxon rank sum test at p < .05. Results: 8 features of gland morphology were significantly different between AA and CA groups and also predictive of biochemical recurrence (Table). Conclusions: We identified 8 computer extracted features of gland morphology that were both differentially expressed between AA and CA men and predictive of biochemical recurrence, suggesting that there are histomorphometric differences in prostate cancer appearance between AA and CA men. [Table: see text]

Computer extracted measurements of vessel tortuosity on baseline CT scans to predict response to nivolumab immunotherapy for non-small cell lung cancer

11566

Background: Immune-checkpoint blockade treatments, particularly drugs targeting the programmed death-1 (PD-1) receptor, demonstrate promising clinical efficacy in patients with non-small cell lung cancer (NSCLC). We sought to evaluate whether computer extracted measurements of tortuosity of vessels in lung nodules on baseline CT scans in NSCLC patients(pts) treated with a PD-1 inhibitor, nivolumab could distinguish responders and non-responders. Methods: A total of 61 NSCLC pts who underwent treatment with nivolumab were included in this study. Pts who did not receive nivolumab after 2 cycles due to lack of response or progression per RECIST were classified as ‘non-responders’, patients who had radiological response per RECIST or had clinical benefit (defined as stable disease >10 cycles) were classified as ‘responders’. A total of 35 quantitative tortuosity features of the vessels associated with lung nodule were investigated. In the training cohort (N=33), the features were ranked in their ability to identify responders to nivolumab using a support vector machine (SVM) classifier. The three most informative features were then used for training the SVM, which was then validated on a cohort of N=28 pts. Results: The maximum curvature ( f1), standard deviation of the torsion ( f2) and mean curvature ( f3) were identified as the most discriminating features. The area under Receiver operating characteristic (ROC) curve (AUC) of the SVM was 0.84 for the training and 0.72 for the validation cohort. Conclusions: Vessel tortuosity features were able to distinguish responders from non-responders for patients with NSCLC treated with nivolumab. Large scale multi-site validation will need to be done to establish vessel tortuosity as a predictive biomarker for immunotherapy. [Table: see text]

Computer extracted shape features of prostate capsule from MRI to predict biochemical recurrence of prostate cancer post-treatment

e16579

Background: Pre-treatment identification of biochemical recurrence (BCR) from MRI may enable the use of aggressive neo-adjuvant therapies for prostate cancer patients to improve prognosis. BCR is often associated with aggressive cancer growth and/or extra prostatic extension resulting in an irregular bulge and focal capsular retraction. This may induce differences in the shape of the prostate capsule between BCR positive (BCR+) and BCR negative (BCR-) patients as observed on MRI. In this work, we show that computer extracted shape features of the prostate capsule on MRI can identify patients that are at a risk of BCR post-treatment Methods: In a single centre IRB approved study, from a registry of 874 patients, availability of complete image datasets (T1w, T2w and ADC map); no treatment for PCa before MRI; presence of clinically localised PCa; availability of Gleason score; and data available for post-treatment PSA and follow-up for at least 3 years in patients without BCR were used as inclusion criteria to select 80 patients. The prostate capsule was manually segmented on T2w MRI by an experienced radiologist. Two atlases A+ and A- were created for BCR+ and BCR- patients respectively with similar Gleason score (6 to 9), similar numbers in each cohort (25 each) and similar tumor stage (T2 to T3). A t-test based analysis corrected for multiple comparison revealed statistically significant prostate shape differences between A+ and A- in surface of interest (SOI). Curvature features (magnitude and surface normal orientations) were extracted from SOI of the two cohorts. A random forest classifier was trained using the 50 training images (from A+ and A-) and validated using a hold-out validation set of 30 patients. Results: The inter-quartile range, variance, skewness and kurtosis of curvature magnitude and normal orientations were found to be predictive of BCR. The RF classifier trained using these features could predict BCR with an accuracy of 78% and an AUC of 0.71 in the validation set. Conclusions: Curvature magnitude and orientation features of the prostate capsule from the SOI may be predictive of BCR. In future a multi centre independent datasets will be used to validate the findings.

Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

OBJECTIVE

To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule.

METHODS

Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT.

RESULTS

Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions.

CONCLUSION

This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT.

KEY POINTS

• 3D reconstructions are generated from 2D histology specimens of ground glass nodules. • The reconstruction methodology used pre-operative in vivo CT as 3D spatial constraint. • The methodology maps adenocarcinoma extent from digitized histology onto in vivo CT. • The methodology potentially facilitates the discovery of CT signature of invasive adenocarcinoma.

Two Cases of NK/T Cell Lymphoma Presenting as Chronic Rhinosinusitis

T/NK cell lymphoma is a rare subtype of lymphoma that is known to be of aggressive nature. We present two cases of this disease that originally presented with symptoms consistent with chronic rhinosinusitis. We outline how we managed the diseases and review literature on it.