Therapeutic value of splenectomy to dissect splenic hilar lymph nodes for type 4 gastric cancer involving the greater curvature, compared with other types

Circular RNA contributes to gastric cancer by targeting Wnt family member 2B as a competing endogenous RNA

BACKGROUND

As a non-coding RNA molecule, circular RNAs (circRNAs) have significant specificity, and existing data suggest a close relationship between them and the prognosis of patients with gastric cancer (GC). However, this mechanism has no evidence yet. This article explores the functions of hsa_circRNA_102415 in the malignant behavior and potential downstream signaling of GC cells. The chosen approach is loss of signal and functional gain.

AIM

To investigate and analyze the relationship between hsa_circRNA_102415 and GC and explore its specific role. Results provide reference for other researchers to develop targeted treatment plans.

METHODS

The gene expression omnibus (GEO) database can be used to obtain the microarray dataset GSE83521. Data were analyzed using the GEO2R tool to identify differences in circRNAs between normal and GC samples. Quantitative real-time polymerase chain reaction was used to detect differentially expressed genes in GC tissue samples and adjacent cancer tissue samples. GC cells were transfected with small interfering-hsa_circRNA_104415 and plasmid DNA (pcDNA)-hsa_ircRNA_102415. Multiple detection methods, such as Transwell and cell counting kit 8, were used to evaluate cellular physiological activities, including cell invasion and proliferation. The relationship between Wnt family members 2B, microRNA (miR)-4529-5p, etc., including argonaute 2-RNA immunoprecipitation and luciferase reporter genes was analyzed. Rescue experiments were conducted to analyze and explore the relationship between the malignant behavior of GC cells and hsa_circRNA_102415.

RESULTS

GEO2R analysis confirmed that hsa_circRNA_102415 had significantly higher expression levels in disease tissues. hsa_circRNA_102415 and miR-4529-5p showed a negative correlation in disease cells, suggesting that hsa_circRNA_102415 upregulated WNT2B expression in GC cells as a competing endogenous RNA for miR-4529-5p. miR-4529-5p mimic or small interfering-WNT2B reversed the effects of pcDNA-hsa_circRNA_102415 or miR-4529-5p inhibitor on cell malignant functions.

CONCLUSION

miR-4529-5p was used to successfully activate the potential of WNT2B, clarify the role of hsa_circRNA_102415 in GC cells, and provide reference for other researchers to develop targeted treatment plans.

Necessity of splenectomy for antral-type scirrhous gastric cancer

BACKGROUND

Total gastrectomy with splenic hilar nodal dissection by splenectomy is frequently selected for resectable scirrhous gastric cancer (GC), irrespective of the whether it is of the antral or body type. However, whether splenectomy is necessary for antral-type scirrhous GC remains unclear.

METHODS

We retrospectively reviewed the data of patients treated at National Cancer Center Hospital in Japan between 2000 and 2018. We selected patients with type IV GC in which the predominant location could be identified, who received D2 or more total gastrectomy with splenectomy, and in whom R0 or R1 resection was achieved. The therapeutic value index was evaluated by multiplying the metastatic rate of each nodal station by the five-year overall survival (OS) rate of patients with metastasis to each node.

RESULTS

In total, 180 patients were included in this study (antral type, n = 19 [10.6 %]; body type, n = 161 [89.4 %]). Both types showed similar and frequent invasion of the greater curvature of the upper stomach. Metastasis to the splenic hilar nodes (#10) was not observed in the antral type (0/19) but was observed in the body type (35/161, 21.7 %); the difference was statistically significant (p = 0.027). The therapeutic value index of #10 was 0 in the antral type but was >7, the fourth highest, in the body type. The only nodes with an index >0 in the antral type were #4d, #3, #4sb, #6, #7, and #1.

CONCLUSIONS

Splenectomy may therefore be unnecessary for antral-type scirrhous GC.

A clinicopathologic feature-based nomogram for preoperative estimation of splenic hilar lymph node metastasis in advanced proximal gastric cancer without invasion of the greater curvature

BACKGROUND

The indications for splenic hilar lymph node dissection in advanced proximal gastric cancer without invasion of the greater curvature are controversial. We aimed to develop a preoperative nomogram for individualized prediction of splenic hilar lymph node metastasis in non-greater curvature advanced proximal gastric cancer.

METHODS

From January 2014 to December 2021, 558 patients with non-greater curvature advanced proximal gastric cancer who underwent D2 lymphadenectomy (including splenic hilar lymph node) were retrospectively analyzed and divided into a training cohort (n = 361) and validation cohort (n = 197), depending on the admission time. A preoperative predictive nomogram of splenic hilar lymph node metastasis was established based on independent predictors identified by multivariate analysis, and the performance and prognostic value were confirmed.

RESULTS

In the training and validation cohorts, 48 (13.3%) and 24 patients (12.2%) had pathologically confirmed splenic hilar lymph node metastasis, respectively. Tumor located in the posterior wall, tumor size ≥5 cm, Borrmann type IV, and splenic hilar lymph node lymphadenectasis on computed tomography were preoperative factors independently associated with splenic hilar lymph node metastasis. The nomogram developed based on these four parameters had a high concordance index of 0.850 (95% confidence interval, 0.793-0.907) and 0.825 (95% confidence interval, 0.743-0.908) in the training and validation cohorts, respectively, with well-fitting calibration plots and better net benefits in the decision curve analysis. In addition, disease-free survival and overall survival were significantly shorter in the high-risk group, with hazard ratios of 3.660 (95% confidence interval, 2.228-6.011; log-rank P < .0001) and 3.769 (95% confidence interval, 2.279-6.231; log-rank P < .0001), respectively.

CONCLUSION

The nomogram has good performance in predicting the risk of splenic hilar lymph node metastasis in non-greater curvature advanced proximal gastric cancer preoperatively, which can help surgeons make rational clinical decisions.

Splenectomy versus splenic preservation in total gastrectomy for gastric cancer: a systematic review and meta-analysis comparing survival benefits and short-term complications

BACKGROUND

There is an ongoing debate regarding the comparative merits of splenectomy (SP) and splenic preservation in the surgical management of gastric cancer. This systematic review and meta-analysis aims to shed light on potential differences in survival outcomes and postoperative complications associated with these two procedures.

METHOD

An exhaustive literature search was conducted across multiple databases, namely PubMed, Embase, Cochrane Library, and Web of Science. We utilized a random-effects model via RevMan 5.4 software to conduct a meta-analysis of the hazard ratios (HRs) and risk ratios (RRs) associated with SP and spleen preservation. Subgroup analyses were based on various attributes of the included studies. We employed funnel plots to assess publication bias, and sensitivity analysis was conducted to gauge the stability of the combined results. Both funnel plots and sensitivity analysis were performed using Stata 12.

RESULT

Our research incorporated 23 observational studies and three randomized controlled trials, involving a total of 6,255 patients. SP did not yield superior survival outcomes in comparison to splenic preservation, a conclusion that aligns with the combined results of the randomized controlled trials. No statistically significant difference in survival prognosis was observed between SP and splenic preservation, irrespective of whether the patients had proximal gastric cancer or proximal gastric cancer invading the stomach's greater curvature. SP exhibited a higher incidence of all postoperative complications, notably pancreatic fistula and intraabdominal abscesses. However, it did not significantly differ from splenic preservation in terms of anastomotic leakage, incision infection, intestinal obstruction, intra-abdominal bleeding, and pulmonary infection. No significant difference in postoperative mortality between SP and splenic preservation was found. Funnel plots suggested no notable publication bias, and sensitivity analysis affirmed the stability of the combined outcomes.

CONCLUSION

Despite the lack of significant differences in certain individual complications and postoperative mortality, the broader pattern of our data suggests that SP is associated with a greater overall frequency of postoperative complications, without providing additional survival benefits compared to splenic preservation. Thus, the routine implementation of SP is not advocated.

Safety and feasibility of minimally invasive gastrectomy following preoperative chemotherapy for highly advanced gastric cancer

BACKGROUND

This study aimed to determine the safety and feasibility of minimally invasive gastrectomy in patients who underwent preoperative chemotherapy for highly advanced gastric cancer.

METHODS

Preoperative chemotherapy was indicated for patients with advanced large tumors (≥ cT3 and ≥ 5 cm) and/or bulky node metastasis (≥ 3 cm × 1 or ≥ 1.5 cm × 2). Between January 2009 and March 2022, 150 patients underwent preoperative chemotherapy followed by gastrectomy with R0 resection, including conversion surgery (robotic, 62; laparoscopic, 88). The outcomes of these patients were retrospectively examined.

RESULTS

Among them, 41 and 47 patients had stage IV disease and underwent splenectomy, respectively. Regarding operative outcomes, operative time was 475 min, blood loss was 72 g, morbidity (grade ≥ 3a) rate was 12%, local complication rate was 10.7%, and postoperative hospital stay was 14 days (Interquartile range: 11-18 days). Fifty patients (33.3%) achieved grade ≥ 2 histological responses. Regarding resection types, total/proximal gastrectomy plus splenectomy (29.8%) was associated with significantly higher morbidity than other types (distal gastrectomy, 3.2%; total/proximal gastrectomy, 4.9%; P < 0.001). Specifically, among splenectomy cases, the rate of postoperative complications associated with the laparoscopic approach was significantly higher than that associated with the robotic approach (40.0% vs. 0%, P = 0.009). In the multivariate analysis, splenectomy was an independent risk factor for postoperative complications [odds ratio, 8.574; 95% confidence interval (CI), 2.584-28.443; P < 0.001].

CONCLUSIONS

Minimally invasive gastrectomy following preoperative chemotherapy was feasible and safe for patients with highly advanced gastric cancer. Robotic gastrectomy may improve surgical safety, particularly in the case of total/proximal gastrectomy combined with splenectomy.

Splenic hilar lymph node dissection enhances survival in Bormann type 4 gastric cancer

Splenic hilar (no.10) lymph node dissection during total gastrectomy is no longer recommended for advanced proximal gastric cancer. However, the treatment efficacy of no.10 lymph node dissection in Borrmann type 4 tumors remains unclear. We enrolled 539 patients who underwent total gastrectomy for Borrmann type 4 tumors between 2006 and 2016 in four major institutions in Korea. We compared the long-term survival of the no.10 lymph node dissection (n = 309) and no-dissection groups (n = 230) using the propensity score (inverse probability of treatment weighting). The treatment effects of no.10 lymph node dissection were estimated in the weighted sample using the Cox proportional hazards regression model with a robust sandwich-type variance estimator. After inverse probability of treatment weighting, there were 540.4 patients in the no.10 lymph node dissection group and 532.7 in the no-dissection group. The two groups showed well-balanced baseline characteristics, including tumor node metastasis stage. The 5-year survival rates in the no.10 lymph node dissection and no-dissection groups were 45.7% and 38.6%, respectively (log-rank p = 0.036, hazard ratio 0.786, 95% confidence interval 0.630-0.982). Multivariate analysis revealed that no.10 lymph node dissection was an independent favorable prognostic factor (adjusted hazard ratio 0.747, 95% confidence interval 0.593-0.940) after adjusting for other prognostic factors. Sensitivity analyses in other inverse probability of treatment weighting models and the propensity score matching model showed similar results. Patients undergoing no.10 lymph node dissection showed improved survival compared to those without. No.10 lymph node dissection is recommended during total gastrectomy for patients with Borrmann type 4 gastric cancer.

Mapping of lymph node dissection determined by the epicenter location and tumor extension for esophagogastric junction carcinoma

BACKGROUNDS

Previous studies identified the extent of lymph node dissection for esophagogastric junction (EGJ) carcinoma based on the metastatic incidence. The study aimed to determine the optimal extent and priority of lymphadenectomy based on the therapeutic efficacy from each station.

METHODS

The studies on the lymph node metastasis (LNM) and therapeutic efficacy index (EI) for EGJ carcinomas were identified until April 2022. The obligatory stations with the LNM rates over 5% and therapeutic EI exceeding 2% should be routinely resected for D2 dissection, whereas the optional stations with EI between 0.5% and 2% should be resected for D3 dissection in selective cases.

RESULTS

The survey yielded 16 eligible articles including 6,350 patients with EGJ carcinoma. The metastatic rates exceeded 5% at no. 1, 2, 3, 7, 9, 11p, and 110 stations and were less than 5% in abdominal no. 4sa~6, 8a, 10, 11d, 12a, and 16a2/b1 and mediastinal no. 105~112 stations. Consequently, obligatory stations with EI over 2% were largely determined by the epicenter location and located at the upper perigastric, lower mediastinal, and suprapancreatic zones, corresponding to those with rates of LNM over 5%. Consistent with the LNM rates less than 5%, the optional stations with EI between 0.5% and 2% were largely dependent on the degree of tumor extension toward the lower perigastric, splenic hilar (grecurvature), para-aortic (less curvature of the cardia), and middle or upper mediastinal zones.

CONCLUSIONS

The obligatory stations can be resected as an "envelope-like" wrap by transhiatal proximal gastrectomy with lower esophagectomy, whereas the optional stations for dissection are indicated by the tumor extension. The extended gastrectomy is required for the lower perigastric in the stomach-predominant tumor with gastric involvement exceeding 5.0 cm, para-aortic dissection in the less curvature-predominant tumor and splenic hilar dissection in the grecurvature-predominant tumor whereas transthoracic subtotal esophagectomy is required for complete mediastinal dissection and adequate negative margin in the esophagus-predominant tumor with esophageal invasion exceeding 3.0 cm.

Surgical Management of Gastric Cancer: A Systematic Review

Gastric cancer is the fifth most common cancer worldwide, and it is responsible for 7.7% of all cancer deaths. Despite advances in the field of oncology, where radiotherapy, neo and adjuvant chemotherapy may improve the outcome, the only treatment with curative intent is represented by surgery as part of a multimodal therapy. Two concepts may be adopted in appropriate cases, neoadjuvant treatment before gastrectomy (G) or primary surgical resection followed by chemotherapy. Such an approach, combined with early detection and better screening, has led to a decrease in the overall incidence of gastric cancer. Unfortunately, malignant tumors of the stomach are often diagnosed in locally advanced or metastatic stages when the median overall survival remains poor. Surgical care in these cases must be provided by a multidisciplinary team in a high-volume center. Important surgical aspects such as optimum resection margins, surgical technique, and number of harvested lymph nodes are important factors for patient outcomes. The standardization of surgical treatment of gastric cancer in accordance with the patient’s profile is of decisive importance for a better outcome. This review aims to summarize the current standards in the surgical treatment of gastric cancer.

Essential updates 2019/2020: Perioperative and surgical management of gastric cancer

Perioperative and surgical management of gastric cancer have been changing as pivotal phase II trials and landmark phase III trials offer new insights to the existing knowledge. The results of many landmark trials have been published or presented in the past year, many of which have changed or will change current clinical practice. For example, FLOT4 has completely changed the regimen of perioperative chemotherapy in Europe. Furthermore, evidence for minimally invasive surgery for clinical Stage I was firmly established by KLASS-01 and JCOG0912 for distal gastrectomy and CLASS-02, KLASS-03, and JCOG1401 for total gastrectomy. Moreover, promising results were provided by CLASS-01 and KLASS-02 for locally advanced gastric cancer. For adjuvant chemotherapy, JACCRO GC-07 (START-2) has provided a new doublet regimen for pathological Stage III, which is often refractory to chemotherapy. Conversely, JCOG0501 poses a significant challenge for advanced tumors, such as large type 3 and scirrhous (type 4) tumors. In this review, we briefly review recent updates and discuss future perspectives of gastric cancer treatment.

Is splenic hilar lymph node dissection necessary for proximal gastric cancer surgery?

Advanced proximal gastric cancer sometimes metastasizes to the splenic hilar lymph nodes (No. 10 LN). Total gastrectomy combined with splenectomy is performed for complete removal of the No. 10 LN and was historically a standard procedure in Japan. However, splenectomy is associated with several disadvantages for patients, such as increased postoperative morbidity, risk of thrombogenic disease, fatal infection from encapsulated bacteria, and the development of other types of cancer in the long term because of loss of immune function. Therefore, splenectomy should only be performed when its estimated oncological effect exceeds such disadvantages. A Japanese randomized controlled trial (JCOG0110) clearly demonstrated that prophylactic splenectomy is not necessary unless the tumor has invaded the greater curvature; thus, splenectomy is no longer routinely performed in Japan. However, several retrospective studies have shown a comparatively high incidence of No. 10 LN metastasis and therapeutic value from LN dissection at that station in the tumors invading the greater curvature. Similar tendencies have also been reported in type 4 or remnant gastric cancer involving the greater curvature. In view of these facts, No. 10 LN dissection is presently recommended for such patients; however, robust evidence is lacking. In recent years, laparoscopic/robotic spleen-preserving splenic hilar dissection utilizing augmented visualization without pancreatic mobilization has been developed. This procedure is expected to replace prophylactic splenectomy and provide an equal oncological effect with lower morbidity. In Japan, a prospective phase-II study (JCOG1809) is currently ongoing to investigate the safety and feasibility of this procedure.

Reappraise role of No. 10 lymphadenectomy for proximal gastric cancer in the era of minimal invasive surgery during total gastrectomy: a pooled analysis of 4 prospective trial

BACKGROUND

For patients with locally advanced proximal gastric cancer (LAPGC), the individualized selection of patients with highly suspected splenic hilar (No. 10) lymph node (LN) metastasis to undergo splenic hilar lymphadenectomy, is a clinical dilemma. This study aimed to re-evaluate the feasibility and safety of laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPSHL) and to identify the population who would benefit from it.

METHODS

A total of 1068 patients (D2 group = 409; D2 + No. 10 group = 659) who underwent laparoscopic total gastrectomy from four prospective trials between January 2015 and July 2019 were analyzed.

RESULTS

No significant difference in the incidence (16.9% vs. 16.4%; P = 0.837) of postoperative complications were found between the two groups. The metastasis rate of No. 10 LN among patients in the D2 + No. 10 group was 10.3% (68/659). Based on the decision tree, patients with LAPGC with tumor invading the greater curvature (Gre), patients with non-Gre-invading LAPGC with a tumor size > 5 cm and clinical positive locoregional LNs were defined as the high-priority No. 10 dissection group. The metastasis rate of No. 10 LNs in the high-priority group was 19.4% (41/211). In high-priority group, the 3-year overall survival of the D2 + No. 10 group was better than that of the D2 group (74.4% vs. 42.1%; P = 0.005), and the therapeutic index of No. 10 was higher than the indices of most suprapancreatic stations.

CONCLUSIONS

LSPSHL for LAPGC is safe and feasible when performed by experienced surgeons. LSPSHL could be recommended for the high-priority group patients even without invasion of the Gre.

Systemic Review and Meta-analysis of Impact of Splenectomy for Advanced Gastric Cancer

BACKGROUND/AIM

Prophylactic splenectomy has shown no inferiority for tumors not invading the greater curvature side. Despite this, the clinical impact of prophylactic splenectomy for proximal advanced gastric cancer is not clear. This review aimed to clarify the impact of splenectomy for advanced gastric cancer in the upper third of the stomach.

MATERIALS AND METHODS

A systematic review and meta-analysis were conducted based on PubMed and EMBASE databases. The following search terms were used: "gastric cancer" OR "splenectomy" OR upper third of the stomach" OR preservation of the spleen.

RESULTS

Out of 765 articles, 18 studies (combined n=6,341) were included in the analysis. Four randomized controlled trials (RCT) and eight retrospective studies suggested the benefits of spleen-preserving gastrectomy. Six retrospective studies showed no significant benefit of spleen-preserving gastrectomy. Prophylactic splenectomy showed a close association with a higher incidence of postoperative morbidity (pancreatic fistula and anastomotic leakage) with no concomitant improvement in overall survival. Prophylactic splenectomy should not be routinely performed and RCTs are necessary to confirm the impact of splenectomy for cN(+) at the splenic hilum tumors and tumors invading the greater curvature.