Introduction/Background*To assess the odds of having positive nodes in women who underwent a sentinel lymph node biopsy compared with those who underwent a lymphadenectomy in the SUCCOR study.

Methodology We used data from the SUCCOR study, a European multicentre study that collected retrospective information of 1272 women who underwent a radical hysterectomy by open or minimally invasive surgery for stage IB1 cervical cancer (FIGO 2009) between January 2013 and December 2014. After exclusions, the final sample included 1157 patients. Missing values were imputed with the median in quantitative variable and grouped in a new category in qualitative ones. The variables associated with the realisation of sentinel node biopsy were used to create a propensity score. When comparing both groups (sentinel vs non sentinel node) significant differences were found in the surgical experience, tumor size and surgical approach. To account for these differences, inverse probability weighting was performed to consider both groups fully comparable.

We used inverse probability weighting to define two comparable groups (sentinel node biopsy vs lymphadenectomy). We performed a logistic regression to calculate the odds of having positive nodes after a sentinel node biopsy compared with a lymphadenectomy in the weighted sample. We also compared the disease-free survival and the overall survival between groups in the weighted cohort.

Result(s)*We found that women who underwent a sentinel node biopsy had smaller tumours and were more using minimally invasive surgery . In the weighted cohort we found that women who underwent a sentinel node biopsy had a 15.7% of positive nodes vs. 10-7 % in the lymphadenectomy arm. Sentinel node patients had 1.63-fold higher odds (95% CI: 1.00-2.64) of having a diagnosis of positive nodes. We did not find that undergoing a sentinel node biopsy had any association neither with disease free survival nor with overall survival.

Conclusion*After applying an Inverse Probability Weighting using a propensity score, the use of Sentinel Lymph Node Biopsy increased the detection of positive nodes by 63% in the SUCCOR study . The standard pelvic lymphadenectomy might underdiagnose the nodal status in early cervical cancer.