"Risk of venous thromboembolism and bleeding after major surgery for ovarian cancer: standard in-hospital versus extended duration of thromboprophylaxis": Comment.

We read with interest the report by Wiegers et al. [ [1] Wiegers H.M.G. Schaafsma M. Guman N.A.M. Zelisse H.S. Mulder F.I. Middeldorp S. van Es N. Mom C.H. Risk of venous thromboembolism and bleeding after major surgery for ovarian cancer: standard in-hospital versus extended duration of thromboprophylaxis. J Thromb Haemost. 2023; 21: 294-302 Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar ] describing the effects of extended prophylaxis on the rates of venous thromboembolism (VTE) and bleeding in patients with ovarian cancer following surgery and the associated commentary [ [2] Alsehly A.A. Wang T.F. Carrier M. Time to rethink extended thromboprophylaxis after cancer surgery?. J Thromb Haemost. 2023; 21: 198-199 Abstract Full Text Full Text PDF Scopus (1) Google Scholar ]. In this “before and after” study, the rates of VTE in the first 28 days following surgery for ovarian cancer were compared between the 2 groups (1 before, and 1 after the introduction of 28-day prophylaxis). Although the study did not have the statistical power to truly examine this effect, the results are in agreement with our previous “before and after study” of 1200 patients with gynecological cancer (including 519 patients with ovarian cancer) [ [3] Abu Saadeh F. Marchocki Z. O’Toole S.A. Ibrahim N. Gleeson N. Norris L.A. Extended thromboprophylaxis post gynaecological cancer surgery; the effect of weight adjusted and fixed dose LMWH (tinzaparin). Thromb Res. 2021; 207: 25-32 Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar ]. In our study, the risk of VTE following extended low molecular weight heparin (LMWH) prophylaxis (adjusted for duration of hospital stay, surgical complexity, tumor site, and body mass index) was not significantly reduced (hazard ratio, 0.677; 95% CI, 0.376-1.219). When only ovarian cancer cases were considered, we found the 30-day postsurgery rate of VTE to be 2.3% in the extended prophylaxis group, which was not significantly lower than the comparator cohort at 3.7% (p = .362).