Study On Risk Factors Of Peritoneal Cytology And Its Relationship With Prognosis In Patients With Endometrial Cancer

ObjectiveEndometrial cancer(EC)is one of the three major gynecological malignancies.The International Federation of Gynecology and Obstetrics(FIGO)updated staging in 2009.Positive peritoneal cytology(PPC)was excluded from the new stage.Since then,there has been controversy about whether PPC could independently affect the prognosis of EC patients.This study aims to explore the risk factors of PPC in EC patients and the effect of PPC on the prognosis of patients by retrospective study and systematic review.MethodsThis retrospective study analyzed EC patients who underwent initial surgery and were pathologically diagnosed in Qilu Hospital of Shandong University from January 2015 to December 2019.Fisher exact test was used to compare the differences between PPC group and negative peritoneal cytology(NPC)group.Univariate and multivariate logistic regression analysis were used to evaluate the risk pathological factors leading to PPC in EC patients.Kaplan-Meier curve was used to evaluate the effect of PPC on progression-free survival(PFS)of EC patients.log-rank test was used to analyze the prognostic factors.Significant risk factors were further included in the Cox proportional hazards regression model multivariate analysis.To further evaluate the impact of PPC on patients with early EC,the independent risk factors and prognosis of patients with stage Ⅰ/Ⅱ PPC were analyzed in subgroups.In the systematic review,a computerized literature search was conducted in two major databases,PubMed and Web of Science.The search was limited to the period since the establishment of the database until June 2022,and the literature was screened,evaluated,and information extracted according to strict inclusion and exclusion criteria.The description of the relationship between the depth of myometrial invasion,lymph node metastasis,lymphatic vasculature infiltration(LVSI)and PPC was described by the Odds ratio(OR).The hazard ratio(HR)and 95%confidence interval(95%CI)were used to observe the survival outcome of patients.ResultsIn the retrospective study,a total of 202 patients were included,183(90.6%)were negative for PC and the remaining 19(9.4%)were positive.There were 180 stage Ⅰ/Ⅱpatients(89.1%)and 22 stage Ⅲ/Ⅳ patients(10.9%).Deep myometrial invasion(OR=3.57,95%CI 1.02-12.45,P=0.046)and lymph node metastasis(OR=7.16,95%CI 1.70-30.23,P=0.007)were independent risk factors for PPC in all stages of endometrial cancer;In a subgroup analysis,the independent risk factor for positive peritoneal cytology in patients with early-stage endometrial cancer was deep myometrial invasion(OR=6.22,95%CI 1.22-31.73,P=0.028).The 3-year PFS for all stages of patients with positive and negative peritoneal cytology was 72.9%and 92.7%respectively,and the difference was statistically significant(P=0.001).The 3-year PFS for early-stage patients was 82.5%and 96.2%respectively,and the difference was statistically significant(P=0.002).A multivariate analysis revealed that PPC was an independent prognostic factor for patients with endometrial cancer.In the systematic review,22 articles were finally included in the literature.Deep myometrial invasion(OR=2.01,95%CI:1.56-2.58,P<0.00001),lymph node metastasis(OR=5.70,95%CI:4.30-7.55,P<0.00001)and LVSI(OR=2.01,95%CI:2.06-2.61,P<0.00001)were the risk factors for PPC in EC patients.Survival analysis found that 5-year PFS/DFS/RFS in PPC group was significantly shorter than that in NPC group(HR=3.79,95%CI:2.93-4.91,P<0.00001),and PPC was an independent prognostic factor for endometrial cancer.Subgroup analysis of early endometrial cancer(HR=4.16,95%CI:3.07-5.64,P<0.00001),type Ⅰ endometrial cancer(HR=3.62,95%CI:2.37-5.54,P<0.00001),type Ⅱ endometrial cancer(HR=4.94,95%CI:2.3710.27,P<0.0001)found that PPC also independently affected the prognosis of earlystage EC,type Ⅰ EC and type Ⅱ EC.ConclusionPPC is associated with many poor prognostic factors in endometrial cancer,which is consistent with the high recurrence rate and low survival rate in patients with PPC.This study confirms that deep muscle infiltration and lymph node metastasis are pathological risk factors for PPC in patients with endometrial cancer.PPC is an independent prognostic factor for patients with endometrial cancer,affecting their PFS.The optimal treatment strategy for patients with PPC should be further explored through prospective multicenter studies.The use of peritoneal cytology has decreased as the existing guidelines do not provide clear treatment recommendations for endometrial cancer in PPC.However,it is concluded from this study that sending peritoneal cytology is still essential.