Faculty Bibliography

OBJECTIVE:To evaluate long-term oncologic outcomes of patients with stage IV pancreatic ductal adenocarcinoma (PDAC) and identify survival benchmarks for comparison when considering resection in these patients. SUMMARY BACKGROUND DATA/BACKGROUND:Highly selected cohorts of patients with liver-oligometastatic pancreas cancer have reported prolonged survival following resection. The long-term impact of surgery in this setting remains undefined due to a lack of appropriate control groups. METHODS:We identified patients with clinical stage IV PDAC with synchronous liver metastases within our cancer registry. We estimated overall survival (OS) among various patient subgroups using the Kaplan-Meier method. To mitigate immortal time bias, we analyzed long-term outcomes of patients who survived beyond 12 months (landmark time) from diagnosis. RESULTS:We identified 241 patients. Median OS was 7 months (95%CI 5-9), both overall and for patients with liver-only metastasis (n=144). Ninety patients (38% of liver-only; 40% of whole cohort) survived at least 12 months; those who received chemotherapy in this subgroup had a median OS of 26 months (95%CI 17-39). Of these patients, those with resectable or borderline resectable primary tumors and resectable liver-only metastasis (n=9, 4%) had a median OS of 39 months (95%CI 13-NR). CONCLUSIONS:The 4% of our cohort that were potentially eligible for surgery experienced a prolonged survival compared to all-comers with stage IV disease. Oncologic outcomes of patients undergoing resection of metastatic pancreas cancer should be assessed in the context of the expected survival of patients potentially eligible for surgery and not relative to all patients with stage IV disease.

INTRODUCTION/BACKGROUND:There is no consensus regarding the role of primary tumor resection for patients with metastatic pancreatic neuroendocrine tumors (panNET). We assessed surgical treatment patterns and evaluated the survival impact of primary tumor resection in patients with metastatic panNET. METHODS:Patients with synchronous metastatic nonfunctional panNET in the National Cancer Database (2004-2016) were categorized based on whether they underwent primary tumor resection. We used logistic regressions to assess associations with primary tumor resection. We performed survival analyses with Kaplan-Meier survival functions, log-rank test, and Cox proportional hazard regression within a propensity score matched cohort. RESULTS:In the overall cohort of 2613 patients, 68% (n = 839) underwent primary tumor resection. The proportion of patients who underwent primary tumor resection decreased over time from 36% (2004) to 16% (2016, p < 0.001). After propensity score matching on age at diagnosis, median income quartile, tumor grade, size, liver metastasis, and hospital type, primary tumor resection was associated with longer median overall survival (OS) (65 vs. 24 months; p < 0.001) and was associated with lower hazard of mortality (HR: 0.39, p < 0.001). CONCLUSION/CONCLUSIONS:Primary tumor resection was significantly associated with improved OS, suggesting that, if feasible, surgical resection can be considered for well-selected patients with panNET and synchronous metastasis.

BACKGROUND:Time to treatment (TTT) varies widely for patients with gastric cancer. We aimed to evaluate relationships between time to treatment, overall survival (OS), and other surgical outcomes in patients with stage I-III gastric cancer. METHODS:We identified patients with clinical stage I-III gastric cancer who underwent curative-intent gastrectomy within the National Cancer Database (2006-2015) and grouped them by treatment sequence: neoadjuvant chemotherapy or surgery upfront. We defined TTT as weeks from diagnosis to treatment initiation (neoadjuvant chemotherapy or definitive surgical procedure, respectively). Survival differences were assessed by Kaplan-Meier estimate, Cox proportional hazard regression, and log rank test. RESULTS:Among the 22,846 patients with stage I-III gastric cancer, most (56%) received surgery upfront. Median TTT was 5 weeks (IQR 4-7) and 6 weeks (IQR 3-9) for patients in the neoadjuvant and surgery upfront groups, respectively. In the neoadjuvant group, increasing TTT was significantly associated with increasing median OS up to TTT of 5 weeks, with no change in median OS when TTT was > 5 weeks. In the surgery group, increasing TTT was significantly associated with increasing median OS up to 6 weeks; however, increasing TTT between 14 and 21 weeks was associated with decreasing median OS. CONCLUSIONS:The relationship between time to treatment and survival outcomes is non-linear. Among patients who underwent surgery upfront, the relationship between time to treatment and OS was bimodal, suggesting that deferring definitive surgery, up to 14 weeks, is not associated with worse OS or oncologic outcomes. The relationship between time to treatment and overall survival among patients was bimodal, suggesting that deferring definitive surgery up to 14 weeks is not associated with worse OS.

SBRT is an emerging locoregional treatment modality for hepatocellular carcinoma (HCC). Although local tumor control rates seem encouraging, large-scale survival data comparing SBRT to surgical resection are lacking. We identified patients with stage I/II HCC from the National Cancer Database amenable for potential surgical resection. Patients undergoing hepatectomy were matched by propensity score (1:2) with patients who underwent SBRT as primary treatment. A total of 3787 (91%) and 366 (9%) patients underwent surgical resection or SBRT between 2004 and 2015, respectively. After propensity matching, the 5-year overall survival was 24% (95% CI 19-30%) in the SBRT group versus 48% (95% CI 43-53%) in the surgery group (p < 0.001). The association of surgery with overall survival was consistent in all subgroups. In patients treated with SBRT, a biologic effective dose (BED) of ≥100 Gy (31%, 95% CI 22%-40%) compared with BED < 100 Gy (13%, 95% CI 8-22%) was associated with a higher 5-year overall survival rate (hazard ratio of mortality of 0.58, 95% CI 0.43-0.77; p < 0.001). Surgical resection may be associated with prolonged overall survival compared with SBRT in patients with stage I/II HCC.

BACKGROUND:The ideal surveillance strategy after partial pancreatectomy for non-invasive IPMN remains undefined and existing guidelines provide conflicting recommendations. The present study was developed in anticipation of the joint meeting of the International Association of Pancreatology (IAP) and the Japan Pancreas Society (JPS) held in Kyoto in July 2022. METHODS:An international team of experts developed the four clinical questions (CQ) to operationalize issues pertaining to surveillance of patients in this context. A systematic review was designed following the PRISMA guidelines and registered in PROSPERO. The search strategy was executed in PubMed/Medline (Ovid), Embase, the Cochrane Library and Web of Science databases. Four investigators individually extracted data from the selected studies and drafted recommendations for each CQ. These were subsequently discussed and agreed upon that the IAP/JPS meeting. RESULTS:From a total of 1098 studies identified through the initial search, 41 studies were included in the review and informed the recommendations. No studies providing level one data were identified in this systematic review, all studies included were cohort or case-control studies. CONCLUSIONS:There is a lack of level 1 data addressing the issue of surveillance of patients following partial pancreatectomy for non-invasive IPMN. The definition of remnant pancreatic lesion in this setting is largely heterogeneous across all studies evaluated. Herein we propose an inclusive definition of remnant pancreatic lesions to guide future prospective efforts for reporting the natural history and long-term outcomes of these patients.

BACKGROUND:Adherence to evidence-based guidelines for gastric cancer is low, particularly at the hospital level, despite a strong association with improved overall survival (OS). We aimed to evaluate patterns of hospital and regional adherence to National Comprehensive Cancer Network guidelines for gastric cancer. METHODS:Using the National Cancer Database (2004-2015), we identified patients with stage I-III gastric cancer. Hospital-level guideline adherence was calculated by dividing the patients who received guideline adherent care by the total patients treated at that hospital. OS was estimated for each hospital. Associations between adherence, region, and survival were compared using mixed-effects, hierarchical regression. RESULTS:Among 576 hospitals, the median hospital guideline adherence rate was 25% (range 0-76%) and varied significantly by region (p = 0.001). Adherence was highest in the Middle Atlantic (29%) and lowest in the East South Central region (19%); hospitals in the New England, Middle Atlantic, and East North Central regions were more likely to be guideline adherent than those in the East South Central region (all p < 0.05), after adjusting for patient and hospital mix. Most (35%) of the adherence variation was attributable to the hospital. Median 2-year OS varied significantly by region. After adjusting for hospital and patient mix, hazard of mortality was 17% lower in the Middle Atlantic (hazard ratio 0.82, 95% confidence interval 0.74-0.90) relative to the East South Central region, with most of the variation (54%) attributable to patient-level factors. CONCLUSIONS:Hospital-level guideline adherence for gastric cancer demonstrated significant regional variation and was associated with longer OS, suggesting that efforts to improve guideline adherence should be directed toward lower-performing hospitals.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Adherence to evidence-based guidelines in gastric cancer is low. We aimed to evaluate adherence to National Comprehensive Cancer Network (NCCN) Guidelines for gastric cancer at both patient- and hospital-levels and examine associations between guideline adherence and treatment outcomes, including overall survival (OS). METHODS:We applied stage-specific, annual NCCN Guidelines (2004-2015) to patients with gastric cancer treated with curative-intent within the National Cancer Database and compared characteristics of patients who did and did not receive guideline-adherent care. Hospitals were evaluated by guideline adherence rate. We identified associations with OS through multivariable Cox regression. RESULTS:Of 37 659 patients included, 32% received NCCN Guideline-adherent treatment. OS was significantly associated with both guideline adherence (51 months for patients receiving guideline-adherent treatment vs. 22 for patients receiving nonadherent treatment, p < 0.001). Treatment at a hospital with higher adherence was associated with longer OS (21 months for patients treated at lowest adherence quartile hospitals vs. 37 months at highest adherence quartile hospitals, p < 0.001), regardless of type of treatment received. CONCLUSIONS:Guideline-adherent treatment was strongly associated with longer median OS. Guideline adherence should be used as a benchmark for focused quality improvement for physicians taking care of patients with gastric cancer and institutions at large.

BACKGROUND:Diagnostic laparoscopy (DL) is a key component of staging for locally advanced gastric adenocarcinoma (GA). We hypothesized that utilization of DL varied between safety net (SNH) and affiliated tertiary referral centers (TRCs). METHODS:Patients diagnosed with primary GA eligible for DL were identified from the US Safety Net Collaborative database (2012-2014). Clinicopathologic factors were analyzed for association with use of DL and findings on DL. Overall survival (OS) was analyzed by Kaplan-Meier method. RESULTS:Among 233 eligible patients, 69 (30%) received DL, of which 24 (35%) were positive for metastatic disease. Forty percent of eligible SNH patients underwent DL compared to 21.5% at TRCs. Lack of insurance was significantly associated with decreased use of DL (OR 0.48, p < 0.01), while African American (OR 6.87, p = 0.02) and Asian race (OR 3.12, p ≤ 0.01), signet ring cells on biopsy (OR 3.14, p < 0.01), and distal tumors (OR 1.62, p < 0.01) were associated with increased use. Median OS of patients with a negative DL was better than those without DL or a positive DL (not reached vs. 32 vs. 12 months, p < 0.005, Figure 1). CONCLUSIONS:Results from DL are a strong predictor of OS in GA; however, the procedure is underutilized. Patients from racial minority groups were more likely to undergo DL, which likely accounts for higher DL rates among SNH patients.