Epidemiologic data has linked obesity to a higher risk of pancreatic cancer, but the underlying mechanisms are poorly understood. To allow for detailed mechanistic studies in a relevant model mimicking diet-induced obesity and pancreatic cancer, a high-fat, high-calorie diet (HFCD) was given to P48+/Cre;LSL-KRASG12D (KC) mice carrying a pancreas-specific oncogenic Kras mutation. The mice were randomly allocated to a HFCD or control diet (CD). Cohorts were sacrificed at 3, 6, and 9 months and tissues were harvested for further analysis. Compared to CD-fed mice, HFCD-fed animals gained significantly more weight. Importantly, the cancer incidence was remarkably increased in HFCD-fed KC mice, particularly in male KC mice. In addition, KC mice fed the HFCD showed more extensive inflammation and fibrosis, and more advanced PanIN lesions in the pancreas, compared to age-matched CD-fed animals. Interestingly, we found that the HFCD reduced autophagic flux in PanIN lesions in KC mice. Further, exome sequencing of isolated murine PanIN lesions identified numerous genetic variants unique to the HFCD. These data underscore the role of sustained inflammation and dysregulated autophagy in diet-induced pancreatic cancer development and suggest that diet-induced genetic alterations may contribute to this process. Our findings provide a better understanding of the mechanisms underlying the obesity-cancer link in males and females, and will facilitate the development of interventions targeting obesity-associated pancreatic cancer.

BackgroundHPV infection is associated with high p16 expression and good prognosis in head and neck squamous cell carcinomas (HNSCCs). Analysis of CDKN2A, the gene encoding p16, may further elucidate the association between p16 expression and prognosis. We sought to determine whether CDKN2A copy number loss was associated with poor survival in HPV-negative HNSCCs.MethodsThe Cancer Genome Atlas HNSCC clinical and genomic data were obtained and integrated. Patients <80 years old with a primary tumor in the oral cavity, oropharynx, hypopharynx, or larynx were included. Stratifying by copy number loss status, CDKN2A mRNA and p16 protein expression levels were examined and overall survival (OS) and disease-free survival (DFS) were evaluated.Results401 patients with HPV-negative HNSCC were identified. 146 patients demonstrated CDKN2A copy number loss. The CDKN2A copy number loss group expressed significantly lower levels of CDKN2A mRNA and p16 protein than did the non-copy number loss group. Median OS for patients with and without CDKN2A copy number loss was 16.5 and 46.6 months, respectively (p = 0.007). Median DFS for both groups was 11.6 and 19.2 months, respectively (p = 0.03). In both univariate and multivariable analyses, stage IV designation, receipt of chemotherapy and CDKN2A copy number loss were predictive of OS.ConclusionCDKN2A copy number loss predicted poor survival independently of other patient and treatment factors and may be a clinically useful prognostic factor.

Aberrant crypt foci (ACF) are the earliest morphologically identifiable lesion found within the human colon. Despite their relatively high frequency in the distal colon, few studies have examined the molecular characteristics of ACF within the proximal colon. In the following study, clinical participants ( = 184) were screened for ACF using high-definition chromoendoscopy with contrast dye-spray. Following pathologic confirmation, ACF biopsies were subjected to laser capture microdissection (LCM), and epithelial cells were evaluated for somatic mutations with a customized colorectal cancer mutation panel using DNA-mass spectrometry. Samples were further characterized for microsatellite instability (MSI). Logistic models were used to associate proximal ACF with synchronous (detected during the same procedure) neoplasia. Thirty-nine percent of participants had at least one histologically confirmed proximal ACF. Individuals with a proximal ACF were significantly more likely to present with a synchronous neoplasm ( = 0.001), and specifically, a proximal, tubular, or tubulovillous adenoma (multivariable OR = 2.69; 95% confidence interval, 1.12-6.47; = 0.027). Proximal ACF were more likely to be dysplastic (52%) compared with distal ACF (13%; < 0.0001). Somatic mutations to , and were detected in 37% of proximal ACF. Hyperplastic ACF were more often MSI-high, but there were no differences in MSI status observed by colonic location. In summary, ACF are identified in the proximal colons of approximately 40% of individuals undergoing chromoendoscopy and more often in patients with synchronous proximal adenomas. This study provides the most complete set of data, to date, that ACF represent the earliest step in the adenoma-carcinoma sequence but remain below the detection limit of conventional endoscopy. http//mcr.accrjournals.org/content/molcanres/16/3/486/F1.large.jpg .

While the progression of mutated colonic cells is dependent upon interactions between the initiated epithelium and surrounding stroma, the nature of these interactions is poorly understood. Here the development of an ultra-sensitive laser-capture microdissection (LCM)/RNA-seq approach for studying the epithelial and stromal compartments of aberrant crypt foci (ACF) is described. ACF are the earliest identifiable pre-neoplastic lesion found within the human colon and are detected using high-definition endoscopy with contrast dye-spray. The current analysis focused on the epithelium of ACF with somatic mutations to either KRAS, BRAF, or APC, with expression patterns compared to normal mucosa from each patient. By comparing gene expression patterns between groups, an increase in a number of pro-inflammatory NF-κB target genes were identified that were specific to ACF epithelium, including TIMP1, RELA and RELB. Distinct transcriptional changes associated with each somatic mutation were observed and a subset display a BRAFV600E-mediated senescence-associated transcriptome characterized by increased expression of CDKN2A. Finally, LCM-captured ACF-associated stroma was found to be transcriptionally distinct from normal stroma, with an up-regulation of genes related to immune cell infiltration and fibroblast activation. Immunofluorescence confirmed increased CD3+ T cells within the stromal microenvironment of ACF and an abundance of activated fibroblasts. Collectively, these results provide new insight into the cellular interplay that occurs at the earliest stages of colonic neoplasia, highlighting the important role of NF-kB, activated stromal fibroblasts and lymphocyte infiltration. Implications Fibroblasts and immune cells in the stromal microenvironment play an important role during the earliest stages of colon carcinogenesis.

Objective Performing tracheotomy in patients with COVID-19 carries a risk of transmission to the surgical team due to potential viral particle aerosolization. Few studies have reported transmission rates to tracheotomy surgeons. We describe our safety practices and the transmission rate to our surgical team after performing tracheotomy on patients with COVID-19 during the peak of the pandemic at a US epicenter. Study Design Retrospective cohort study. Setting Tertiary academic hospital. Methods Tracheotomy procedures for patients with COVID-19 that were performed April 15 to May 28, 2020, were reviewed, with a focus on the surgical providers involved. Methods of provider protection were recorded. Provider health status was the main outcome measure. Results Thirty-six open tracheotomies were performed, amounting to 65 surgical provider exposures, and 30 (83.3%) procedures were performed at bedside. The mean time to tracheotomy from hospital admission for SARS-CoV-2 symptoms was 31 days, and the mean time to intubation was 24 days. Standard personal protective equipment, according to Centers for Disease Control and Prevention, was worn for each case. Powered air-purifying respirators were not used. None of the surgical providers involved in tracheotomy for patients with COVID-19 demonstrated positive antibody seroconversion or developed SARS-CoV-2–related symptoms to date. Conclusion Tracheotomy for patients with COVID-19 can be done with minimal risk to the surgical providers when standard personal protective equipment is used (surgical gown, gloves, eye protection, hair cap, and N95 mask). Whether timing of tracheotomy following onset of symptoms affects the risk of transmission needs further study.

To examine clinicodemographic determinants associated with breast cancer survivorship follow-up during COVID-19. Methods: We performed a retrospective, population-based cohort study including early stage (Stage I-II) breast cancer patients who underwent resection between 2006 and 2018 in a New York City hospital system. The primary outcome was oncologic follow-up prior to and during the COVID-19 pandemic. Secondary analyses compared differences in follow-up by COVID-19 case rates stratified by ZIP code. Results: A total of 2942 patients with early-stage breast cancer were available for analysis. 1588 (54%) of patients had attended follow-up in the year prior to the COVID-19 period but failed to continue to followup during the pandemic, either in-person or via telemedicine. 1242 (42%) patients attended a follow-up appointment during the COVID-19 pandemic. Compared with patients who did not present for follow-up during COVID-19, patients who continued their oncologic follow-up during the pandemic were younger (p ¼ 0.049) more likely to have received adjuvant radiation therapy (p ¼ 0.025), and have lower household income (p ¼ 0.031) on multivariate modeling. When patients who live in Bronx, New York, were stratified by ZIP code, there was a modest negative association (r ¼ À0.56) between COVID-19 cases and proportion of patients who continued to follow-up during the COVID-19 period. Conclusion:We observed a dramatic disruption in routine breast cancer follow-up during the COVID-19 pandemic. Providers and health systems should emphasize reintegrating patients who missed appointments during COVID-19 back into regular surveillance programs to avoid significant morbidity and mortality from missed breast cancer recurrences.

Aberrant crypt foci (ACF) are the earliest morphologically identifiable lesions in the colon that can be detected by high-definition chromoendoscopy with contrast dye spray. Although frequently associated with synchronous adenomas, their role in colorectal tumor development, particularly in the proximal colon, is still not clear. The goal of this study was to evaluate the profile of colon-adherent bacteria associated with proximal ACF and to investigate their relationship to the presence and subtype of synchronous polyps present throughout the colon. Forty-five subjects undergoing a screening or surveillance colonoscopy were included in this retrospective study. Bacterial cells adherent to the epithelia of ACF and normal mucosal biopsies were visualized by in situ hybridization within confocal tissue sections. ACF showed significantly greater heterogeneity in their bacterial microbiome profiles compared with normal mucosa. One of the bacterial community structures we characterized was strongly correlated with the presence of synchronous polyps. Finally, using DNA mass spectrometry to evaluate a panel of colorectal cancer hotspot mutations present in the ACF, we found that three APC gene mutations were positively associated with the presence of Instestinibacter sp., whereas KRAS mutations were positively correlated with Ruminococcus gnavus. This result indicates a potential relationship between specific colon-associated bacterial species and somatically acquired CRC-related mutations. Overall, our findings suggest that perturbations to the normal adherent mucosal flora may constitute a risk factor for early neoplasia, demonstrating the potential impact of mucosal dysbiosis on the tissue microenvironment and behavior of ACF that may facilitate their progression towards more advanced forms of neoplasia.

We report for the first time, in a typical risk US clinical population, a lack of protective association of aspirin for polyps among active smokers. Future prospective studies are recommended to confirm this mitigating effect in order to improve the precision of the growing evidence base about the chemopreventive benefit of aspirin in colorectal cancer.