title: Is it necessary to perform routine appendectomy for mucinous ovarian neoplasms? A retrospective study and meta-analysis.
abstract: OBJECTIVE
  To evaluate whether routine appendectomy is necessary in all patients with mucinous borderline ovarian tumor (mBOT) or mucinous ovarian cancer (MOC) who undergo gynecologic surgery.
  
  
  METHODS
  The database of Qilu Hospital was searched for women who underwent appendectomy in a primary surgery for an ovarian tumor between June 2005 and June 2015 and whose final diagnosis was mBOT, MOC or primary appendiceal tumor. A retrospective review was performed, as well as a meta-analysis of the literature to further validate the findings.
  
  
  RESULTS
  Seventy-one patients, 29 with mBOT and 42 with malignant mucinous tumors (including 40 with primary MOC and 2 with appendiceal mucinous adenocarcinoma), underwent appendectomy at the time of primary surgery. Among those with mBOT, two (6.9%) appendices were grossly abnormal and pathologically diagnosed with appendiceal implantation by mBOT. In the 42 patients with malignant disease, five (12%) appendices had a grossly abnormal appearance, one (2.4%) was diagnosed with an appendiceal metastasis from MOC and two (4.7%) were primary appendiceal adenocarcinoma. For grossly normal appendices, only one (2.4%) was confirmed to have microscopic metastasis from MOC. The meta-analysis included a total of 914 mBOT and MOC cases with appendectomies, including our current cases. The estimated rate of overall appendiceal pathology is 4.97%, and the pooled odds ratio (OR) showed statistical differences between MOC and mBOT (MOC vs. mBOT, OR=2.15, P<0.05). The estimated malignant pathology rate in macroscopically normal vs. abnormal appendices is 1.4% and 59%, respectively, with an estimated OR up to 97.5 (95% CI 28.1-338.5, P<0.05).
  
  
  CONCLUSIONS
  There is not sufficient evidence to support a routine appendectomy for patients with a grossly normal appendix in mBOT and MOC. A careful intra-operative exploration of the appendix is crucial, but appendectomy is only warranted when the appendix is abnormal.
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Aoshuang
authors.initials: A
authors.lastname: Cheng
authors.affiliation: Shandong University School of Medicine, Ji'nan, Shandong 250012, PR China.
authors.forename: Minghao
authors.initials: M
authors.lastname: Li
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, 250 East Superior Street, Chicago, IL 60611, USA.
authors.forename: Margaux J
authors.initials: MJ
authors.lastname: Kanis
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China; Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China; Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Baoxia
authors.initials: B
authors.lastname: Cui
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: YouZhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China.
authors.forename: Xingsheng
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China; Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Ji'nan, Shandong 250012, PR China. Electronic address: kongbeihua@sud.edu.cn.
authors.forename: Beihua
authors.initials: B
authors.lastname: Kong
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology / Q000601:surgery; D000328:Adult; D001062:Appendectomy; D001063:Appendiceal Neoplasms / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D005260:Female; D006801:Humans; D008875:Middle Aged; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D010051:Ovarian Neoplasms / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies
keywords: Appendectomy; Borderline; Malignancy; Ovarian mucinous tumors