Intraoperatively assessed macroscopic serosal changes in patients with curatively resected advanced gastric cancer: clinical implications for prognosis and peritoneal recurrence

Adjuvant treatment for locally advanced gastric cancer: an Asian perspective

Standard adjuvant treatment for locally advanced gastric cancer (LAGC) is regionally different. Whereas perioperative chemotherapy is the standard in Western populations, D2 gastrectomy followed by adjuvant chemotherapy has been the standard in East Asia. Recently, the pivotal phase 3 PRODIGY and RESOLVE studies have demonstrated survival benefits of adding neoadjuvant chemotherapy to surgery followed by adjuvant chemotherapy over up-front surgery followed by adjuvant chemotherapy in Asian patients. Based on these results, neoadjuvant chemotherapy is considered one of the viable options for patients with LAGC. In this review, various aspects of neoadjuvant chemotherapy will be discussed for its optimal application in Asia. Candidates for neoadjuvant chemotherapy should be carefully chosen in consideration of the inaccurate aspects of radiological clinical staging and its potential benefit over up-front surgery followed by a decision on adjuvant chemotherapy according to the pathological stage. Efforts should continuously be made to optimally apply neoadjuvant chemotherapy to patients with LAGC, considering various factors, including a more accurate radiological assessment of the tumor burden and the optimization of post-operative chemotherapy. Future neoadjuvant trials involving novel agents for Asian patients should be designed based on proven Asian regimens rather than adopting Western regimens.

Impact of Subclassification of Serosal Invasion on the Survival of Patients With T4a Gastric Cancer

BACKGROUND/AIM

In the Japanese Classification of Gastric Carcinoma, T4a gastric cancer is defined as tumor invasion contiguous to the serosa or penetrating the serosa with exposure to the peritoneal cavity. The aim of this study was to assess the impact of T4a subclassification of gastric cancer on survival.

PATIENTS AND METHODS

A total of 326 patients with T4a cancer who had undergone gastrectomy were enrolled. The T4a tumors were classified into two groups: serosa-contiguous or serosa-exposed.

RESULTS

The serosa-exposed group had a significantly worse prognosis, and multivariate analysis identified the T4a subclass as an independent prognostic factor. Analysis of the risk factors for recurrence identified the T4a subclass as a significant risk factor for peritoneal recurrence in patients undergoing curative gastrectomy.

CONCLUSION

The serosa-contiguous and serosa-exposed subgroups of T4a gastric cancer showed different biological behaviors. These groups may need to be treated as separate.

Diagnosis of Serosal Invasion in Gastric Adenocarcinoma by Dual-Energy CT Radiomics: Focusing on Localized Gastric Wall and Peritumoral Radiomics Features

Objectives

To build a radiomics model and combined model based on dual-energy CT (DECT) for diagnosing serosal invasion in gastric adenocarcinoma.

Materials and methods

231 gastric adenocarcinoma patients were enrolled and randomly divided into a training (n = 132), testing (n = 58), and independent validation (n = 41) cohort. Radiomics features were extracted from the rectangular ROI of the 120-kV equivalent mixed images and iodine map (IM) images in the venous phase of DECT, which was manually delineated perpendicularly to the gastric wall in the deepest location of tumor infiltration, including the peritumoral adipose tissue within 5 mm outside the serosa. The random forest algorithm was used for radiomics model construction. Traditional features were collected by two radiologists. Univariate and multivariate logistic regression was used to construct the clinical model and combined model. The diagnostic efficacy of the models was evaluated using ROC curve analysis and compared using the Delong's test. The calibration curves were used to evaluate the calibration performance of the combined model.

Results

Both the radiomics model and combined model showed high efficacy in diagnosing serosal invasion in the training, testing and independent validation cohort, with AUC of 0.90, 0.90, and 0.85 for radiomics model; 0.93, 0.93, and 0.89 for combined model. The combined model outperformed the clinical model (AUC: 0.76, 0.76 and 0.81).

Conclusion

The radiomics model and combined model constructed based on tumoral and peritumoral radiomics features derived from DECT showed high diagnostic efficacy for serosal invasion in gastric adenocarcinoma.

Risk Assessment and Preventive Treatment for Peritoneal Recurrence Following Radical Resection for Gastric Cancer

As the most common recurrence pattern after radical gastric cancer resection, peritoneal recurrence is a major cause of mortality, which affects the prognosis of patients to a very large extent. Peritoneal status and risk of peritoneal recurrence can be evaluated by peritoneal lavage cytology, photodynamic diagnosis, imaging examination, and pathologic analysis. Presently, there is no standard approach for preventing peritoneal recurrence after radical surgery; furthermore, controversies exist regarding the effects of some preventive methods. Among the preventive methods, there are high expectations about the potential of preoperative therapy, surgical skill improvement, hyperthermic intraperitoneal chemotherapy, and postoperative treatment to reduce the incidence of peritoneal recurrence after radical gastrectomy. This study aimed to analyze the results of previous studies on the risk assessment and preventive methods of peritoneal recurrence after radical gastrectomy in recent years. We hope to provide references for better approach to clinical diagnosis and treatment strategies for peritoneal recurrence after radical gastrectomy.

Predicting postoperative peritoneal metastasis in gastric cancer with serosal invasion using a collagen nomogram

Accurate prediction of peritoneal metastasis for gastric cancer (GC) with serosal invasion is crucial in clinic. The presence of collagen in the tumour microenvironment affects the metastasis of cancer cells. Herein, we propose a collagen signature, which is composed of multiple collagen features in the tumour microenvironment of the serosa derived from multiphoton imaging, to describe the extent of collagen alterations. We find that a high collagen signature is significantly associated with a high risk of peritoneal metastasis (P < 0.001). A competing-risk nomogram including the collagen signature, tumour size, tumour differentiation status and lymph node metastasis is constructed. The nomogram demonstrates satisfactory discrimination and calibration. Thus, the collagen signature in the tumour microenvironment of the gastric serosa is associated with peritoneal metastasis in GC with serosal invasion, and the nomogram can be conveniently used to individually predict the risk of peritoneal metastasis in GC with serosal invasion after radical surgery.

Radiologic serosal invasion sign as a new criterion of T4a gastric cancer on computed tomography: diagnostic performance and prognostic significance in patients with advanced gastric cancer

PURPOSE

To investigate the diagnostic performance and prognostic significance of a new criterion for radiologic T4a staging on computed tomography (CT) in patients with advanced gastric cancer (AGC).

METHODS

Between January 2010 and April 2019, 101 patients with pathologically confirmed gastric cancer were collected. Among them, 53 patients with pathologic T3 and T4a cancers were included in this study. Three reviewers assessed preoperative CT scans for radiologic T staging in two sessions, independently and in consensus at a 2-week interval, while blinded about the pathologic T stage. The radiologic serosal invasion sign was defined as a nodular extension from the outer gastric wall reaching beyond the perigastric vascular plane and adopted as a new CT criterion for T4a cancer. We evaluated the diagnostic performance, interobserver agreement, and prognostic significance of this sign for the postoperative recurrence.

RESULTS

There were 46 pathologic T3 cancers (86.7%) and seven pathologic T4a cancers (13.2%). The diagnostic performance of the radiologic serosal invasion sign in the differentiation between T3 and T4a cancers was as follows: sensitivity, 91.3%; specificity, 71.43%; and accuracy, 88.68% for R1 and sensitivity, 78.26%; specificity, 85.71%; and accuracy, 79.25% for R2. The k-value was 0.64. Among the clinical and pathologic variables, radiologic T4a sign [hazard ratio (HR): 7.96; 95% confidence interval (CI) 2.36-26.86, p = 0.001], pathologic T4a (HR 9.82, 95% CI 2.35-40.95, p = 0.002), tumor size (HR 1.18, 95% CI 1.02-1.35, p = 0.026), and lymphovascular invasion (HR 6.39, 95% CI 1.42-28.75, p = 0.015) were the significant factors for postoperative recurrence.

CONCLUSIONS

Radiologic serosal invasion sign is reliable as a new CT criterion for T4a cancer staging in patients with advanced gastric cancer, demonstrating 80% to 88% accuracy. Radiologic serosal invasion sign can also serve as a prognostic factor for postoperative recurrence as well as pathologic T4a stage.

Total saponins from Lilium lancifolium: a promising alternative to inhibit the growth of gastric carcinoma cells

Bulbus Lilii, as a medicinal and edible plant, has anti-inflammatory, anti-oxidative and immunopotentiating pharmacological activities, which seems to be therapeutic on cancer prevention. The purpose of this study was to investigate the effects of total saponins from Lilium lancifolium (TSLL) on proliferation, apoptosis and migration of human gastric carcinoma cells lines SGC-7901 and HGC-27 and its underlying mechanism. The results showed that TSLL inhibited the proliferation of gastric carcinoma cells by suppressing the level of proliferating cell nuclear antigen (PCNA) and increased p21 level. TSLL induced cells apoptosis by up-regulating expression of pro-apoptotic protein Bax and down-regulating anti-apoptotic protein Bcl-2 expression. Meanwhile, TSLL remarkably inhibited cell migration and invasion, decreased matrix metalloproteinase-2 (MMP-2) expression and increased tissue inhibitor of metalloproteinases-1 (TIMP-1) expression. Notably, TSLL had stronger anti-cancer effect on undifferentiated HGC-27 cells than differentiated SGC-7901 cells. Accordingly, TSLL might be a promising candidate to prevent and suppress the growth of gastric carcinoma cells.

The prognostic significance of macroscopic serosal change in subserosal invasion (stage T3) gastric cancer

BACKGROUND

For patients with gastric cancer intraoperative macroscopic serosal change is not always consistent with pathological T stage. We investigated whether macroscopic serosal change is associated with unfavourable prognosis of patients with gastric cancer.

METHODS

We reviewed 856 patients with stage T3 gastric cancer who underwent curative gastrectomy in our institution. All patients were classified as serosa negative and serosa positive according to the macroscopic serosal change during the operation. The prognostic difference between two groups was compared and clinicopathologic features were analysed.

RESULTS

The percentage of macroscopic serosal change accounted for 55.7% of all patients. Compared with normal serosal surface, the patients with macroscopic serosal change had larger tumour size, more extensive stomach involvement and more advanced stage N. The prognosis of stage T3 with macroscopic serosal change was significantly poorer than that of those with normal serosal surface, especially for those with stages T3N0 and T3N1. Multivariate analysis identified macroscopic serosal change as an independent factor associated with unfavourable prognosis of stage T3 cancer.

CONCLUSION

Although the depth of tumour invasion mainly depends on pathological evaluation after surgery, the prognostic significance of intraoperative macroscopic serosal change should not be ignored for those patients with subserosal invasion.

Clinical Implication of the Width of Subserosal Invasion in T3N0 Gastric Cancer

BACKGROUND

The aim of this study was to clarify the impact of the horizontal width of tumor invasion into the subserosal layer on prognosis in patients with T3N0 gastric cancer.

PATIENTS AND METHODS

A total of 72 patients with T3N0 cancer were enrolled. Relapse-free survival of the subgroups classified according to width of subserosal invasion was compared to that of 34 patients with T4aN0 cancer.

RESULTS

The group with wide invasion (≥1.5 cm) had a significantly poorer prognosis than those with narrow invasion (<1.5 cm) (p=0.014). Multivariate analysis revealed the width of subserosal invasion to be an independent prognostic factor. There was no significant difference between the T3N0 group with wide invasion and the T4aN0 group in the prognosis and recurrent status.

CONCLUSION

The malignant potential of T3N0 gastric cancer with wide subserosal invasion was found to be similar to that of T4aN0 cancer.

Regional but fatal: Intraperitoneal metastasis in gastric cancer

Peritoneal carcinomatosis appears to be the most common pattern of metastasis or recurrence and is associated with poor prognosis in gastric cancer patients. Many efforts have been made to improve the survival in patients with peritoneal metastasis. Hyperthermic intraperitoneal chemotherapy remains a widely accepted strategy in the treatment of peritoneal dissemination. Several phase II-III studies confirmed that the combined cytoreducitve surgery and hyperthermic intraperitoneal chemotherapy resulted in longer survival in patients with peritoneal carcinomatosis. In addition, proper selection and effective regional treatment in patients with high risk of peritoneal recurrence after resection will further improve prognosis in local advanced gastric cancer patients.