title: Complications and thromboembolic events associated with tamoxifen therapy in patients with breast cancer undergoing microvascular breast reconstruction: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Tamoxifen therapy is integral in the treatment of patients with hormone receptor-positive breast cancer. However, there is an association between tamoxifen and thromboembolic events. Flap and systemic thromboembolic events have devastating consequences in microvascular breast reconstruction. Currently, there are conflicting data on the association between tamoxifen therapy and thromboembolic complications for patients undergoing microvascular breast reconstruction. The objective of this study is to determine if perioperative tamoxifen therapy modifies the risk of complications and thromboembolic events for patients with breast cancer undergoing microvascular breast reconstruction.
  
  
  METHODS
  A comprehensive literature search was performed across six databases from January 2003 to February 2016. Pooled estimates and relative risk (RR) were calculated using a random-effects model, confounding was examined with meta-regression, and risk of bias was evaluated. Primary outcomes were thrombotic flap complications and total flap loss. Study quality was assessed using Downs and Black criteria.
  
  
  RESULTS
  Of 95 studies reviewed, 4 studies comprising 1700 patients and 2245 procedures were included for analysis. Compared to non-recipients, patients on tamoxifen were at increased risk of developing thrombotic flap complications (pooled RR 1.5; 95% CI 1.14-1.98) and total flap loss (pooled RR 3.35; 95% CI 0.95-11.91). There was no significant heterogeneity present in either outcome and no evidence of publication bias.
  
  
  CONCLUSIONS
  Perioperative tamoxifen therapy may increase the risk of thrombotic flap complications and flap loss for patients with breast cancer undergoing microvascular reconstruction. These findings further the ability of providers to make evidence-based recommendations in the perioperative management of patients with breast cancer.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA. parikhr@wudosis.wustl.edu.|Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA. parikhr@wudosis.wustl.edu.|Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, 660 S. Euclid Ave, Suite 1150 NW Tower, Box 8238, St. Louis, MO, 63110, USA. parikhr@wudosis.wustl.edu.
authors.forename: Rajiv P
authors.initials: RP
authors.lastname: Parikh
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.|Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Odom
authors.affiliation: Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Liyang
authors.initials: L
authors.lastname: Yu
authors.affiliation: Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Graham A
authors.initials: GA
authors.lastname: Colditz
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Terence M
authors.initials: TM
authors.lastname: Myckatyn
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D006801:Humans; D016462:Mammaplasty; D064887:Observational Studies as Topic; D011183:Postoperative Complications / Q000139:chemically induced*; D016032:Randomized Controlled Trials as Topic; D013524:Surgical Flaps / Q000098:blood supply; D013629:Tamoxifen / Q000009:adverse effects* / Q000627:therapeutic use; D013923:Thromboembolism / Q000139:chemically induced*; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen
keywords: Breast cancer; Breast reconstruction; Selective estrogen receptor modulator; Tamoxifen; Thromboembolism