Impact of splenic hilar lymph node metastasis on prognosis in patients with advanced gastric cancer

Is Splenic Hilar Lymph Node Dissection Without Splenectomy Essential for Proximal Advanced Gastric Cancer?

BACKGROUND

The standard surgery for proximal advanced gastric cancer (PAGC) is total gastrectomy with D2 lymph node dissection (LND). Although prophylactic splenectomy for splenic hilar LND (No. 10) is not recommended due to any survival advantage, prophylactic LND (No. 10) without splenectomy remains controversial. Thus, we aimed to evaluate whether No. 10 LND is essential for patients' survival benefit in PAGC.

METHODS

We conducted a retrospective study of 1038 patients with PAGC who underwent total gastrectomy without splenectomy. After adjusting for confounders and propensity score matching (PSM), patients were grouped into Group 1 (D2 LND without splenic hilar LN; n = 288) or Group 2 (D2 LND with splenic hilar LN; n = 288). Variables between the two groups (5-year overall survival [OS] and disease-free survival [DFS]) were compared, as well as in patients with tumors located in the greater curvature and those with Borrmann type IV disease.

RESULTS

The 5-year OS and DFS rates after PSM were not significantly different between Groups 1 and 2 (57.3% vs. 62.1%, p = 0.300; 52.8% vs. 59.7%, p = 0.100, respectively). Furthermore, the 5-year OS and DFS rates in patients with greater curvature involvement (54.4% vs. 61.9%, p = 0.500; 50.0% vs. 57.6%, p = 0.400, respectively) and Borrmann type IV disease (23.8% vs. 38.6%, p = 0.400; 16.7% vs. 33.9%, p = 0.200, respectively) after PSM were also not significantly different between the two groups.

CONCLUSIONS

Prophylactic splenic hilar LND without splenectomy does not improve long-term survival in PAGC. Therefore, this procedure might not be essential for patients with PAGC as well greater curvature involvement and Borrmann type IV disease.

Current status of lymph node dissection in gastric cancer

Gastrectomy with lymph node (LN) dissection has been regarded as the standard surgery for gastric cancer (GC), however, the rational extent of lymphadenectomy remains controversial. Though gastrectomy with extended lymphadenectomy beyond D2 is classified as a non-standard gastrectomy, its clinical significance has been evaluated in many studies. Although hard evidence is lacking, D2 plus superior mesenteric vein (No. 14v) LN dissection is recommended when harbor metastasis to No. 6 nodes is suspected in the lower stomach, and dissection of splenic hilar (No. 10) LN can be performed for advanced GC invading the greater curvature of the upper stomach, and D2 plus posterior surface of the pancreatic head (No. 13) LN dissection may be an option in a potentially curative gastrectomy for cancer invading the duodenum. Prophylactic D2+ para-aortic nodal dissection (PAND) was not routinely recommended for advanced GC patients, but therapeutic D2 plus PAND may offer a chance of cure in selected patients, preoperative chemotherapy was considered as the standard treatment for GC with para-aortic node metastasis. There has been no consensus on the extent of lymphadenectomy for the adenocarcinoma of the esophagogastric junction (AEG) so far. The length of esophageal invasion can be used as a reference point for mediastinal LN metastases, and the distance from the esophagogastric junction to the distal end of the tumor is essential for determining the optimal extent of resection. The quality of lymphadenectomy may influence prognosis in GC patients. Both hospital volume and surgeon volume were important factors for the quality of radical gastrectomy. Centralization of GC surgery may be needed to improve prognosis.

Surgical treatment of gastric cancer: Current status and future directions

Surgery is the most important and effective method for the treatment of gastric cancer. Since the first gastrectomy in the early 19th century, surgical treatment of gastric cancer has undergone more than 100 years of development. With the increasing understanding of gastric cancer and the promotion of a series of clinical trials, the concept of gastric cancer surgery has evolved from the initial "bigger is better" to today's "standardized surgery" and is developing towards individualized surgery focusing on accurate resection and quality of life. This trend has had a tremendous impact on the development of surgical treatments, such as minimally invasive surgeries, function-preserving surgeries, and the optimal extent of lymph node dissection. Understanding the development and current status of gastric cancer surgery and exploring the remaining academic controversies are goals that every gastric surgeon should constantly pursue. However, how should gastric cancer surgery develop in the future? What opportunities and challenges will we encounter? In this review, we elaborate on the development and current status of gastric cancer surgery based on a series of clinical studies and discuss the controversy in the development of gastric cancer surgery.

The Retropancreatic Fusion Fascia Oriented Splenic Hilar Lymphadenectomy Versus Laparoscopic Approach In D2 Total Gastrectomy

BACKGROUND The retropancreatic fusion fascia is recognized as the anatomical landmark during retropancreatic mobilization. However, its role in D2 total gastrectomy for proximal advanced gastric cancer (PAGC) remains unexplored. This study aimed to develop the retropancreatic fusion fascia-oriented ex vivo approach for splenic hilar lymphadenectomy (RP-SL) to avoid difficulty in using the total laparoscopic approach (TL-SL). MATERIAL AND METHODS The data for patients with PAGC who underwent D2 total gastrectomy were retrieved from our clinical database and electronic medical records (December 2016 to December 2018), with a 1:1 match ratio for balance of the 2 groups. RESULTS In sum, 84 matched patients were included in the study. There were 2360 retrieved lymph nodes (LNs), with an average of 28.10. Sixteen patients were confirmed with positive splenic hilar lymphadenectomy, and the mean harvested lymph nodes (LNs) were significantly increased in the RP-SL group compared to the TL-SL group (3.07 vs. 2.29, P<0.001), decreased operative time (193.21 min vs. 247.74 min, P<0.001), and less blood loss (96.90 mL vs. 185.24 mL, P=0.001) in the RP-SL group. Postoperative hospital stay (6.55 days vs. 7.26 days), rate of morbidity (9.50% vs. 11.91%), and overall costs (¥65255.64 vs. ¥64419.91) were comparable between the groups (P>0.05).  CONCLUSIONS The landmark at the conjunction between the superior mesenteric vessels and the inferior pancreatic margin made it feasible to identify the retropancreatic areolar. The RP-SL approach was safe and efficient for splenic hilar lymphadenectomy.

Advantages of Splenic Hilar Lymph Node Dissection in Proximal Gastric Cancer Surgery

Gastrectomy with lymph node dissection remains the gold standard for curative treatment of gastric cancer. Dissection of splenic hilar lymph nodes has been included as a part of D2 lymph node dissection for proximal gastric cancer. Previously, pancreatico-splenectomy has been performed for dissecting splenic hilar lymph nodes, followed by pancreas-preserving splenectomy and spleen-preserving lymphadenectomy. However, the necessity of routine splenectomy or splenic hilar lymph node dissection has been under debate due to the increased morbidity caused by splenectomy and the poor prognostic feature of splenic hilar lymph node metastasis. In contrast, the relatively high incidence of splenic hilar lymph node metastasis, survival advantage, and therapeutic value of splenic hilar lymph node dissection in some patient subgroups, as well as the effective use of novel technologies, still supports the necessity and applicability of splenic hilar lymph node dissection. In this review, we aimed to evaluate the need for splenic hilar lymph node dissection and suggest the subgroup of patients with favorable outcomes.

Laparoscopic splenic hilar lymph node dissection for advanced gastric cancer: to be or not to be

The incidence of proximal gastric cancer has increased in both the East and the West. Although some novel reconstructions like double-tract or double-flap anti-reflux procedure related to proximal gastrectomy are promising, total radical gastrectomy still accounts for a significant portion of these procedures. D2 radical gastrectomy is the globally accepted standard surgical procedure for advanced gastric cancer, and lymph node (LN) dissection is considered as the critical point of radical surgery and closely related to the prognosis. The splenic hilar LNs (No. 10) are LNs that need to be removed during standard D2 surgery for proximal and total gastrectomy. Lymphadenectomy does not only provide valuable information on the prognosis of gastric cancer, but the thoroughness of the sweep itself is directly related to postoperative survival. The incidence of splenic hilar LN (No. 10) metastasis rate is not high. Although the LN metastasis pathway around the spleen is complicated, the feasibility of laparoscopic splenic hilar LN dissection in locally advanced gastric cancer has been verified. However, these results are mostly from small volume clinical studies, and the fact is that the dissection of the splenic hilar is technique-demanding even for open surgery. The rational strategy for LN dissection for surgeons is still controversial. For splenic LN dissection in radical gastric cancer surgery, whether to select individualized splenic LN dissection for those patients highly suspected of clinical metastasis or to advocate the evidence-based strategy and neglect dissection in lower risk patients to avoid over-removing of LNs, is a vital question that needs to be clarified.

Prognostic Impact of Extended Lymph Node Dissection versus Limited Lymph Node Dissection on pN0 Proximal Advanced Gastric Cancer: a Propensity Score Matching Analysis

Purpose

Splenic hilar lymph node dissection (LND) during total gastrectomy is regarded as the standard treatment for proximal advanced gastric cancer (AGC). This study aimed to investigate whether splenic hilar LND or D2 LND is essential for proximal AGC of pT2-4aN0M0 stage.

Materials and Methods

Data of curative total gastrectomies (n=370) performed from 2000 to 2010 for proximal AGC of pT2-4aN0 stage were retrospectively reviewed. Clinicopathological characteristics and long-term outcomes were compared using propensity score matching between patients who underwent splenectomy (n=43) and those who did not (n=327) and between patients who underwent D2 LND (n=122) and those who underwent D1+ LND (n=248).

Results

Tumors of larger size and a more advanced T stage and significantly lower overall and relapse-free survival (P<0.001) were observed in the splenectomy group than in the 2 spleen-preserving groups. Before propensity score matching, worse overall and relapse-free survival (P<0.001) was observed in the splenectomy group than in the non-splenectomy group. After matching, although the overall survival became similar (P=0.123), relapse-free survival was worse in the splenectomy group (P=0.021). Compared with D1+ LND, D2 LND had no positive impact on the overall (P=0.619) and relapse-free survival (P=0.112) after propensity score matching.

Conclusions

Splenic hilar LND with or without splenectomy may not have an oncological benefit for patients with pathological AGC with no LN metastasis.

Current status of laparoscopic total gastrectomy

In this article, the current state of laparoscopic total gastrectomy (LTG) was reviewed, focusing on lymph node dissection and reconstruction. Lymph node dissection in LTG is technically similar to that in laparoscopic distal gastrectomy for early gastric cancer; however, LTG for advanced gastric cancer requires extended lymph node dissections including splenic hilar lymph nodes. Although a recent randomized controlled trial clearly indicated no survival benefit in prophylactic splenectomy for lymph node dissection at the splenic hilum, some patients may receive prognostic benefit from adequate splenic hilar lymph node dissection. Considering reconstruction, there are two major esophagojejunostomy (EJS) techniques, using a circular stapler (CS) or using a linear stapler (LS). A few studies have shown that the LS method has fewer complications; however, almost all studies have reported that morbidity (such as anastomotic leakage and stricture) is not significantly different for the two methods. As for CS, we grouped various studies addressing complications in LTG into categories according to the insertion procedure of the anvil and the insertion site in the abdominal wall for the CS. We compared the rate of complications, particularly for leakage and stricture. The rate of anastomotic leakage and stricture was the lowest when inserting the CS from the upper left abdomen and was significantly the highest when inserting the CS from the midline umbilical. Scrupulous attention to EJS techniques is required by surgeons with a clear understanding of the advantages and disadvantages of each anastomotic device and approach.

Metastatic patterns and surgical methods for lymph nodes No. 5 and No. 6 in proximal gastric cancer

Objective

The current surgical treatment guidelines for early proximal gastric cancer (PGC) still lack agreement. Lymphadenectomy of lymph nodes No. 5 and No. 6 is the major difference between total and proximal gastrectomy. We elucidated the appropriate surgical procedure for PGC by investigating the pathological characteristics and prognostic significance of lymph nodes No. 5 and No. 6.

Methods

In total, 333 PGC patients who underwent total gastrectomy were enrolled in this study. We investigated their clinicopathological characteristics and the metastatic patterns of the lymph nodes. Patients with metastasis in lymph nodes No. 5 and No. 6 were combined into one group and we compared the difference in survival between those with and without metastasis in lymph nodes No. 5, 6 (lymph nodes No. 5 and No. 6 in any group of metastasis) for different subgroups.

Results

The metastatic rates for lymph nodes No. 5 and No. 6 in PGC were 9.91% and 16.11%, respectively. The metastatic rate for both lymph nodes No. 5, 6 was 20.42%. Multivariate analysis showed that positive metastasis in lymph node No. 4, depth of invasion, and tumor size were independently correlated with the presence of metastasis in lymph nodes No. 5, 6.

Conclusions

When lymph node No. 4 is positive (intraoperative pathology) or tumor size ≥5 cm or T4 stage, lymphadenectomy should be performed for lymph nodes No. 5 and No. 6, and total gastrectomy is recommended.

Analysis of survival and prognosis of 298 gastric adenocarcinoma patients with no distant metastasis

This study investigated the survival and prognosis of 298 gastric adenocarcinoma patients with no distant metastasis. For analysis and comparison of the prognosis of patients, a retrospective analysis was performed in 298 patients with perfect clinical data and follow-up data who received the D2 resections for gastric cancer in Shandong Provincial Hospital Affiliated to Shandong University between January, 2005 and January, 2012, and were diagnosed as gastric adenocarcinoma with no distant metastasis in postoperative pathological examination. Among the gastric adenocarcinoma patients without distant metastasis, we found that differences of sex, age, differentiation and position of tumor had no statistical significance (P>0.05), while comparisons of the tumor diameter, regional lymphatic metastasis, vascular invasion and pathological TNM stages (pTNM; T for tumor, N for lymph node and M for metastasis) showed statistical significance (P<0.05). One-way analysis of variance (ANOVA) indicated the correlation between the prognosis of gastric adenocarcinoma patients and tumor diameter, regional lymphatic metastasis, vascular invasion and pTNM stages of patients (P<0.05). Multivariate analysis of Cox regression models was performed for discovering the factors associated with the prognosis of patients, and the results suggested that position of tumor (P=0.016), regional lymphatic metastasis (P=0.042), vascular invasion (P=0.021) and pTNM stage (P=0.009) were the independent risk factors affecting the prognosis of gastric adenocarcinoma patients. During 60-month follow-up, the median survival duration of gastric adenocarcinoma patients with no distant metastasis was 38 months, while the 5-year accumulate survival rate was 49.3%. The results indicated that in gastric adenocarcinoma patients without distant metastasis, tumor diameter, regional lymphatic metastasis, vascular invasion and pTNM stage are major indicators affecting the prognosis of patients.