Treatment Disparities Partially Mediate Socioeconomic- and Race/Ethnicity-Based Survival Disparities in Stage I-II Hepatocellular Carcinoma.

BACKGROUND: Low socioeconomic status (SES) patients with early-stage hepatocellular carcinoma (HCC) receive procedural treatments less often and have shorter survival. Little is known about the extent to which these survival disparities result from treatment-related disparities versus other causal pathways. We aimed to estimate the proportion of SES-based survival disparities that are mediated by treatment- and facility-related factors among patients with stage I-II HCC. METHODS: We analyzed patients aged 18-75 years diagnosed with stage I-II HCC in 2008-2016 using the National Cancer Database. Inverse odds weighting mediation analysis was used to calculate the proportion mediated by three mediators: procedure type, facility volume, and facility procedural interventions offered. Intersectional analyses were performed to determine whether treatment disparities played a larger role in survival disparities among Black and Hispanic patients. RESULTS: Among 46,003 patients, 15.0% had low SES, 71.6% had middle SES, and 13.4% had high SES. Five-year overall survival was 46.9%, 39.9%, and 35.7% among high, middle, and low SES patients, respectively. Procedure type mediated 45.9% (95% confidence interval [CI] 31.1-60.7%) and 36.7% (95% CI 25.7-47.7%) of overall survival disparities for low and middle SES patients, respectively, which was more than was mediated by the two facility-level mediators. Procedure type mediated a larger proportion of survival disparities among low-middle SES Black (46.6-48.2%) and Hispanic patients (92.9-93.7%) than in White patients (29.5-29.7%). CONCLUSIONS: SES-based disparities in use of procedural interventions mediate a large proportion of survival disparities, particularly among Black and Hispanic patients. Initiatives aimed at attenuating these treatment disparities should be pursued.

Quality and Location of the Surgical Episode Mediate a Large Proportion of Socioeconomic-Based Survival Disparities in Patients with Resected Stage I-III Colon Cancer.

INTRODUCTION: Lower socioeconomic status (SES) is associated with shorter overall survival (OS) in patients with locoregional colon cancer. We aimed to estimate: (1) the proportion of SES-based OS disparities mediated by disparities in the quality and location of surgical treatment in patients with resected stage I-III colon cancer and (2) the relative importance of components of surgical quality. PATIENTS AND METHODS: We examined patients ages 18-80 years with resected stage I-III colon adenocarcinoma using the 2010-2016 National Cancer Database. SES was defined at the zip code level. Inverse odds weighting mediation analysis was used to estimate the proportion mediated (PM) for nine treatment quality-related and facility-related factors and composite PMs in models including all nine mediators. Models compared high SES patients with each lower SES stratum. RESULTS: Among 171,009 patients, 5-year OS increased from 70.4% in low SES patients to 78.1% in high SES. When high SES patients were compared with low, lower-middle, and upper-middle SES patients, PM ranges among lower SES strata were: minimally invasive surgery 16.0-16.6%, lymph nodes examined 7.7-9.6%, positive margins 3.8-6.5%, length of stay 16.7-28.1%, readmissions insignificant to 3.7%, treatment at > 1 CoC facility 2.7-3.1%, facility type insignificant to 7.3%, facility volume 2.9-8.2%, and adjusted facility 90-day mortality rates 33.2-42.8%. Composite PMs were 76.9% (95% CI 61.3%, 92.4%) for low SES, 68.7% (95% CI 56.4%, 81.1%) for lower-middle SES, and 60.9% (95% CI 43.1%, 78.6%) for upper-middle SES. CONCLUSIONS: These data suggest that improving the quality of the surgical episode for disadvantaged patients undergoing resection for locoregional colon cancer could decrease SES-based survival disparities by over half.

Decompositions of the Contribution of Treatment Disparities to Survival Disparities in Stage I-II Pancreatic Adenocarcinoma.

BACKGROUND: Higher socioeconomic status (SES) and non-Hispanic White (NHW) race/ethnicity are associated with higher treatment rates and longer overall survival (OS) among US patients with stage I-II pancreatic ductal adenocarcinoma. The proportion of OS disparities mediated through treatment disparities (PM) and the proportion predicted to be eliminated (PE) if treatment disparities were eliminated are unknown. METHODS: We analyzed 2007-2015 data from the Surveillance, Epidemiology, and End Results (SEER) census tract-level database and the National Cancer Database (NCDB) using causal mediation analysis methods to understand the extent to which treatment disparities mediate OS disparities. In the first set of decompositions, race/ethnicity was controlled for as a covariate proximal to SES, and lower SES strata were compared with the highest SES stratum. In the second set, an intersectional perspective was taken and each SES-race/ethnicity combination was compared with highest SES-NHW patients, who had the highest treatment rates and longest OS. RESULTS: The SEER and NCDB cohorts contained 16,921 patients and 44,638 patients, respectively. When race/ethnicity was controlled for, PMs ranged from 43 to 48% and PEs ranged from 46 to 50% for various lower SES strata. When separately comparing each SES-race/ethnicity combination with the highest SES-NHW patients, results were similar for lower SES-NHW patients but differed markedly for non-Hispanic Black and Hispanic patients, for whom PMs ranged from 60 to 80% and PEs ranged from 55 to 75% for most lower SES strata. CONCLUSIONS: These results suggest that efforts to reduce treatment disparities are worthwhile, particularly for NHB and Hispanic patients, and simultaneously point to the importance of non-treatment-related causal pathways.

County-level Variation in Use of Surgery and Cancer-specific Survival for Stage I-II Pancreatic Adenocarcinoma.

OBJECTIVE: The aim of the study was to describe county-level variation in use of surgery for stage I-II pancreatic ductal adenocarcinoma (PDAC) and the association between county surgery rates and cancer-specific survival (CSS). BACKGROUND: The degree of small geographic area variation in use of surgery for stage I-II PDAC and the association between area surgery rates and CSS remain incompletely defined. METHODS: This is a retrospective cohort study of patients aged 18 to 80 years in the 2007 to 2015 Surveillance, Epidemiology, and End Results database with stage I-II PDAC without contraindications to surgery or refusal. Multilevel models were used to characterize county-level variation in use of surgery and CSS. County-specific risk- and reliability-adjusted surgery rates and CSS rates were calculated. RESULTS: Of 18,100 patients living in 581 counties, 10,944 (60.5%) underwent surgery. Adjusted county-specific surgery rates varied 1.5-fold from 49.9% to 74.6%. Median CSS increased in a graded fashion from 13 months [interquartile range (IQR) 13-14] in counties with surgery rates of 49.9% to 56.9% to 18 months (IQR 17-19) in counties with surgery rates of 68.0% to 74.6%. Results were similar in multivariable analyses. Adjusted county 18-month CSS rates varied 1.6-fold from 32.7% to 53.7%. Adjusted county surgery and 18-month CSS rates were correlated (r = 0.54; P < 0.001) and county surgery rates explained approximately half of county-level variation in CSS. Only 18 (3.1%) counties had adjusted surgery rates of 68.0% to 74.6%, which was associated with the longest CSS. CONCLUSIONS: County-specific rates of surgery varied substantially, and patients living in areas with higher surgery rates lived longer. These data suggest that increasing use of surgery in stage I-II PDAC could lead to improvements in survival.

Size and Importance of Socioeconomic Status-Based Disparities in Use of Surgery in Nonadvanced Stage Gastrointestinal Cancers.

BACKGROUND: The size and importance of socioeconomic status (SES)-based disparities in use of surgery for non-advanced stage gastrointestinal (GI) cancers have not been quantified. METHODS: The exposure in this study of patients age 18-80 with one of nine non-advanced stage GI cancers in the 2007-2015 SEER database was a census tract-level SES composite. Multivariable models assessed associations of SES with use of surgery. Causal mediation analysis was used to estimate the proportion of survival disparities in SES quintiles 1 versus 5 that were mediated by disparities in use of surgery. RESULTS: Lowest SES quintile patients underwent surgery at significantly lower rates than highest quintile patients in each cancer. SES-based disparities in use of surgery were large and graded in esophagus adenocarcinoma, intrahepatic and extrahepatic cholangiocarcinoma, and pancreatic adenocarcinoma. Smaller but clinically relevant disparities were present in stomach, ampulla, and small bowel adenocarcinoma, whereas disparities were small in colorectal adenocarcinoma. Five-year all-stage overall survival (OS) was correlated with the size of disparities in use of surgery in SES quintiles 1 versus 5 (r = - 0.87; p = 0.003). Mean OS was significantly longer (range 3.5-8.9 months) in SES quintile 5 versus 1. Approximately one third of SES-based survival disparities in poor prognosis GI cancers were mediated by disparities in use of surgery. The size of disparities in use of surgery in SES quintiles 1 versus 5 was correlated with the proportion mediated (r = 0.98; p < 0.001). CONCLUSIONS: Low SES patients with poor prognosis GI cancers are at substantial risk of undertreatment. Disparities in use of surgery contribute to diminished survival.

Implementation of a Quality Improvement Initiative to Decrease Opioid Prescribing in General Surgery.

BACKGROUND: There is increasing need to avoid excess opioid prescribing after surgery. We prospectively assessed overprescription in our hospital system and used these data to design a quality improvement intervention to reduce overprescription. MATERIALS AND METHODS: Beginning in January 2017, an e-mail-based survey to assess the quantity of opioids used postoperatively as well as patient-reported pain control was sent to all surgical patients in a 23-hospital system. In January 2018, as a quality improvement initiative, guidelines were given to surgeons based on patient consumption data. Prescription and consumption were then tracked prospectively. Wilcoxon signed-rank, analysis of variance, and Cuzick trend tests were used to assess for overprescription and changes over time in opioid prescribing and consumption. RESULTS: We included 2239 patients in our cohort. The amount prescribed (median [IQR]: 30 [24-45] versus 18 [12-30], P < 0.001) and consumed (median [IQR]: 12 [7-20] versus 8 [3-15], P < 0.001) each decreased between the first and last quarter studied. Academic hospitals prescribed fewer opioids than nonacademic hospitals (median [IQR]: 24[15-40] versus median [IQR]: 30 [20-45], P < 0.001). There was no difference in the quantity of opioids consumed between patients treated at academic and nonacademic facilities (median [IQR]: 10[3-19] versus 10.5 [4-20], P = 0.08). Patients consumed a median of 42% of the opioids prescribed, and there was no significant trend in the percent consumed over time (P = 0.8). CONCLUSIONS: Patients used far fewer opioids than prescribed after common adult general surgery procedures. When surgeons were provided with patient consumption data, the number of opioids prescribed decreased significantly.

Recurrence patterns in patients with Stage II melanoma: The evolving role of routine imaging for surveillance.

BACKGROUND AND OBJECTIVES: The relatively recent availability of effective systemic therapies for metastatic melanoma necessitates reconsideration of current surveillance patterns. Evidence supporting surveillance guidelines for resected Stage II melanoma is lacking. Prior reports note routine imaging detects only 21% of recurrent disease. This study aims to define recurrence patterns for Stage II melanoma to inform future surveillance guidelines. METHODS: This is a retrospective study of patients with Stage II melanoma. We analyzed risk factors for recurrence and methods of recurrence detection. We also assessed survival. Yearly hazards of recurrence were visualized. RESULTS: With a median follow-up of 4.9 years, 158 per 580 patients (27.2%) recurred. Overall, most recurrences were patient-detected (60.7%) or imaging-detected (27.3%). Routine imaging was important in detecting recurrence in patients with distant recurrences (adjusted rate 43.1% vs. 9.4% for local/in-transit; p = .04) and with Stage IIC melanoma (42.5% vs. 18.5% for IIA; p = .01). Male patients also self-detected recurrent disease less than females (52.1% vs. 76.8%; p < .01). CONCLUSIONS: Routine imaging surveillance played a larger role in detecting recurrent disease for select groups in this cohort than noted in prior studies. In an era of effective systemic therapy, routine imaging should be considered for detection of asymptomatic relapse for select, high-risk patient groups.

Hospital-level Variation in Utilization of Surgery for Clinical Stage I-II Pancreatic Adenocarcinoma.

OBJECTIVE: To (1) evaluate rates of surgery for clinical stage I-II pancreatic ductal adenocarcinoma (PDAC), (2) identify predictors of not undergoing surgery, (3) quantify the degree to which patient- and hospital-level factors explain differences in hospital surgery rates, and (4) evaluate the association between adjusted hospital-specific surgery rates and overall survival (OS) of patients treated at different hospitals. BACKGROUND: Curative-intent surgery for potentially resectable PDAC is underutilized in the United States. METHODS: Retrospective cohort study of patients ≤85 years with clinical stage I-II PDAC in the 2004 to 2014 National Cancer Database. Mixed effects multivariable models were used to characterize hospital-level variation across quintiles of hospital surgery rates. Multivariable Cox proportional hazards models were used to estimate the effect of adjusted hospital surgery rates on OS. RESULTS: Of 58,553 patients without contraindications or refusal of surgery, 63.8% underwent surgery, and the rate decreased from 2299/3528 (65.2%) in 2004 to 4412/7092 (62.2%) in 2014 (P < 0.001). Adjusted hospital rates of surgery varied 6-fold (11.4%-70.9%). Patients treated at hospitals with higher rates of surgery had better unadjusted OS (median OS 10.2, 13.3, 14.2, 16.5, and 18.4 months in quintiles 1-5, respectively, P < 0.001, log-rank). Treatment at hospitals in lower surgery rate quintiles 1-3 was independently associated with mortality [Hazard ratio (HR) 1.10 (1.01, 1.21), HR 1.08 (1.02, 1.15), and HR 1.09 (1.04, 1.14) for quintiles 1-3, respectively, compared with quintile 5] after adjusting for patient factors, hospital type, and hospital volume. CONCLUSIONS: Quality improvement efforts are needed to help hospitals with low rates of surgery ensure that their patients have access to appropriate surgery.

Optimal extent of lymphadenectomy for gastric adenocarcinoma: A 7-institution study of the U.S. gastric cancer collaborative.

BACKGROUND AND OBJECTIVES: The optimal extent of lymphadenectomy in the treatment of gastric adenocarcinoma is debated. We compared gastrectomy outcomes following limited (D1) or extended (D2) lymphadenectomy. METHODS: Using the multi-institutional US Gastric Cancer Collaborative database, we reviewed the morbidity, mortality, recurrence, and overall survival (OS) of patients receiving D1 or D2 lymphadenectomies. RESULTS: Between 2000 and 2012, 266 and 461 patients received a D1 and D2 lymphadenectomy, respectively. ASA class, mean number of comorbidities, grade, and stage were similar between groups. While major morbidity was similar (P = 0.85), mortality was worse for those receiving a D1 lymphadenectomy (4.9% vs. 1.3%, P = 0.004). D2 lymphadenectomy was associated with improved median OS in stage I (4.7 years for D1 vs. not reached for D2, P = 0.003), stage II (3.6 years for D1 vs. 6.3 for D2, P = 0.42), and stage III patients (1.3 years for D1 vs. 2.1 for D2, P = 0.01). After adjusting for predictors of OS, D2 lymphadenectomy remained a significant predictor of improved survival (HR 1.5, 95%CI 1.1-2.0, P = 0.008). CONCLUSIONS: D2 lymphadenectomy can be performed without increased risk of morbidity and mortality. Additionally, D2 lymphadenectomy is associated with improved survival especially in early stages, and should be considered for gastric adenocarcinoma patients. J. Surg. Oncol. 2016;113:750-755. © 2016 Wiley Periodicals, Inc.

Value of Peritoneal Drain Placement After Total Gastrectomy for Gastric Adenocarcinoma: A Multi-institutional Analysis from the US Gastric Cancer Collaborative.

BACKGROUND: The effect of routine drainage after abdominal surgery with enteric anastomoses is controversial. In particular, the role of peritoneal drain (PD) placement after total gastrectomy for adenocarcinoma is not well established. METHODS: Patients who underwent total gastrectomy for gastric adenocarcinoma (GAC) at seven institutions from the US Gastric Cancer Collaborative, from 2000 to 2012, were identified. The association of PD placement with postoperative outcomes was analyzed. RESULTS: Overall, 344 patients were identified and 253 (74 %) patients received a PD. The anastomotic leak rate was 9 %. Those with PD placement had similar American Society of Anesthesiologists score, tumor size, TNM stage, and the need for additional organ resection when compared with their counterparts. No difference was observed in the rate of any complication (54 vs. 48 %; p = 0.45), major complication (25 vs. 24 %; p = 0.90), or 30-day mortality (7 vs. 4 %; p = 0.51) between the two groups. In addition, no difference in anastomotic leak (9 vs. 10 %; p = 0.90), the need for secondary drainage (10 vs. 9 %; p = 0.92), or reoperation (13 vs. 8 %; p = 0.28) was identified. On multivariate analysis, PD placement was not associated with decreased postoperative complications. Subset analysis, stratified by patients who did not undergo concomitant pancreatectomy (n = 319) or those who experienced anastomotic leak (n = 31), similarly demonstrated no association of PD placement with reduced complications or mortality. CONCLUSIONS: PD placement after total gastrectomy for GAC is associated with neither a decrease in the frequency and severity of adverse postoperative outcomes, including anastomotic leak and mortality, nor a decrease in the need for secondary drainage procedures or reoperation. Routine use of PDs is not warranted.

Efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in the management of malignant ascites.

BACKGROUND: In peritoneal surface disease, accumulation of malignant ascites represents a difficult problem to treat, with adverse impact on quality of life. The role of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) in controlling malignant ascites is not well defined. METHODS: A retrospective analysis of a prospectively maintained database of 1,000 procedures was performed. Type of malignancy, resolution of ascites, duration and agent of chemoperfusion, performance status, resection status, morbidity, mortality, and survival were reviewed. RESULTS: Ascites was found in 299 patients (310 procedures) either before or during exploration. A total of 142 (46 %) procedures were performed for appendiceal primary disease, 53 (17 %) colorectal, 20 (6 %) gastric, 45 (15 %) mesothelioma, and 26 (8 %) ovarian. A total of 288 (93 %) patients had resolution of ascites by 3 months' follow-up. In patients with ascites, complete cytoreduction was obtained in 15 versus 59 % when ascites was not present (p < 0.001). In the group of patients who had their ascites controlled, 243 of 288 (84 %) had resection with residual macroscopic disease (R2 status). Twenty-two patients (7 %) had persistent ascites at 3 months' follow-up, 19 (86 %) of whom had an R2 resection. Univariate analysis revealed that type of primary disease, resection status, duration or agent of chemoperfusion, and performance status did not predict failure. CONCLUSIONS: CRS-HIPEC is effective in controlling ascites in 93 % of patients with malignant ascites, even when a complete cytoreduction is not feasible. Ascites is predictive of incomplete cytoreduction and worse overall survival. Although complete cytoreduction remains the goal of this procedure, HIPEC can provide palliative value in selected patients with malignant ascites.

Obesity and peritoneal surface disease: outcomes after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for appendiceal and colon primary tumors.

BACKGROUND: It is estimated that 37% of the U.S. population is obese. It is unknown how obesity influences the operative and survival outcomes of cytoreductive surgery (CRS)/hyperthermic intraperitoneal chemotherapy (HIPEC) procedures. METHODS: A retrospective analysis of a prospective database of 1,000 procedures was performed. Type of malignancy, performance status, resection status, hospital and intensive care unit stay, comorbidities, morbidity, mortality, and survival were reviewed. RESULTS: A total of 246 patients with body mass index (BMI) of >30 kg/m(2) underwent 272 CRS/HIPEC procedures. Ninety-five (38.6%) were severely obese (BMI > 35 kg/m(2)). A total of 135 (49.6%) procedures were performed for appendiceal and 60 (22.1%) for colon cancer. Median follow-up was 52 months. Both major and minor morbidity were similar for obese and non-obese patients. The 30-day mortality rates for obese and non-obese patients were 1.5 and 2.5%, respectively. Median intensive care unit and hospital stay were 1 and 9 days, regardless of BMI. The 30-day readmission rate was similar between obese and non-obese patients (24.8 vs. 19.4%, p = 0.11). Median survival for low-grade appendiceal cancer (LGA) was 76 months for obese patients and 107 months for non-obese patients (p = 0.32). Survival was worse for severely obese patients (median survival 54 months) versus non-obese patients with LGA (p = 0.04). Survival was similar for obese and non-obese patients with peritoneal surface disease (PSD) from colon cancer or high-grade appendiceal cancer. CONCLUSIONS: Obesity does not influence postoperative morbidity or mortality of patients with PSD, regardless of primary tumor. Severe obesity is associated with decreased long-term survival only in patients with LGA primary disease; however, application of CRS/HIPEC still offers meaningful prolongation of life. Obesity should not be considered a contraindication for CRS/HIPEC procedures.

Routine retrieval of pelvic sentinel lymph nodes for melanoma rarely adds prognostic information or alters management.

Pelvic sentinel lymph nodes (SLNs) are commonly identified during inguinal SLN biopsy for melanoma, but retrieval is not uniform among surgeons/centers. Few studies have assessed rates of micrometastases in pelvic versus superficial inguinal SLNs. Previous studies suggested that presence of pelvic SLNs was predicted by aggressive pathologic features and that their presence portended a worse prognosis. The objectives of this study were to examine presurgical predictors of pelvic SLNs among patients undergoing inguinal SLN biopsy, assess rates of micrometastases in superficial inguinal versus pelvic SLNs, and determine whether presence of pelvic SLNs was associated with long-term outcomes. Multivariable regression was used to assess presurgical factors associated with presence of pelvic SLNs. Rates of micrometastases in superficial inguinal versus pelvic SLNs in patients who had a pelvic SLN were compared with McNemar's test. Groin recurrence, disease-free survival (DFS), and disease-specific survival were analyzed by Kaplan-Meier method. A multivariable Cox model for DFS was performed. Pelvic SLNs were retrieved in 100/537 (18.6%) superficial inguinal SLN biopsies and no preoperative factors predicted their presence. In patients with a pelvic SLN, micrometastases were present in 3.0% of pelvic versus 34.0% of superficial inguinal SLN biopsies (P<0.001). There were no differences in groin recurrence, DFS, and disease-specific survival for patients with/without pelvic SLNs in univariate analyses (all P>0.2) or in the multivariable Cox model for DFS (hazard ratio: 1.1, 95% confidence interval: 0.6-2.1). In conclusion, pelvic SLNs harbor micrometastases less frequently than superficial inguinal SLNs do, suggesting that omission of pelvic SLN biopsy may be reasonable.

Prescription vs. consumption: Opioid overprescription to children after common surgical procedures.

BACKGROUND: In the setting of a national opioid epidemic there are concerns about routine overprescription of opioids postoperatively in both children and adults, which introduces excess opioids into the community. PURPOSE: We sought to examine current opioid prescribing practices by surgeons and consumption of prescribed opioids by pediatric surgical patients following discharge. METHODS: Starting in January 2017 we began an emailed survey for all postoperative patients in a 23-hospital system about the opioids they were prescribed and consumed following discharge. They were then asked if their pain was controlled. Responses of pediatric patients (age 10-18) were examined. FINDINGS: Data from 277 patients were analyzed. After surgical procedures, patients were prescribed significantly more opioids (given in hydrocodone 5 mg equivalents) than they consumed: for appendectomy (median 10 vs. 2) cholecystectomy (12 vs. 5), hernia repair (20 vs. 14), tonsillectomy (30 vs. 17), sinus surgery (30 vs. 5), septoplasty (27 vs. 9.5), knee arthroscopy (30 vs. 12.5), open reduction and internal fixation (ORIF) of the hand and wrist (20 vs. 8.5), and ORIF of the foot and ankle (27 vs. 13.5). The majority (84%) of patients agreed or strongly agreed with the statement that their pain was controlled. Of patients with excess opioids, 64% reported keeping them in their home. CONCLUSIONS: Providers prescribed more opioid tablets than were used by patients. Despite using fewer tablets, patients reported good pain control. Current prescribing practices contribute to excess opioids in the community and represent an opportunity to alter the current epidemic. LEVEL OF EVIDENCE: III.

Disparities in utilization of treatment for clinical stage I-II pancreatic adenocarcinoma by area socioeconomic status and race/ethnicity.

BACKGROUND: Utilization of multimodality therapy for clinical stage I-II pancreatic ductal adenocarcinoma is associated with meaningful prolongation of survival. Although the qualitative existence of disparities in treatment utilization by socioeconomic status and race/ethnicity is well documented, the absolute magnitudes of these disparities have not been previously quantified. METHODS: The exposures in this retrospective cohort study of the 2010-2015 National Cancer Database were a 7-value area-level socioeconomic status index and race/ethnicity. Main outcomes were surgery, chemotherapy, and multimodality therapy (surgery and chemotherapy). Adjusted rate differences were calculated after logistic regression. Models excluded intermediate variables. Overall survival was evaluated in unadjusted and adjusted analyses. RESULTS: Of 43,760 patients, 63.4% underwent surgery. Of 39,808 patients without chemotherapy contraindications, refusal, or missing data, 75.1% received chemotherapy and 51.4% received multimodality therapy. Adjusted rate differences for utilization of surgery, chemotherapy, and multimodality therapy in the lowest socioeconomic status patients were -10.0 (95% confidence interval [CI] -12.4 to -7.5), -12.7 (95% CI -16.3 to -9.1), and -15.4 (95% CI -18.8 to -12.0), respectively, versus the highest socioeconomic status patients. Adjusted rate differences for multimodality therapy utilization in non-Hispanic Black and Hispanic patients were -10.1 (95% CI -13.6 to -6.7) and -11.8 (95% CI -14.3 to -9.2), respectively, versus non-Hispanic White patients. Median overall survival increased in a graded fashion from 14.1 (95% CI 13.4-14.8) months in the lowest socioeconomic status patients to 20.2 months (95% CI 19.6-20.8) in the highest socioeconomic status patients. Survival differences were attenuated but not eliminated in multivariable Cox models. CONCLUSION: Socioeconomic status and race/ethnicity are more powerful determinants of whether patients receive treatment for clinical stage I-II pancreatic ductal adenocarcinoma than previously appreciated. Nationwide quality improvement efforts aimed at addressing these inequities are warranted.

Lymph Node Ratio in Pancreatic Adenocarcinoma After Preoperative Chemotherapy vs. Preoperative Chemoradiation and Its Utility in Decisions About Postoperative Chemotherapy.

BACKGROUND: Single-center studies in pancreatic adenocarcinoma have suggested that preoperative chemotherapy (PCT) is associated with higher lymph node ratio (LNR) than preoperative chemoradiation (PCRT). The association of postoperative chemotherapy with overall survival (OS) in patients treated with PCT and PCRT remains unclear. Our objectives were to investigate whether (1) PCT is associated with higher LNR than PCRT and (2) postoperative chemotherapy is associated with longer OS after PCT and PCRT in LNR-stratified cohorts. METHODS: A retrospective cohort study was performed of patients with pancreatic adenocarcinoma treated with PCT or PCRT followed by resection between 2006 and 2014 in the National Cancer Database. Temporal trends were evaluated with Cuzick's test. OS was evaluated with multivariable Cox regression and inverse probability weighted (IPW) Cox regression. RESULTS: Of 4187 patients, 1993 (47.6%) received PCT. PCT rates were stable at approximately 30% in 2006-2010 (p = 0.33) but increased to 64.9% by 2014 (p < 0.001). Node positivity rates were higher after PCT than PCRT (62.7 vs. 41.8%, P < 0.001) and mean LNR was higher (0.10 [95% CI 0.096, 0.11] vs. 0.058 [95% CI 0.052, 0.063], P < 0.001). Postoperative chemotherapy was associated with longer OS in patients with LNR 0.01-0.149 after PCT by univariate analysis (median OS 34.5 vs. 26.5 months, P = 0.002), multivariable Cox regression (HR 0.64, 95% CI 0.48, 0.84), and IPW Cox regression (HR 0.72, 95% CI 0.55, 0.94). Postoperative chemotherapy was not associated with longer OS for patients who were node-negative or who had LNR ≥ 0.15 after PCT or for any patient subgroups after PCRT. CONCLUSIONS: PCT is associated with a higher LNR and higher rates of node positivity than PCRT. Postoperative chemotherapy is associated with longer OS than observation in patients with a LNR of 0.01-0.149 after PCT.