"Infiltrative" Versus "Mass-Forming" Pancreatic Cancer: A New Radiological Classification System for Pancreatic Head Ductal Carcinoma and Its Pathological Correlation

Purpose

Resectability in localized pancreatic ductal adenocarcinoma (PDAC) is deemed through radiological criteria. Despite initial evaluation classifying tumors as "resectable," they often have ill-defined borders that can result in more extensive cancer than predicted on final pathology analysis. We attempt to categorize these tumors radiologically and define them as "infiltrative" and contrast them to more well-defined or "mass-forming" tumors and assess their correlation with surgical oncological outcomes. We hypothesize that mass-forming lesions will result in fewer positive resection margins.

Methods

Patients diagnosed with PDAC of the head of the pancreas and who underwent subsequent curative intent resection between 2016 and 2018 were included. A retrospective chart review of patients was conducted and computed tomography images at the time of diagnosis were reviewed by two radiologists and scored as "mass forming" or "infiltrative" using a newly developed classification system. These classifications were then correlated with margin status.

Results

Sixty-eight consecutive pancreatoduodenectomies performed for PDAC from 2016 to 2018 were identified. After screening, 54 patients were eligible for inclusion. Radiologically defined mass-forming lesions had a trend toward a lower rate of positive resection margins (35.7% vs. 50.0%; p = 0.18), specifically the bile duct margin and pancreas margin as well as an overall larger size (4.03 cm vs. 3.25 cm, p = 0.02) compared with infiltrative lesions.

Conclusion

We propose a new radiological definition of PDAC into "mass forming" and "infiltrative," a nomenclature that resonates with other tumor sites. Infiltrative lesions trended toward a higher rate of positive resection margins. This classification may help tailor therapy for infiltrative tumors toward a neoadjuvant approach even if they appear resectable.

Hiatal Hernia After Esophagectomy: A Single-Center Retrospective Analysis of a Rare Postoperative Phenomenon

Development of a post-esophagectomy hiatal hernia (PEHH) is a rare, but problematic, sequela with the current reported prevalence ranging up to 20%. To determine the incidence rate of PEHH at our institution, a retrospective review of all transhiatal esophagectomies performed from 2012 to 2020 was conducted. Demographic, operative, and oncologic data were collected, rates of PEHH were calculated, and characteristics of subsequent repair were reviewed and analyzed. A total of 160 transhiatal esophagectomies were included, of which four patients (2.5%) developed a PEHH at a mean of 12 months postoperatively (range: 3-28 months) with symptomatology driving the diagnosis for three patients. The limited size of our study does not allow for statistically significant determinations regarding risk factors or method of repair. The true prevalence of a hiatal defect is likely higher than reported, as clinically asymptomatic patients are not captured in our current literature.

Surgical Treatment of High-Grade Dysplasia and Early Esophageal Cancer

BACKGROUND

The treatment of early-stage esophageal cancer and high-grade dysplasia of the esophagus has changed significantly in recent years. Many early tumors that were traditionally treated with esophagectomy can now be resected with endoscopic therapy alone. These new endoscopic modalities can offer similar survival outcomes without the associated morbidity of a major operation. However, a number of these cases may still require surgical intervention as the best treatment option.

METHODS

The current scientific literature, national and international guidelines were reviewed for recommendations regarding optimal treatment of early esophageal malignancy.

RESULTS

The primary advantage of surgery over endoscopic treatment lies in the reduced risk of recurrence as well as the ability to assess harvested lymph nodes for regional disease. We recommend that esophageal tumors that have invaded into the submucosa (T1b) or beyond should be treated with an esophagectomy. In addition, dysplastic lesions and cancers that demonstrate poorly differentiated pathology or lymphovascular or perineural invasion should be surgically resected. Finally, large tumors, multifocal lesions, tumors within a long segment of Barrett's esophagus, tumors adjacent to a hiatal hernia, tumors that cannot be resected enbloc with endoscopic techniques should also be treated with an esophagectomy.

CONCLUSIONS

When performed at high-volume centers in experienced hands, esophagectomy can have consistently good outcomes for high-grade dysplasia and early esophageal cancers, and should be considered as a treatment option.

Laparoscopic ischemic conditioning of the stomach increases neovascularization of the gastric conduit in patients undergoing esophagectomy for cancer

BACKGROUND AND OBJECTIVES

Gastric ischemic preconditioning has been proposed to improve blood flow and reduce the incidence of anastomotic complications following esophagectomy with gastric pull-up. This study aimed to evaluate the effect of prolonged ischemic preconditioning on the degree of neovascularization in the distal gastric conduit at the time of esophagectomy.

METHODS

A retrospective review of a prospectively maintained database identified 30 patients who underwent esophagectomy. The patients were divided into three groups: control (no preconditioning, n = 9), partial (short gastric vessel ligation only, n = 8), and complete ischemic preconditioning (left and short gastric vessel ligation, n = 13). Microvessel counts were assessed, using immunohistologic analysis to determine the degree of neovascularization at the distal gastric margin.

RESULTS

The groups did not differ in age, gender, BMI, pathologic stage, or cancer subtype. Ischemic preconditioning durations were 163 ± 156 days for partial ischemic preconditioning, compared to 95 ± 50 days for complete ischemic preconditioning (P = 0.2). Immunohistologic analysis demonstrated an increase in microvessel counts of 29% following partial ischemic preconditioning (P = 0.3) and 67% after complete ischemic preconditioning (P < 0.0001), compared to controls.

CONCLUSIONS

Our study indicates that prolonged ischemic preconditioning is safe and does not interfere with subsequent esophagectomy. Complete ischemic preconditioning increased neovascularization in the distal gastric conduit.

Evolution in the Treatment of Esophageal Disease at a Single Academic Institution: 2004-2013

INTRODUCTION

Management of benign and malignant esophageal disease has changed rapidly over the past decade. The aim of this study was to analyze evolution in surgical management of esophageal disease at a single academic medical center during this period.

MATERIALS AND METHODS

We reviewed a retrospective cohort of patients who underwent esophagectomy between 2004 and 2013. Patient, institutional, treatment, and outcomes variables were reviewed.

RESULTS

317 patients were analyzed. Median age was 63.5 years; 80% were male. Average inhospital mortality rate was 3.8%. Operative indications changed significantly from 2004 to 2013, with more operations performed for invasive malignancy (77% vs. 95%) and fewer for high-grade dysplasia (12% vs. 3%, P = .008). In 2004, Ivor Lewis esophagectomy was the most common surgical technique, but the three-field technique was the operation of choice in 2013. A minimally invasive approach was used in 19% of cases in 2004 and 100% of cases in 2013 (P < .001). Anastomotic leak ranged from 0% to 21% with no significant difference over the study period (P = .18). Median lymph node harvest increased from seven to 18 nodes from 2004 to 2013 (P = .001). Hospital length of stay decreased from 15 to 8 days (P = .001). In 2013, 79% of patients were discharged to home, compared to 73% in 2004 (P = .04).

DISCUSSION

Over the last decade, our treatment of esophageal disease has evolved from a predominantly open Ivor Lewis to a minimally invasive three-field approach. Operations for malignancy have also increased dramatically. Postoperative complications and mortality were not significantly changed, but were consistently low during the latter years of the study.

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios can Predict Treatment Response to Neoadjuvant Therapy in Esophageal Cancer

INTRODUCTION

We hypothesized that serum neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios may predict pathologic complete response to neoadjuvant chemoradiotherapy in esophageal cancer patients. The ability to predict favorable treatment response to therapy may aid in determining optimal treatment regimens.

MATERIALS AND METHODS

A retrospective review of a prospective esophageal disease registry was conducted. Neutrophil-to-lymphocyte ratio was defined as the pre-chemoradiotherapy serum neutrophil count divided by lymphocyte count. Platelet-to-lymphocyte ratio was similarly defined. Logistic regression was applied to analyze these ratios and their effect on pathologic complete response. A Cox proportional-hazards model was used to analyze survival.

RESULTS

Sixty patients were included. Elevated neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were both negative predictors of pathologic complete response (odds ratio: 0.62; 95% confidence interval: 0.37-0.89, P = 0.037 and odds ratio: 0.91; 95% confidence interval: 0.82-0.98, P = 0.028, respectively). Only platelet-to-lymphocyte ratio was predictive of decreased overall survival (hazard ratio: 1.05, 95% confidence interval: 0.94-1.16, P = 0.40).

CONCLUSION

Elevated neutrophil and platelet-to-lymphocyte ratios were significant predictors of a poor treatment response to neoadjuvant therapy. Only elevated platelet-to-lymphocyte ratio was predictive of worse overall survival. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios may offer a simple serum test to assess the likelihood of a pathologic complete response after neoadjuvant therapy in esophageal cancer.

Plasmodium infection in a Leadbeater's possum (Gymnobelideus leadbeateri)

CASE REPORT

A wild-caught, adult female Leadbeater's possum (Gymnobelideus leadbeateri) died while in captivity after suffering from chronic ill-thrift that progressed to acute respiratory distress. On histopathological examination of tissues, the cause of death was determined to be severe acute pneumonia with pulmonary oedema associated with an intracellular protozoan parasite present within erythrocytes. Transmission electron microscopy was performed on lung tissues and organisms consistent for Plasmodium sp. were identified within numerous erythrocytes. Molecular characterisation of the parasite from DNA extracted from tissue blocks of fixed lung determined the organism to belong to the genus Plasmodium (100% similarity to Plasmodium species when a BLAST analysis was performed); however, speciation of the organism was not possible.

CONCLUSION

This is the first report of Plasmodium sp. infection and subsequent disease in a native Australian mammal. The lifecycle of this parasite remains unknown. It is also unknown what effects haemoparasitism may have on the population dynamics of this endangered possum species.

Identifying belief targets to increase bone marrow registry participation among students who have never donated blood

New members on bone marrow registries worldwide are needed to allow sufficient diversity in the donor pool to meet patient needs. We used the theory of planned behaviour belief-basis and surveyed students who had not donated blood previously (i.e. non-donors) (N = 150) about the behavioural, normative, and control beliefs informing their intentions to join the Australian Bone Marrow Donor Registry. Key beliefs predicting non-donors' intentions included: viewing bone marrow donation as an invasion of the body (β = -.35), normative support from parents (β = .40), anticipating pain/side effects from giving blood (β = -.27), and lack of knowledge about how to register (β = -.30). Few non-donors endorsed these beliefs, suggesting they are ideal targets for change in strategies encouraging bone marrow donor registration.

Cohorts for the study of HIV‐1-exposed but uninfected individuals: benefits and limitations

Since the late 1980s, with the first identification of individuals who were exposed to human immunodeficiency virus type 1 (HIV-1) yet remained uninfected, or "HIV-1-resistant" individuals, a large number of cohorts that include HIV-exposed seronegative (HESN) subjects have been identified globally for the purpose of investigating the genetic, immunologic, and environmental factors that may help alter susceptibility to HIV-1. In this article, in light of the recent International Symposium on Natural Immunity to HIV, we review the characteristics of different groups with respect to their relative risks and briefly summarize the known cohorts that include exposed uninfected subjects worldwide.

Chondrodysplastic calves in Northeast Victoria

Outbreaks of chondrodysplasia in calves occur sporadically every 10-15 years, particularly following prolonged drought conditions, throughout Northeastern Victoria and the Southern Tablelands of New South Wales, Australia. An outbreak spanning 2 calving seasons (2003-2004) involving numerous losses through stillbirth, perinatal loss, and poor growth was investigated. Investigations of 4 representative cases are presented here with a definition of the gross and histopathologic defects and an overview of epidemiologic data gathered from affected farms. Calves showed variable disproportionate dwarfism without arthrogryposis. Long bones were shortened and showed axial rotation. Articular surfaces were distorted with misshapen weight-bearing surfaces associated with variable thickness of articular cartilage. Physes were distorted and variable in thickness with occasional foci of complete closure. The major histologic abnormality in the physes was disorderly development of the zones of cartilage hypertrophy, with reduced number and irregular arrangement of hypertrophic chondrocytes; similar less severe changes were present in the zones of cartilage proliferation. Histochemical staining of the cartilage matrix was variable in intensity, and there was evidence of abnormal resorption of cartilage matrix at the level of the primary spongiosa. Osteoid formation and subsequent bone remodelling seemed unaffected, and diaphyseal cortical bone appeared normal at the gross and light microscopic level. No infectious agents were identified, and other known causes for chondrodysplasia in calves were excluded. The most likely cause for the syndrome was considered to be congenital manganese deficiency. Further surveys of tissue and blood manganese levels from cows and calves with and without clinical signs from the region are planned.