|LETTER TO EDITOR
|Year : 2020 | Volume
| Issue : 4 | Page : 864-865
Liquid biopsy of bodily fluids: A rich resource of genomic information
Rajiv Gandhi Cancer Institute and Research Centre, Delhi, India
|Date of Submission||28-Oct-2020|
|Date of Decision||11-Nov-2020|
|Date of Acceptance||11-Nov-2020|
|Date of Web Publication||25-Dec-2020|
Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Suryavanshi M. Liquid biopsy of bodily fluids: A rich resource of genomic information. Cancer Res Stat Treat 2020;3:864-5
We have come a long way since the liquid biopsy statement paper from the International Association for the study of lung cancer (IASLC) was issued in 2018. Liquid biopsy was indicated only in patients with acquired resistance to first- and second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) or in treatment-naive patients in whom a tissue biopsy was not logistically feasible.,There have been numerous research publications since then in this field. We are now on the cusp of having many more additions to the previous statement from IASLC on liquid biopsy. Robust validations and newer techniques with improved turnaround time have been introduced, leading to increased confidence in this relatively novel concept.
Among the prominent studies is the NILE study, which suggests that liquid biopsy can be used to initiate treatment with TKIs before the tissue biopsy results become available. FLAURA, another trial with breakthrough findings, showed the clearance of circulating tumor DNA (ctDNA) using droplet digital polymerase chain reaction (ddPCR) in patients treated with osimertinib. These findings also reinforce the role of liquid biopsy in the detection of minimal residual disease. The BFAST trial has extended the promise of liquid biopsy in ALK-translocated lung cancers. Moreover, the findings from Nabet et al.'s study suggest that in addition to radiological methods, liquid biopsy could also be used to predict the response to immunotherapy. These new developments demonstrate that liquid biopsy is rich with genomic information which can be clinically beneficial. Therefore, it would not be fair to restrict this valuable technique to blood plasma. Other bodily fluids such as the cerebrospinal fluid (CSF), pleural effusion, ascites, and urine have an obvious advantage in certain clinical scenarios.
Chougule et al. in their article have reported the concordance of EGFR exon 19 deletion and exon 21 L858R mutation between the bodily fluids and formalin-fixed paraffin embedded tissue from the primary tumor in patients with non-small cell lung cancer. They analyzed the data from 11 patients with metastatic NSCLC harboring an EGFR mutation. Seven patients (63.6%) had an EGFR exon 19 deletion and four (36.4%) had the exon 21 L858R point mutation. Among these, an EGFR sensitizing mutation could be detected in the CSF for 6 (54.5%) patients, pleural effusion for 3 (27.3%), ascites for 1 (9.1%), and pericardial effusion for 1 patient (9.1%). Thus, there was a 100% concordance with the initial mutation detected on tissue. In fact, there was lower concordance (63.6%) for mutation detection between plasma and the primary tumor tissue. Furthermore, the exon 20 T790M resistance mutation was detected in the plasma for 3 (27.3%) and other bodily fluids for 9 of the 11 patients (81.8%) at progression. Both these findings suggest that bodily fluids other than plasma can serve as good or, at times, even better sources of tumor DNA for the detection of EGFR mutations. These fluids are locally enriched with DNA harboring mutations, and therefore, offer a huge advantage for mutation detection over plasma. Plasma has much higher proportions of normal cell-free DNA compared to these bodily fluids, which lowers its relative ctDNA yield, thus making other bodily fluids a better option. The genomic analysis of other bodily fluids has the added advantage of diagnosing and confirming local metastasis, as in the case of leptomeningeal/pleural involvement in patients with EGFR-mutant tumors.,
With the advent of liquid biopsy have emerged various sensitive and ultrasensitive techniques like ddPCR and next-generation sequencing to capture the minuscule tumor-related nucleic acids floating in the superabundant normal nuclear material. The studies on other bodily fluids are limited and with a small sample size but are valuable. They lay the premise for integrating “liquid biopsy” approaches from unconventional sources into our standard clinical practice.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Rolfo C, Mack PC, Scagliotti GV, Baas P, Barlesi F, Bivona TG, et al
. Liquid Biopsy for advanced non-small cell lung cancer (NSCLC): A statement paper from the IASLC. J Thorac Oncol 2018;13:1248-68.
Pandey A, Dutt S, Singh A, Kumar A, Singh S. Outcomes with liquid biopsy to determine the EGFR mutation status in poor performance status, biopsy-ineligible, advanced NSCLC patients. Cancer Res Stat Treat 2019;2:197-203. [Full text]
Choughule A, D'Souza H. Liquid biopsy in lung cancer-hope or hype?. Cancer Res Stat Treat 2019;2:221-3. [Full text]
Leighl NB, Page RD, Raymond VM, Daniel DB, Divers SG, Reckamp KL, et al
. Clinical utility of comprehensive cell-free DNA analysis to identify genomic biomarkers in patients with newly diagnosed metastatic non-small cell lung cancer. Clin Cancer Res 2019;25:4691-700.
Zhou C, Imamura F, Cheng Y, Okamoto I, Cho BC, Lin MC, et a
l. Early clearance of plasma EGFR mutations as a predictor of response to osimertinib and comparator EGFRTKIs in the FLAURA trial. J Clin Oncol 2019;37 Suppl 15:9020.
Gadgeel SM, Mok TSK, Peters S, Alexander JAA, Leighl NB, Sriuranpong V, et al
. LBA81_PR Phase II/III blood first assay screening trial (BFAST) in patients (pts) with treatment-naive NSCLC: Initial results from ALK+cohort. Ann Oncol 2019;30 Suppl 5: v851-v934.
Nabet BY, Esfahani MS, Moding EJ, Hamilton EG, Chabon JJ, Rizvi H, et al
. Noninvasive early identification of therapeutic benefit from immune checkpoint inhibition. Cell 2020;183:363-76.e13.
Chougule A, Pange P, Kale S, Jagtap V, Nambiar K, Nikam A, et al
. Concordance of epidermal growth factor receptor mutation detection in bodily fluids other than blood with tissue biopsy: A retrospective analysis. Cancer Res Stat Treat 2020;3:475-80. [Full text]
Suryavanshi M, Jaipuria J, Panigrahi MK, Goyal N, Singal R, Mehta A, et al
. CSF cell-free DNA EGFR testing using DdPCR holds promise over conventional modalities for diagnosing leptomeningeal involvement in patients with non-small cell lung cancer. Lung Cancer 2020;148:33-9.
Zhang P, Wu X, Tang M, Nie X, Li L. Detection of EGFR gene mutation status from pleural effusions and other body fluid specimens in patients with lung adenocarcinoma. Thorac Cancer 2019;10:2218-24.