Immunosuppressive factor from the spleen in gastric cancer patients

Impact of spleen-preserving total gastrectomy on postoperative infectious complications and 5-year overall survival: systematic review and meta-analysis of contemporary randomized clinical trials

Background

The role of splenectomy in proximal gastric cancer is still debated. The objective of the present meta-analysis was to provide more-robust evidence about the effect of spleen-preserving total gastrectomy on postoperative infectious complications, overall morbidity, and 5-year overall survival (os).

Methods

PubMed, embase, and the Web of Science were consulted. Pooled effect measures were calculated using an inverse-variance weighted or Mantel-Haenszel in random effects meta-analysis. Heterogeneity was evaluated using I ² index and Cochran Q-test.

Results

Three randomized controlled trials published between 2000 and 2018 were included. Overall, 451 patients (50.1%) underwent open total gastrectomy with spleen preservation and 448 (49.9%) underwent open total gastrectomy with splenectomy. The patients ranged in age from 24 to 78 years. No differences were found in the number of harvested lymph nodes (p = 0.317), the reoperation rate (p = 0.871), or hospital length of stay (p = 0.347). The estimated pooled risk ratios for infectious complications, overall morbidity, and mortality were 1.53 [95% confidence interval (ci): 1.09 to 2.14; p = 0.016], 1.51 (95% ci: 1.11 to 2.05; p = 0.008), and 1.23 (95% ci: 0.40 to 3.71; p = 0.719) respectively. The estimated pooled hazard ratio for 5-year os was 1.06 (95% ci: 0.78 to 1.45; p = 0.707).

Conclusions

Spleen-preserving total gastrectomy should be considered in patients with curable gastric cancer because it is significantly associated with decreased postoperative infectious complications and overall morbidity, with no difference in the 5-year os. Those observations appear worthwhile for establishing better evidence-based treatment for gastric cancer.

Immunosuppressive Factors: Role in Cancer Development and Progression

The concept of the immunological surveillance against neoplastic cells was initially proposed by Erlich in 1909 and later elaborated by Burnet. This hypothesis states that the normal function of the immune system, in particular the cell-mediated immunity, is to recognize and destroy the transformed and proliferating tumor cells. The role of cell-mediated immunity during the first steps of tumorigenesis remains controversial. However, there is certain evidence about its importance in the progression and dissemination of cancer. The frequent immunosuppressed condition of cancer patients at tumor relapse or recurrence of secondary tumors is a clinical sign supporting this hypothesis, and many studies have demonstrated a defective immune response in patients diagnosed with advanced cancer. Several mechanisms of escape from the immune surveillance have been described, including the immunoselection of tumor antigen-negative variants, the downregulation of MHC class I expression, suppressive T cells, and the elaboration of immunosuppressive cytokines and other factors. Because of the technical difficulty of isolating the very small amounts from culture supernatants or body fluids, only a few of these substances have been characterized and studied with respect to their biological activity: transforming growth factor-β (TGF-β), the protein p15E, interleukin 10 (IL-10), prostaglandin E2 (PGE2), mucins, suppressive E-receptor (SER), immunosuppressive acidic protein (IAP), and adhesion molecules. The possibility of monitoring cancer patients by testing biochemical factors related to cancer growth led to a proposal to measure a number of these factors as tumor markers. Some of them, e.g mucins, enjoy the consensus of the oncologic community, as for some indications they can help the clinician in the management of cancer patients. Except for the class of mucins, the other above-mentioned immunosuppressive factors have not found any clinical application in the laboratory routine because the information deriving from their measurement, although of speculative and scientific interest, has limited clinical value at present. Nevertheless, even if they have no impact on patient management, these substances do have a potential role to play in the study of cancer patients, and should be taken into account when developing new therapeutic strategies.

Splenic hilar lymph node metastasis independently predicts poor survival for patients with gastric cancers in the upper and/or the middle third of the stomach

BACKGROUND

Effectiveness of splenectomy for advanced gastric cancers occupying the upper and/or the middle third of the stomach is still in debate. The aim of the present study is to elucidate the impact of splenectomy on patient survival by investigating the pathological characteristics and prognostic significance of splenic hilar lymph node metastasis.

METHODS

Clinicopathologic and prognostic data of 265 patients with gastric cancer in the upper and/or the middle third of the stomach who underwent the operation of en bloc resection of primary cancer and D2/D3 lymphadenectomy combined with splenectomy were retrospectively reviewed.

RESULTS

Multivariate analysis revealed pT category, pN category, and distant lymph node metastasis independently correlated with the presence of splenic hilar lymph node metastasis. Prognoses of patients with positive splenic hilar lymph nodes were significantly poorer than that of patients with negative splenic hilar lymph nodes for the entire study population and for those who underwent R0 resection, but not for those who underwent R1-2 resection. There was no significant difference in survival between patients who underwent R0 resection with positive splenic hilar lymph nodes and those who underwent R1-2 resection. Splenic hilar lymph node metastasis was one of independent indicators predicting worse prognosis and the presence of distant metastasis after surgery. Subset analysis according to the TNM stage revealed there were significant differences in survival between patients with and without splenic hilar lymph node metastasis.

CONCLUSIONS

Splenic hilar lymph node metastasis should be considered as one of incurable factors. Consequently, the efficiency of splenectomy aiming at prolonging survival for patients with high risk of splenic hilar lymph nodes metastasis should be questioned, although resection of invasive organs form gastric cancers has been recommended if R0 surgery could be achieved.

Modified radical lymphadenectomy without splenectomy in patients with proximal gastric cancer: comparison with standard D2 lymphadenectomy for distal gastric cancer

BACKGROUND AND OBJECTIVES

We assessed the optimal extent of lymph node dissection and the effect of splenectomy in patients with proximal gastric cancer.

METHOD

Recurrence and survival rates were compared between 881 patients with proximal gastric cancer who underwent modified radical lymphadenectomy and 3,098 patients with distal gastric cancer who underwent standard D2 lymphadenectomy.

RESULTS

The recurrence rate was significantly higher in the total than in the distal gastrectomy group (32.5% vs. 16.5%, P < 0.001), but the rates were similar after adjustment for TNM stage. The overall 5-year survival rate was significantly higher in the distal than in the total gastrectomy group (80.4% vs. 66.2%, P < 0.001), but this difference was not observed after adjustment for TNM stage. Multivariate analysis showed that patient age, number of retrieved lymph nodes, depth of invasion, and nodal metastasis were independent prognostic determinants for survival, whereas type of lymphadenectomy was not.

CONCLUSION

Long-term outcomes were similar in patients with proximal gastric cancer who underwent modified lymphadenectomy without splenectomy and in patients with distal gastric cancer who underwent standard D2 lymphadenectomy. These findings indicate that modified radical lymphadenectomy without splenectomy is sufficient for optimal lymph node dissection in patients with proximal gastric cancer.

Randomized clinical trial of splenectomy versus splenic preservation in patients with proximal gastric cancer

BACKGROUND

Preservation or removal of the spleen during total gastrectomy for proximal gastric cancer is a matter of debate.

METHODS

A randomized clinical trial included patients with gastric adenocarcinoma who underwent total gastrectomy either with (104 patients) or without (103) splenectomy. Postoperative outcome in the two groups was compared, including morbidity, mortality and survival.

RESULTS

Gastrectomy combined with splenectomy tended to be associated with slightly higher morbidity and mortality rates, a slightly greater incidence of lymph node metastasis at the splenic hilum and along the splenic artery, and marginally better survival, but there were no statistically significant differences between the groups. Splenectomy had no impact on survival in patients with metastatic lymph nodes at the hilum of the spleen or in those with metastatic lymph nodes along the splenic artery.

CONCLUSION

These results do not support the use of prophylactic splenectomy to remove macroscopically negative lymph nodes near the spleen in patients undergoing total gastrectomy for proximal gastric cancer.

Impact of splenectomy on circulating T-lymphocyte subsets in stage III gastric cancer

BACKGROUND

The role of splenectomy remains unclear in patients with gastric cancer who undergo total gastrectomy. The aim of this study was to prospectively evaluate the impact of splenectomy on circulating T-lymphocyte subsets and survival in advanced gastric cancer.

METHODS

Analysis of lymphocyte subsets was performed in 40 patients with American Joint Committee on Cancer (AJCC) stage III gastric adenocarcinoma located on the upper one-third of the stomach, who underwent a curative total gastrectomy with or without splenectomy. Circulating T-lymphocyte subsets were measured on venous blood by using flow cytometry and monoclonal antibodies at preoperative day 1, and postoperative months 1, 3, 6, 12 and 18.

RESULTS

The proportion of lymphocytes and the values of CD3, CD8, CD16 and CD25 subsets were higher in the splenectomy group of patients at postoperative month 3. In the spleen preservation group at the same point of treatment, the proportion of granulocytes and the values of CD4 and CD4 : CD8 ratio were higher. Except for CD16 levels, all T-lymphocyte subsets showed no significant difference between splenectomy and spleen preservation groups after postoperative month 3. Increased CD16 levels in the splenectomy group were not associated with improvement in patients' 5-year survival rates.

CONCLUSION

These results suggest that the long-term impact of splenectomy does not play an important role in postoperative quantitative changes of circulating T-lymphocyte subsets of patients with stage III gastric cancer who have undergone total gastrectomy. Furthermore, splenectomy does not give a prognostic benefit, based on tumour recurrence and survival of patients with proximal one-third gastric cancer who undergo total gastrectomy.

A prospective randomized study comparing D2 total gastrectomy versus D2 total gastrectomy plus splenectomy in 187 patients with gastric carcinoma

BACKGROUND

Classic surgical treatment of upper third gastric carcinoma is based on an extended total gastrectomy, including splenectomy. The purpose of this study was to perform a prospective randomized clinical trial comparing the early and late results of total gastrectomy (TG) versus total gastrectomy plus splenectomy (TGS).

METHODS

One hundred eighty-seven patients with gastric carcinoma were included. In all patients a D2 total gastrectomy was performed. During surgery they were randomized to 1 of 2 operative options. They were monitored to their death or to 5 years later if they were alive.

RESULTS

Operative mortality was similar after both operations (3% after TG and 4% after TGS). Septic complications after surgery were higher after TGS compared with TG (P <.04). Five-year survival rates were not statistically different between groups or in subset analysis according to stage of disease.

CONCLUSIONS

On the basis of the results of the present prospective randomized trial, splenectomy is not necessary in early stages of disease. A low operative mortality rate (less than 3%) must be achieved to obtain good long-term results.

Durable remission after splenectomy for Waldenström's macroglobulinemia with massive splenomegaly in leukemic phase

A patient with M-proteinemia (IgM, kappa type), lymphocytosis, anemia, and massive splenomegaly, was diagnosed as having Waldenström's macroglobulinemia (WM). Since this case was refractory to chemotherapy, splenic irradiation was performed, which effectively reduced the serum IgM level, spleen size, and lymphocyte counts; however, its effect was transient. Splenectomy was then carried out. The spleen contained abundant IgM-producing lymphocytes, and after splenectomy, the serum IgM values decreased and the peripheral blood counts returned to near normal. The transient increases of serum IgM occurred during two infectious episodes postoperatively. The patient has now been in a satisfactory remission for six years after splenectomy. The removal of an IgM-producing/secreting site and release from hypersplenism may be the major mechanisms involved in achieving the durable remission after splenectomy. In individual cases of WM with massive splenomegaly, we recommend splenectomy as part of the management of this disorder.

Perioperative allogeneic blood transfusion exacerbates surgical stress-induced postoperative immunosuppression and has a negative effect on prognosis in patients with gastric cancer

The immunomodulative effect of perioperative allogeneic blood transfusion on host immunocompetence was studied in 109 patients with gastric cancer at various stages. Mitogen-induced lymphocyte blastogenesis, lymphocyte surface markers (specific for T, B, CD4, and CD8 populations), and the activity of natural killer (NK) cells were examined before surgery and then 2 and 4 weeks after surgery. The effects on host immunocompetence of transfusion alone, in the absence of any effect of surgical stress, were studied, preoperatively, in nine patients who received preoperative transfusion. Although a tendency towards a decrease in the posttransfusion activity of NK cells was observed, there were no statistically significant differences between pre- and posttransfusion levels. Mitogen-induced blastogenesis and the activity of NK cells were significantly impaired 2 weeks after surgery in transfused patients as compared to those in nontransfused patients with gastric cancer at stage III and stage IV, and postoperative survival was significantly lower in transfused as compared to nontransfused patients. These results indicate that perioperative allogeneic blood transfusion exacerbates surgical stress-induced postoperative immunosuppression and has a negative effect on prognosis in patients with gastric cancer.

Splenectomy does not correlate with length of survival in patients undergoing curative total gastrectomy for gastric carcinoma. Univariate and multivariate analyses

The relationship between splenectomy and survival time after curative total gastrectomy for advanced gastric cancer was examined by reviewing retrospectively data on 252 patients treated in our clinics between 1965 and 1985. One hundred three patients (40.9%) did not undergo splenectomy and 149 (59.1%) did. In patients subjected to splenectomy, advanced stages of the malignancy were more frequent and metastasis was noticed in 8.1% of splenic hilar lymph nodes and in 10.1% of the lymph nodes associated with the splenic artery. A univariate analysis revealed that the survival time of patients with splenectomy was significantly less than those for whom splenectomy was not done (P less than 0.05). In a subgroup of our patients stratified to adjust for the stage of disease, there was no significant difference between the survival rates. Subsequently, multivariate analysis using the Cox regression analysis adjusted for sex, age, and other covariates indicated that serosa invasion, lymph node metastasis, and tumor size were the most important prognostic factors, and there was no correlation whatever with splenectomy. Our findings rule out any relationship between splenectomy and length of survival time in patients undergoing curative total gastrectomy for advanced gastric cancer.

Splenectomy does not correlate with length of survival in patients undergoing curative total gastrectomy for gastric carcinoma. Univariate and multivariate analyses

The relationship between splenectomy and survival time after curative total gastrectomy for advanced gastric cancer was examined by reviewing retrospectively data on 252 patients treated in our clinics between 1965 and 1985. One hundred three patients (40.9%) did not undergo splenectomy and 149 (59.1%) did. In patients subjected to splenectomy, advanced stages of the malignancy were more frequent and metastasis was noticed in 8.1% of splenic hilar lymph nodes and in 10.1% of the lymph nodes associated with the splenic artery. A univariate analysis revealed that the survival time of patients with splenectomy was significantly less than those for whom splenectomy was not done (P less than 0.05). In a subgroup of our patients stratified to adjust for the stage of disease, there was no significant difference between the survival rates. Subsequently, multivariate analysis using the Cox regression analysis adjusted for sex, age, and other covariates indicated that serosa invasion, lymph node metastasis, and tumor size were the most important prognostic factors, and there was no correlation whatever with splenectomy. Our findings rule out any relationship between splenectomy and length of survival time in patients undergoing curative total gastrectomy for advanced gastric cancer.

Isolated soluble fractions from spleen cell culture supernatants induce tumor enhancement

Supernatants of spleen cell culture from small-tumor-bearing mice, large-tumor-bearing mice, and large-tumor resected mice were fractionated by Sephadex G-100. The biological activity on tumor growth of all fractions was tested in vivo. It was found that only one fraction (MW: 220-250 kD) from spleen cell supernatants of small-tumor-bearing mice or large-tumor resected mice enhanced tumor growth. In spleen cell supernatants from large-tumor-bearing mice, two fractions had enhancing activity (MW: 220-250 and 100-10 kD). Thus, the surgical resection of large tumor induced disappearance of enhancing activity from the fraction of lower molecular weight.

Node dissection in gastric cancer

Three hundred patients who underwent absolute and relative curative gastrectomy and lymph node dissection for gastric cancer were reviewed with respect to postoperative mortality; proportion of patients with node involvement according to the extent of dissection; number of metastatic nodes dissected according to the extent of dissection; accuracy of macroscopic evaluation of node involvement and microscopic node involvement according to tumour location. If more nodes were dissected the proportion of patients with node involvement and the total number of metastatic nodes increased; conversely within R0 and R3 the extent of dissection did not affect postoperative survival. Finally when the presence and extent of node involvement was only macroscopically evaluated, the patients were classified incorrectly in 9.5 per cent of the N0 group and 20.2 per cent of the N1 group. The data suggest that lymph node dissection may be useful in the treatment of gastric cancer, and within the extent studied the employment of this procedure does not affect the postoperative mortality.