Evaluation of Acute Supplementation With the Ketone Ester (R)-3-Hydroxybutyl-(R)-3-Hydroxybutyrate (deltaG) in Healthy Volunteers by Cardiac and Skeletal Muscle 31P Magnetic Resonance Spectroscopy

In this acute intervention study, we investigated the potential benefit of ketone supplementation in humans by studying cardiac phosphocreatine to adenosine-triphosphate ratios (PCr/ATP) and skeletal muscle PCr recovery using phosphorus magnetic resonance spectroscopy (³¹P-MRS) before and after ingestion of a ketone ester drink. We recruited 28 healthy individuals: 12 aged 23–70 years for cardiac ³¹P-MRS, and 16 aged 60–75 years for skeletal muscle ³¹P-MRS. Baseline and post-intervention resting cardiac and dynamic skeletal muscle ³¹P-MRS scans were performed in one visit, where 25 g of the ketone monoester, deltaG^®, was administered after the baseline scan. Administration was timed so that post-intervention ³¹P-MRS would take place 30 min after deltaG^® ingestion. The deltaG^® ketone drink was well-tolerated by all participants. In participants who provided blood samples, post-intervention blood glucose, lactate and non-esterified fatty acid concentrations decreased significantly (−28.8%, p ≪ 0.001; −28.2%, p = 0.02; and −49.1%, p ≪ 0.001, respectively), while levels of the ketone body D-beta-hydroxybutyrate significantly increased from mean (standard deviation) 0.7 (0.3) to 4.0 (1.1) mmol/L after 30 min (p ≪ 0.001). There were no significant changes in cardiac PCr/ATP or skeletal muscle metabolic parameters between baseline and post-intervention. Acute ketone supplementation caused mild ketosis in blood, with drops in glucose, lactate, and free fatty acids; however, such changes were not associated with changes in ³¹P-MRS measures in the heart or in skeletal muscle. Future work may focus on the effect of longer-term ketone supplementation on tissue energetics in groups with compromised mitochondrial function.

Inclusion of Wheat Dried Distillers' Grains with Solubles from Bioethanol Plants in Diets for Dairy Cows

Simple Summary

There are environmental concerns about feeding imported soya bean meal to dairy cows in Europe. An alternative protein source is dried distillers’ grains with solubles (DDGS), a co-product of bioethanol manufacture. Corn is the main source of bioethanol and DDGS in the USA, and corn DDGS is widely researched. Wheat is used for bioethanol and DDGS manufacture in Canada and Europe, but most studies of wheat DDGS in dairy diets have used one dietary inclusion level. Responses of dairy cows to inclusion level of wheat DDGS made in Europe are unknown. In this study, we tested two batches of wheat DDGS from UK bioethanol plants, which replaced soya and rapeseed meal in diets for high-yielding dairy cows. One batch of wheat DDGS had a low proportion of solubles, which decreased its metabolisable energy content and limited inclusion level to below 20% of diet dry matter before dry matter intake and milk yield were depressed. The other batch of wheat DDGS had a typical proportion of solubles, resulting in higher metabolisable energy content, and could be included to at least 22.5% of diet dry matter without affecting dry matter intake and milk yield. Results of this study give confidence that wheat DDGS produced in Europe can be used at high inclusion levels in diets for high-yielding dairy cows.

Abstract

Dried distillers’ grains with solubles (DDGS) from bioethanol production can replace soya in diets for dairy cows, but the optimum inclusion level of European wheat DDGS (wDDGS) is unknown. Two batches of wDDGS from different UK bioethanol plants were fed to 44 (Experiment 1) and 40 (Experiment 2) cows in a Latin square design. Each wDDGS replaced soya and rapeseed at four inclusion levels (g/kg of diet dry matter (DM): 0, 80, 160 and 240—Experiment 1; 0, 75, 150 and 225—Experiment 2). Diets were balanced for metabolisable energy (ME) and protein (MP), and for minimum starch and saturated fat in Experiment 2. In Experiment 1, DM intake (29 kg/day) and milk yield (42.3 kg/day) were unaffected by wDDGS inclusion up to 160 g/kg but were lower than control with 240 g/kg inclusion, which was attributed to the low proportion of solubles in this wDDGS batch. In Experiment 2, DM intake (22.4 kg/day) and milk yield (32.1 kg/day) were unaffected by wDDGS inclusion up to 225 g/kg. ME content of wDDGS, determined in vivo (MJ/kg DM) was 12.1 (Experiment 1) and 13.4 (Experiment 2). It is concluded that the optimum inclusion level of wDDGS is at least 225 g/kg DM in diets balanced for minimum starch and saturated fat as well as ME and MP supplies.

Geographical and seasonal variation in iodine content of cow's milk in the UK and consequences for the consumer´s supply

BACKGROUND

Dairy products provide a crucial source of dietary iodine for the majority of the UK population, contributing approximately 30-40 % of daily intake. Fluctuations in the iodine content of purchased milk both seasonally and annually implies potential fragility of iodine supply likely through fluctuating supplementation practices in cow herds. We set out to establish the level of national variation in herds and identify factors which might impact milk iodine content.

METHODS

Milk samples were obtained from 98 herds across the UK via the National Milk Laboratories in August and December 2016. Iodine concentration of samples was measured using ICP-MS. Milk samples and feed intake data were additionally taken from 22 cows from the University of Nottingham (UON) dairy herd.

RESULTS

There was considerable variation in milk iodine content from < 0.012 (Limit of Detection) to 1558 μg L^-1, with a summer median of 197 μg L^-1 and winter median 297 μg L^-1. Overall, winter values were higher than summer counterparts (P < 0.001) and this held true for samples taken from the North West (P = 0.002) and South West (P = 0.006) but not for other regions studied. Data from the UON herd showed a negative relationship between iodine content and milk yield (P = 0.03) and we found that milk iodine content varied considerably despite apparently similar iodine intakes.

CONCLUSIONS

Regional differences in milk iodine concentration between summer and winter suggests that feeding practices are far from uniform across the country. The negative association observed between iodine concentration and milk yield in UON samples, suggests that reduced summer values may be influenced by dilution in addition to seasonal differences in concentrate feed provision.

Genome-Wide Association Studies for Methane Production in Dairy Cattle

Genomic selection has been proposed for the mitigation of methane (CH₄) emissions by cattle because there is considerable variability in CH₄ emissions between individuals fed on the same diet. The genome-wide association study (GWAS) represents an important tool for the detection of candidate genes, haplotypes or single nucleotide polymorphisms (SNP) markers related to characteristics of economic interest. The present study included information for 280 cows in three dairy production systems in Mexico: 1) Dual Purpose (n = 100), 2) Specialized Tropical Dairy (n = 76), 3) Familiar Production System (n = 104). Concentrations of CH₄ in a breath of individual cows at the time of milking (MEIm) were estimated through a system of infrared sensors. After quality control analyses, 21,958 SNPs were included. Associations of markers were made using a linear regression model, corrected with principal component analyses. In total, 46 SNPs were identified as significant for CH₄ production. Several SNPs associated with CH₄ production were found at regions previously described for quantitative trait loci of composition characteristics of meat, milk fatty acids and characteristics related to feed intake. It was concluded that the SNPs identified could be used in genomic selection programs in developing countries and combined with other datasets for global selection.

A heritable subset of the core rumen microbiome dictates dairy cow productivity and emissions

A 1000-cow study across four European countries was undertaken to understand to what extent ruminant microbiomes can be controlled by the host animal and to identify characteristics of the host rumen microbiome axis that determine productivity and methane emissions. A core rumen microbiome, phylogenetically linked and with a preserved hierarchical structure, was identified. A 39-member subset of the core formed hubs in co-occurrence networks linking microbiome structure to host genetics and phenotype (methane emissions, rumen and blood metabolites, and milk production efficiency). These phenotypes can be predicted from the core microbiome using machine learning algorithms. The heritable core microbes, therefore, present primary targets for rumen manipulation toward sustainable and environmentally friendly agriculture.

Prognostic Impact of Serum Pancreastatin Following Chemoembolization for Neuroendocrine Tumors

PURPOSE

The objective of this study was to investigate the prognostic impact of the biomarker serum pancreastatin in patients with metastatic neuroendocrine tumors (NETs) treated with transarterial chemoembolization (TACE).

METHODS

Patients with metastatic NET treated with TACE at a single institution from 2000 to 2013 were analyzed. Patient demographics, response to therapy, and long-term survival were compared with baseline pancreastatin level and changes in pancreastatin levels after TACE.

RESULTS

A total of 188 patients underwent TACE during the study period. An initial pancreastatin level greater than 5000 pg/mL correlated with worse overall survival (OS) from time of first TACE (median OS, 58.5 vs. 22.1 months, p < 0.001). A decrease in pancreastatin level by 50% or more after TACE treatment correlated with improved OS (median OS 53.8 vs. 29.9 months, p = 0.032). Patients with carcinoid syndrome were more likely to have a subsequent increase in pancreastatin after initial drop post-TACE (78.1 vs. 55.2%, p = 0.002). Patients with an increase in pancreastatin levels after initial drop post-TACE were more likely to have liver progression on imaging (70.7 vs. 40.7%, p = 0.005) and more likely to need repeat TACE (21.1 vs. 6.7%, p = 0.009).

CONCLUSIONS

For patients with liver metastases from NET treated with TACE, pancreastatin measurement may be a useful prognostic indicator. Extreme high levels before TACE can predict poor outcomes, whereas significant drops in pancreastatin after TACE correlate with improved survival. An increase in levels after initial decrease may predict progressive liver disease requiring repeat TACE. As such, pancreastatin levels should be measured throughout the TACE treatment period.

Does the diurnal pattern of enteric methane emissions from dairy cows change over time?

Diet manipulation and genetic selection are two important mitigation strategies for reducing enteric methane (CH4) emissions from ruminant livestock. The aim of this study was to assess whether the diurnal pattern of CH4 emissions from individual dairy cows changes over time when cows are fed on diets varying in forage composition. Emissions of CH4 from 36 cows were measured during milking in an automatic (robotic) milking station in three consecutive feeding periods, for a total of 84 days. In Periods 1 and 2, the 36 cows were fed a high-forage partial mixed ration (PMR) containing 75% forage, with either a high grass silage or high maize silage content. In Period 3, cows were fed a commercial PMR containing 69% forage. Cows were offered PMR ad libitum plus concentrates during milking and CH4 emitted by individual cows was sampled during 8662 milkings. A linear mixed model was used to assess differences among cows, feeding periods and time of day. Considerable variation was observed among cows in daily mean and diurnal patterns of CH4 emissions. On average, cows produced less CH4 when fed on the commercial PMR in feeding Period 3 than when the same cows were fed on high-forage diets in feeding Periods 1 and 2. The average diurnal pattern for CH4 emissions did not significantly change between feeding periods and as lactation progressed. Emissions of CH4 were positively associated with dry matter (DM) intake and forage DM intake. It is concluded that if the management of feed allocation remains constant then the diurnal pattern of CH4 emissions from dairy cows will not necessarily alter over time. A change in diet composition may bring about an increase or decrease in absolute emissions over a 24-h period without significantly changing the diurnal pattern unless management of feed allocation changes. These findings are important for CH4 monitoring techniques that involve taking measurements over short periods within a day rather than complete 24-h observations.

Impact of lymph node ratio in selecting patients with resected gastric cancer for adjuvant therapy

BACKGROUND

The impact of adjuvant chemotherapy and chemo-radiation therapy in the treatment of resectable gastric cancer remains varied. We sought to define the clinical impact of lymph node ratio on the relative benefit of adjuvant chemotherapy or chemo-radiation therapy among patients having undergone curative-intent resection for gastric cancer.

METHODS

Using the multi-institutional US Gastric Cancer Collaborative database, 719 patients with gastric adenocarcinoma who underwent curative-intent resection between 2000 and 2013 were identified. Patients with metastasis or an R2 margin were excluded. The impact of lymph node ratio on overall survival among patients who received chemotherapy or chemo-radiation therapy was evaluated.

RESULTS

Median patient age was 65 years, and the majority of patients were male (56.2%). The majority of patients underwent either subtotal (40.6%) or total gastrectomy (41.0%), with the remainder undergoing distal gastrectomy or wedge resection (18.4%). On pathology, median tumor size was 4 cm; most patients had a T3 (33.0%) or T4 (27.9%) lesion with lymph node metastasis (59.7%). Margin status was R0 in 92.5% of patients. A total of 325 (45.2%) patients underwent resection alone, 253 (35.2%) patients received 5-FU or capecitabine-based chemo-radiation therapy, whereas the remaining 141 (19.6%) received chemotherapy. Median overall survival was 40.9 months, and 5-year overall survival was 40.3%. According to lymph node ratio categories, 5-year overall survival for patients with a lymph node ratio of 0, 0.01-0.10, >0.10-0.25, >0.25 were 54.1%, 53.1 %, 49.1 % and 19.8 %, respectively. Factors associated with worse overall survival included involvement of the gastroesophageal junction (hazard ratio 1.8), T-stage (3-4: hazard ratio 2.1), lymphovascular invasion (hazard ratio 1.4), and lymph node ratio (>0.25: hazard ratio 2.3; all P < .05). In contrast, receipt of adjuvant chemo-radiation therapy was associated with an improved overall survival in the multivariable model (versus resection alone: hazard ratio 0.40; versus chemotherapy: hazard ratio 0.45, both P < .001). The benefit of chemo-radiation therapy for resected gastric cancer was noted only among patients with lymph node ratio >0.25 (versus resection alone: hazard ratio R 0.34; versus chemotherapy: hazard ratio 0.45, both P < .001). In contrast, there was no noted overall survival benefit of chemotherapy or chemo-radiation therapy among patients with lymph node ratio ≤0.25 (all P > .05).

CONCLUSION

Adjuvant chemotherapy or chemo-radiation therapy was utilized in more than one-half of patients undergoing curative-intent resection for gastric cancer. Lymph node ratio may be a useful tool to select patients for adjuvant chemo-radiation therapy, because the benefit of chemo-radiation therapy was isolated to patients with greater degrees of lymphatic spread (ie, lymph node ratio >0.25).

Readmission Following Gastric Cancer Resection: Risk Factors and Survival

BACKGROUND

This study utilized a multi-institutional database to evaluate risk factors for readmission in patients undergoing curative gastrectomy for gastric adenocarcinoma with the intent of describing both perioperative risk factors and the relationship of readmission to survival.

METHODS

Patients who underwent curative resection of gastric adenocarcinoma from 2000 to 2012 from seven academic institutions of the US Gastric Cancer Collaborative were analyzed. In-hospital deaths and palliative surgeries were excluded, and readmission was defined as within 30 days of discharge. Univariate and multivariable logistic regression analyses were employed and survival analysis conducted.

RESULTS

Of the 855 patients, 121 patients (14.2 %) were readmitted. Univariate analysis identified advanced age (p < 0.0128), American Society of Anesthesiology status ≥3 (p = 0.0045), preexisting cardiac disease (p < 0.0001), hypertension (p = 0.0142), history of smoking (p = 0.0254), increased preoperative blood urea nitrogen (BUN; p = 0.0426), concomitant pancreatectomy (p = 0.0056), increased operation time (p = 0.0384), estimated blood loss (p = 0.0196), 25th percentile length of stay (<7 days, p = 0.0166), 75th percentile length of stay (>12 days, p = 0.0256), postoperative complication (p < 0.0001), and total gastrectomy (p = 0.0167) as risk factors for readmission. Multivariable analysis identified cardiac disease (odds ratio (OR) 2.4, 95 % confidence interval (CI) 1.6-3.3, p < 0.0001), postoperative complication (OR 2.3, 95 % CI 1.6-5.4, p < 0.0001), and pancreatectomy (OR 2.2, 95 % CI 1.1-4.1, p = 0.0202) as independent risk factors for readmission. There was an association of decreased overall median survival in readmitted patients (39 months for readmitted vs. 103 months for non-readmitted). This was due to decreased survival in readmitted stage 1 (p = 0.0039), while there was no difference in survival for other stages. Stage I readmitted patients had a higher incidence of cardiac disease than stage I non-readmitted patients (58 vs. 24 %, respectively, p = 0.0002).

CONCLUSIONS

Within this multi-institutional study investigating readmission in patients undergoing curative resection for gastric cancer, cardiac disease, postoperative complication, and concomitant pancreatectomy were identified as significant risk factors for readmission. Readmission was associated with decreased overall median survival, but on further analysis, this was driven by differences in survival for stage I disease only.

Efficacy of ACL injury risk screening methods in identifying high-risk landing patterns during a sport-specific task

Screening methods sensitive to movement strategies that increase anterior cruciate ligament (ACL) loads are likely to be effective in identifying athletes at-risk of ACL injury. Current ACL injury risk screening methods are yet to be evaluated for their ability to identify athletes' who exhibit high-risk lower limb mechanics during sport-specific maneuvers associated with ACL injury occurrences. The purpose of this study was to examine the efficacy of two ACL injury risk screening methods in identifying high-risk lower limb mechanics during a sport-specific landing task. Thirty-two female athletes were screened using the Landing Error Scoring System (LESS) and Tuck Jump Assessment. Participants' also completed a sport-specific landing task, during which three-dimensional kinematic and kinetic data were collected. One-dimensional statistical parametric mapping was used to examine the relationships between screening method scores, and the three-dimensional hip and knee joint rotation and moment data from the sport-specific landing. Higher LESS scores were associated with reduced knee flexion from 30 to 57 ms after initial contact (P = 0.003) during the sport-specific landing; however, no additional relationships were found. These findings suggest the LESS and Tuck Jump Assessment may have minimal applicability in identifying athletes' who exhibit high-risk landing postures in the sport-specific task examined.

Predictors of Unintentional Injuries in Paediatric Immigrants in Ontario

BACKGROUND: Unintentional injury is a frequent reason for emergency department visits and is the leading cause of death for Canadian children. Injury is associated with a number of socio-demographic variables but it is not known whether being an immigrant changes this risk.

OBJECTIVES: To examine the association between family immigrant status and unintentional injury; and to test this relationship within immigrants by refugee status.

DESIGN/METHODS: Retrospective population-based cross-sectional study of children ages 0 to 14 years residing in Ontario, Canada from 2008 to 2012, using linked health administrative databases and Citizenship and Immigration Canada’s Permanent Resident Database. The main exposure was immigration status (immigrant or child of an immigrant vs. Canadian born). Secondary exposure was refugee status. Main outcome measure was unintentional injury events (emergency department visits, hospitaliza-tions, deaths), annualized. Data were analyzed using Poisson regression models to estimate risk ratios (RR) for unintentional injuries.

RESULTS: There were 11 464 317 injuries per year. Non-immigrant children sustained 12051 injuries/100 000 and immigrants had 6837 injuries/100 000, annually. In adjusted models, immigrants had a significantly lower risk of injury compared with non-immigrant children (RR 0.60; 95% confidence interval [CI] 0.57, 0.63). Overall, the most materially deprived neighbourhood quintile was associated with a higher rate of injury (RR 1.13; 95% CI 1.07, 1.02, quintile 5 vs. 1) whereas within immigrants, material deprivation was associated with a lower rate of injury (RR 0.96; 95% CI 0.94, 0.98, quintile 5 vs. 1). Other predictors of injury included age (0 to 4 years: RR 0.84; 95% CI 0.81, 0.88; 5 to 9 years: RR 0.70; 95% CI 0.67, 0.73), male sex (RR 1.30; 95% CI 1.26, 1.35), and rural residence (RR 1.50; 95% CI 1.43, 1.57). Injury rates were lower in immigrants across all types of unintentional injuries. Within immigrants, refugees had a higher risk of injury compared with non-refugees (RR 1.12; 95% CI 1.10, 1.14). This risk was particularly high for motor vehicle accidents (RR = 1.58; 95% CI 1.46, 1.71) and scald burns (RR 1.23; 95% CI 1.11, 1.35).

CONCLUSION: Risk of unintentional injury is lower among immigrants compared with Canadian-born children. These findings support a healthy immigrant effect. Socioeconomic status has a different effect on injury risk in immigrant and non-immigrant populations, suggesting alternative causal pathways for injuries in immigrants. Risk of unintentional injury is higher in refugees versus non-refugee immigrants, highlighting a population in need of targeted injury prevention strategies.

Interaction of Postoperative Morbidity and Receipt of Adjuvant Therapy on Long-Term Survival After Resection for Gastric Adenocarcinoma: Results From the U.S. Gastric Cancer Collaborative

BACKGROUND

Postoperative complications (POCs) can negatively impact survival after oncologic resection. POCs may also decrease the rate of adjuvant therapy completion. We evaluated the impact of complications on gastric cancer survival and analyzed the combined effect of complications and adjuvant therapy on survival.

METHODS

We analyzed 824 patients from 7 institutions of the U.S. Gastric Cancer Collaborative who underwent curative resection for gastric adenocarcinoma between 2000 and 2012. POC were graded using the modified Clavien-Dindo system. Survival probabilities were estimated using the method of Kaplan and Meier and analyzed using multivariate Cox regression.

RESULTS

Median follow-up was 35 months. The overall complication rate was 41 %. The 5-year overall survival (OS) and recurrence-free survival (RFS) of patients who experienced complications were 27 and 23 %, respectively, compared with 43 and 40 % in patients who did not have complications (p < 0.0001 for OS and RFS). On multivariate analysis, POC remained an independent predictor for decreased OS and RFS (HR 1.3, 95 % CI 1.1-1.6, p = 0.03 for OS; HR 1.3, 95 % CI 1.01-1.6, p = 0.03 for RFS). Patients who experienced POC were less likely to receive adjuvant therapy (OR 0.5, 95 % CI 0.3-0.7, p < 0.001). The interaction of complications and failure to receive adjuvant therapy significantly increased the hazard of death compared with patients who had neither complications nor adjuvant therapy (HR 2.3, 95 % CI 1.6-3.2, p < 0.001).

CONCLUSIONS

Postoperative complications adversely affect long-term outcomes after gastrectomy for gastric cancer. Not receiving adjuvant therapy in the face of POC portends an especially poor prognosis following gastrectomy for gastric cancer.

Preoperative Helicobacter pylori Infection is Associated with Increased Survival After Resection of Gastric Adenocarcinoma

BACKGROUND

Limited data exist on the prognosis of preoperative Helicobacter pylori (H. pylori) infection in gastric adenocarcinoma (GAC).

METHODS

Patients who underwent curative-intent resection for GAC from 2000 to 2012 at seven academic institutions comprising the United States Gastric Cancer Collaborative were included in the study. The primary end points of the study were overall survival (OS), recurrence-free survival (RFS), and disease-specific survival (DSS).

RESULTS

Of 559 patients, 104 (18.6 %) who tested positive for H. pylori were younger (62.1 vs 65.1 years; p = 0.041), had a higher frequency of distal tumors (82.7 vs 71.9 %; p = 0.033), and had higher rates of adjuvant radiation therapy (47.0 vs 34.9 %; p = 0.032). There were no differences in American Society of Anesthesiology (ASA) class, margin status, grade, perineural invasion, lymphovascular invasion, nodal metastases, or tumor-node-metastasis (TNM) stage. H. pylori positivity was associated with longer OS (84.3 vs 44.2 months; p = 0.008) for all patients. This relationship with OS persisted in the multivariable analysis (HR 0.54; 95 % CI 0.30-0.99; p = 0.046). H. pylori was not associated with RFS or DSS in all patients. In the stage 3 patients, H. pylori was associated with longer OS (44.5 vs 24.7 months; p = 0.018), a trend of longer RFS (31.4 vs 21.6 months; p = 0.232), and longer DSS (44.8 vs 27.2 months; p = 0.034).

CONCLUSIONS

Patients with and without preoperative H. pylori infection had few differences in adverse pathologic features at the time of gastric adenocarcinoma resection. Despite similar disease presentations, preoperative H. pylori infection was independently associated with improved OS. Further studies examining the interaction between H. pylori and tumor immunology and genetics are merited.

The importance of the proximal resection margin distance for proximal gastric adenocarcinoma: A multi-institutional study of the US Gastric Cancer Collaborative

BACKGROUND

A 5 cm margin is advocated for distal gastric adenocarcinoma (GAC). The optimal proximal resection margin (PM) length for proximal GAC is not established.

METHODS

Patients who underwent curative-intent resection for proximal GAC from 2000 to 2012 at 7 centers in the US Gastric Cancer Collaborative were included. PM length was sequentially dichotomized and analyzed at 0.5 cm increments (0.5-6.5 cm). Outcomes after negative margin (R0) and positive microscopic margin (R1) resections were compared. Primary endpoints were local recurrence (LR) and overall survival (OS).

RESULTS

All patients (n = 162) had R0 distal margins. 151 (93.2%) had an R0-PM with mean length of 2.6 cm (median:1.7 cm; range:0.1-15 cm). A greater PM distance was not associated with LR or OS. An R1-PM was associated with higher N-stage (N3:73% vs. 26%; P = 0.007) and increased LR (HR6.1; P = 0.009) but not associated with decreased OS. On multivariate analysis, an R1-PM was also not independently associated with LR.

CONCLUSIONS

For resection of proximal gastric adenocarcinoma, proximal margin length is not associated with local recurrence or overall survival. An R1 margin is associated with advanced N-stage but is not independently associated with recurrence or survival. When performing resection of proximal gastric adenocarcinoma, efforts to achieve a specific margin distance, especially if it necessitates an esophagectomy, should be abandoned.

The Prognostic Value of Signet-Ring Cell Histology in Resected Gastric Adenocarcinoma

BACKGROUND

Conflicting data exist on the prognostic implication of signet-ring cell (SRC) histology in gastric adenocarcinoma (GAC).

METHODS

All patients who underwent curative-intent resection of GAC from the seven institutions of the U.S. Gastric Cancer Collaborative between 2000 and 2012 were included. Primary end points were recurrence-free survival (RFS) and overall survival (OS). Stage-specific analyses were performed.

RESULTS

A total of 768 patients met the inclusion criteria. SRC was present in 40.6 % of patients and was associated with female sex (52.9 vs. 38.6 %; p < 0.001), younger age (61 vs. 67 years; p < 0.001), poor differentiation (94.8 vs. 50.3 %; p < 0.001), perineural invasion (PNI) (41.4 vs. 23 %; p < 0.001), microscopically positive resection margins (R1, 24.7 vs. 8.6 %; p < 0.001), distal location (82.2 vs. 70.1 %; p < 0.001), receipt of adjuvant therapy (63 vs. 51.2 %; p = 0.002), and more advanced stage (stage 3: 55.2 vs. 36.5 %; p < 0.001). SRC was associated with earlier recurrence (56.7 months vs. median not reached; p = 0.009) and decreased OS (33.7 vs. 46.6 months; p = 0.011). When accounting for other adverse pathologic features, PNI (hazard ratio [HR] 1.57; p = 0.016) and higher stage (HR 2.64; p < 0.001) were associated with decreased RFS, but SRC was not. Although PNI (HR 1.52; p = 0.007), higher stage (HR 2.11; p < 0.001), greater size (HR 1.05; p = 0.016), and adjuvant therapy (HR 0.50; p < 0.001) were associated with OS, SRC was not. Similarly, when accounting for adverse pathologic factors on multivariate analysis, stage-specific analyses showed no association between SRC and RFS or OS.

CONCLUSIONS

SRC histology is associated with adverse pathologic features including poor differentiation, higher stage, and microscopically positive resection margins but is not independently associated with reduced RFS or OS. Identification of signet-ring histology during preoperative evaluation should not, in isolation, dictate treatment strategy.

Effect of Perioperative Transfusion on Recurrence and Survival after Gastric Cancer Resection: A 7-Institution Analysis of 765 Patients from the US Gastric Cancer Collaborative

BACKGROUND

The prognostic effect of perioperative blood transfusion on recurrence and survival in patients undergoing resection of gastric adenocarcinoma (GAC) remains controversial.

STUDY DESIGN

All patients who underwent resection for GAC from 2000 to 2012 at the 7 institutions of the US Gastric Cancer Collaborative were identified. The effect of transfusion on recurrence-free (RFS) and overall survival (OS) in the context of adverse clinicopathologic variables was examined by univariate and multivariate regression analyses.

RESULTS

Of 965 patients, 765 underwent curative intent R0 resection. Median follow-up was 44 months; 30-day mortalities were excluded. Median estimated blood loss (EBL) was 200 mL, and 168 patients (22%) received perioperative allogeneic blood transfusions. Transfused patients were less likely to receive adjuvant therapy (44% vs 56%; p = 0.01). Transfusion was associated with significantly decreased median RFS (13.5 vs 37.2 months, p < 0.001). Median OS was similarly decreased in patients receiving transfusions (18.6 vs 49.8 months, p < 0.001). On multivariate analysis, transfusion remained an independent risk factor for decreased RFS (hazard ratio [HR] 1.63; 95% CI 1.13 to 2.37; p = 0.010) and decreased OS (HR 1.79; 95% CI 1.21 to 2.67; p = 0.004), regardless of EBL or need for splenectomy. Timing (intraoperative vs postoperative) and volume of transfusion did not alter the negative prognostic effect of transfusion on survival.

CONCLUSIONS

Perioperative allogeneic blood transfusion is associated with decreased RFS and OS after resection of gastric cancer, independent of adverse clinicopathologic factors. This supports the judicious use of perioperative transfusion during resection of gastric cancer.

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.

Can the risk of non-home discharge after resection of gastric adenocarcinoma be predicted: a seven-institution study of the US Gastric Cancer Collaborative

BACKGROUND

There are no validated methods to preoperatively identify patients with increased risk of discharge to skilled nursing facilities following resection of gastric cancer. We sought to identify preoperative predictors of non-home discharge to optimize transition of care to skilled nursing facility.

METHODS

Patients who underwent resection of gastric cancer from 2000 to 2012 from seven participating institutions of the US Gastric Cancer Collaborative were analyzed. Fisher's exact tests, Student t tests, and logistic regression analyses identified preoperative variables associated with non-home discharge. A prediction tool was created and validated through c-indices. Survival analysis was conducted according to the methods of Kaplan and Meier.

RESULTS

Out of the 918 patients identified, 93 (10 %) were discharged to nonhome location. Univariate analysis identified advancing age, American Society of Anesthesiology (ASA) score, hypertension, decreasing preoperative albumin, and lack of neoadjuvant chemotherapy as risk factors for non-home discharge (NHD). Multivariable analysis identified advanced age (odds ratio (OR) = 1.07, 95 % confidence interval (CI) = 1.04-1.10, p < 0.0001), depressed preoperative albumin (OR = 2.17, 95 % CI = 1.47-3.19, p = 0.0001), and total gastrectomy (OR = 2.56, 95 % CI = 1.53-4.3, p = 0.0003) as risk factors for NHD. The c-index of the model and the validation population were 0.76 and 0.8, respectively. Additionally, there was an association of decreased overall survival in patients discharged to nonhome location (35.5 months, home discharge, vs 12 months, NHD, p < 0.0001).

CONCLUSIONS

Older patients with compromised nutritional status have greater risk of NHD following resection of gastric cancer. The prediction tool can augment preoperative planning to optimize transition of care to skilled nursing facility.

Optimal extent of lymphadenectomy in gastric adenocarcinoma: A seven-institution study of the U.S. Gastric Cancer Collaborative

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Background: The optimal extent of lymphadenectomy in the treatment of gastric adenocarcinoma continues to be a subject of intense debate. We aimed to compare gastrectomy outcomes following limited (D1) or extended (D2) lymphadenectomy. Methods: Using the multi-institutional U.S. Gastric Cancer Collaborative database, we reviewed the morbidity, mortality, recurrence, and overall survival (OS) of 727 patients receiving D1 or D2 lymphadenectomies. Patients with stage IV disease, prior gastrectomy, and age 85 or greater were excluded. Multivariate analyses included variables with p values less than 0.1. Results: Between 2000 and 2014, 266 (36.6%) and 461 (63.4%) patients received a D1 and D2 lymphadenectomy, respectively. ASA class, mean number of comorbidities, grade, stage, and signet ring cell subtypes were similar between groups. Neoadjuvant and adjuvant chemotherapy was more common in the D2 group (p<0.001). The mean number of lymph nodes recovered was significantly higher in patients receiving a D2 lymphadenectomy (21.5 for D2 vs. 17.1 for D1, p<0.001). Median follow up was 1.3 years. While Clavien III/IV major morbidity was similar (15.0% for D1 vs. 14.5% for D2, p=0.85), mortality was worse for those receiving a D1 lymphadenectomy (4.9% vs. 1.3%, p=0.004). Recurrence rates for patients receiving D1 and D2 lymphadenectomies were 25.8% and 27.0%, respectively (p=0.74). 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 significant predictors of OS which included ASA, stage, grade, neoadjuvant chemotherapy, and adjuvant radiation, D2 lymphadenectomy remained a significant predictor of improved survival when compared with D1 lymphadenectomy (HR 1.5, 95% CI 1.1-2.0, p=0.008). Conclusions: D2 lymphadenectomy is associated with improved survival that is more prominent in early stages of disease. It can be performed safely without increased risk of morbidity and perioperative mortality and should be the preferred lymphadenectomy technique for the treatment of gastric adenocarcinoma.

The prognostic value of preoperative helicobacter pylori infection in resected gastric cancer

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Background: Limited data exist on the prognostic implication of pre-operative Helicobacter pylori (H. pylori) infection in gastric adenocarcinoma (GAC). Our aim was to assess the association of H. pyloriwith recurrence and survival in patients undergoing resection of GAC. Methods: All patients who underwent curative intent resection for GAC from 2000 to 2012 at seven academic institutions comprising the US Gastric Cancer Collaborative were included. 30-day mortalities were excluded. Survival analyses were conducted with Kaplan Meier log rank and multivariate Cox regression. Primary endpoints were recurrence-free survival (RFS) and overall survival (OS). Results: Of 965 patients, 559 met inclusion criteria and had documented pre-operative H. pylori testing. 18.6% (n=104) of patients tested positive for H. pylori pre-operatively. Data regarding treatment of H. pylori was not available. H. pylori infection was associated with younger age (62.1 vs 65.1 years; p=0.041), distal tumor location (82.7% vs 71.9%; p=0.033), and receipt of adjuvant radiation therapy (47.0% vs 34.9%; p=0.032). There were no significant differences in ASA class, margin status, Grade, PNI, LVI, or nodal metastases. The distribution of TNM stage I-III was similar between the two groups. H. pylori status was not associated with tumor recurrence. However, pre-operative H. pylori infection was associated with longer OS (84.3 mo vs 44.2 mo; p=0.008). When accounting for differences in age, tumor location, and delivery of radiation therapy, H. pylori infection persisted as a positive prognostic factor for OS (HR 0.60; CI 0.40-0.91; p = 0.016). Conclusions: Patients with and without preoperative H. pylori infection had no significant differences in adverse pathologic factors including positive margin, high grade, lymph node metastases, or advanced TNM stage. Despite similar disease presentation, pre-operative H. pylori infection was independently associated with improved overall survival. Further studies examining the interaction between H. pylori and tumor immunology and genetics are needed to better understand the relationship between H. pylori and survival in gastric cancer.

The optimal length of the proximal resection margin in patients with proximal gastric adenocarcinoma: A multi-institutional study of the U.S. Gastric Cancer Collaborative

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Background: A 5cm margin is advocated for distal gastric cancers. The optimal length of the proximal resection margin (PM) for proximal (GEJ Siewert II and III, cardia, and fundus) gastric adenocarcinoma (GAC) is not established. Methods: Patients who underwent curative intent abdominal-approach resection for proximal GAC from 2000-2012 at 7 academic US institutions were included. Patients with positive distal margins were excluded. PM length was analyzed by 0.5cm increments and was also dichotomized at the mean and median value. Primary endpoints were local recurrence (LR), recurrence-free survival (RFS) and overall survival (OS). Results: Out of 965 patients, 211 had proximal GAC, and 162 had data available on PM length. 151 patients had negative microscopic margins with a mean value of 2.6cm and a median of 1.7cm (range 0.1-15cm). When PM length was sequentially dichotomized and analyzed at 0.5cm increments (0.5-6.5cm), a greater margin distance for each analysis was not associated with LR, RFS, or OS. Similarly, a PM distance greater than the mean or median value was not associated with LR, RFS, or OS. 11 patients had a positive PM (R1), which was associated with higher N-stage (N3: 73% vs 26%; p=0.007) and increased LR (HR6.1; p=0.009). When accounting for other adverse prognostic factors (grade, lymphovascular invasion, tumor size, T-stage, and N-stage), a positive PM was not independently associated with LR. A positive PM was also not associated with decreased RFS or OS. Conclusions: For an abdominal-approach resection of proximal gastric adenocarcinoma, the length of the proximal margin is not associated with local recurrence, recurrence-free survival, or overall survival. A positive microscopic margin is associated with advanced N-stage but is not independently associated with recurrence or survival. When performing an abdominal-approach resection of proximal gastric adenocarcinoma, a grossly negative proximal margin is sufficient. Efforts to achieve a specific margin distance, especially if it necessitates an esophagectomy, should be abandoned.

Is linitis plastica a contraindication for surgical resection? A 7-institution study of the U.S. Gastric Cancer Collaborative

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Background: Linitis plastica (LP) describes a diffusively infiltrative gastric adenocarcinoma that portends poor prognosis. Current treatment guidelines do not differentiate between LP and non-LP cancers and it is not known if the same staging system should be applied to both situations. Methods: Using the multi-institutional U.S. Gastric Cancer Collaborative database, 869 patients with gastric adenocarcinoma who underwent resection between 2000-2012 were identified. Clinicopathologic, perioperative and survival outcomes of the 58 patients with LP were compared to the 811 patients without LP. Results: Advanced disease (stage III/IV) at presentation was more common in patients with LP compared to non-LP patients (90 vs 44%, p<0.01). Despite the fact that most LP patients underwent total gastrectomy (88% vs 57%, p<0.01), positive margins were more common in LP patients (33 vs 7%, p<0.01). There was no difference in perioperative complications (48 vs 43%, p=0.45) or mortality (7 vs 3%, p=0.12) between LP and non-LP patients. While survival correlated with stage in non-LP patients, there was no difference in median overall survival (OS) of LP patients based on stage (I/II, 17.3 mos; III, 10.6 mos; IV, 12.0 mos; p=0.46). Median OS was significantly worse in patients with LP (11.6 vs 37.8 months, p<0.01) when margin status and extent of lymphadenectomy were not factored in the analysis. However, when analyzing only patients with optimal resections (R0, D2 lymphadenectomy), the median OS for stage III LP (n=22) and non-LP (n=185) patients was nearly identical (26.8 vs 25.3 mos, p=0.69). There were no independent prognostic factors identified to predict survival in LP patients undergoing curative resection. Conclusions: The poor prognosis of LP gastric cancer is due primarily to its advanced stage at diagnosis. However, LP patients who undergo optimal resections can expect similar long term survival compared to optimally resected non-LP patients with advanced stage disease. Patient selection and multidisciplinary management are paramount when considering surgical resection in patients with gastric LP.

The prognostic value of signet ring cell histology in resected gastric cancer

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Background: Conflicting data exist on the prognostic implication of signet ring cell (SRC) histology in gastric adenocarcinoma (GAC). Our aim was to assess the association of SRC with recurrence and survival in patients undergoing resection of GAC. Methods: All pts who underwent curative intent resection for GAC from 2000 to 2012 at 7 academic institutions comprising the US Gastric Cancer Collaborative were included. 30-day mortalities were excluded. Survival analyses included Kaplan Meier log rank and multivariate Cox regression. Primary endpoints were recurrence-free survival (RFS) and overall survival (OS). Stage-specific analysis was performed. Results: Of 965 pts, 768 met inclusion criteria. SRC was present in 39.5% and was associated with female gender (52.9% vs 38.6%; p<0.001), younger age (61 vs 67 yrs; p<0.001), poor differentiation (94.8% vs 50.3%; p<0.001), perineural invasion (PNI: 41.4% vs 23%; p<0.001), distal location (82.2% vs 70.1%; p<0.001), receipt of adjuvant therapy (63% vs 51.2%; p=0.002), and more advanced stage (Stage 3: 55.2% vs 36.5%; p<0.001). SRC was associated with earlier recurrence (56.7mo vs median not reached (MNR); p=0.009) and decreased OS (33.7mo vs 46.6mo; p=0.011). When accounting for other adverse pathologic features, PNI (HR 1.57; p=0.016) and higher TNM stage (HR 2.63; p<0.001) were associated with decreased RFS, but SRC was not. PNI (HR 1.53; p=0.006), higher TNM Stage (HR 2.10; p<0.001), greater size (HR 1.05; p=0.014), and adjuvant therapy (HR 0.50; p<0.001) were associated with OS. SRC was not an independent predictor of OS. Stage-specific analysis showed no association between SRC and RFS or OS in Stage 1 or 3. In Stage 2, SRC was associated with earlier recurrence (38.1mo vs MNR; p=0.005) but not OS. The negative association of SRC with decreased RFS persisted in multivariate analysis (HR 3.11; p=0.015). Conclusions: Signet ring histology is associated with other adverse pathologic features including higher grade and higher TNM stage but is not independently associated with reduced RFS or OS. Identification of signet ring histology during preoperative evaluation should not, in isolation, dictate treatment strategy.

Value of peritoneal drain placement after total gastrectomy for gastric adenocarcinoma: A multi-institutional analysis from the U.S. Gastric Cancer Collaborative

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Background: A recent randomized trial of peritoneal drain (PD) placement after pancreaticoduodenectomy concluded that placement of PDs decreased the frequency and severity of complications. The role of PD placement after total gastrectomy for gastric adenocarcinoma (GAC) is not well-established. Methods: Patients who underwent total gastrectomy for GAC at 7 institutions from the U.S. Gastric Cancer Collaborative from 2000-2012 were identified. Univariate and multivariate analyses were performed to evaluate the association of PD placement with postoperative outcomes. Results: 344 patients were identified and anastomotic leak rate was 9%.253 (74%) patients received a PD. Those with PD placed had similar ASA class, tumor size, TNM stage, and need for additional organ resection when compared to their counterparts with no PD. 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), 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 a decrease in frequency or severity of postoperative complications. Subset analysis of patients stratified by whether they underwent concomitant pancreatectomy similarly demonstrated no association of PD placement with reduced complications or mortality. In patients who experienced an anastomotic leak (n=31), placement of PD was similarly not associated with a decrease in complications, need for secondary drainage, or mortality. Conclusions: Peritoneal drain placement after total gastrectomy for adenocarcinoma, regardless of concomitant pancreatectomy, is not associated with a decrease in the frequency and severity of adverse postoperative outcomes, including anastomotic leak and mortality, or decrease in the need for secondary drainage procedures or reoperation. Routine use of peritoneal drains is not warranted.

A nomogram to predict overall survival and disease-free survival after curative resection of gastric adenocarcinoma

BACKGROUND

The American Cancer Society projects there will be over 22,000 new cases, resulting in nearly 11,000 deaths, related to gastric adenocarcinoma in the US in 2014. The aim of the current study was to find clinicopathologic variables associated with disease-free survival (DFS) and overall survival (OS) following curative resection of gastric adenocarcinoma, and create a nomogram for individual risk prediction.

METHODS

A nomogram to predict DFS and OS following surgical resection of gastric adenocarcinoma was constructed using a multi-institutional cohort of patients who underwent surgery for primary gastric adenocarcinoma at seven major institutions in the US between January 2000 and August 2013. Discrimination and calibration of the nomogram were tested by C-statistic, Kaplan-Meier curves, and calibration plots.

RESULTS

A total of 719 patients who underwent surgery for primary gastric adenocarcinoma were included in the study. Using the backward selection of clinically relevant variables with Akaike information criteria, age, sex, tumor site, depth of invasion, and lymph node ratio (LNR) were selected as factors predictive of OS, while age, tumor site, depth of invasion, and LNR were incorporated in the prediction of DFS. A nomogram was constructed to predict OS and DFS using these variables. Discrimination and calibration of the nomogram revealed good predictive abilities (C-index, DFS 0.711; OS 0.702).

CONCLUSION

Independent predictors of recurrence and death following surgery for primary gastric adenocarcinoma were used to create a nomogram to predict DFS and OS. The nomogram was able to stratify patients into prognostic groups, and performed well on internal validation.

Is it time to abandon the 5-cm margin rule during resection of distal gastric adenocarcinoma? A multi-institution study of the U.S. Gastric Cancer Collaborative

BACKGROUND

A proximal margin distance of 5 cm is advocated for resection of gastric adenocarcinoma (GAC). We assessed the prognostic value of proximal margin (PM) distance on survival outcomes after resection of distal GAC.

METHODS

All patients who underwent resection of distal GAC (antrum/body) from 2000 to 2012 at seven institutions of the U.S. Gastric Cancer Collaborative were included. Patients with positive distal margins or macroscopic residual disease were excluded. The prognostic value of PM distance (assessed in 0.5-cm increments) on overall (OS) and recurrence-free survival (RFS) was assessed by Kaplan-Meier and multivariate regression analysis.

RESULTS

A total of 465 patients underwent resection of distal GAC. Of these, 435 had R0 resections; 30 patients had a positive PM. 143 patients had stage I, and 322 had stage II-III tumors. Median follow-up was 44 months. Average PM distance was 4.8 cm. Median OS for patients with PM of 3.1-5.0 cm (n = 110) was superior to patients with PM ≤ 3.0 cm (n = 176) (48.1 vs. 29.3 months; p = 0.01), while a margin >5.0 cm (n = 179) offered equivalent survival to PM 3.1-5.0 cm (50.6 months, p = 0.72). The prognostic value of margin distance was stage specific. On multivariate analysis of stage I patients, PM 3.1-5.0 cm remained associated with improved OS [hazard ratio (HR), 0.16; 95 % confidence interval (95 % CI), 0.04-0.60; p = 0.01]. In stage II-III, neither PM 3.1-5.0 cm nor PM > 5.0 cm was significantly associated with OS; OS was dictated by T stage and nodal involvement.

CONCLUSIONS

The prognostic value of proximal margin distance after resection of distal gastric cancer appears stage specific. In stage I, a 3.1- to 5.0-cm proximal margin is associated with the same improved OS as a > 5.0-cm margin. In stage II-III disease, other adverse pathologic factors more strongly impact survival than proximal margin distance.

Conditional survival after surgical resection of gastric cancer: a multi-institutional analysis of the us gastric cancer collaborative

BACKGROUND

Survival estimates following surgical resection of gastric adenocarcinoma are traditionally reported as survival from the date of surgery. Conditional survival (CS) estimates, however, may be more clinically relevant by accounting for time already survived. We assessed CS following surgical resection for gastric adenocarcinoma.

METHODS

We analyzed 807 patients who underwent resection for gastric adenocarcinoma from 2000 to 2012 at seven participating institutions in the U.S. Gastric Cancer Collaborative. Cox proportional hazards models were used to evaluate factors associated with overall survival. Three-year CS estimates at "x" year after surgery were calculated as follows: CS3 = S(x+3)/S(x).

RESULTS

Overall 1-, 3-, and 5-year overall survival rates after gastric resection were 42, 34, and 30 %, respectively. Using CS estimates, the probability of surviving an additional 3 years given that the patient had survived at 1, 3, and 5 years were 56, 71, and 82 %, respectively. Patients with higher risk at baseline (i.e., stage III or IV disease, lymphovascular invasion) demonstrated the greatest increase in CS over time.

CONCLUSIONS

Survival estimates following surgical resection of gastric adenocarcinoma is dynamic; the probability of survival increases with time already survived. Patients with worse prognostic features at the time of surgery had the greatest increases in CS over time. Conditional survival estimates provide important information about the changing probability of survival over time and should be used among patients with resected gastric adenocarcinoma to guide subsequent follow-up strategies.

Utility of the proximal margin frozen section for resection of gastric adenocarcinoma: a 7-Institution Study of the US Gastric Cancer Collaborative

BACKGROUND

The proximal gastric margin dictates the extent of resection for gastric adenocarcinoma (GAC). The value of achieving negative margins via additional gastric resection after a positive proximal margin frozen section (FS) is unknown.

METHODS

The US Gastric Cancer Collaborative includes all patients who underwent resection of GAC at seven institutions from 2000-2012. Intraoperative proximal margin FS data and final permanent section (PS) data were classified as R0 or R1, respectively; positive distal margins were excluded. The primary aim was to evaluate the impact on local recurrence of converting a positive proximal FS-R1 margin to a PS-R0 final margin by additional resection. Secondary endpoints were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Of 860 patients, 520 had a proximal margin FS and 67 were positive. Of these, 48 were converted to R0 on PS by additional resection. R0 proximal margin was achieved in 447 patients (86 %), PS-R1 in 25 (5 %), and converted FS-R1-to-PS-R0 in 48 (9 %). The median follow-up was 44 months. Local recurrence was significantly decreased in the converted FS-R1-to-PS-R0 group compared to the PS-R1 group (10 vs. 32 %; p = 0.01). Median RFS was similar between the FS-R1-to-PS-R0 and PS-R1 cohorts (25 vs. 20 months; p = 0.49), compared to 37 months for the PS-R0 group. Median OS was similar between the FS-R1-to-PS-R0 conversion and PS-R1 groups (36 vs. 26 months; p = 0.14) compared to 50 months for the PS-R0 group. On multivariate analysis, increasing T-stage and N-stage were associated with worse OS; the FS-R1-to-PS-R0 proximal margin conversion was not significantly associated with improved RFS (p = 0.68) or OS (p = 0.44).

CONCLUSION

Conversion of a positive intraoperative proximal margin frozen section during gastric cancer resection may decrease local recurrence, but it is not associated with improved RFS or OS. This may guide decisions regarding the extent of resection.

Impact of external-beam radiation therapy on outcomes among patients with resected gastric cancer: a multi-institutional analysis

BACKGROUND

Use of perioperative chemotherapy (CTx) alone versus chemoradiation therapy (cXRT) in the treatment of resectable gastric cancer remains varied. We sought to define the utilization and effect of CTx alone versus cXRT on patients having undergone curative-intent resection for gastric cancer.

METHODS

Using the multi-institutional US Gastric Cancer Collaborative database, we identified 505 gastric cancer patients between 2000 and 2012 who received perioperative therapy in addition to curative-intent resection. The impact of perioperative therapy on survival was analyzed by the use of propensity-score matching of clinicopathologic factors among patients who received CTx alone versus cXRT.

RESULTS

Median patient age was 62 years, and most patients were male (58.2 %). Most patients had a T3 (38.7 %) or T4 (36.8 %) lesion and lymph node metastasis (73.4 %). A total of 211 (42.8 %) patients received perioperative CTx alone, whereas the remaining 294 (58.2 %) patients received cXRT. Factors associated with receipt of cXRT were younger age (odds ratio, 1.93) and lymph node metastasis (odds ratio, 4.02; both P < 0.05). At a median follow-up of 28 months, the median overall survival (OS) was 33.4 months, and the 5-year OS was 36.7 %. Factors associated with worse overall survival included large tumor size [hazard ratio (HR), 1.83], T3 (HR 2.96) or T4 (HR 4.02) tumors, and lymph node metastasis (HR 1.57; all P < 0.05). In contrast, receipt of cXRT was associated with improved long-term OS (CTx alone, 20.9 months; cXRT, 46.7 months; HR 0.51; P < 0.001).

CONCLUSIONS

cXRT was utilized in 58 % of patients undergoing curative-intent resection for gastric cancer. With propensity score-matched analysis, cXRT was an independent factor associated with improved recurrence-free survival and OS.

Impact of external-beam radiation therapy on outcomes among patients with resected gastric cancer: A multi-institutional analysis

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Background: Use of perioperative chemotherapy (CTx) alone versus chemo-radiation therapy (cXRT) in the treatment of resectable gastric cancer remains varied. We sought to define the utilization and effect of CTx alone versus cXRT on patients having undergone curative-intent resection for gastric cancer. Methods: Using the multi-institutional U.S. Gastric Cancer Collaborative database, we identified 505 patients between 2000 and 2012 with gastric cancer who received perioperative therapy in addition to curative-intent resection. The impact of perioperative therapy on survival was analyzed by the use of propensity-score matching of clinicopathologic factors among patients who received CTx alone versus cXRT. Results: Median patient age was 62 years and the majority of patients were male (58%). Surgical resection involved either partial gastrectomy (54%) or total gastrectomy (46%). On pathology, median tumor size was 5.0 cm; most patients had a T3 (37%) or T4 (36%) lesion and lymph node metastasis (74%). Margin status was R0 in most patients (89%). 211 (42%) patients received perioperative CTx alone whereas the remaining 294 (58%) patients received 5-FU based cXRT. Factors associated with receipt of cXRT were younger age (OR 0.98), T3 tumors (OR 1.52), and lymph node metastasis (OR 2.03) (all P < .05). Recurrence occurred in 214 (39%) patients. At a median follow-up of 28 months, median overall survival (OS) was 33.4 months and 5-year survival was 36.7%. Factors associated with worse OS included tumor size (HR 1.1), T-stage (HR 1.5), and lymph node metastasis (HR 1.58) (all P<0.05). In contrast, receipt of cXRT was associated with improved long-term OS (CTx alone: 21 months vs. cXRT 45 months; p<0.001). In the propensity-matched multivariate model that adjusted for tumor size, T-stage, and nodal status, cXRT remained associated with an improved long-term disease-free (HR 0.43) and overall (HR 0.41) survival (both P<0.001). Conclusions: XRT was utilized in 58% of patients undergoing curative-intent resection for gastric cancer. Using propensity-matched analysis, cXRT was an independent factor associated with improved recurrence-free and overall survival.

Factors associated with recurrence in lymph node-negative gastric adenocarcinoma: Results from the U.S. Gastric Cancer Collaborative

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Background: Lymph node (LN) status is a predictor of recurrence after gastrectomy for gastric adenocarcinoma. Clinicopathologic predictors of recurrence in patients with node-negative disease are less well established. Methods: Patients who underwent surgery with curative intent for gastric adenocarcinoma from between 2000-2012 from participating institutions of the U.S. Gastric Cancer Collaborative were analyzed. Patients who died within 30 days of surgery were excluded. Univariate (UV) and multivariate (MV) analysis of clinicopathologic factors was associated with recurrence was performed. Results: Nine-hundred sixty-five patients from seven institutions were included in the analysis. Three-hundred forty-five (36%) had LN- disease, of whom 63 (18%) had disease recurrence after a median follow-up of 24 months. The most common patterns of recurrence were: peritoneal alone (44%), liver (22%), or combined liver/peritoneal (9%). This distribution did not differ significantly from LN+ disease. UV analysis identified tumor size, linitis plastica, diffuse histology, poor differentiation, signet ring histology, T stage ≥3, perineural invasion, and lymphvascular invasion as risk factors for recurrence (Table). On MV analysis, T stage≥3 (OR 3.6, 95% CI=1.7-7.5) and poorly differentiated histology (OR 2.4, 95% CI=1.2-4.9) were independent predictors of recurrence. Conclusions: Despite the presence of negative lymph nodes, patients with T stage ≥3 and poorly differentiated histology are at high risk of recurrence after gastrectomy for adenocarcinoma of the stomach. These factors, along with other patient and treatment-related variables, may be used to select patients who may benefit from more aggressive adjuvant therapy and to guide subsequent monitoring for disease recurrence. [Table: see text]