UNASSIGNED: Routine omentectomy is generally performed during surgery for patients with epithelial ovarian cancer (EOC). The current study aims to evaluate the impact of omentectomy on cause-specific survival of Stage I-IIIA EOC patients.
UNASSIGNED: Patients who presented with clinical Stage I-IIIA serous, clear cell, endometrioid, and mucinous ovarian cancers were selected from the SEER Database for the period between 2004 and 2018. We extracted clinicopathological data and surgical information with the focus on the performance of omentectomy and lymphadenectomy. Binary logistic regression and recursive partitioning analyses were conducted to identify the significant factors for the performance of omentectomy during surgery. Propensity score matching (PSM) and inverse probability treatment weighting (IPTW) techniques were utilized to balance confounding factors. Multivariate, exploratory subgroup analyses and sensitivity analyses were conducted to evaluate the impact of omentectomy on cause-specific survival (CSS).
UNASSIGNED: A total of 13,302 patients with EOC were enrolled in the study. The cohort comprised 3,569 endometrioid, 4,915 serous, 2,407 clear cell, and 2,411 mucinous subtypes. A total of 48.62% (6,467/13,302) of patients underwent the procedure of omentectomy during primary surgery, and only 3% absolute improvement in CSS at the individual level was observed, without statistical significance based on multivariate analysis. According to the regression-tree model with recursive partitioning analysis, the procedure of lymphadenectomy was found to be the strongest factor to distinguish the performance of omentectomy, followed by the tumor stage. Patients who underwent omentectomy were more likely to be managed in Stage I than those who underwent lymphadenectomy. After PSM-IPTW adjustment, the inclusion of omentectomy in the initial surgical procedure did not demonstrate a beneficial impact on CSS compared with those who did not undergo the procedure. Exploratory subgroup analysis indicated that the performance of omentectomy improved 5-year CSS in Stage II-IIIA patients. In the sensitive analyses for various tumor stages, omentectomy appeared to benefit only Stage II patients. However, patients across various stages seemed to benefit from the performance of lymphadenectomy, irrespective of the performance of omentectomy on them.
UNASSIGNED: Routine omentectomy may not be associated with survival benefit for patients with a grossly normal-appearing omentum, especially for those with clinical Stage I epithelial ovarian cancers.

This study assessed the effect of omentectomy on the prognosis and fertility in patients with clinically early-stage (I, II) malignant ovarian germ cell tumours (MOGCT).
A retrospective multicentre study.
Four university teaching hospitals in China.
A total of 268 patients with clinically apparent early-stage (I, II) MOGCT.
Data were obtained from the medical records. Additionally, the propensity score matching (PSM) algorithm was adopted.
Prognostic outcomes were disease-free survival (DFS) and overall survival (OS). Fertility outcomes were pregnancy and live birth rates.
A total of 187 (69.8%) patients underwent omentectomy. Kaplan-Meier analysis showed no significant differences in DFS and OS between the omentectomy and non-omentectomy groups before and after PSM (p > 0.05). Additionally, subgroup analysis stratified by age (<18 and ≥18 years) showed similar results. International Federation of Gynecology and Obstetrics (FIGO) stage was the only risk factor associated with DFS (hazard ratio [HR] 14.71, 95% confidence interval [CI] 4.47-48.38, p < 0.001) and OS (HR 37.36, 95% CI 3.87-361.16, p = 0.002). Pregnancy and live birth rates in the total population were 80.3% and 66.7%, respectively. There were no significant differences between the two groups before and after PSM.
Omentectomy did not improve survival or affect fertility in patients with clinically apparent early-stage (I, II) MOGCT, regardless of the age. The clinical FIGO stage was an independent risk factor for recurrence and death.

Total omentectomy is often performed with gastrectomy as radical surgery for gastric cancer (GC) patients. However, it remains controversial whether GC patients can benefit from omentectomy. The aim of this study was to analyze the incidence and clinical significance of tumor deposits (TDs) in different anatomical subregions of perigastric omentum in GC patients undergoing gastrectomy with total omentectomy.
From October 2011 to December 2013, 1253 patients who underwent gastrectomy with total omentectomy for GC were retrospective reviewed. The TDs in different anatomical subregions of perigastric omentum were examined.
Of 1253 patients, TDs positivity was 11.2%. Tumor deposits in the omentum of greater curvature and in the omentum of lesser curvature were associated with lymphovascular invasion, perineural invasion, advanced tumor node metastasis stages, and unfavorable survival. Besides, TDs in the proximal omentum of greater curvature and in the omentum of lesser curvature correlated with older patients and larger tumors. Kaplan-Meier curves showed that patients with TDs had worser overall survival (OS) than those without, regardless of TD positions. Patients with TDs in the omentum of greater curvature had the worst prognosis, followed by patients with TDs in the omentum of lesser curvature and patients with no TDs. Tumor deposits in the proximal omentum of greater curvature was an independent prognostic factor for OS. Moreover, only patients classified as pT4 had TDs in the distal omentum of greater curvature.
Patients with TDs in the omentum of greater curvature had the worst prognosis, followed by patients with TDs in the omentum of lesser curvature and patients with no TDs. In addition, partial omentectomy might be practicable for gastric cancer patients classified as T3 or shallower tumors.

BACKGROUND: Omentectomy has been traditionally a part of standard radical gastrectomy. Its clinical benefit for locally advanced gastric cancer (LAGC) remains controversial. This study aimed at evaluating the impact of gastrectomy with omentum preservation (GOP) on survival, recurrence, surgical outcomes and postoperative complications by comparing with gastrectomy with omentum resection (GOR).
METHODS: Original studies comparing GOP with GOR in LAGC were searched. Meta-analysis was performed using RevMan 5.4.
RESULTS: Seven studies involving 1879 patients were analyzed. Compared with GOR, GOP achieved significantly better overall survival (HR = 0.75 [0.60, 0.95], P = 0.01), with similar relapse-free survival (HR = 0.84 [0.68, 1.03], P = 0.10). The two groups had similar total recurrence rate (OR = 0.86 [0.68, 1.08], P = 0.19) and no significant differences in rates of peritoneal, hematogenous, locoregional or distant lymph node recurrences. GOP had significantly less blood loss (MD = -83 [-139, -28] ml, P = 0.003) and tended to have shorter operation time (MD = -28 [-58, 2] min, P = 0.06), with similar harvested number of lymph nodes (MD = -0.4 [-2.6, 1.8], P = 0.70). The incidences of total all grade and major complications were similar in GOP and GOR (all grade: 31.8% vs. 30.3%, OR = 1.08 [0.79, 1.46], P = 0.64; major: 9.2% vs. 10.1%, OR = 1.14 [0.55, 2.34], P = 0.73). There were no significant differences in incidences of complication or postoperative mortality.
CONCLUSIONS: Omentum preservation did not affect curability or survival in LAGC. These findings require validation in randomized controlled trials with large sample sizes.

UNASSIGNED: Complete omentectomy is considered to be essential in the radical gastrectomy for gastric cancer (GC), but its clinical benefit remains unclear. This study aims to evaluate the efficacy of omentum-preserving gastrectomy (OPG) for patients with GC.
UNASSIGNED: Studies comparing the surgical and oncological outcomes of OPG and gastrectomy with complete omentectomy (GCO) for GC up to March 2021 were systematically searched from PubMed, Web of Science, Embase, and Cochrane Library. A pooled analysis was performed for the available data regarding the baseline features, surgical and oncological outcomes. The RevMan 5.3 software was used to perform the statistical analysis. Quality evaluation and publication bias were also conducted.
UNASSIGNED: Nine studies with a total of 3335 patients (1372 in the OPG group and 1963 in the GCO group) undergoing gastrectomy were included. In the pooled analysis, the baseline data in two groups were all comparable (p > 0.05). However, the OPG group was associated with shorter operative time (MD = -18.67, 95% CI = -31.42 to -5.91, P = 0.004) and less intraoperative blood loss (MD = -38.09, 95% CI = -53.78 to -22.41, P < 0.00001) than the GCO group. However, the number of dissected lymph nodes (MD = 2.16, 95% CI = -0.61 to 4.93, P = 0.13), postoperative complications (OR = 0.92, 95% CI = 0.74 to 1.15, p = 0.47), overall recurrence rate (OR = 0.83, 95% CI = 0.66 to 1.06, p = 0.14), peritoneal recurrence rate (OR = 0.91, 95% CI = 0.65 to 1.29, p = 0.60), 3-year relapse-free survival (RFS) rate (OR = 1.40, 95% CI = 0.86 to 2.27, p = 0.18), and 5-year RFS rate (OR = 1.21, 95% CI = 0.95 to 1.55, p = 0.12) of the two groups were comparable.
UNASSIGNED: OPG might be an oncologically safe procedure with better surgical outcomes for patients with GC than GCO. However, high-quality randomized controlled trials are needed to confirm this benefit.

BACKGROUND: We performed a meta-analysis to investigate the efficacy of complete omentectomy (CO) in patients undergoing radical gastrectomy for gastric cancer.
METHODS: We conducted a literature search in PubMed, Web of Science, and the Cochrane Library databases for clinical research that compared CO with non-complete omentectomy (NCO). These articles were published prior to April 2021. Overall survival (OS) rates, relapse-free survival (RFS) rates, recurrence rates, operation times, estimates of blood loss, numbers of harvested lymph nodes, complications, and lengths of hospital stays were compared using relative risks (RRs) and weighted mean differences (WMDs). RevMan 5.3 software was used for statistical analysis.
RESULTS: Nine studies that included 3329 patients (1960 in the CO group) and 1369 in the NCO group comprised the analysis. The meta-analysis showed that CO was associated with a decreased 3-year OS rate (RR = 0.94, 95% CI 0.90-0.98, P = 0.005) and 5-year OS rate (RR = 0.93, 95% CI 0.88-0.98, P = 0.007). However, it was not associated with the 3-year RFS rate (RR = 0.97, 95% CI 0.90-1.04, P = 0.44), 5-year RFS (RR = 0.98, 95% CI 0.90-1.06, P = 0.60), or recurrence rate (RR = 1.17, 95% CI 0.95-1.45, P = 0.15) compared to the NCO group. For surgical-related outcomes, significant heterogeneity existed between the studies. Compared to the NCO group, CO was found to be associated with significantly more estimated blood loss (WMD = 250.90, 95% CI 105.90-396.28, P = 0.0007) and less harvested lymph nodes (WMD = - 3.59, 95% CI - 6.88, - 0.29, P = 0.03). Although, there was no significant difference in the surgical time (WMD = 15.93, 95% CI - 0.21, 32.07, P = 0.05). No statistically significant differences were observed in the rates of overall (P = 0.79) and major complications (P = 0.90), or the lengths of hospital stays (P = 0.11) between the two groups.
CONCLUSIONS: Based on the available evidence, CO is not superior to NCO in terms of survival. CO is not recommended as a routine surgery for gastric cancer. Future well-designed high-quality RCTs are warranted.

Although complete omentectomy is traditionally performed in patients with gastric cancer as part of radical gastrectomy to ensure the elimination of micrometastases, the prognostic value of omentectomy during gastrectomy remains unclear. Retrospective studies have shown that the incidence of metastases in the greater omentum is very low in T1-T3 gastric cancer. Thus radical gastrectomy with D2 lymphadenectomy and preservation of the greater omentum may be a proper curative treatment for gastric cancer patients with T1-T3 tumors. The aim of this article is to describe the design and rationale for this prospective, randomized controlled DRAGON-05 trial, conducted to evaluate the prognostic value of omentum-preserving gastrectomy for patients with T1-T3 gastric cancer. Clinical trial registration: ChiCTR2000040045 (ClinicalTrials.gov).

OBJECTIVE: The aims of this study were to assess the role of omentectomy in the staging of uterine serous carcinoma (USC) and to evaluate its impact on patient outcomes.
METHODS: Patients diagnosed with USC at the First Affiliated Hospital of Sun Yat-sen University of China were retrospectively reviewed. The clinicopathological characteristics and survival data of 187 patients were analyzed. Risk factors for omental metastasis were evaluated. Kaplan-Meier survival curves were used to compare survival status and the presence of omental metastasis.
RESULTS: We found that 35 of 187 patients (18.7%) had omental metastases. Omental metastasis was significantly associated with adnexal involvement (40.0% vs 19.1%, P = 0.008, OR 2.828, 95% CI 1.286-6.218). Multivariate analysis showed that in addition to lymph node metastases and suboptimal surgery, omental metastasis in USC remained an independent predictor of decreased PFS and OS (PFS, HR 1.48, 95% CI 1.14-4.63, P = 0.024; OS, HR 1.39, 95% CI 1.04-3.60, P = 0.043).
CONCLUSIONS: The incidence of omental metastasis is not low in patients with USC. Visual assessment and omental biopsy may be insufficient for recognizing occult metastases. Omentectomy should be part of the staging surgery in USC patients because it provides additional information about survival. Prospective studies are needed to confirm these results.

OBJECTIVE: To evaluate the role of omentectomy and lymphadenectomy in the treatment of clinically apparent early-stage malignant ovarian germ cell tumors.
METHODS: We retrospectively reviewed 245 patients with malignant ovarian germ cell tumors (yolk sac tumor, dysgerminoma, and immature teratoma) and with clinically early-stage disease, who were treated at Sun Yat-sen University Cancer Center between January 1, 1970 and December 31, 2017. The survival of patients who underwent either omentectomy or lymphadenectomy, or both (omentectomy/lymphadenectomy group) was compared with that of patients who did not undergo omentectomy or lymphadenectomy (non-omentectomy/lymphadenectomy group).
RESULTS: Sixty patients were diagnosed with yolk sac tumor, 74 with dysgerminoma, and 111 with immature teratoma. Of these 245 patients, 216 patients had stage I disease, 28 patients had stage II, and 1 patient had stage IIIA. There were 190 patients who underwent omentectomy and/or lymphadenectomy and 55 patients in the non-omentectomy/lymphadenectomy group, respectively. In the omentectomy/lymphadenectomy group, 112 patients underwent both omentectomy and lymphadenectomy, 71 underwent omentectomy only, and 7 underwent lymphadenectomy only. Two hundred and fourteen of 245 patients (87.3%) received post-operative chemotherapy. Median follow-up was 73 months (range 1-388). The 10-year overall survival rates in the omentectomy/lymphadenectomy group and non-omentectomy/lymphadenectomy groups were 96.8% and 100%, respectively (p=0.340). Multivariate analysis evaluating all potential prognostic factors showed that omentectomy and lymphadenectomy are not prognostic factors for survival.
CONCLUSIONS: Omentectomy and lymphadenectomy do not appear to improve survival and may be omitted in patients with clinically apparent early-stage malignant ovarian germ cell tumors.

BACKGROUND: Malignant ovarian germ cell tumours (MOGCTs) are usually detected at an early stage, with patients achieving a satisfactory prognosis. However, the role of staging surgery in the treatment of apparent early-stage MOGCTs remains controversial.
OBJECTIVE: To investigate the role of staging procedures in apparent early-stage patients.
METHODS: We performed a retrospective review of 102 patients who were diagnosed with MOGCTs and had malignant lesions confined to their ovaries, between January 1997 and October 2014 at the Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China. Statistical analysis was carried out using SPSS software which included survival analysis by Kaplan-Meier method and Fisher\'s exact test.
RESULTS: Three patients relapsed and one died. The five-year overall survival rate and disease-free survival rate were 98.7% and 96.4%, respectively. Eighty-nine patients (87.3%) received adjuvant chemotherapy and only 23 patients (22.5%) were completely staged. In total, 3/49 (6.1%), 1/44 (2.3%) and 0/49 (0.0%) patients were diagnosed with malignant cells in peritoneal fluid, pelvic lymph nodes and omentum, respectively. Positive tumour cells were not correlated with recurrence. Univariate analysis revealed that neither complete staging surgery nor individual factors were useful prognostic factors for disease-free survival.
CONCLUSIONS: The staging surgery could be omitted for apparent early-stage patients affected by MOGCTs without adverse impact upon survival.