Sentinel lymph node biopsy compared with systematic lymphadenectomy in patients with uterine carcinosarcoma (536)

Abstract

<b>Objectives:</b> To assess survival among patients with newly diagnosed uterine carcinosarcoma undergoing sentinel lymph node biopsy (SLN) alone and those undergoing systematic lymphadenectomy (LND). <b>Methods:</b> We identified all patients with newly diagnosed uterine carcinosarcoma who underwent primary surgical management at our institution from January 1996 to December 2019. Patients with gross extrauterine disease of any type were excluded. The SLN cohort underwent SLN biopsy alone, with bilateral SLNs identified. The systematic LND cohort did not undergo SLN biopsy. Progression-free survival (PFS) and overall survival (OS) were defined from the date of surgery to the event. Appropriate statistical testing was performed. <b>Results:</b> We identified 99 SLN and 100 LND patients. Median age and BMI were not different between the groups. Minimally invasive surgery was the approach in 56 (56.6%) SLN (56.6%) and 47 (47%) LND patients (p=0.2). There was no significant difference between cohorts with respect to the degree of myoinvasion (<50%, >50%), presence of lymphovascular space invasion (LVSI), stage, or positive washings. The median total node count was four (range: 1-13) for SLN and 19 (range: 2-50) for LN (p<0.001). Nodal metastasis was noted in 26 (26%) SLN and 21 (21%) LND (p=0.4). Postoperative therapy was given to 91 (92%) SLN and 87 (87%) LND (p=0.3). The type of postoperative therapy administered was as follows: none in eight (8%) SLN and 14 (14%) LND; chemotherapy with or without radiation (RT) in 86 (87%) SLN and 71 (71%) LND; RT alone in five (5%) SLN and 15 (15%) LND (p=0.02). Median follow-up was 51.3 months (range: 0.9-211.1) for the SLN cohort compared with 40.8 months (range: 0.5-269.1) for the LND cohort (p=0.3). The 4-year PFS was 62.4% (SE 5.3%) for SLN and 47.7% (SE 5.5%) for LND (p=0.07). The 4-year OS was 72.4% (SE 4.9%) for SLN and 62.2% (SE 4.2%) for LND (p=0.2). There was no difference in PFS or OS when adjusted for the type of postoperative therapy (chemotherapy with or without RT vs none/RT). An isolated nodal recurrence occurred in two (2%) SLN and four (4%) LND patients (p=0.2). <b>Conclusions:</b> There is no difference in PFS or OS among patients who have uterine carcinosarcoma and undergo SLN biopsy versus systematic LND. SLN biopsy adequately detects the presence of nodal metastasis in these patients. SLN biopsy alone does not compromise oncologic outcomes, and systematic LND is unnecessary in the setting of successful bilateral SLN mapping.