Uninvited Reply Letter - A response to - A commentary on “Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry”

Sep 24, 2026

A letter to the editor responds to a commentary by Chen et al. on a colorectal cancer study using intraoperative flow cytometry (iFC) to detect cancer cells and assess tumor margins. The authors address concerns about cell-type diversity, DNA index calculation, assay sensitivity, and the study’s focus on proliferation-related properties, arguing the added data and broader literature support iFC effectiveness and clinical relevance, while acknowledging limitations and ongoing validation efforts.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Response to commentary on iFC cancer-cell detection

Cell-type diversity in resection margins

Validity of DNA Index and assay detection limit

Scope of proliferation-related identification and future work

’Uninvited Reply Letter A response to ‘A commentary on “Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative ﬂow cytometry”’ Christina Bali, PhDa , Vaia K. Georvasili, MDa , Michail Mitsis, PhDa,b , George Vartholomatos, PhDc , Georgios S. Markopoulos, PhDa,c,* Dear Editor, We are grateful for the thoughtful commentary provided by Chen et al. [1] on our study, ‘Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative ﬂow cytometry’[2] . Their insights and concerns are valuable to the ongoing development and reﬁnement of this technique. However, we believe that there are additional data in our original work and in the broader literature that successfully address their concerns. First, the authors express concern about the diversity of cell types in the resection margin tissues, which they argue could complicate the identiﬁcation of cancer cells by intraoperative ﬂow cytometry (iFC) . While we acknowledge the complexity of cell types in these tissues, it’s important to note that our study was designed with this complexity in mind. In that manner, the samples taken from the cancer as well as normal, uninvolved tissue from each patient, provided an objective reference to deal with this diversity and the possibility of tumor heterogeneity. In addition, our calculations, based on a cut-off value of 10.5% for the tumor index (fraction of cells in S and G2/M cell cycle phases), were developed to account for this diversity. Our results, having pathology assessment as the gold standard, showed that this cutoff value predicts with > 90% accuracy the presence of cancer cells, suggesting that despite the presence of various cell types and the possibility of heterogeneous tumor cells, the technique can still effectively identify cancer cells. This is a signiﬁcant ﬁnding that underscores the potential of iFC in cancer detection. Inversely, our study indicated that following treatment in a subpopulation of rectal cancer patients, the proliferative potential of cancer cells is signiﬁcantly lower than in non-treated cancers. This notion, on the one hand, may lead to a drop in accuracy to a aDepartment of Surgery, University Hospital of Ioannina and Faculty of Medicine, School of Health Sciences, bBiobank Cancer Center, University of Ioannina and cHematology Laboratory-Unit of Molecular Biology and Translational Flow Cytometry, University Hospital of Ioannina, Ioannina, Greece Sponsorships or competing interests that maybe relevant to content are disclosed atthe end of this article. *Corresponding author. Address: University Hospital of Ioannina: Panepistemiako Geniko Nosokomeio Ioanninon, University of Ioannina, Ioannina 45110, Greece. Tel.: +30 265 [109 9726. E-mail: geomarkop@gmail.com](109 9726. E-mail: geomarkop@gmail.com) (G. S. Markopoulos). Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms. International Journal of Surgery (2023) 109:3740–3741 Received 28 July 2023; Accepted 30 July 2023 Published online 18 September 2023 [http://dx.doi.org/10.1097/JS9.0000000000000667](http://dx.doi.org/10.1097/JS9.0000000000000667) fraction of 9% but may also signify the effectiveness of treatment. Currently, we are working toward this end to clarify the prognostic potential of iFC following treatment. Second, the authors question the calculation validity of the DNA Index used in the study. While we understand their concerns, it’s important to note that the DNA Index is a wellestablished measure that has been used in numerous studies to successfully differentiate between cancerous and non-cancerous cells[3] . It should be

FAQs

What is the purpose of this letter?

It replies to a commentary on the authors’ colorectal cancer study using intraoperative flow cytometry to detect cancer cells and evaluate tumor margins.

How do the authors address concerns about cell-type diversity in resection margins?

They state their study design accounts for tissue complexity using patient-specific cancer and normal uninvolved samples and calculations based on a tumor index cut-off that predicts cancer-cell presence with >90% accuracy.

What issues are raised about the DNA Index, and how are they answered?

The letter argues the DNA Index is a validated measure used to distinguish cancerous from non-cancerous cells, notes not all tumors show aneuploidy, and reports the assay’s detection limit for pathological cells as 0.4–0.8%.

Sep 24, 2026

Uploaded by 4398046744996