Barriers to resection following neoadjuvant chemotherapy for resectable pancreatic adenocarcinoma: A national and local perspective.

BACKGROUND: Neoadjuvant chemotherapy (NAC) use for pancreatic ductal adenocarcinoma (PDAC) has increased, but some patients never get resection following NAC. METHODS: Data from January 2012 to December 2019 for all clinically resectable patients across two health networks were utilized, as well as data from the ACS NCDB registry. Univariate testing, multivariable logistic regression, and survival analyses were employed to evaluate failure to resection after neo-adjuvant chemotherapy. RESULTS: Of the 10 007 registry patients eligible for resection, the resected group was younger (64.6 vs. 69.5 years; p < 0.001) and had a slightly lower mean comorbidity index (0.41 vs. 0.45; p < 0.001) than the nonsurgical group. The nonsurgical group was composed of a higher percentage of Black and Hispanic patients (17.5 vs. 13.1%; p < 0.001). After adjusting for age and comorbidities, the factors associated with decreased probability of resection after NAC were evaluation at a community hospital (OR 2.4), Black or Hispanic race (OR 1.6), areas of increased high school drop-out rates (OR 1.4), and lack of private health insurance (OR 1.3). The median overall survival for nonsurgery was markedly worse than the surgical cohort (10.6 vs. 26.6 months; p < 0.001). The most frequent reasons for a lack of definitive resection were operative upstaging to unresectable (39.6%), patient preference (14.5%), progression on NAC (13.2%), deconditioning or comorbidity severity (12.5%), and nonreferral to a surgeon (8.8%). CONCLUSIONS: Racial, economic, and educational disparities have a considerable influence on the successful completion of a neoadjuvant approach for resectable PDAC. A comprehensive closed or highly collaborative/communicative multidisciplinary neoadjuvant program is optimal for treatment success and completion.

Diagnosis of Pancreatic Cancer after Cholecystectomy in the Elderly.

BACKGROUND: Previous studies evaluating whether recent cholecystectomy is associated with a pancreas cancer diagnosis are limited. We aimed to examine if cholecystectomy was performed more frequently in the year prior to cancer diagnosis than would be expected in a similar non-cancer population. METHODS: SEER-Medicare linked files were used to identify patients with pancreatic adenocarcinoma. Cancer diagnoses were considered to be "timely" if within 2 months of cholecystectomy or "delayed" if 2-12 months after cholecystectomy. Clinical factors and survival outcomes were compared using chi-square and Kaplan-Meier analyses. RESULTS: Rate of cholecystectomy in the year prior to diagnosis of cancer was 1.9% for the cancer group, compared to .4% in the non-cancer group (OR = 4.7, 95% CI 4.4-5.1). Differences in the cancer vs non-cancer cohorts at the time of cholecystectomy included a higher age (74 vs 70, P < .0001), more males (49.9% vs 41.7%, P < .0001), and more frequent open technique (21.0% vs 9.4%, P < .0001). Acute pancreatitis was nearly twice as common in the cancer cohort (19.1%) vs the non-cancer cohort (10.7%), P < .0001. There were no differences between patients who had a timely diagnosis after cholecystectomy compared to a delayed diagnosis with regard to age, gender, comorbidity index, race, or rural/urban designation. The rates of localized disease and subsequent resection were also similar between the delayed and timely groups. Overall unadjusted survival was no different between timely and delayed diagnoses, P = .96. DISCUSSION: Elderly patients diagnosed with pancreatic adenocarcinoma are more likely to have had a recent cholecystectomy compared to those without.

Locally advanced pancreatic cancer: a reliable contraindication to resection in the modern era?

BACKGROUND: The aim of this study is to present radiologically designated LAPC found to be resectable upon surgical exploration and evaluate the outcomes of such resections. METHODS: Sequential LAPC patients between 2013 and 2019 were staged and underwent resection were included in the analysis of both perioperative and long-term outcomes. RESULTS: Twenty-eight patients with radiologically-designated LAPC underwent surgical resection after chemotherapy with a median follow-up of 31.7 m,75% underwent pancreaticoduodenectomy. The margin positivity and local recurrence rates were 21.4% and 35.7%, respectively. When compared to the 30 BRPC controls, the LAPC group had a higher rates of an arterial resection (11vs.1; p = 0.002), but the groups were similar with regard to all other preoperative and intraoperative variables (p < 0.05). Perioperative morbidity rates were similar (25.9%vs21.4%; p = 0.53). The LAPC and BRPC groups were also equivalent with respect to median recurrence-free survival (9.0mo; 95%CI 6.3, 11.7vs.8.3mo; 95%CI 5.4, 11.2) and median overall survival (19.9mo; 95%CI 17.0, 22.7 vs. 19.9mo; 95%CI 14.8, 25.1), respectively. CONCLUSION: Despite a radiologic designation of locally advanced pancreatic cancer, certain subtypes of LAPC warrant surgical exploration provided the operative surgeon is prepared for major arterial and/or venous resection. Pancreatectomy in these patients has acceptable morbidity and oncologic outcomes, similar to patients who are radiologically borderline resectable.

Preventing Futile Liver Resection: A Risk-Based Approach to Surgical Selection in Major Hepatectomy for Colorectal Cancer.

BACKGROUND: Early recurrence following liver resection for metastatic colorectal cancer generally portends poor survival. We sought to identify factors associated with early disease recurrence after major hepatectomy for metastatic colorectal cancer in order to improve patient selection and prevent futile hepatectomy. METHODS: Sequential major (four or more segments) liver resections performed for metastatic colorectal cancer between 1995 and 2019 were selected from our prospectively maintained database. Univariate analyses, multivariable regression modelling, and survival analyses were used to identify predictors of futile resection (recurrence within 6 months of hepatectomy). RESULTS: Of 259 patients included, the median age was 61.3 years (interquartile range [IQR] 15.3) and the median number of liver tumors was 3.0 (IQR 2.0); 78.0% of patients received prehepatectomy chemotherapy. Surgeries were right (56.4%), left (19.3%), and extended hepatectomy (24.3%). Futile resection occurred in 26 (12.6%) patients. Margin positivity was similar in the futile resection group compared with the non-futile resection group (11.5% vs. 11.4%). Extrahepatic disease that disappeared with chemotherapy was present in 23.1% of patients with a futile resection and 7.2% of those without (p = 0.019). After multivariable regression, the factors predictive of futile resection were extrahepatic disease (odds ratio [OR] 5.6; p = 0.004), more than three liver lesions (OR 4.9; p = 0.001), and extended hepatectomy (OR 2.6; p = 0.038). Notably, 70.8% of futile recurrences occurred within the liver remnant and 20.8% were pulmonary metastases. Overall survival was 11.7 months (95% confidence interval [CI] 7.1-16.2) for the futile resection cohort versus 45.6 (95% CI 39.1-52.1) for non-futile hepatectomies (p < 0.001). CONCLUSIONS: Futile hepatic resection can be predicted based on preoperative factors and carries a poor prognosis. Improved risk stratification for futility will aid in patient selection and treatment discussions.

An Improved Staging System for Locally Advanced Pancreatic Cancer: A Critical Need in the Multidisciplinary Era.

BACKGROUND: Locally-advanced pancreatic cancer (LAPC) is traditionally considered stage III unresectable disease. Advances in induction systemic therapy regimens, surgical technique, and perioperative care have led to successful resection of an increasing number of these tumors with reasonable perioperative outcomes and disease-free intervals. Certain anatomic characteristics that meet criteria for locally-advanced disease, however, are more likely to result in a successful surgical outcome. METHODS: A practical and consistent system is needed to communicate such nuance between surgical and nonsurgical oncologists for optimal treatment planning and to improve recording for cancer registries and research studies. RESULTS: The present study proposes a novel subclassification system for stage III pancreatic cancers based on their pattern of vascular involvement and examines the current evidence for resection in each scenario. Introducing needed detail into the current catch-all stage III categorization will help to direct patient referrals and increase the body of knowledge about the variable presentations of this complex malignancy. CONCLUSION: This proposed staging revision for LAPC is designed to convey more actionable tumor descriptions for treating oncologists, clinical trial eligibility, and surgical patient selection in the era of effective induction systemic therapy.

Isolation and identification of adipose-derived stromal/stem cells from breast cancer patients after exposure neoadjuvant chemotherapy.

BACKGROUND: With recent research advances, adipose-derived stromal/stem cells (ASCs) have been demonstrated to facilitate the survival of fat grafts and thus are increasingly used for reconstructive procedures following surgery for breast cancer. Unfortunately, in patients, following radiation and chemotherapy for breast cancer suggest that these cancer treatment therapies may limit stem cell cellular functions important for soft tissue wound healing. For clinical translation to patients that have undergone cancer treatment, it is necessary to understand the effects of these therapies on the ASC's ability to improve fat graft survival in clinical practice. AIM: To investigate whether the impact on ASCs function capacity and recovery in cancer patients may be due to the chemotherapy. METHODS: ASCs were isolated from the cancerous side and noncancerous side of the breast from the same patients with receiving neoadjuvant chemotherapy (NAC) or not-receiving NAC. ASCs were in vitro treated with 5-fluorouracil (5-FU), doxorubicin (DXR), and cyclophosphamide (Cytoxan) at various concentrations. The stem cells yield, cell viability, and proliferation rates were measured by growth curves and MTT assays. Differentiation capacity for adipogenesis was determined by qPCR analysis of the specific gene markers and histological staining. RESULTS: No significant differences were observed between the yield of ASCs in patients receiving NAC treatment and not-receiving NAC. ASCs yield from the cancerous side of the breast showed lower than the noncancerous side of the breast in both patients receiving NAC and not-receiving NAC. The proliferation rates of ASCs from patients didn't differ much before and after NAC upon in vitro culture, and these cells appeared to retain the capacity to acquire adipocyte traits simile to the ASCs from patients not-receiving NAC. After cessation and washout of the drugs for another a week of culturing, ASCs showed a slow recovery of cell growth capacity in 5-FU-treated groups but was not observed in ASCs treated with DXR groups. CONCLUSION: Neoadjuvant therapies do not affect the functioning capacity of ASCs. ASCs may hold great potential to serve as a cell source for fat grafting and reconstruction in patients undergoing chemotherapy.

Cancer Immunotherapy for the General Surgeon.

Progress in the arena of cancer immunotherapy has been immense in recent years. The fact remains that most of the cancer resections in the United States are performed by general surgeons and not oncologic specialists. A busy practice in general surgery will invariably make it difficult to keep pace with such rapid advancement. This review offers a concise summary of the major concepts and trials that have driven the immunotherapy revolution and their implications for surgeons who deliver cancer care.

Acceleration of diabetic wound healing with adipose-derived stem cells, endothelial-differentiated stem cells, and topical conditioned medium therapy in a swine model.

OBJECTIVE: The purpose of our study was to investigate the effect of adipose-derived stem cells (ASCs), endothelial-differentiated ASCs (EC/ASCs), and various conditioned media (CM) on wound healing in a diabetic swine model. We hypothesized that ASC-based therapies would accelerate wound healing. METHODS: Diabetes was induced in four Yorkshire swine through intravenous injection of streptozotocin. ASCs were harvested from flank fat and cultured in either M199 or EGM-2 medium. A duplicate series of seven full-thickness dorsal wounds were surgically created on each swine. The wounds in the cellular treatment group underwent injection of low-dose or high-dose ASCs or EC/ASCs on day 0, with a repeat injection of one half of the initial dose on day 15. Wounds assigned to the topical CM therapy were covered with 2 mL of either serum-free M199 primed by ASCs or human umbilical vein endothelial cells every 3 days. Wounds were assessed at day 0, 10, 15, 20, and 28. The swine were sacrificed on day 28. ImageJ software was used to evaluate the percentage of wound healing. The wounded skin underwent histologic, reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay examinations to evaluate markers of angiogenesis and inflammation. RESULTS: We found an increase in the percentage of wound closure rates in cell-based treatments and topical therapies at various points compared with the untreated control wounds (P < .05). The results from the histologic, messenger RNA, and protein analyses suggested the treated wounds displayed increased angiogenesis and a diminished inflammatory response. CONCLUSIONS: Cellular therapy with ASCs, EC/ASCs, and topical CM accelerated diabetic wound healing in the swine model. Enhanced angiogenesis and immunomodulation might be key contributors to this process.

Spectral analysis of heart rate variability predicts mortality and instability from vascular injury.

BACKGROUND: Spectral analysis of continuous blood pressure and heart rate variability provides a quantitative assessment of autonomic response to hemorrhage. This may reveal markers of mortality as well as endpoints of resuscitation. METHODS: Fourteen male Yorkshire pigs, ranging in weight from 33 to 36 kg, were included in the analysis. All pigs underwent laparotomy and then sustained a standardized retrohepatic inferior vena cava injury. Animals were then allowed to progress to class 3 hemorrhagic shock and where then treated with abdominal sponge packing followed by 6 h of crystalloid resuscitation. If the pigs survived the 6 h resuscitation, they were in the survival (S) group, otherwise they were placed in the nonsurvival (NS) group. Fast Fourier transformation calculations were used to convert the components of blood pressure and heart rate variability into corresponding frequency classifications. Autonomic tones are represented as the following: high frequency (HF) = parasympathetic tone, low frequency (LF) = sympathetic, and very low frequency (VLF) = renin-angiotensin aldosterone system. The relative sympathetic to parasympathetic tone was expressed as LF/HF ratio. RESULTS: Baseline hemodynamic parameters were equal for the S (n = 11) and NS groups. LF/HF was lower at baseline for the NS group but was higher after hemorrhage and the resuscitation period indicative of a predominately parasympathetic response during hemorrhagic shock before mortality. HF signal was lower in the NS group during the resuscitation indicating a relatively lower sympathetic tone during hemorrhagic shock, which may have contributed to mortality. Finally, the NS group had a lower VLF signal at baseline (e.g., [S] 16.3 ± 2.5 versus [NS] 4.6 ± 2.9 P < 0.05,) which was predictive of mortality and hemodynamic instability in response to a similar hemorrhagic injury. CONCLUSIONS: An increased LF/HF ratio, indicative of parasympathetic predominance following injury and during resuscitation of hemorrhagic shock was a marker of impending death. Spectral analysis of heart rate variability can also identify autonomic lability following hemorrhagic injuries with implications for first responder triage. Furthermore, a decreased VLF signal at baseline indicates an additional marker of hemodynamic instability and marker of mortality following a hemorrhagic injury. These data indicate that continuous quantitative assessment of autonomic response can be a predictor of mortality and potentially guide resuscitation of patients in hemorrhagic shock.

The endothelial cell secretome as a novel treatment to prime adipose-derived stem cells for improved wound healing in diabetes.

BACKGROUND: Chronic wounds are a common surgical problem exacerbated by diabetes and ischemia. Although adipose-derived stem cells (ASCs) have shown promise as a wound healing therapy, their function and proliferation are hindered in diabetes. This study examines the ability of the human umbilical vein endothelial cell (HUVEC) secretome to reverse the deleterious effects of high glucose concentrations on ASCs through priming, thereby enhancing their ability to participate in angiogenesis and wound healing. METHODS: Institutional review board-approved human ASCs were cultured in M199 medium with or without glucose (30 mmol/L). HUVEC were grown in 30 mmol/L glucose-containing M199 medium; the resulting conditioned medium (HUVEC-CM) was collected every 3 days and used to prime ASCs. An aliquot of HUVEC-CM was heated (85°C for 30 minutes) to produce thermal denaturation of protein. Viability, proliferation, and endothelial differentiation were measured by MTT assays, growth curves, and quantitative polymerase chain reaction, respectively. A Matrigel assay was used to assess the ability of primed ASCs to participate in capillary-like tube formation. An Institutional Animal Care and Use Committee-approved in vivo murine model of diabetic and ischemic hindlimbs was used to evaluate the angiogenic potential of primed stem cells. Human ASCs were cultured with either control M199 or HUVEC-CM. Mice were randomized to a control group, an unprimed ASC group, or a HUVEC-primed ASC group. Cellular therapies were injected into the ischemic muscle. Thirty days later, slides were made. Microvessels were counted by three blinded observers. RESULTS: MTT assays revealed that HUVEC-priming induced a 1.5 times increase in cell viability over diabetic controls. This promoting effect was lost with heated HUVEC-CM (P < .001), indicating that the active molecules are of protein origin. After 9 days, ASCs cultured in 30 mmol/L glucose solution showed a 14% reduction in growth from nondiabetic controls (P = .013) and exhibited atrophic morphology. Conversely, diabetic HUVEC-primed stem cells demonstrated a nearly four-fold increase in proliferation (P < .05) and took on a fusiform, endothelial-like phenotype. Polymerase chain reaction demonstrated enhanced expression of CD31 messenger RNA by 4.7-fold after 14 days in the HUVEC-primed group, and endothelial nitric oxide synthase messenger RNA messenger RNA was increased 20.1-fold from controls. Unlike unprimed controls, HUVEC-primed ASCs readily formed capillary-like tube networks on Matrigel. Diabetic mice that were injected with HUVEC-primed ASCs demonstrated greater vessel density than both controls (2.1-fold) and unprimed stem cell treatments (P < .001). CONCLUSIONS: HUVECs secrete protein factors that significantly increase proliferation and endothelial differentiation of ASCs under diabetic conditions. Injection of ischemic hindlimbs in diabetic mice with HUVEC-primed ASCs leads to enhanced angiogenesis.

Histone Deacetylase Inhibitors Enhance Cytotoxicity Towards Breast Tumors While Preserving the Wound-Healing Function of Adipose-Derived Stem Cells.

INTRODUCTION: Paclitaxel improves the oncologic response of breast cancer resections; however, it may negatively affect the wound-healing potential of human adipose-derived stem cells (hASCs) for fat grafting and reconstructive surgery. Histone deacetylase inhibitors (HDACis) modify the epigenetic regulation of gene expression and stabilize microtubules similarly to paclitaxel, thus, creating a synergistic mechanism of cell cycle arrest. We aim to combine these drugs to enhance cytotoxicity towards breast cancer cells, while preserving the wound-healing function of hASCs for downstream reconstructive applications. METHODS: Triple negative breast cancer cells (MBA-MB-231) and hASCs (institutional review board-approved clinical isolates) were treated with a standard therapeutic dose of paclitaxel (1.0 µM) or with low-dose paclitaxel (0.1 µM) combined with the HDACi suberoylanilide hydroxamic acid or trichostatin A. Cell viability, gene expression, apoptosis, and wound-healing/migration were measured via methylthiazol tetrazolium assay, quantitative real-time polymerase chain reaction, annexin V assay, and fibroblast scratch assay, respectively. RESULTS: Combined HDACi and low-dose paclitaxel therapy maintained cytotoxicity towards breast cancer cells and preserved adipose-derived stem cell viability. Histone deacetylase inhibitor demonstrated selective anti-inflammatory effects on adipose-derived stem cell gene expression and decreased expression of the proapoptotic gene FAS. Furthermore, HDACi therapy did not increase relative apoptosis within hASCs. A scratch assay demonstrated enhanced wound healing among injured fibroblasts indirectly co-cultured with HDACi-treated hASCs. CONCLUSIONS: Combining HDACi with low-dose paclitaxel improved cytotoxicity towards breast cancer cells and preserved hASC viability. Furthermore, enhanced wound healing was observed by improved migration in a fibroblast scratch assay. These results suggest that the addition of HDACi to taxane chemotherapy regimens may improve oncologic results and wound-healing outcomes after reconstructive surgery.

Primary Malignancy Is an Independent Determinant of Morbidity and Mortality after Liver Resection.

Although outcomes after liver resection have improved, there remains considerable perioperative morbidity and mortality with these procedures. Studies suggest a primary liver cancer diagnosis is associated with poorer outcomes, but the extent to which this is attributable to a higher degree of hepatic dysfunction is unclear. To better delineate this, we performed a matched pair analysis of primary versus metastatic malignancies using a national database. The American College of Surgeons National Surgical Quality Improvement Program (2005-2013) was analyzed to select elective liver resections. Diagnoses were sorted as follows: 1) primary liver cancers and 2) metastatic neoplasms. A literature review identified factors known to impact hepatectomy outcomes; these variables were evaluated by a univariate analysis. The most predictive factors were used to create similar groups from each diagnosis category via propensity matching. Multivariate regression was used to validate results in the wider study population. Outcomes were compared using chi-squared test and Fisher exact test. Matched groups of 4838 patients were similar by all variables, including indicators of liver function. A number of major complications were significantly more prevalent with a primary diagnosis; overall major morbidity rates in the metastatic and primary groups were 29.3 versus 41.6 per cent, respectively. The mortality rate for primary neoplasms was 4.6 per cent (vs 1.6%); this represents a risk of death nearly three-times greater (95% confidence interval = 2.20-3.81, P < 0.0001) in cancers of hepatic origin. Hepatectomy carries substantially higher perioperative risk when performed for primary liver cancers, independent of hepatic function and resection extent. This knowledge will help to improve treatment planning, patient education, and resource allocation in oncologic liver resection.

Kaolin-based hemostatic dressing improves hemorrhage control from a penetrating inferior vena cava injury in coagulopathic swine.

BACKGROUND: Retrohepatic inferior vena cava (RIVC) injuries are often lethal due to challenges in obtaining hemorrhage control. We hypothesized that packing with a new kaolin-based hemostatic dressing (Control+; Z-Medica, Wallingford, CT) would improve hemorrhage control from a penetrating RIVC injury compared with packing with standard laparotomy sponges alone. METHODS: Twelve male Yorkshire pigs received a 25% exchange transfusion of blood for refrigerated normal saline to induce a hypothermic coagulopathy. A laparotomy was performed and a standardized 1.5 cm injury to the RIVC was created which was followed by temporary abdominal closure and a period of uncontrolled hemorrhage. When the mean arterial pressure reached 70% of baseline, demonstrating hemorrhagic shock, the abdomen was re-entered, and the injury was treated with perihepatic packing using standard laparotomy sponges (L; n = 6) or a new kaolin-based hemostatic dressing (K; n = 6). Animals were then resuscitated for 6 hours with crystalloid solution. The two groups were compared using the Wilcoxon rank sum test and Fisher exact test. A p value of 0.05 or less was considered statistically significant. RESULTS: There was no difference in the animal's temperature, heart rate, mean arterial pressure, cardiac output, and blood loss at baseline or before packing was performed (all p > 0.05). In the laparotomy sponge group, five of six pigs survived the entire study period, whereas all six pigs treated with kaolin-based D2 hemostatic dressings survived. Importantly, there was significantly less blood loss after packing with the new hemostatic kaolin-based dressing compared with packing with laparotomy sponge (651 ± 180 mL vs. 1073 ± 342 mL; p ≤ 0.05). CONCLUSION: These results demonstrate that the use of this new hemostatic kaolin-based dressing improved hemorrhage control and significantly decreased blood loss in this penetrating RIVC model. LEVEL OF EVIDENCE: This is basic science research based on a large animal model, level V.

Detecting allosteric sites of HIV-1 reverse transcriptase by X-ray crystallographic fragment screening.

HIV-1 reverse transcriptase (RT) undergoes a series of conformational changes during viral replication and is a central target for antiretroviral therapy. The intrinsic flexibility of RT can provide novel allosteric sites for inhibition. Crystals of RT that diffract X-rays to better than 2 Å resolution facilitated the probing of RT for new druggable sites using fragment screening by X-ray crystallography. A total of 775 fragments were grouped into 143 cocktails, which were soaked into crystals of RT in complex with the non-nucleoside drug rilpivirine (TMC278). Seven new sites were discovered, including the Incoming Nucleotide Binding, Knuckles, NNRTI Adjacent, and 399 sites, located in the polymerase region of RT, and the 428, RNase H Primer Grip Adjacent, and 507 sites, located in the RNase H region. Three of these sites (Knuckles, NNRTI Adjacent, and Incoming Nucleotide Binding) are inhibitory and provide opportunities for discovery of new anti-AIDS drugs.