Effectiveness and safety of splenectomy for gastric carcinoma: A meta-analysis

Table 1 The characteristics of the included randomized trials

Study	Participants	Interventions	Outcomes
Csendes et al[63], 2002	187 patients with gastric carcinoma entered this study. 97 patients with total gastrectomy and 90 patients with total gastrectomy and splenectomy	Total gastrectomy vs total gastrectomy plus splenectomy. The follow-up was at least 5 years	Five-year overall survival and survival by stage. Postoperative morbidity and mortality. Kaplan-Meier survival curve. Duration of operation and hospital stay
Toge et al[6], 1985	The patients underwent total gastrectomy and had the main location of the tumor on lesser curvature region. They were divided into 2 groups at random: 41 in splenectomy (+) and 38 in splenectomy (-) groups	Splenectomy vs splenic preservation. The follow-up was at least 5 years	Kaplan-Meier survival curve. 5-year overall survival were from reported percentages data
Yu et al[64], 2006	A total of 216 patients with proximal gastric cancer were randomized. 103 patients had the spleen preserved and 104 had a splenectomy	Splenectomy vs splenic preservation. Of the 207 patients, 7 were lost to follow-up (follow-up rate 96.6%) and mean duration of follow-up was 5.4 years	Harvested lymph nodes. Postoperative morbidity and mortality. Kaplan-Meier survival curve. 5-year overall survival were from reported percentages data

Table 2 The quality of the included randomized trials

Study	Truly random	Concealed allocation	Baseline features	Eligibility criteria	Blinding assessment	Loss to follow-up	Intention to treat	Study quality
Csendes et al[63], 2002	Yes	Unclear	Yes	Yes	Unclear	Yes	No	Fair
Toge et al[6], 1985	Unclear	Unclear	No	No	Unclear	Unclear	Unclear	Poor
Yu et al[64], 2006	Yes	Unclear	Yes	Yes	Unclear	Yes	Unclear	Fair

Table 3 Outcomes of a meta-analysis of overall survival rates, safety, operation-related events and overall survival rates stratified by location of tumor

	No. of studies	Splenectomy (n1/N)	Splenic preservation (n1/N)	RR/WMD (95% CI)	P-value for effect size	P-value for heterogeneity	Effect model
Overall survival rate stratified by different length of follow-up
	3	122/231	105/235	1.17 (0.97, 1.41)	0.1	0.85	Fixed
Postoperative morbidity and mortality
Morbidity	1	16/104	9/103	1.76 (0.82, 3.80)	0.15	NA	Fixed
Mortality	2	6/194	4/200	1.58 (0.45, 5.50)	0.47	0.82	Fixed
Operation-related events
No. of harvested lymph nodes	1	1042	1032	0.00 (-6.06, 6.06)	1	NA	Fixed
Operation time (min)	1	902	972	10.00 (-14.37, 34.37)	0.42	NA	Fixed
Length of hospital stay (d)	1	902	972	3.20 (-1.60, 8.00)	0.19	NA	Fixed
Reoperation	1	10/90	9/97	1.20 (0.51, 2.81)	0.68	NA	Fixed
Overall survival rate stratified by location of tumor (proximal and whole stomach)
	2	93/190	84/197	1.14 (0.92, 1.41)	0.23	0.91	Fixed

¹Represents the patients alive;

²The summed number of patients in each group; RR: Relative risk; WMD: Weighted mean differences; CI: Confidence interval; NA: Not applicable.

Table 4 Sensitivity results of meta-analysis of overall survival rates and safety (excluding the trial with low quality)

	No. of studies	Splenectomy (n1/N)	Splenic preservation (n1/N)	RR/WMD (95% CI)	P-value for effect size	P-value for heterogeneity	Effect model
Overall survival rate stratified by different length of follow-up
	2	93/190	84/197	1.14 (0.92, 1.41)	0.23	0.91	Fixed
Postoperative morbidity and mortality
Morbidity	1	16/104	9/103	1.76 (0.82, 3.80)	0.15	NA	Fixed
Mortality	2	6/194	4/200	1.58 (0.45, 5.50)	0.47	0.82	Fixed

¹Represents the patients alive; NA: Not applicable.