Cytology cell blocks are suitable for immunohistochemical testing for PD-L1 in lung cancer

Wang, H.; Agulnik, J.; Kasymjanova, G.; Wang, A.; Jiménez, Patricia Pérez; Cohen, Victor; Small, David; Pepe, C.; Sakr, Lama; Fiset, Pierre; Auger, Manon; Camilleri-Broët, Sophie; Din, M. Alam El; Chong, George; Kempen, Léon C van; Spatz, Alan

doi:10.1093/annonc/mdy126

Cited by 99 publications

(135 citation statements)

References 25 publications

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“…Recommendations on type and length of fixation (10% neutral buffered formalin, fixation time between 6 and 48 hours) and cut sections storage modalities (stable temperature for 4–6 weeks) are well suggested35 36; interestingly, some authors have previously reported a slightly higher rate of high expression of PD-L1 (TPS>50%) in cytology specimens compared with small biopsies or resection specimens 20 28. As possible explanation relied on the likely probability of delayed or improper overfixation of surgical resection specimens 20. This is not confirmed by our results.…”

Section: Discussioncontrasting

confidence: 73%

PD-L1 expression on routine samples of non-small cell lung cancer: results and critical issues from a 1-year experience of a centralised laboratory

et al. 2019

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AimsOur laboratory is a centralised centre receiving routine non-small cell lung cancer (NSCLC) samples for programmed death ligand-1 (PD-L1) immunohistochemical (IHC) evaluation. Since literature data are not concordant here we review our clinical records to assess the rate of PD-L1 positive and negative NSCLC cases in real-world practice.MethodsPD-L1 expression was evaluated by a validated 22C3 IHC laboratory developed test on 211 prospectively collected routine NSCLC samples, received from 10 outside institutions. PD-L1 expression was assessed by the tumour proportion score (TPS) and reported by using a three cut-point system: TPS<1, TPS 1%–49% and TPS≥50%.ResultsOverall, 193 out of 211 samples (91.5%) meet the criteria for adequacy (more than 100 viable neoplastic cells). In 62.7% (121/193) of samples TPS was <1%; 17.6% of samples (34/193) expressed PD-L1 with a TPS of 1%–49% and 19.7% (38/193) with a TPS of >50%. There was no significant difference in PD-L1 expression rates between different histotypes and site of sampling. Instead, a statistically significant difference was associated to the type of samples: in fact, cytological samples were more frequently negative for PD-L1 expression (TPS<1%) and less often displayed PD-L1 expression at high levels (TPS>50%) than surgical resections and biopsies.ConclusionsWe present a referral laboratory experience on IHC PD-L1 expression of prospectively collected routine NSCLC samples. Data from the real-world practice can better clarify the percentage of PD-L1 positive and negative cases, to establish benchmarks for good practice standards.

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Section: Discussioncontrasting

confidence: 73%

PD-L1 expression on routine samples of non-small cell lung cancer: results and critical issues from a 1-year experience of a centralised laboratory

et al. 2019

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“…Assessing PD‐L1 expression by IHC on cytology samples is feasible . Although to the best of our knowledge there currently is no commercially validated PD‐L1 assay for cytology samples, more and more studies have shown that protocols optimized for formalin‐fixed paraffin‐embedded (FFPE) tissues can be adjusted for cytological samples . The majority of these studies used cytology cell blocks only and very few studies tested cytological FNA specimens .…”

Section: Introductionmentioning

confidence: 99%

Programmed death–ligand 1 expression on direct Pap‐stained cytology smears from non–small cell lung cancer: Comparison with cell blocks and surgical resection specimens

Lozano

Abengozar-Muela

Echeveste

et al. 2019

Cancer Cytopathology

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Background Programmed death–ligand 1 (PD‐L1) expression, as assessed by immunohistochemistry (IHC), is used to select patients with non–small cell lung cancer (NSCLC) for anti‐programmed cell death protein 1 (PD‐1)/PD‐L1 therapy. The current study evaluated the feasibility and efficacy of PD‐L1 immunostaining and quantitation on direct Papanicolaou‐stained cytological smears compared with formalin‐fixed paraffin‐embedded samples (cytological cell blocks and surgical resection specimens) in NSCLC cases using 2 commercially available assays: the PD‐L1 IHC 22C3 pharmDx assay (Agilent Technologies/Dako, Carpinteria, CA, USA) and the Ventana SP263 Assay (Ventana Medical Systems Inc, Tucson, Arizona). Methods PD‐L1 immunostaining using either both or one of the assays was tested in 117 sets of paired samples obtained from 62 NSCLC cases. The tumor proportion score was reported in every case following the recommendations of the International Association for the Study of Lung Cancer (IASLC). Results In 57 sets of samples, both PD‐L1 assays were used. Due to the availability of samples, only 1 assay was performed in 3 sets of samples and in 2 cases, only cytology smears were used and tested for both assays. A total of 113 sets of paired samples finally were evaluated; 4 cases could not be studied due to intense nonspecific background staining. A significant concordance between the 2 assays on cytological smears was found. Concordance between paired cytological smears and formalin‐fixed paraffin‐embedded samples was observed in 97.3% of the cases. Conclusions The quantification of PD‐L1 expression on direct Papanicolaou‐stained cytology smears is feasible and reliable for both PD‐L1 assays.

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“…Cytology samples are sometimes microdissected, or they can also be directly scraped without microdissection [25]. The advantage of this approach is that there is no formaldehyde fixation and that the cell block can then be spared for other more appropriate analyses such as immunohistochemistry for diagnostic/therapeutic markers such as ALK, ROS, and PD-L1 expression [28, 29]. …”

Section: Introductionmentioning

confidence: 99%

Diff-Quik Cytology Smears from Endobronchial Ultrasound Transbronchial Needle Aspiration Lymph Node Specimens as a Source of DNA for Next-Generation Sequencing Instead of Cell Blocks

et al. 2019

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Background: Next-generation sequencing (NGS) in lung cancer specimens from endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is usually performed on formalin-fixed paraffin-embedded cell block material. Objectives: Since DNA can be damaged by this process, we investigated the potential of using DNA extracted from Diff-Quik cytology smears made for rapid on-site evaluation during EBUS-TBNA. Methods: In a prospective study, 67 patients undergoing diagnostic EBUS-TBNA were analysed. We compared cell blocks and smears for DNA yields and sequencing (TruSeq Amplicon Cancer Panel) outcomes. Smears were also evaluated for tumour cell fraction and overall cellularity (cell count). Results: Primary lung cancer was diagnosed in 64 patients and metastatic malignancy in 3 patients. The DNA yield from smears was significantly higher than that obtained from matched cell blocks (mean 1,740 vs. 434 ng; p = 0.001). For 33 cases with matched smears and cell blocks the mutation profiles were similar. Smears with abundant malignant cells (using a cut-off of > 25% tumour cell fraction and > 1,000 cells) accurately predicted high (> 50 ng) DNA yield and therefore success in triaging samples to sequencing. In terms of tissue workflow, using only smears as source DNA for sequencing was an improvement in the use of only cell blocks (54/67 [80.6%] vs. 41/67 [61.2%]); however, the use of cell blocks when smears were not available or did not yield sufficient DNA further improved the success rate to 62/67 (92.5%) cases. Conclusion: We recommend smears in laboratory workflows as the primary source of DNA for NGS following an EBUS procedure.

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Cytology cell blocks are suitable for immunohistochemical testing for PD-L1 in lung cancer

Cited by 99 publications

References 25 publications

PD-L1 expression on routine samples of non-small cell lung cancer: results and critical issues from a 1-year experience of a centralised laboratory

PD-L1 expression on routine samples of non-small cell lung cancer: results and critical issues from a 1-year experience of a centralised laboratory

Programmed death–ligand 1 expression on direct Pap‐stained cytology smears from non–small cell lung cancer: Comparison with cell blocks and surgical resection specimens

Diff-Quik Cytology Smears from Endobronchial Ultrasound Transbronchial Needle Aspiration Lymph Node Specimens as a Source of DNA for Next-Generation Sequencing Instead of Cell Blocks

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