Neoadjuvant chemotherapy is associated with improved disease-free survival in pancreatic cancer patients undergoing pancreaticoduodenectomy with vascular resection.

BACKGROUND AND OBJECTIVES: Neoadjuvant chemotherapy (NAC) is becoming favored for all pancreatic adenocarcinoma (PDAC). Patients with seemingly resectable disease infrequently still display vascular involvement intraoperatively. Outcomes following NAC versus upfront surgery in patients undergoing pancreaticoduodenectomy (PD) with vascular resection are unknown. METHODS: We performed a retrospective cohort study of PDAC patients who underwent PD with vascular resection between January 1, 2013, to December 31, 2020, within a single academic center. Clinicopathologic characteristics and disease-free survival (DFS) were compared between NAC versus upfront surgery cohorts using the Kaplan-Meier estimate and Cox proportional-hazards regression model. RESULTS: Eighty-one patients who underwent PD with vascular resection for PDAC were included. Forty-six patients (56%) received NAC. The NAC cohort more often had pathologic N0 status (47.8% vs. 8.6%, p < 0.001), had decreased vascular invasion (11% vs. 40%, p = 0.002), and completed chemotherapy (80% vs. 40%, p < 0.01). The NAC cohort demonstrated improved DFS (40.5 vs. 14.3 months, p = 0.007). In multivariable analysis, NAC remained independently associated with increased DFS (HR = 0.48, p = 0.02). CONCLUSIONS: NAC was associated with improved clinicopathologic outcomes and DFS in PD with vascular resection. These findings demonstrate the advantage of NAC in PDAC patients undergoing PD with vascular resection.

Oncogenic pathway signatures predict the risk of progression and recurrence in well-differentiated pancreatic neuroendocrine tumors.

BACKGROUND: Pancreatic neuroendocrine tumors (pNETs) are genomically diverse tumors. The management of newly diagnosed well-differentiated pNETs is limited by a lack of sensitivity of existing biomarkers for prognostication. Our goal was to investigate the potential utility of genetic markers as a predictor of progression-free survival (PFS) and recurrence-free survival (RFS). METHODS: Whole-exome sequencing of resected well-differentiated, low and intermediate-grade (G1 and G2) pNETs and normal adjacent tissue from patients who underwent resection from 2005 to 2015 was performed. Genetic alterations were classified using pan-genomic and oncogenic pathway classifications. Additional samples with genetic and clinicopathologic data available were obtained from the publicly available International Cancer Genome Consortium (ICGC) database and included in the analysis. The prognostic relevance of these genomic signatures on PFS and RFS was analyzed. RESULTS: Thirty-one patients who underwent resection for pNET were identified. Genomic analysis of mutational, copy number, cytogenetic, and complex phenomena revealed similar patterns to prior studies of pNETs with relatively few somatic gene mutations but numerous instances of copy number changes. Analysis of genomic and clinicopathologic outcomes using the combined data from our study as well as the ICGC pNET cohort (n = 124 patients) revealed that the recurrent pattern of whole chromosome loss (RPCL) and metastatic disease were independently associated with disease progression. When evaluating patients with local disease at the time of resection, RPCL and alterations in the TGFß oncogenic pathway were independently associated with the risk of recurrence. CONCLUSIONS: Well-differentiated pNETs are genomically diverse tumors. Pathway signatures may be prognostic for predicting disease progression and recurrence.

Hispanic/Latino Ethnicity is an Independent Predictor of Worse Survival for Gastric Cancer in a Multicenter Safety-Net Patient Population.

BACKGROUND: Various population-based studies have shown Hispanic/Latino ethnicity is a risk factor for worse survival in patients with gastric cancer linked to disparate access to care. We aimed to address whether Hispanic patients treated within safety-net hospital systems continue to experience this survival deficit compared to non-Hispanic patients. METHODS: We performed a retrospective cohort study comparing survival between Hispanic and non-Hispanic patients diagnosed with gastric adenocarcinoma between January 1, 2016 to December 31, 2020 within Los Angeles County's safety-net hospital system. Gastric cancer-specific survival was compared between the two cohorts using the Kaplan-Meier estimate and Cox proportional-hazards regression model. RESULTS: 448 patients who received care from five medical centers were included. 348 (77.7%) patients self-identified as Hispanic and 100 (22.3%) as non-Hispanic. Mean follow-up time was 2.0 years (median 0.91 years, IQR, 0.34-2.5 years). Hispanic patients were found to be diagnosed at a younger age (55.6 vs 60.7 years, p <0.01), demonstrate higher state area deprivation index (6.4 vs 5.0, p <0.01), and present with metastatic disease (59.8% vs 45%, p =0.04). After adjusting social and oncologic variables, Hispanic ethnicity remained an independent risk factor for worse survival (HR 1.56, [95% CI 1.06-2.28], p = 0.02). CONCLUSIONS: Hispanic patients treated within a large, multi-center safety-net hospital system experience worse survival compared to non-Hispanic patients. This suggests ethnic disparities exist within safety-net hospital systems, independent of known clinicopathologic factors. IMPACT: Improving outcomes for Hispanic patients with gastric cancer requires future efforts aimed at defining and addressing these unidentified barriers to care.