Routine liquid-based cytology specimens support lung cancer NGS panel testing
The study reports a feasibility analysis of applying routine liquid-based cytology suspensions to the Lung Cancer Compact Panel, a multiplex DNA and RNA next-generation sequencing assay. Investigators assessed 69 clinical specimens and found that DNA integrity was generally preserved, whereas RNA quality varied by fixative, with CytoRich Red yielding higher DV200 values than ThinPrep. Among 46 evaluable non-small cell lung cancer samples with known driver alterations, the assay achieved 95.7% concordance and 92.3% sensitivity, or 88.9% when RNA module failures were classified as negatives. These results demonstrate that standard cytology workflows can directly feed into comprehensive molecular profiling without dedicated preservation tubes, reducing preanalytical complexity in clinical laboratories.
The original study
Feasibility of routine clinical liquid-based cytology for lung cancer compact panel testing.
- Authors
- Shinomiya Y, Hatanaka KC, Okumura A, Nange A, Yamamoto M, Azuma M, et al.
- Journal
- Cancer cytopathology
- Type
- Journal Article
- PMID
- 42557973
Original abstract
BACKGROUND: The Lung Cancer Compact Panel (cPANEL) is a recently approved highly sensitive multiplex gene panel in Japan that supports both DNA- and RNA-based next-generation sequencing. Although cytological specimens are acceptable for cPANEL, unfixed cell pellets or dedicated preservation tubes are typically recommended. However, evidence remains limited regarding whether residual liquid-based cytology (LBC) cell suspensions prepared for routine cytological diagnosis can be used directly for cPANEL testing without dedicated molecular preservation or additional preanalytical processing. In this study, we evaluated the feasibility of applying LBC specimens that are widely used in contemporary clinical practice to cPANEL. METHODS: We analyzed DNA and RNA quality in 69 clinical LBC specimens. Among these, 51 specimens containing non-small cell lung cancer cells with previously determined driver alteration status were subjected to cPANEL testing to evaluate assay concordance with clinical companion diagnostic results. RESULTS: DNA integrity was generally well preserved (DNA Integrity Number [DIN]: 6.2 ± 1.5). In contrast, RNA integrity showed greater variability (DV200: 16.4 ± 12.1%). ThinPrep-fixed specimens demonstrated lower DIN and DV200 values compared with CytoRich Red-fixed specimens. Although all samples successfully passed the DNA-based cPANEL assay, six cases (11.8%) failed the RNA-based assay, with RNA yield being a major contributing factor. Among the 46 evaluable specimens, concordance was 95.7% and sensitivity was 92.3%, or 88.9% including RNA module failures as cPANEL-negative. CONCLUSIONS: With appropriate fixative selection and adequate cellularity, cPANEL using clinical LBC specimens may serve as a practical diagnostic platform. We demonstrated that routine LBC specimens can be directly applied to cPANEL without special preanalytical processing.