The Role of Novel Tiered Reporting System in Serous Fluid Cytology and Risk of Malignancy Assessment: A Retrospective Study in a Tertiary Care Center

Abstract

Background: Serous effusion cytology (SEC) reporting is important for the management of the cancer patient. The International System for Reporting Serous Fluid Cytology (ISRSFC) provides tiered reporting terminology to standardize practice, looking into the risk of malignancy (MAL) for each category. In this study, we have assessed the utility of the ISRSFC and reported our experience at a tertiary cancer center. Materials and Methods: Serous fluid cytology reported from January 2019 to December 2020 was categorized according to ISRSFC diagnostic categories: nondiagnostic (ND), negative for MAL (NFM), atypia of undetermined significance (AUS), suspicious for MAL (SFM), and MAL. The risk of MAL (ROM) and performance parameters were calculated. Results: A total of 2150 serous effusions including 1160 pleural, 929 peritoneal, and 61 pericardial effusions from 2071 patients were reported. There were 742 males and 1329 females. The patient’s age ranged from less than 1 yr to 95 years. The volume of the sample ranged from 0.5 ml to 2000 ml. There were 114 ND (5.32%), 1068 NFM (49.67%), 144 AUS (6.69%), 82 SFM (3.81%), and 742 MAL (34.51%) cases. Adenocarcinoma was the most common MAL involving serous fluids (91.50%). The calculated ROM was 15.38% for ND, 24.26% for NFM, 62.96% for AUS, 79.16% for SFM, and 100% for MAL. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were, respectively, 68.04%, 96.96%, 96.35%, 72.07%, and 81.33%. Conclusion: ISRSFC provides consistent reporting terminology and the ROM for each category aids in clinical correlation and management.

The International System for Reporting Serous Fluid Cytopathology: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies

“…One potential reason could be the different cancer prevalence found, based on the population tested in various centers. For instance, in the included studies performed exclusively in cancer hospitals, 16,24,25,30 we found higher pooled ROMs in the ND [40% (95% CI; 21%-62%) vs. 22% (95% CI; 11%-39%)], NFM [20% (95% CI; 13%-30%) vs. 9% (95% CI; 5%-17%)], and AUS categories [55% (95% CI; 47%-63%) vs. 46% (95% CI; 31%-62%)], respectively, compared with academic and community hospitals serving the general population. Another reason might be the reported interobserver variability among pathologists when interpreting effusion cytology specimens, following the published TIS diagnostic criteria.…”

“…However, we ran a subgroup analysis to minimize the effect of the different follow-up methodology. In addition, the patient population sample was not representative in some studies, deriving exclusively from cancer hospitals, 16,24,25,30 and we similarly run a subgroup analysis to evaluate their effect. Last, as shown in the funnel plot, there was potential publication bias in this study.…”

“…Table 1 shows the main characteristics of the 16 studies included in this review. Seven of them were performed in India, [22][23][24][25][26][27][28] 2 in Portugal, 15,16 2 in China (including 1 in Hong Kong), 29,30 2 in the United States, 31,32 and 1 in Singapore, 33 Greece, 34 and Korea. 35 Furthermore, 3 studies used exclusively histology as their follow-up methodology.…”

“…In the "index test" domain, most studies did not mention if cytology was interpreted without knowing the reference standard findings, resulting in an "unclear risk of bias" interpretation. Last, 4 studies 16,24,25,30 were conducted in cancer hospitals, resulting in a "high concern" regarding applicability.…”