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Smad4, a critical tumor suppressor gene, plays a significant role in pancreatic biology and tumorigenesis. Genetic background and sex are known to influence phenotypic outcomes, but their impact on pancreatic weight in Smad4-deficient mice remains unclear. This study investigates the impact of Smad4 deficiency on pancreatic weight in first-generation (F1) mice from diverse collaborative cross (CC) lines, focusing on the influence of genetic background and sex. F1 mice were generated by crossbreeding female CC mice with C57BL/6J-Smad4tm1Mak males. Genotyping confirmed the presence of Smad4 knockout alleles. Mice were housed under standard conditions, euthanized at 80 weeks, and their pancreatic weights were measured, adjusted for body weight, and analyzed for effects of Smad4 deficiency, sex, and genetic background. The overall population of F1 mice showed a slight but non-significant increase in adjusted pancreatic weights in heterozygous knockout mice compared to wild-type mice. Sex-specific analysis revealed no significant difference in males but a significant increase in adjusted pancreatic weights in heterozygous knockout females. Genetic background analysis showed that lines CC018 and CC025 substantially increased adjusted pancreatic weights in heterozygous knockout mice. In contrast, other lines showed no significant difference or varied non-significant changes. The interplay between genetic background and sex further influenced these outcomes. Smad4 deficiency affects pancreatic weight in a manner significantly modulated by genetic background and sex. This study highlights the necessity of considering these factors in genetic research and therapeutic development, demonstrating the value of the collaborative cross mouse population in dissecting complex genetic interactions.

Weight loss and exocrine pancreatic insufficiency are common in advanced pancreatic ductal adenocarcinoma (PDAC) and are associated with adverse outcomes. However, there is limited evidence on the impact of pancreatic enzyme replacement therapy (PERT) in patients with advanced PDAC. We retrospectively studied 501 patients with advanced PDAC and exocrine pancreatic insufficiency from the Virginia Mason Pancreas Cancer Program Data Resource treated between 2010 and 2019 with first-line chemotherapy. Clinical outcomes were compared between those who received PERT and those who did not at 8 weeks after chemotherapy start. In total 188 (38%) patients received PERT; 313 patients (62%) did not. PERT patients experienced less weight loss (-1.5 vs -2.5 kg, P = .04), less decline in the prognostic nutrition index -1.9 vs -3.0, P = .01), and a greater reduction in the additive score of the Patient-Generated Subjective Global Assessment (-8.4 vs --6.0, P = .02). Importantly, median (95% CI) overall survival (OS) was significantly longer in the PERT vs non-PERT group (17.1 months vs 12.5 months, respectively P = .001), and the adjusted hazards ratio indicated superior median OS in patients prescribed PERT (HR = 0.73, P < .001). Our findings suggest that treatment of exocrine pancreatic insufficiency (EPI) in advanced PDAC is associated with improvements in nutrition and overall survival.

A priority in cancer research is to innovate therapies that are not only effective against tumor progression but also address comorbidities such as cachexia that limit quality and quantity of life. We demonstrate that TLR7/8 agonist R848 induces anti-tumor responses and attenuates cachexia in murine models of pancreatic ductal adenocarcinoma (PDAC). In vivo, tumors from two of three cell lines were R848-sensitive, resulting in smaller tumor mass, increased immune complexity, increased CD8 + T-cell infiltration and activity, and decreased Treg frequency. R848-treated mice demonstrated improvements in behavioral and molecular cachexia manifestations, resulting in a near-doubling of survival duration. Knockout mouse studies revealed that stromal, not neoplastic, TLR7 is requisite for R848-mediated responses. In patient samples, we found Tlr7 is ubiquitously expressed in stroma across all stages of pancreatic neoplasia, but epithelial Tlr7 expression is relatively uncommon. These studies indicate immune-enhancing approaches including R848 may be useful in PDAC and cancer-associated cachexia. In the treatment of pancreatic ductal adenocarcinoma (PDAC), comorbidities such as cachexia limit quality of life and survival. Here, the authors show TLR7/8 agonist R848 remodels host and tumour immune responses, promoting survival and attenuating cachexia in murine models of PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is a highly desmoplastic tumor with a dismal prognosis for most patients. Fibrosis and inflammation are hallmarks of tumor desmoplasia. We have previously demonstrated that preventing the activation of pancreatic stellate cells (PSCs) and alleviating desmoplasia are beneficial strategies in treating PDAC. Metformin is a widely used glucose-lowering drug. It is also frequently prescribed to diabetic pancreatic cancer patients and has been shown to associate with a better outcome. However, the underlying mechanisms of this benefit remain unclear. Metformin has been found to modulate the activity of stellate cells in other disease settings. In this study, we examine the effect of metformin on PSC activity, fibrosis and inflammation in PDACs. In overweight, diabetic PDAC patients and pre-clinical mouse models, treatment with metformin reduced levels of tumor extracellular matrix (ECM) components, in particular hyaluronan (HA). In vitro, we found that metformin reduced TGF-ß signaling and the production of HA and collagen-I in cultured PSCs. Furthermore, we found that metformin alleviates tumor inflammation by reducing the expression of inflammatory cytokines including IL-1β as well as infiltration and M2 polarization of tumor-associated macrophages (TAMs) in vitro and in vivo. These effects on macrophages in vitro appear to be associated with a modulation of the AMPK/STAT3 pathway by metformin. Finally, we found in our preclinical models that the alleviation of desmoplasia by metformin was associated with a reduction in ECM remodeling, epithelial-to-mesenchymal transition (EMT) and ultimately systemic metastasis. Metformin alleviates the fibro-inflammatory microenvironment in obese/diabetic individuals with pancreatic cancer by reprogramming PSCs and TAMs, which correlates with reduced disease progression. Metformin should be tested/explored as part of the treatment strategy in overweight diabetic PDAC patients.

Background Malnutrition and weight loss are commonly observed in patients with pancreatic cancer and contribute to poor survival. Pancreatic exocrine insufficiency (PEI), which can be caused by ductal obstruction by a tumor, causes maldigestion and malabsorption of nutrients, thus contributing to malnutrition in these patients. In this study, we evaluated the effects of pancreatic enzyme replacement therapy (PERT) on survival in patients with unresectable pancreatic cancer. Methods A retrospective analysis was conducted on a database of patients with unresectable, pathologically confirmed pancreatic cancer. All patients were evaluated for palliative chemotherapy and received the optimal palliative care. Patients were divided into two groups: Group 1 received standard therapy; Group 2 underwent additional evaluation of the pancreatic function and therapy with PERT, if needed. Survival (median and 95% confidence interval [CI]) was analyzed using Kaplan–Meier and Cox regression; groups were compared using the log-rank test. Results Overall, 160 patients with unresectable pancreatic cancer were included in the analysis (mean age: 70.5 years [range 28–100]; gender: 57.5% male; tumor stage: 78.7% Stage IV). Eighty-six patients (53.75%) were in Group 1 and 74 (46.25%) were in Group 2. Age, gender, tumor size, location and stage, weight loss, and serum CA 19–9 were similar between groups. Ninety-three (58.1%) patients received palliative chemotherapy; 46.5% in Group 1 and 71.6% in Group 2 ( P  < 0.001). Forty-nine (66.2%) patients in Group 2 and none in Group 1 received PERT. Survival in Group 2 (189 days, 95% CI 167.0–211.0 days) was significantly longer than in Group 1 (95.0 days, 95% CI 75.4–114.6 days) (HR 2.117, 95% CI 1.493–3.002; P  < 0.001). Chemotherapy and PERT were significantly and independently associated with longer survival in a model controlled by age and tumor stage. In patients with significant weight loss at diagnosis (> 10% bodyweight within 6 months), PERT was associated with longer survival (HR 2.52, 95% CI 1.55–4.11; P  < 0.001). Conclusions In patients with unresectable pancreatic cancer, PERT in patients with PEI was associated with longer survival compared with those not receiving PERT, especially in those experiencing significant weight loss. This finding should guide future prospective clinical trials of similar interventions.

Purpose Cachexia influences the patient’s physical wellbeing and quality of life, and the patient’s ability to tolerate their cancer therapies, especially cytotoxic chemotherapy. The purpose of this study was to investigate the frequency and timing of onset of cancer cachexia during chemotherapy and its association with prognosis and toxicity in patients with pancreatic ductal adenocarcinoma (PDAC). Methods We performed a retrospective study in patients who underwent first-line chemotherapy after diagnosis of advanced PDAC between 6 June 2008 and 31 March 2017. Base cachexia (weight loss up to 6 months before starting first-line chemotherapy) and follow-up cachexia (after starting first-line chemotherapy) were defined as weight loss > 2% with a body mass index (BMI) < 20 kg/m 2 or weight loss > 5%. Results A total of 150 patients were registered. The median age and BMI were 65 years and 21.7 kg/m 2 , respectively. Base cachexia occurred in 50% of patients. Follow-up cachexia occurred in 32% within 12 weeks of starting first-line chemotherapy, reaching 64% at 1 year. Overall survival was not significantly different between patients with and without follow-up cachexia, regardless of whether cancer cachexia occurred within 12, 24, or 48 weeks of starting first-line treatment. Appetite loss, fatigue, nausea, and diarrhea were more frequent in patients with follow-up cachexia than in those without follow-up cachexia. Conclusion Follow-up cachexia had an early onset, but was not a prognostic factor for overall survival in patients with PDAC. Some adverse events tended to be more frequent in patients with follow-up cachexia than in those without follow-up cachexia.

Background By the traditional definition of unintended weight loss, cachexia develops in ~80% of patients with pancreatic ductal adenocarcinoma (PDAC). Here, we measure the longitudinal body composition changes in patients with advanced PDAC undergoing 5‐fluorouracil, leucovorin, irinotecan, and oxaliplatin therapy. Methods We performed a retrospective review of 53 patients with advanced PDAC on 5‐fluorouracil, leucovorin, irinotecan, and oxaliplatin as first line therapy at Indiana University Hospital from July 2010 to August 2015. Demographic, clinical, and survival data were collected. Body composition measurement by computed tomography (CT), trend, univariate, and multivariate analysis were performed. Results Among all patients, three cachexia phenotypes were identified. The majority of patients, 64%, had Muscle and Fat Wasting (MFW), while 17% had Fat‐Only Wasting (FW) and 19% had No Wasting (NW). NW had significantly improved overall median survival (OMS) of 22.6 months vs. 13.0 months for FW and 12.2 months for MFW (P = 0.02). FW (HR = 5.2; 95% confidence interval = 1.5–17.3) and MFW (HR = 1.8; 95% confidence interval = 1.1–2.9) were associated with an increased risk of mortality compared with NW. OMS and risk of mortality did not differ between FW and MFW. Progression of disease, sarcopenic obesity at diagnosis, and primary tail tumours were also associated with decreased OMS. On multivariate analysis, cachexia phenotype and chemotherapy response were independently associated with survival. Notably, CT‐based body composition analysis detected tissue loss of >5% in 81% of patients, while the traditional definition of >5% body weight loss identified 56.6%. Conclusions Distinct cachexia phenotypes were observed in this homogeneous population of patients with equivalent stage, diagnosis, and first‐line treatment. This suggests cellular, molecular, or genetic heterogeneity of host or tumour. Survival among patients with FW was as poor as for MFW, indicating adipose tissue plays a crucial role in cachexia and PDAC mortality. Adipose tissue should be studied for its mechanistic contributions to cachexia.

BackgroundDecision-making in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas depends on scaling the risk of malignancy with the surgical burden of a pancreatectomy. This study aimed to develop a preoperative, disease-specific tool to predict surgical morbidity for IPMNs.MethodsBased on preoperative variables of resected IPMNs at two high-volume institutions, classification tree analysis was applied to derive a predictive model identifying the risk factors for major morbidity (Clavien–Dindo ≥3) and postoperative pancreatic insufficiency.ResultsAmong 524 patients, 289 (55.2%) underwent pancreaticoduodenectomy (PD), 144 (27.5%) underwent distal pancreatectomy (DP), and 91 (17.4%) underwent total pancreatectomy (TP) for main-duct (18.7%), branch-duct (12.6%), or mixed-type (68.7%) IPMN. For 98 (18.7%) of the patients, major morbidity developed. The classification tree distinguished different probabilities of major complications based on the type of surgery (area under the surve [AUC] 0.70; 95% confidence interval [CI], 0.63–0.77). Among the DP patients, the presence of preoperative diabetes identified two risk classes with respective probabilities of 5% and 25% for the development of major morbidity, whereas among the PD/TP patients, three different classes with respective probabilities of 15%, 20%, and 36% were identified according to age and body mass index (BMI). Overall, history of diabetes, age, and cyst size segregated three different risk classes for new-onset/worsening diabetes.ConclusionsIn presumed IPMNs, the disease-specific risk of major morbidity and pancreatic insufficiency can be determined in the preoperative setting and used to personalize the possible surgical indication. Age and overweight status in case of PD/TP and diabetes in case of DP tip the scale toward less aggressive clinical management in the absence of features suggestive for malignancy.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States. Despite the high prevalence of Kras mutations in pancreatic cancer patients, murine models expressing the oncogenic mutant Kras (Krasmut) in mature pancreatic cells develop PDAC at a low frequency. Independent of cell of origin, a second genetic hit (loss of tumor suppressor TP53 or PTEN) is important for development of PDAC in mice. We hypothesized ectopic expression and elevated levels of oncogenic mutant Kras would promote PanIN arising in pancreatic ducts. To test our hypothesis, the significance of elevating levels of K-Ras and Ras activity has been explored by expression of a CAG driven LGSL-KrasG12V allele (cKras) in pancreatic ducts, which promotes ectopic Kras expression. We predicted expression of cKras in pancreatic ducts would generate neoplasia and PDAC. To test our hypothesis, we employed tamoxifen dependent CreERT2 mediated recombination. Hnf1b:CreERT2;KrasG12V (cKrasHnf1b/+) mice received 1 (Low), 5 (Mod) or 10 (High) mg per 20 g body weight to recombine cKras in low (cKrasLow), moderate (cKrasMod), and high (cKrasHigh) percentages of pancreatic ducts. Our histologic analysis revealed poorly differentiated aggressive tumors in cKrasHigh mice. cKrasMod mice had grades of Pancreatic Intraepithelial Neoplasia (PanIN), recapitulating early and advanced PanIN observed in human PDAC. Proteomics analysis revealed significant differences in PTEN/AKT and MAPK pathways between wild type, cKrasLow, cKrasMod, and cKrasHigh mice. In conclusion, in this study, we provide evidence that ectopic expression of oncogenic mutant K-Ras in pancreatic ducts generates early and late PanIN as well as PDAC. This Ras rheostat model provides evidence that AKT signaling is an important early driver of invasive ductal derived PDAC. In this study, the authors provide evidence that ectopic expression of oncogenic mutant Kras in pancreatic ducts generates early and late (PanIN) and pancreatic ductal adenocarcinoma (PDAC) . They characterized this Ras rheostat model which reveals elevated Kras mutation frequency and loss of PTEN are important drivers of PanIN and invasive ductal derived PDAC.

Cancer patients experience weight loss for a variety of reasons, commencing with the tumor’s metabolism (Warburg effect) and proceeding via cachexia to loss of appetite. In pancreatic cancer, several other factors are involved, including a loss of appetite with a particular aversion to meat and the incapacity of the pancreatic gland to function normally when a tumor is present in the pancreatic head. Pancreatic exocrine insufficiency is characterized by a deficiency of the enzymes secreted from the pancreas due to the obstructive tumor, resulting in maldigestion. This, in turn, contributes to malnutrition, specifically a lack of fat-soluble vitamins, antioxidants, and other micronutrients. Patients with pancreatic cancer and pancreatic exocrine insufficiency have, overall, an extremely poor prognosis with regard to surgical outcome and overall survival. Therefore, it is crucial to be aware of the mechanisms involved in the disease, to be able to diagnose pancreatic exocrine insufficiency early on, and to treat malnutrition appropriately, for example, with pancreatic enzymes.