Factor affecting lymph node metastasis in uterine papillary serous carcinomas: a retrospective analysis.

The aim of this study was to investigate the risk factors for lymph node metastasis (LNM) in patients with uterine serous cancer (USC) who underwent systematic staging surgery. Eighty patients who were operated on for pure uterine serous papillary carcinoma between 2008 and 2020 in our clinic were retrospectively analysed. The effects of demographic information and clinicohistopathological characteristics of the included patients on LNM were examined. The median age of the patients included in the study was 64.3 and the tumour diameter was 3.8 cm. At the time of diagnosis, 65.8% of the cases were in the advanced stage, while 34.2% were in the early stage. There was no LNM in 42 (52.5%) of the cases, only pelvic in six (7.5%), only paraaortic LNM in four (5%) patients, and both pelvic and paraaortic LNM in 24 (30%) patients. When factors that may affect LNM were evaluated with multivariate analysis, lymphovascular space invasion (LVSI) and cytology positivity were found to be independent risk factors ( p  < 0.05). In addition, the rate of isolated paraaortic lymph node involvement in LNM positive patients is 5%, which is 100% associated with LVSI.Impact Statement What is already known on this subject? Uterine papillary serous carcinomas (UPSC) are an uncommon and aggressive histological subtype of endometrial cancer. The high risk of recurrence and tendency to migrate into the abdomen of these tumours is not always connected with lymph node and distant organ metastasis, tumour size, LVSI positive and depth of myometrial invasion. What do the results of this study add? Most patients with UPSC are diagnosed at an advanced stage. In this study, in which 80 patients with pure serous histology were evaluated retrospectively, and LVSI and peritoneal cytology positivity were found to be two important prognostic factors for lymph node metastasis. What are the implications of these findings for clinical practice and/or further research? In this study, cytology and LVSI positivity were identified as two predictive markers for LNM, and it is seen that cytology positivity still maintains its importance in these tumours with peritoneal spread. Furthermore, patients with isolated paraaortic lymph node involvement were shown to be LVSI positive, and isolated paraaortic LNM should be investigated in patients with LVSI positivity.