A new scoring system to evaluate adjuvant chemotherapy for patients with T2N0M0 gastric cancer after D2 gastrectomy.

BACKGROUND: At present, there is insufficient medical evidence to determine whether adjuvant chemotherapy is necessary for T2N0M0 gastric cancer. AIM: To obtain a risk score to assess the need for adjuvant chemotherapy in patients with T2N0M0 gastric cancer. METHODS: We identified 325 patients with pathological T2N0M0 stage primary gastric cancer at the National Cancer Center between 2011 and 2018. Univariate and multivariate Cox regression analyses were performed to predict factors affecting prognosis. Vascular invasion, tumor site, and body mass index were assessed, and a scoring system was established. We compared the survival outcomes and benefits of adjuvant chemotherapy between the different subgroups. RESULTS: Five-year survival rates of the score 0, 1, 2, and 3 groups were 92%, 95%, 80%, and 50%, respectively (P < 0.001). In the score 2-3 group, five-year survival rates for patients in the adjuvant chemotherapy group and postoperative observation group were 95% and 61%, respectively (P = 0.021). CONCLUSION: For patients with T2N0M0 stage gastric cancer and two or more risk factors, adjuvant chemotherapy after D2 gastrectomy may have a survival benefit.

Low body mass index is an independent predictor of poor long-term prognosis among patients with resectable gastric cancer.

BACKGROUND: The association between body mass index (BMI) and clinical outcomes remains unclear among patients with resectable gastric cancer. AIM: To investigate the relationship between BMI and long-term survival of gastric cancer patients. METHODS: This retrospective study included 2526 patients who underwent radical gastrectomy for gastric cancer between September 2013 and June 2018. The patients were divided into four groups: Group A (low BMI, < 18.5 kg/m2), group B (normal BMI, 18.5-24.9 kg/m2), group C (overweight, 25-29.9 kg/m2), and group D (obese, ≥ 30 kg/m2). Clinicopathological findings and survival outcomes were recorded and analyzed. RESULTS: Preoperative weight loss was more common in the low-BMI group, while diabetes was more common in the obese group. Upper-third gastric cancer accounted for a large proportion of cases in the higher BMI groups. Major perioperative complications tended to increase with BMI. The 5-year overall survival rates were 66.4% for group A, 75.0% for group B, 77.1% for group C, and 78.6% for group D. The 5-year overall survival rate was significantly lower in group A than in group C (P = 0.008) or group D (P = 0.031). Relative to a normal BMI value, a BMI of < 18.5 kg/m2 was associated with poor survival (hazard ratio: 1.558, 95% confidence interval: 1.125-2.158, P = 0.008). CONCLUSION: Low BMI, but not high BMI, independently predicted poor survival in patients with resectable gastric cancer.

Treatment strategies for gastric cancer during the COVID-19 pandemic.

The coronavirus disease 2019 pandemic has become a major global public health problem. Governments are taking the necessary steps to reduce the movement of people to contain the spread of the virus. However, these measures have caused considerable distress to patients with gastric cancer who are newly diagnosed or are undergoing treatment. In addition to the cancer, they must deal with longer waiting times for surgery and poor communication with doctors. Furthermore, gastric cancer patients generally have low immunity and a poor nutritional status, so they are a high-risk group for infection with the novel coronavirus. Therefore, it is necessary to formulate reasonable outpatient management strategies to reduce the adverse effects of the pandemic on their treatment. We summarize the management strategies for patients with gastric cancer during the pandemic.

Feasibility and nutritional impact of laparoscopic assisted tailored subtotal gastrectomy for middle-third gastric cancer.

BACKGROUND: Laparoscopic assisted total gastrectomy (LaTG) is associated with reduced nutritional status, and the procedure is not easily carried out without extensive expertise. A small remnant stomach after near-total gastrectomy confers no significant nutritional benefits over total gastrectomy. In this study, we developed a modified laparoscopic subtotal gastrectomy procedure, termed laparoscopic-assisted tailored subtotal gastrectomy (LaTSG). AIM: To evaluate the feasibility and nutritional impact of LaTSG compared to those of LaTG in patients with advanced middle-third gastric cancer (GC). METHODS: We retrospectively analyzed surgical and oncological outcomes and postoperative nutritional status in 92 consecutive patients with middle-third GC who underwent radical laparoscopic gastrectomy at Department of Pancreatic Stomach Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College between 2013 and 2017. Of these 92 patients, 47 underwent LaTSG (LaTSG group), and the remaining underwent LaTG (LaTG group). RESULTS: Operation time (210 ± 49.8 min vs 208 ± 50.0 min, P > 0.05) and intraoperative blood loss (152.3 ± 166.1 mL vs 188.9 ± 167.8 mL, P > 0.05) were similar between the groups. The incidence of postoperative morbidities was lower in the LaTSG group than in the LaTG group (4.2% vs 17.8%, P < 0.05). Postoperatively, nutritional indices did not significantly differ, until postoperative 12 mo. Albumin, prealbumin, total protein, hemoglobin levels, and red blood cell counts were significantly higher in the LaTSG group than in the LaTG group (P < 0.05). No significant differences in Fe or C-reaction protein levels were found between the two groups. Endoscopic examination demonstrated that reflux oesophagitis was more common in the LaTG group (0% vs 11.1%, P < 0.05). Kaplan-Meier analysis showed a significant improvement in the overall survival (OS) and disease free survival (DFS) in the LaTSG group. Multivariate analysis showed that LaTSG was an independent prognostic factor for OS (P = 0.048) but not for DFS (P = 0.054). Subgroup analysis showed that compared to LaTG, LaTSG improved the survival of patients with stage III cancers, but not for other stages. CONCLUSION: For advanced GC involving the middle third stomach, LaTSG can be a good option with reduced morbidity and favorable nutritional status and oncological outcomes.

Surgical resection of gastric stump cancer following proximal gastrectomy for adenocarcinoma of the esophagogastric junction.

BACKGROUND: Proximal gastrectomy (PG) is performed widely as a function-preserving operation for early gastric cancer located in the upper third of the stomach and is an important function-preserving approach for esophagogastric junction (EGJ) adenocarcinoma. The incidence of gastric stump cancer (GSC) after PG is increasing. However, little is known about the GSC following PG because very few studies have been conducted on the disease. AIM: To clarify clinicopathologic features, perioperative complications, and long-term survival rates after the resection of GSC following PG. METHODS: Data for patients with GSC following PG for adenocarcinoma of the EGJ diagnosed between January 1998 and December 2016 were retrospectively reviewed. Multivariate analysis was performed to identify factors associated with overall survival (OS). GSC was defined in accordance with the Japanese Gastric Cancer Association. RESULTS: A total of 35 patients were identified. The median interval between the initial PG and resection of GSC was 4.9 (range 0.7-12) years. In 21 of the 35 patients, the tumor was located in a nonanastomotic site of the gastric stump. Total gastrectomy was performed in 27 patients; the other 8 underwent partial gastrectomy. Postoperative complications occurred in 6 patients (17.1%). The tumor stage according to the depth of tumor invasion was T1 in 6 patients, T2 in 3 patients, T3 in 9 patients, and T4 in 17 patients. Lymph node metastasis was observed in 18 patients. Calculated 1-, 3-, and 5-year OS rates were 86.5%, 62.3%, and 54.2%, respectively. Multivariate analysis showed advanced T stage to be associated with OS. CONCLUSION: This study reveals the characteristics of GSC following PG for adenocarcinoma of the EGJ and suggests that a surgical approach can lead to a satisfactory outcome.

Liposarcoma of the stomach: Report of two cases and review of the literature.

Liposarcoma of the stomach is extremely rare, and only 37 cases have been reported worldwide. We herein report two cases of liposarcoma of the stomach. The first patient was referred to our hospital with upper abdominal discomfort. The endoscopic examination revealed a tumor mass about 3 cm in diameter. The patient underwent a partial gastrectomy and had an uneventful recovery. The histopathological examination revealed a well-differentiated liposarcoma. The second patient had symptoms of upper abdominal discomfort combined with nausea and anorexia. Several palpable masses were found with endoscopy. Endoscopic submucosal dissection was the treatment used, and the postoperative course was uneventful. The histopathological diagnosis was a well-differentiated liposarcoma. The two patients did not undergo any adjuvant therapy. They are both currently in good condition without recurrence. Therefore, we believe that the outcome of liposarcoma of the stomach is positive, and surgical resection may be the first choice for treatment at present.

Density functional theory study of mixed-phase TiO2: heterostructures and electronic properties.

In this work, density functional theory calculations have been performed to study the geometric, electronic, and energetic properties of two-phase TiO2 composites built by joining two single-phase TiO2 slabs, aiming at verifying possible improvement of the photo-activities of the composites through phase separation of excitons. We find that such desired electronic properties can be determined by several factors. When both the HOMO and LUMO levels of one of the two single-phase TiO2 slabs are higher than the corresponding ones of the other, the composite may have native electronic structures with phase-separated HOMO-LUMO states, especially when the two slabs exhibit highly matched surface lattices. For those pairs of TiO2 slabs with the HOMO and LUMO levels of one phase being within the range of those of the other, though the energetically favored composite give HOMO-LUMO states within one phase, one may still be able to separate them and move the HOMO state to the interface region by destabilizing the interactions between the two slabs.

¹³C NMR guides rational design of nanocatalysts via chemisorption evaluation in liquid phase.

The search for more efficient heterogeneous catalysts remains critical to the chemical industry. The Sabatier principle of maximizing catalytic activity by optimizing the adsorption energy of the substrate molecule could offer pivotal guidance to otherwise random screenings. Here we show that the chemical shift value of an adsorbate (formic acid) on metal colloid catalysts measured by (13)C nuclear magnetic resonance (NMR) spectroscopy in aqueous suspension constitutes a simple experimental descriptor for adsorption strength. Avoiding direct contact between the (13)C atom and the metal surface eliminates peak broadening that has confounded prior efforts to establish such correlations. The data can guide rational design of improved catalysts, as demonstrated here for the cases of formic acid decomposition and formic acid electro-oxidation reactions.

New directions for atomic steps: step alignment by grazing incident ion beams on TiO2(110).

Grazing incidence low energy ion beams preferentially erode steps with directional components normal to the azimuthal direction of the beam, thus generating step edges aligned along the beam direction. With this kinetic method, the fabrication of thermodynamically metastable low index step-edge orientations is demonstrated on TiO2(110). The 11[over ]0 step edge is prepared, enabling its atomic structure determination by scanning tunneling microscopy and density-functional theory. A reconstructed atom configuration is revealed, which is reminiscent of the structure of the rutile-TiO2(001)-(2 x 1) face.