LVSI Classification and Impact on Outcomes in Stage I Endometrial Cancer with Drs. Christian Dagher and Nadeem Abu-Rustum

Nadeem Abu-Rustum bio: Dr. Abu-Rustum is a board-certified gynecologic oncologist who specializes in the surgical treatment of gynecologic cancers at Memorial Sloan Kettering Cancer Center. He is also a professor of obstetrics and gynecology at Weill Cornell Medical College. Dr. Abu-Rustum has a special interest in minimally invasive surgery (laparoscopy) for the treatment of cancerous and noncancerous diseases of the female reproductive system, and his clinical research focuses on surgical therapy for gynecologic cancers and innovative surgical approaches to treating gynecologic disorders. Christian Dagher bio: Christian Dagher is a former research fellow at Memorial Sloan Kettering, and current OBGYN resident at the University of Pennsylvania. He holds a master's degree in clinical epidemiology and health-services research from Weill-Cornel. Before moving to the US, he completed an OBGYN residency at the American University of Beirut and is interested in studying survival biomarkers in endometrial cancer.  Highlights: The 2023 FIGO staging system for endometrioid endometrial carcinomas included the extent of lymphovascular invasion as a determinant of stage. The new staging system, groups tumors with no lymphovascular space invasion and those with focal invasion (<5 vessels) into one category and upstages those with substantial invasion ( 5 or more vessels). This study aimed to evaluate the relationship between the extent of lymphovascular invasion and oncologic outcomes in patients with stage I endometrioid endometrial cancer. This study is a retrospective analysis of 1555 patients with FIGO 2009 stage I endometrioid endometrial cancer who underwent total hysterectomy and lymph node assessment at two tertiary centers between 2012 and 2019, categorized by the extent of lymphovascular invasion (no, focal, or substantial invasion as defined by the WHO). Key findings showed that both focal and substantial lymphovascular invasion were linked to lower 5-year progression-free survival (68.7% and 70.5% for substantial and focal invasion, respectively, compared to 90.7% for no invasion). This was true even after limiting the analysis to myoinvasive grades 1 and 2.  In conclusion, focal and no lymphovascular invasion have different prognostic outcomes and should not be combined into a single category as proposed by the FIGO staging system. Focal and substantial lymphovascular invasion were not associated with distinct prognostic outcome that could support upstaging of the latter.