Multivisceral resection compared to standard gastrectomy for gastric adenocarcinoma: A propensity score-matching analysis.

BACKGROUND: Multivisceral resection (MVR) in locally advanced gastric cancer (GC) is a morbid procedure. However, the precise impact of removing additional organs remains controversial. This study aimed to compare the outcomes of MVR versus standard gastrectomy (SG) in an unbiased cohort. METHODS: Patients who underwent curative-intent surgery for gastric adenocarcinoma were considered. Those submitted to SG were compared to the ones who received MVR using Propensity Score Matching (PSM) analysis. RESULTS: A total of 685 GC patients were included (621 SG and 64 MVR). Groups were distinct concerning the extent of the gastrectomy, tumor size, pTNM, R0, postoperative complications, and 90-day mortality. After PSM, 57 patients were matched in each group. All variables assigned in the score were well matched. Postoperative complication, 90-day mortality, and overall survival (OS) became similar among groups. Age >65 years old and resection of two or more organs, besides the stomach, were factors associated with 90-day mortality. R1 and not received multimodal therapy were independent prognostic factors for worse OS. CONCLUSIONS: After PSM, the difference in morbidity, mortality, and survival of MVR compared to SG was no longer statistically significant, suggesting that MVR is an acceptable therapeutic strategy to patients with advanced GC.

Prognostic implications of tumor-infiltrating lymphocytes in association with programmed cell death ligand 1 expression in remnant gastric cancer.

Objective: Remnant gastric cancer (RGC) is usually associated with a worse prognosis. As they are less common and very heterogeneous tumors, new prognostic and reliable determinants are required to predict patients' clinical course for RGC. This study aimed to investigate the tumor-infiltrating lymphocytes (TILs) and programmed cell death ligand 1 (PD-L1) status as prognostic biomarkers in a cohort of patients with RGC to develop an immune-related score. Methods: Patients with gastric cancer (GC) who underwent curative intent gastrectomy were retrospectively investigated. RGC resections with histological diagnosis of gastric adenocarcinoma were enrolled in the study. The risk score based on immune parameters was developed using binary logistic regression analysis. RGCs were divided into high-risk (HR), intermediate-risk (IR), and low-risk (LR) groups based on their immune score. The markers (CD3+, CD4+/CD8+ T cells and PD-L1) were selected for their potential prognostic, therapeutic value, and evaluated by immunohistochemistry (IHC). Results: A total of 42 patients with RGC were enrolled in the study. The score based on immune parameters exhibited an accuracy of 79% [the area under the receiver operating characteristic curve (AUC)=0.79, 95% confidence interval (95% CI), 0.63-0.94, P=0.002], and the population was divided into 3 prognostic groups: 10 (23.8%) patients were classified as LR, 15 (35.7%) as IR, and 17 (40.5%) as HR groups. There were no differences in clinicopathological and surgical characteristics between the three groups. In survival analysis, HR and IR groups had worse disease-free survival and overall survival rates compared to the LR group. In the multivariate analysis, lymph node metastasis and the immune score risk groups were independent factors related to worse survival. Conclusions: A scoring system with immune-related markers was able to distinguish prognostic groups of RGC associated with survival. Accordingly, tumor-infiltrating immune lymphocytes and PD-L1 status may serve as a potential prognostic biomarker for patients with RGC.

Epstein-Barr Virus Positive Gastric Cancer: A Distinct Subtype Candidate for Immunotherapy.

BACKGROUND: Epstein-Barr virus (EBV) positive gastric cancer (GC) has been described as a distinct molecular subtype of the disease, especially associated with gastric carcinoma with lymphoid stroma (GCLS). The possibility that EBV associated GC (EBVaGC) had better prognosis and may be susceptible to immunotherapy has increased the interest in this subtype. However, immune checkpoint and survival of EBVaGC are still controversial, especially with regard to GCLS and conventional gastric adenocarcinoma (CGA). This study aimed to evaluate the clinicopathological characteristics, immunohistochemical profiles and prognosis of EBVaGC according to the histological type GCLS and CGA. METHODS: we retrospectively evaluated a series of EBVaGC who underwent gastrectomy with D2-lymphadenectomy. Biomarkers and tumor-infiltrating cells were evaluated by immunohistochemistry. PD-L1 was evaluated using a combined positive score (CPS). RESULTS: From a total of 30 EBVaGC, 14 (46.7%) were identified as GCLS and 16 (53.3%) as CGA (9 Intestinal, 6 diffuse, 1 undetermined). There were no significant differences in age, sex, and pTNM between GCLS and CGA. CPS-positivity and high-CD8+ was significantly higher in GCLS compared with CGA (P = 0.007 and P = 0.005, respectively). Diffuse EBVaGC had worse survival than intestinal type (P = 0.020). There was no difference in survival between GCLS and intestinal CGA (P = 0.260). In multivariate analysis, CPS and pN status were related with survival in EBVaGC. CONCLUSIONS: CGLS was associated with a predominance of CD8+ cell infiltration and PD-L1 expression. CPS and lymph node metastasis were independent factors associated with prognosis in EBVaGC. These results suggest that specifically EBV-positive GCLS may be prime candidates for PD-1 directed therapy.

Cytotoxic T-lymphocyte-associated protein 4 in gastric cancer: Prognosis and association with PD-L1 expression.

BACKGROUND: Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is one of the most studied immune checkpoint in gastric cancer (GC). However, the prognostic role of CTLA-4 expression in GC is poorly described. This study aimed to evaluate CTLA-4 expression in GC and its impact on survival, including patients treated with standard platinum-based chemotherapy (CMT), and association with PD-L1 expression. METHODS: All GC patients who underwent D2-gastrectomy were investigated retrospectively. Tumor samples were examined for CTLA-4 and PD-L1 by immunohistochemistry. Tumor-infiltrating inflammatory cells, including CD4 + and CD8 + , were also examined. RESULTS: Among the 284 GC patients included, 159 (56%) were CTLA-4 positive and the remaining 125 (44%) were classified as negative. CTLA-4 positive GC was associated with increased inflammatory cell infiltration (p < 0.001), high CD8 + T cells (p = 0.016) and PD-L1 expression (p = 0.026). Considering GC referred for treatment, CTLA-4 negative patients who received CMT had a significant improvement in disease-free survival compared to untreated CLTA-4 negative (p = 0.028). In multivariate analysis, GC positive for both CTLA-4 and PD-L1 had a prognostic impact on survival. CONCLUSION: CTLA-4 positive was associated with PD-L1 expression and a high tumor-infiltrating CD8 + T cells. Accordingly, positivity for both CTLA-4 and PD-L1 was an independent factor associated to better survival in GC patients.

Impact of neoadjuvant chemotherapy on surgical and pathological results of gastric cancer patients: A case-control study.

BACKGROUND AND OBJECTIVE: Neoadjuvant chemotherapy (NACT) followed by radical surgery represents a treatment option for patients with advanced gastric cancer (GC). This case-control study aimed to evaluate the clinicopathological characteristics and surgical outcomes of GC patients who received NACT, and its impact on survival. METHODS: We retrospectively reviewed all patients with GC who underwent gastrectomy. A total of 45 cases with NACT were matched with consecutive 45 patients who underwent upfront gastrectomy for the following characteristics: gender, age, gastrectomy type, lymphadenectomy extent, American Society of Anesthesiologists class, histological type, cT and cN. RESULTS: NACT group had smaller tumors (4.9 vs 6.8 cm P = .006), lower lymphatic invasion rate (40% vs 73.3%, P = .001), lower venous invasion rate (18% vs 46.7%, P = .003) and lower perineural invasion rate (35% vs 77.8%, P < .0001). The ypTNM stage was lower in patients treated with NACT (P < .001). The major postoperative complication (POC) rate was lower in NACT patients (6.7% vs 24.4%, P = .02), as was hospital length of stay (10.8 vs 17 days, P = .005). CONCLUSIONS: NACT allowed nodal and tumor downstaging. In addition, patients who underwent NACT had fewer POC and shorter length of hospital stay.

Lymph node regression after neoadjuvant chemotherapy: A predictor of survival in gastric cancer.

BACKGROUND AND OBJECTIVE: Neoadjuvant chemotherapy (nCMT) has been increasingly used in advanced gastric cancer (GC). However, the prognostic impact of tumor response remains unclear. This study aimed to evaluate if tumor response at the primary site and lymph nodes (LN) correlate with survival in GC patients after nCMT. METHODS: Patients with gastric adenocarcinoma treated with nCMT followed by gastrectomy were evaluated. Residual tumor was graded from 0% to 100%, defining two groups: poor (PR) and major response (MR). LN regression rate (LNRR) was determined based on tumor/fibrosis examination at each LN and a cutoff value established by receiver operating characteristic curve. RESULTS: Among 62 cases, 20 (32.2%) had MR and 42 (67.7%) PR. Smaller size, diffuse histology, lower ypT status and less advanced stage were associated with the MR group. Based on cutoff value of 57, 45.6% and 54.4% patients were classified as low-LNRR and high-LNRR. High-LNRR correlated with absence of venous, lymphatic and perineural invasion, and less advanced stage. Survival was equivalent between MR and PR (P = .956). High-LNRR had better disease-free survival (DFS) than low-LNRR (P < .001). In multivariate analysis, only LNRR associated with DFS. CONCLUSION: High-LNRR associates with DFS in GC treated with nCMT. Response at the primary site does not correlate with survival.

Lymph Node Yield After Neoadjuvant Chemoradiotherapy in Rectal Cancer Specimens: A Randomized Trial Comparing Two Fixatives.

BACKGROUND: It is widely reported that neoadjuvant chemoradiation reduces lymph node yield in rectal cancer specimens. Some have questioned the adequacy of finding ≥12 lymph nodes for accurate staging, and fewer nodes were correlated with good response. Others reported that low lymph node count raises the chance for understaging and correlates with worse survival. In addition, a few studies demonstrated that diligent specimen analysis increases lymph node count. OBJECTIVE: The aim of this study was to compare Carnoy's solution and formalin concerning lymph node yield in specimens of patients with rectal cancer after neoadjuvant chemoradiation. DESIGN: This is a prospective randomized trial that was conducted from 2012 to 2015. SETTINGS: This study was performed in a reference cancer center in Brazil. PATIENTS: Patients who underwent low anterior resection with total mesorectal excision after neoadjuvant chemoradiation for rectal adenocarcinoma were included. INTERVENTION: Rectosigmoid specimens were randomized for fixation with Carnoy's solution or formalin. MAIN OUTCOME MEASURES: A total of 130 specimens were randomized. After dissection, the residual fat from the formalin group was immersed in Carnoy's solution in search for missed lymph nodes (Revision). RESULTS: The Carnoy's solution group had superior lymph node count (24.0 vs 16.3, p < 0.01) and fewer cases with <12 lymph nodes (6 vs 22, p = 0.001). The Revision group found lymph nodes in all cases (mean, 11.1), retrieving metastatic lymph nodes in 6 patients. It reduced the formalin cases with <12 lymph nodes from 33.8% to 4.6% and upstaged 2 patients. Tumor response to neoadjuvant chemoradiotherapy was not associated with lymph node count. LIMITATIONS: This was a unicentric study. CONCLUSIONS: Compared with formalin, the Carnoy's solution increases lymph node count and reduces the cases with <12 lymph nodes. Harvested lymph nodes are missed following routine analysis and this is clinically relevant. Finding <12 lymph nodes is not a sign of good response to neoadjuvant chemoradiation (www.clinicaltrials.gov. Unique identifier: NCT02629315). See Video Abstract at http://links.lww.com/DCR/A694.

Immunohistochemical expression of thymidylate synthase and prognosis in gastric cancer patients submitted to fluoropyrimidine-based chemotherapy.

OBJECTIVE: Adjuvant chemotherapy with 5-fluorouracil (5-FU) has been widely used in gastric cancer (GC) patients to prevent relapse after curative resection. 5-FU acts by inhibiting thymidylate synthase (TS), and high levels of TS correlate with resistance to treatment with fluoropyrimidines. The aim of this study was to evaluate the expression of TS in GC patients, and its relation with clinicopathological characteristics and prognosis in adjuvant chemotherapy with 5-FU. METHODS: We retrospectively evaluated 285 patients who underwent D2-gastrectomy with curative intent. TS expression was determined by immunohistochemistry (IHC) in tumor cells by tissue microarray (TMA). TS level was evaluated according to the intensity and percentage of cells marked by a score system. Patients were divided in three groups according to their TS-score: negative, low and high. RESULTS: TS expression was positive in 92.3% of GC. TS-high, TS-low and TS-negative were observed in 46.3%, 46.0% and 7.7% of patients, respectively. High-TS GC were associated with older age (P=0.007), high neutrophil/lymphocyte ratio (P=0.048), well/moderately differentiated histology (P=0.001), intestinal Lauren type (P<0.001) and absence of perineural invasion (P=0.003). Among 285 patients, 133 stage II/III patients (46.7%) received chemotherapy with 5-FU. In survival analysis, TS-high was associated with worse disease-free survival (DFS) in stage III GC patients who received 5-FU-based chemotherapy (P=0.007). Multivariate analysis revealed that total gastrectomy, poorly differentiated tumors and high TS-score were associated with worse DFS in stage III GC patients. CONCLUSIONS: High TS-score in stage III GC was associated with poor DFS in patients treated with fluoropyrimidine-based chemotherapy.

Lymphoepithelioma-like gastric carcinoma: clinicopathological characteristics and infection status.

BACKGROUND: Lymphoepithelioma-like gastric carcinoma (LLGC) is a rare subtype of gastric carcinoma (GC) characterized by prominent lymphocytic infiltration. LLGC may be associated with latent Epstein-Barr virus (EBV) infection or microsatellite instability (MSI). This study aims to assess the clinicopathological characteristics, EBV infection, and MSI status in LLGC. METHODS: A retrospective analysis of GC patients submitted to potentially curative resection between 2009 and 2014 was performed. The LLGC subtype specimens were examined for EBV by in situ hybridization and MSI by immunohistochemical analysis. The LLGC profile was analyzed accordingly to clinicopathological parameters. RESULTS: From 255 patients, seven were identified on the pathological report as LLGC. Six cases were EBV-positive and one had MSI, showing loss of MLH1 and PMS2 expression. LLGC was more frequently seen in men, and the mean age was 69 years. When compared to non-LLGC, LLGC cases were larger (∼5.8 cm) poorly differentiated tumors and had lower incidence of lymph node metastasis (P = 0.045). Mean number of lymph nodes dissected in the LLGC group was 39.5, and only one patient had a single positive lymph node. In addition, two patients presented associated lesions. LLGC was not associated with HER-2, chromogranin and synaptophysin positivity or Helicobacter pylori infection. CONCLUSIONS: Distinct pathological aspects and clinical behavior of LLGC reinforce the need for proper recognition of this histological subtype to choose better therapeutic approaches.

Carnoy's solution increases the number of examined lymph nodes following gastrectomy for adenocarcinoma: a randomized trial.

BACKGROUND: Pathological examination of a minimum of 16 lymph nodes is recommended following surgery for gastric adenocarcinoma, despite this a longer survival is expected when 30 or more lymph nodes are examined. Small lymph nodes are difficult to identify, and fat-clearing solutions have been proposed to improve this, but there is no evidence of their clinical benefit. METHODS: Fifty D2 subtotal gastrectomy specimens were randomized for fixation in Carnoy's solution (CS) or 10% neutral buffered formalin (NBF), with subsequent fat dissection. After dissection, the residual fat from the NBF group, instead of being discarded, was immersed in CS and dissected again. Data from 25 D2 subtotal gastrectomies performed before the study were also analyzed. RESULTS: The mean number of examined lymph nodes was 50.4 and 34.8 for CS and NBF, respectively (p < 0.001). Missing lymph nodes were found in all cases from the residual fat group (mean of 16.9), and in eight of them (32%) metastatic lymph nodes were present; this allowed the upstaging of two patients. Lymph nodes in the CS group were smaller than those in the NBF group (p = 0.01). The number of retrieved lymph nodes was similar among the NBF and Retrospective groups (p = 0.802). CONCLUSIONS: Compared with NBF, CS increases lymph node detection following gastrectomy and allows a more accurate pathological staging. No influence of the research protocol on the number of examined lymph nodes was observed.