I.A. Kruglova1,4, S.V. Zinovev2, O.V. Utkin3, A.N. Denisenko1, P.S. Zubeev4, E.P. Abalikhina4, E.Yu. Chernavina4, N.A. Illarionova2, S.V. Gamayunov2

1City Hospital №35, Nizhny Novgorod

2Nizhny Novgorod Regional Clinical Oncological Dispensary, Nizhniy Novgorod

3Nizhny Novgorod Research Institute of Epidemiology and Microbiology named after acad. I.N. Blokhina of Rospotrebnadzor, Nizhny Novgorod

4City Hospital №33, Nizhny Novgorod

Kruglova Irina A. ― doctor of clinical laboratory diagnostics (cytologist) of the clinical diagnostic laboratory of the City Hospital №35

47 Respublikanskaya Str., Nizhny Novgorod, 603089, Russian Federation, tel.: (831) 428-81-21, +7-908-239-52-71, e-mail:, ORCID ID: 0000-0001-7955-349X

Abstract. Ovarian cancer is a heterogeneous group of malignant neoplasms, where due to the absence of specific clinical symptoms at an early stage of the disease, more than 75% of patients are diagnosed at a late stage. One of the main, and often the only first signs of the disease is the accumulation of ascitic fluid. In this regard, there is an urgent need to take ascitic fluid for the purpose of cytological examination to confirm serositis and refer the patient to an oncologist, as well as to optimize the examination protocol at the pre-hospital stage. The same priority arises with regard to the intake of pleural fluid, because often due to general intoxication, pleurisy can be reactive, the verification of which plays a key role in choosing the tactics of treatment of the patient. The «gold standard» for determining the nature of effusion fluids is cytological examination. At the same time, its diagnostic effectiveness is 48-88% for the study of ascitic fluid and 62-90% for pleural fluid. To increase the efficiency of the method, it is necessary to apply an integrated approach using ICC research. In 2022, the first test system for immunocytochemical research in the biochip format was registered in the Russian Federation. With its help, it is possible to perform ICC studies without additional laboratory equipment due to the «Laboratory-on-a-chip» principle, which creates the necessary conditions for verifying the diagnostic process already at the stage of outpatient polyclinic care centers, reducing the time to start treatment for a specific category of patients.

The aim of the work is to evaluate the diagnostic informativeness of using the SER-1 test system (RUSSELL, Russia) in the biochip format to detect the dissemination of ovarian cancer.

Material and methods. 131 samples of biological material (78 samples of ascitic fluid, 34 abdominal flushing and 19 samples of pleural fluid) obtained from patients with suspected PC were analyzed. All fluid samples were initially studied cytologically with an assessment of the nature of the exudate, cellularity. Further, the results of the study were classified according to the International cytological classification of effusion fluids (TIS RSFC). In the future, the cases that the cytologist attributed to the groups «atypia of unclear significance», «suspicion of a malignant process» were sent to the ICC study. Using the SER-1 test system (RUSSELL LLC, Russia). The diagnostic effectiveness of the method was evaluated both in general and separately for ascitic, pleural fluids and intraoperative flushes using the method of constructing the ROC curve.

Results. The performance indicators of the primary cytological examination of the generalized material calculated during the ROC analysis (Fig. 4a) were: accuracy ― 66,4%, sensitivity ― 63,2%, specificity ― 73,5%. When analyzing the performance indicators of primary cytological examination based on the results of ROC analysis of the material according to localization, the following data were obtained: for ascitic fluids, accuracy, sensitivity and specificity were determined at the level of 67,6%, 62%, 81%, respectively; for pleural effusion at the level of 66,7%, 62,5%, 71,4%, respectively; and for intraoperative flushes at the level of 62,5%, 66,7%, 50%, respectively. The calculated indicators of the effectiveness of complex cytological and ICC studies according to ROC analysis were: for the general sample: accuracy, sensitivity, specificity ― 67,3%, 57,9%, 88,2%, respectively; for ascitic fluid: 67,6%, 58%, 90,5%; for pleural effusion: 66,7%, 50%, 85,7%; for intraoperative flushing: 66,7%, 61,1%, 83,3%.

Conclusion. The use of an integrated approach in the form of cytological and ICC studies of effusion fluids in the case of RS allows to increase the detectability of malignant tumor cells in cytological samples by 2.0 times and reduces the proportion of conclusions with atypia of unclear significance by 10% or more. The use of the SER-1 test system contributes to more accurate detection of tumor cells in exudates from serous cavities in ovarian cancer, increasing the effectiveness of cytological examination.

Key words: ovarian cancer, ascites, cytological examination, ICC, SER-1.