Ikuko Emoto

Possible overestimation of treatment effects of pelvic and para-aortic lymphadenectomy for early-stage ovarian clear cell carcinoma: a retrospective propensity-score weighted multi-center cohort study

The treatment effects of lymphadenectomy in early-stage ovarian clear cell carcinoma (OCCC) reported in previous studies may have been overestimated owing to confounding factors. This study aimed to investigate the treatment effect of pelvic and para-aortic lymphadenectomy (PeNPAN) in early-stage OCCC, with careful adjustment for potential confounders. This retrospective multi-center cohort study involved women with preoperatively suspected stage I OCCC. We included patients who underwent surgery for OCCC between 2005 and 2019 at 11 affiliated institutions. The exposure (PeNPAN) group comprised patients who underwent PeNPAN. The primary outcome was disease-free survival (DFS). Additionally, hazard ratios (HRs) of lymphadenectomy for DFS were estimated using unadjusted and propensity score-weighted Cox regression models and biased models applied in previous studies. To identify strong confounders, we further examined factors associated with recurrence that differed between the groups. We analyzed 304 women who underwent surgery for preoperatively suspected stage I OCCC. The unadjusted HR for DFS was 0.63 (95% confidence interval [CI]=0.36-1.09; p=0.10), and the propensity-score adjusted HR was 0.82 (95% CI=0.42-1.58; p=0.55). The biased model showed a statistically significant HR of 0.59 (95% CI=0.36-1.00; p=0.048). Adhesions in the Douglas' pouch and cardiovascular disease were associated with recurrence and were more prevalent in the control group, suggesting potential confounders. After adjusting for potential confounders, the observed treatment effects of lymphadenectomy in the biased models were no longer statistically significant. Future investigations should carefully account for possible confounders, including intraoperative adhesions and comorbidities.

Differentiation of uterine fibroids and sarcomas by MRI and serum LDH levels: a multicenter study of the KAMOGAWA study

In the differential diagnosis between uterine fibroids and uterine sarcomas, real-world magnetic resonance imaging (MRI) diagnostic information is scarce; furthermore, high diagnostic sensitivity is important in clinical practice. We previously developed a diagnostic algorithm to detect uterine sarcoma with high sensitivity using simple MRI images and serum lactate dehydrogenase (LDH) levels. In this multicenter study, we investigated the preoperative diagnosis of sarcoma in the real world and further validated the usefulness of our diagnostic algorithm. Of 154 uterine sarcomas and 154 uterine fibroids treated at 15 centers between January 2006 and December 2020, 139 sarcomas (16 smooth muscle tumors of uncertain malignant potential) and 141 fibroids with diffusion-weighted imaging information were included in the analysis. The diagnostic algorithm was validated by 3 radiologists who were blinded to the clinical information and pathologic diagnoses and who read the MRIs. The sensitivity/specificity of preoperative diagnosis was 77.7%/92.9% for the preoperative report; 92.1%/72.3% for algorithm A; and 82.0%/85.8% for algorithm B (McNemar's test p<0.05). Comparison of overall survival rates among 3 groups (Group 1: negative A, Group 2: positive A and negative B; Group 3: positive B) using algorithms A and B showed p=0.012. On multivariate analysis, stage, and serum LDH level were independent prognostic factors. MRI is useful for preoperative diagnosis of uterine sarcoma, and the sarcoma diagnostic algorithm presented in this study is an option for diagnosing sarcoma with greater sensitivity. This information should be shared with patients.