Genomic Landscape of Adenocarcinomas Across the Gastroesophageal Junction: Moving on from the Siewert Classification.

OBJECTIVE: To investigate how the Siewert classification of gastroesophageal junction adenocarcinomas correlates with genomic profiles. SUMMARY/BACKGROUND DATA: Current staging and treatment guidelines recommend that tumors with an epicenter less than 2 cm into the gastric cardia be treated as esophageal cancers, while tumors with epicenter greater than 2 cm into the cardia be staged and treated as gastric cancers. To date, however, few studies have compared the genomic profiles of the 3 Siewert classification groups to validate this distinction. METHODS: Using targeted tumor sequencing data on patients with adenocarcinoma of the gastroesophageal junction previously treated with surgery at our institution, we compared genomic features across Siewert classification groups. RESULTS: A total of 350 patients were included: 121 had Siewert type I, 170 type II, and 59 type III. Comparisons by Siewert location revealed that Siewert type I and II were primarily characterized as the chromosomal instability (CIN) molecular subtype and displayed Barrett's metaplasia and p53 and cell cycle pathway dysregulation. Siewert type III tumors, by contrast, were more heterogeneous, including higher proportions of microsatellite instability (MSI) and genomically stable (GS) tumors and more frequently displayed ARID1A and somatic CDH1 alterations, signet ring cell features, and poor differentiation. Overall, Siewert type I and II tumors demonstrated greater genomic overlap with lower esophageal tumors, while Siewert type III tumors shared genomic features with gastric tumors. CONCLUSIONS: Overall, our results support recent updates in treatment and staging guidelines. Ultimately, however, molecular rather than anatomic classification may prove more valuable in determining staging, treatment, and prognosis.

The role of autophagy in vascular biology.

There is increasing interest in the role of autophagic flux in maintaining normal vessel wall biology and a growing suspicion that autophagic dysregulation may be a common pathway through which vascular aging and associated pathologies develop. Within endothelial and smooth muscle cells, diverse but important triggers that range from oxidized lipids to ß-amyloid seem to stimulate autophagosome formation potently. In addition, emerging evidence links autophagy to a wide array of vascular processes ranging from angiogenesis to calcification of the vessel wall. Alterations in autophagic flux are also increasingly being implicated in disease processes that include both atherosclerosis and pulmonary hypertension. Finally, recent insights point toward an important role of autophagy in the paracrine regulation of vasoactive substances from the endothelium. Here, we review the progress in understanding how autophagy can contribute to vascular biology and the emerging strategies to target this process for therapeutic benefit.

The Role of the TP53 Pathway in Predicting Response to Neoadjuvant Therapy in Esophageal Adenocarcinoma.

PURPOSE: In patients with locally advanced esophageal adenocarcinoma, response to neoadjuvant therapy strongly predicts survival, but robust molecular predictors of response have been lacking. We therefore sought to discover meaningful predictors of response in these patients. EXPERIMENTAL DESIGN: We retrospectively identified all patients with adenocarcinoma of the lower esophagus or gastroesophageal junction who (i) were treated with multimodality therapy with curative intent at our institution from 2014 through 2020 and (ii) underwent prospective sequencing by Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets. Clinicopathologic and genomic data were analyzed to identify potential genomic features, somatic alterations, and oncogenic pathways associated with treatment response. RESULTS: In total, 237 patients were included. MDM2 amplification was independently associated with poor response to neoadjuvant therapy [OR, 0.10 (95% confidence interval, 0.01-0.55); P = 0.032], when accounting for significant clinicopathologic variables, including clinical stage, tumor grade, and chemotherapy regimen. Moreover, TP53 pathway alterations, grouped according to inferred severity of TP53 dysfunction, were significantly associated with response to neoadjuvant therapy (P = 0.004, q = 0.07). Patients with MDM2 amplifications or truncating biallelic TP53 mutations had similar outcomes in terms of poor responses to neoadjuvant therapy and, consequently, shorter progression-free survival, compared with patients with TP53 pathway wild-type tumors. Thus, worsening TP53 dysfunction was directly correlated with worse outcomes. CONCLUSIONS: MDM2 amplification and TP53 status are associated with response to therapy in patients with esophageal adenocarcinoma. Given the dearth of actionable targets in esophageal adenocarcinoma, MDM2 inhibition, in combination with cytotoxic chemotherapy, may represent an important therapeutic strategy to overcome treatment resistance and improve outcomes in these patients.

Safety and feasibility of esophagectomy following combined immunotherapy and chemoradiotherapy for esophageal cancer.

OBJECTIVES: We sought to determine the safety and feasibility of esophagectomy after neoadjuvant immunotherapy and chemoradiotherapy in clinical trial patients with locally advanced esophageal cancer. METHODS: We retrospectively identified patients who were treated with neoadjuvant immunotherapy and chemoradiotherapy (n = 25) or chemoradiotherapy alone (n = 143) at our institution between 2017 and 2020. The primary end point was risk of 30-day major complications (Clavien-Dindo classification system grade ≥ 3), which was assessed between groups using a multivariable log-binomial regression model to obtain adjusted relative risk ratios. Secondary end points were interval to surgery, 30-day readmission rate, and 30-day mortality. RESULTS: All included patients successfully completed neoadjuvant therapy and underwent esophagectomy with negative margins. Age, sex, performance status, clinical stage, histologic subtype, procedure type, and operative approach were similar between groups. Neoadjuvant immunotherapy was not associated with a statistically significantly increased risk of developing a major pulmonary (relative risk, 1.43; 95% confidence interval, 0.53-3.84; P = .5), anastomotic (relative risk, 1.34; 95% confidence interval, 0.45-3.94; P = .6), or other complication (relative risk, 1.29; 95% confidence interval, 0.26-6.28; P = .8). Median (interquartile range) interval to surgery was 54 days (47-61 days) in the immune checkpoint inhibitor group versus 53 days (47-66 days) in the control group (P = .6). Minimally invasive approaches were successful in 72% of cases, with only 1 conversion. Thirty-day mortality and readmission rates were 0% and 17%, respectively, in the immune checkpoint inhibitor group and 1.4% and 13%, respectively, in the control group. CONCLUSIONS: On the basis of our preliminary experience, esophagectomy appears to be safe and feasible following combined neoadjuvant immunotherapy and standard chemoradiotherapy for locally advanced esophageal cancer.

Next-Generation Sequencing of 487 Esophageal Adenocarcinomas Reveals Independently Prognostic Genomic Driver Alterations and Pathways.

PURPOSE: To delineate recurrent oncogenic driver alterations and dysregulated pathways in esophageal adenocarcinoma and to assess their prognostic value. EXPERIMENTAL DESIGN: We analyzed a large cohort of patients with lower esophageal and junctional adenocarcinoma, prospectively sequenced by MSK-IMPACT with high-quality clinical annotation. Patients were subdivided according to treatment intent, curative versus palliative, which closely mirrored clinical staging. Genomic features, alterations, and pathways were examined for association with overall survival using Cox proportional hazard models, adjusted for relevant clinicopathologic factors knowable at the time of diagnosis. RESULTS: Analysis of 487 patients revealed 16 oncogenic driver alterations, mostly amplifications, present in ≥5% of patients. Patients in the palliative-intent cohort, compared with those in the curative-intent cohort, were more likely to have metastatic disease, ERBB2 amplifications, Cell-cycle and RTK-RAS pathway alterations, as well as a higher fraction of genome altered and rate of whole-genome doubling. In multivariable analyses, CDKN2A alterations, SMAD4 alterations, KRAS amplifications, Cell-cycle and TGFß pathways, and overall number of oncogenic drivers were independently associated with worse overall survival. ERBB2 amplification was associated with improved survival, presumably due to trastuzumab therapy. CONCLUSIONS: Our study suggests that higher levels of genomic instability are associated with more advanced disease in esophageal adenocarcinoma. Furthermore, CDKN2A, KRAS, and SMAD4 represent prognostic biomarkers, given their strong association with poor survival.

Primary lung cancer in women after previous breast cancer.

BACKGROUND: Breast cancer is the most common malignancy among women in the USA. Improved survival has resulted in increasing incidence of second primary malignancies, of which lung cancer is the most common. The United States Preventive Services Task Force (USPSTF) guidelines for lung-cancer screening do not include previous malignancy as a high-risk feature requiring evaluation. The aim of this study was to compare women undergoing resection for lung cancer with and without a history of breast cancer and to assess whether there were differences in stage at diagnosis, survival and eligibility for lung-cancer screening between the two groups. METHODS: Women who underwent lung-cancer resection between 2000 and 2017 were identified. Demographic, clinicopathological, treatment and outcomes data were compared between patients with a history of breast cancer (BC-Lung) and patients without a history of breast cancer (P-Lung) before lung cancer. RESULTS: Of 2192 patients included, 331 (15.1 per cent) were in the BC-Lung group. The most common method of lung-cancer diagnosis in the BC-Lung group was breast-cancer surveillance or work-up imaging. Patients in the BC-Lung group had an earlier stage of lung cancer at the time of diagnosis. Five-year overall survival was not statistically significantly different between groups (73.3 per cent for both). Overall, 58.4 per cent of patients (1281 patients) had a history of smoking, and 33.3 per cent (731 patients) met the current criteria for lung-cancer screening. CONCLUSION: Differences in stage at diagnosis of lung cancer and treatment selection were observed between patients with and without a history of breast cancer. Overall, there were no statistically significant differences in genomic or oncogenic pathway alterations between the two groups, which suggests that lung cancer in patients who previously had breast cancer may not be affected at the genomic level by the previous breast cancer. The most important finding of the study was that a high percentage of women with lung cancer, regardless of breast-cancer history, did not meet the current USPSTF criteria for lung-cancer screening.

The MRL/MpJ Mouse Strain Is Not Protected From Muscle Atrophy and Weakness After Rotator Cuff Tear.

Chronic rotator cuff tears are a common source of shoulder pain and disability. Patients with rotator cuff tears often have substantial weakness, fibrosis, and fat accumulation, which limit successful surgical repair and postoperative rehabilitation. The Murphy Roths Large (MRL) strain of mice have demonstrated superior healing and protection against pathological changes in several disease and injury conditions. We tested the hypothesis that, compared with the commonly used C57Bl/6 (B6) strain, MRL mice would have less muscle fiber atrophy and fat accumulation, and be protected against the loss in force production that occurs after cuff tear. Adult male B6 and MRL mice were subjected to a rotator cuff tear, and changes in muscle fiber contractility and histology were measured. RNA sequencing and shotgun metabolomics and lipidomics were also performed. The muscles were harvested one month after tear. B6 and MRL mice had a 40% reduction in relative muscle force production after rotator cuff tear. RNA sequencing identified an increase in fibrosis-associated genes and a reduction in mitochondrial metabolism genes. The markers of glycolytic metabolism increased in B6 mice, while MRL mice appeared to increase amino acid metabolism after tear. There was an accumulation of lipid after injury, although there was a divergent response between B6 and MRL mice in the types of lipid species that accrued. There were strain-specific differences between the transcriptome, metabolome, and lipidome of B6 and MRL mice, but these differences did not protect MRL mice from weakness and pathological changes after rotator cuff tear. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:811-822, 2020.

PINK1/Parkin Influences Cell Cycle by Sequestering TBK1 at Damaged Mitochondria, Inhibiting Mitosis.

PINK1 and Parkin are established mediators of mitophagy, the selective removal of damaged mitochondria by autophagy. PINK1 and Parkin have been proposed to act as tumor suppressors, as loss-of-function mutations are correlated with enhanced tumorigenesis. However, it is unclear how PINK1 and Parkin act in coordination during mitophagy to influence the cell cycle. Here we show that PINK1 and Parkin genetically interact with proteins involved in cell cycle regulation, and loss of PINK1 and Parkin accelerates cell growth. PINK1- and Parkin-mediated activation of TBK1 at the mitochondria during mitophagy leads to a block in mitosis due to the sequestration of TBK1 from its physiological role at centrosomes during mitosis. Our study supports a diverse role for the far-reaching, regulatory effects of mitochondrial quality control in cellular homeostasis and demonstrates that the PINK1/Parkin pathway genetically interacts with the cell cycle, providing a framework for understanding the molecular basis linking PINK1 and Parkin to mitosis.