Importance Although patients with resected pancreatic adenocarcinoma are at high risk for disease recurrence, few markers are available to inform patient outcomes. Objective To evaluate alterations of the four main driver genes for pancreatic adenocarcinoma and patient outcomes after cancer resection. Design, Setting, and Participants We analyzed protein expression and DNA alterations for KRAS, CDKN2A, SMAD4, and TP53 by immunohistochemistry and next-generation sequencing in formalin-fixed, paraffin-embedded tumors from 356 patients with resected pancreatic adenocarcinoma evaluated at three U.S. centers. Associations of driver gene alterations with disease-free survival (DFS) and overall survival (OS) were evaluated using Cox proportional hazards regression with estimation of hazard ratios (HR) and 95% confidence intervals (CI) and adjustment for age, sex, tumor characteristics, institution, and peri-operative treatment. Main Outcomes DFS and OS among patients with resected pancreatic adenocarcinoma Results Patients with KRAS mutant tumors had worse DFS and OS compared to patients with KRAS wild-type tumors, with median OS of 20.3 versus 38.6 months and 5-year OS of 13.0% versus 30.2%, respectively. Particularly poor outcomes were identified in patients with KRAS G12D-mutant tumors, who had median OS of 15.3 months. Patients whose tumors lacked CDKN2A expression had worse DFS and OS compared to patients whose tumors retained CDKN2A, with median OS of 19.7 versus 24.6 months and 5-year OS of 11.9% versus 19.5%, respectively. SMAD4 status was not associated with DFS or OS, while TP53 status was associated only with DFS (P=0.04). Patients had worse DFS and OS with greater number of altered driver genes. Compared to patients with 0-2 altered genes, those with 4 altered genes had HR for DFS of 1.79 (1.24-2.59; P<0.01) and OS of 1.38 (0.98-1.94; P=0.06). Five-year OS was 18.4% for patients with 0-2 gene alterations, 14.1% for 3 alterations and 8.2% for 4 alterations. Alterations in the four driver genes were not significantly associated with local recurrence as the first site of disease recurrence. Conclusions and Relevance Patient outcomes are associated with alterations of the four main driver genes in resected pancreatic adenocarcinoma.

Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

Malignancy is accompanied by changes in the metabolism of both cells and the organism. Pancreatic ductal adenocarcinoma (PDAC) is associated with wasting of peripheral tissues, a metabolic syndrome that lowers quality of life and has been proposed to decrease survival of patients with cancer. Tissue wasting is a multifactorial disease and targeting specific circulating factors to reverse this syndrome has been mostly ineffective in the clinic. Here we show that loss of both adipose and muscle tissue occurs early in the development of pancreatic cancer. Using mouse models of PDAC, we show that tumour growth in the pancreas but not in other sites leads to adipose tissue wasting, suggesting that tumour growth within the pancreatic environment contributes to this wasting phenotype. We find that decreased exocrine pancreatic function is a driver of adipose tissue loss and that replacement of pancreatic enzymes attenuates PDAC-associated wasting of peripheral tissues. Paradoxically, reversal of adipose tissue loss impairs survival in mice with PDAC. When analysing patients with PDAC, we find that depletion of adipose and skeletal muscle tissues at the time of diagnosis is common, but is not associated with worse survival. Taken together, these results provide an explanation for wasting of adipose tissue in early PDAC and suggest that early loss of peripheral tissue associated with pancreatic cancer may not impair survival.

Background:Few studies have simultaneously assessed the prognostic value of the multiple classification systems for lymph node (LN) metastases in resected pancreatic ductal adenocarcinoma (PDAC).Methods:In 600 patients with resected PDAC, we examined the association of LN parameters (AJCC 7th and 8th editions, LN ratio (LNR), and log odds of metastatic LN (LODDS)) with pattern of recurrence and patient survival using logistic regression and Cox proportional hazards regression, respectively. Regression models adjusted for age, sex, margin status, tumour grade, and perioperative therapy.Results:Lymph node metastases classified by AJCC 7th and 8th editions, LNR, and LODDS were associated with worse disease free-survival (DFS) and overall survival (OS) (all Ptrend<0.01). American Joint Committee on Cancer 8th edition effectively predicted DFS and OS, while minimising model complexity. Lymph node metastases had weaker prognostic value in patients with positive margins and distal resections (both Pinteraction<0.03). Lymph node metastases by AJCC 7th and 8th editions did not predict the likelihood of local disease as the first site of recurrence.Conclusions:American Joint Committee on Cancer 8th edition LN classification is an effective and practical tool to predict outcomes in patients with resected PDAC. However, the prognostic value of LN metastases is attenuated in patients with positive resection margins and distal pancreatectomies.

This prospective study aimed to determine the accuracy of radiation oncologists in predicting the survival of patients with metastatic disease receiving radiation therapy and to understand factors associated with their accuracy. Methods and Materials: This single-institution study surveyed 22 attending radiation oncologists to estimate patient survival. Survival predictions were defined as accurate if the observed survival (OS) was within the correct survival prediction category (0-6 months, >6-12 months, >12-24 months, and >24 months). The physicians made survival estimates for each course of radiation, yielding 877 analyzable predictions for 689 unique patients. Data analysis included Stuart's Tau C, logistic regression models, ordinal logistic regression models, and stepwise selection to examine variable interactions. Results: Of the 877 radiation oncologists' predictions, 39.7% were accurate, 26.5% were underestimations, and 33.9% were overestimations. Stuart's Tau C showed low correlation between OS and survival estimates (0.3499), consistent with the inaccuracy reported in the literature. However, results showed less systematic overprediction than reported in the literature. Karnofsky performance status was the most significant predictor of accuracy, with greater accuracy for patients with shorter OS. Estimates were also more accurate for patients with lower Karnofsky performance status. Accuracy by patient age varied by primary site and race. Physician years of experience did not correlate with accuracy. Conclusions: The sampled radiation oncologists have a 40% accuracy in predicting patient survival. Future investigation should explore how survival estimates influence treatment decisions and how to improve survival prediction accuracy.