PD-L1 on CTCs enables monitoring, recurrence tracking, and minimal residual disease. Publications | June 3, 2025 Circulating tumor cells and clusters exhibiting expression of PD-L1 in colorectal patients. High prevalence of PD-L1–positive circulating tumor cells in colorectal cancer highlights their role in minimal residual disease and recurrence monitoring. Background The role of circulating tumor cells (CTCs) has been well established in predicting survival in metastatic settings, particularly in breast, colorectal, and prostate cancers. However, their clinical utility has been limited due to high costs, variability in sensitivity and accuracy, and the use of cutoff-based interpretations. The biological significance of CTCs—from extravasation and invasion to their contribution to tumor microenvironment dynamics and tumor burden—suggests greater clinical relevance than is currently applied in practice. Their role in monitoring minimal cellular residual disease (MCRD), especially in early-stage cancers post-surgery, remains underexplored, including decisions regarding therapy duration in diseases such as colorectal cancer and longitudinal monitoring for recurrence. Dynamic PD-L1 expression on CTCs may indicate incomplete tumor resection or treatment response and may also reflect cellular dormancy in circulation, potentially enabling immune evasion. In this study, we report the expression of PD-L1 on CTCs and CTC clusters in colorectal cancer patients. Methods We retrospectively analyzed 666 colorectal cancer patients (63.06% male and 36.94% female), spanning early- to late-stage disease, for the presence of CTCs with and without PD-L1 expression, as well as CTC clusters. CTCs were detected using the CDSCO-approved OncoDiscover platform in 1.5 mL of peripheral blood. Cells were classified as CTCs if they were EpCAM⁺, CK18⁺, DAPI⁺, and CD45⁻, and were identified using an automated Zeiss microscope system. Results At baseline analysis, 74.25% (n = 591) of patients had ≥1 CTC per 1.5 mL of blood. CTC counts ranged from 1 to 20 cells. Among patients with detectable CTCs, 74.62% (n = 441) exhibited PD-L1 expression. The highest proportion of CTCs (~25.86%, n = 352) was observed in the 61–70 years age group. CTC clusters were detected in 13.00% (n = 156) of patients, and notably, more clusters were observed during follow-up compared with baseline. The mean CTC count (including clusters) was 1.71, while the mean PD-L1–positive CTC count was 1.02. Conclusions PD-L1 expression on CTCs may contribute to their ability to persist in circulation through immune evasion, potentially enabling dormancy via surface protein overexpression that helps them avoid elimination by immune T cells. The CTC–PD-L1 assay shows strong potential for patient surveillance both before and after treatment in assessing minimal cellular residual disease. Further clinical studies in this direction are strongly warranted. View Publication Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

PD-L1-positive CTCs may predict treatment outcomes and occult residual disease. Publications | September 1, 2026 Longitudinal Assessment of Circulating Tumor Cells Expressing PD-L1 and Clusters in Esophageal Cancer Patients A longitudinal study of 110 esophageal cancer patients evaluated CTCs, PD-L1 expression, and CTC clusters, highlighting their potential as predictive biomarkers for treatment outcomes and occult minimal cellular residual disease. Background Carcinoma esophagus (CA esophagus) has a high recurrence rate and poor survival outcomes. Despite complete response (CR), a notable number of patients experience recurrence. Thus, pathological ‘no evidence of disease’ may not always indicate disease-free survival (DFS), particularly in the presence of occult systemic disease and micro-metastasis. Circulating tumor cells (CTCs) with PD-L1 overexpression may offer both prognostic and predictive value. Similar approaches, such as AR-V7 expression in the PROPHECY study, have demonstrated the potential of CTC-based biomarkers in predicting treatment outcomes in metastatic castration-resistant prostate cancer. Longitudinal CTC assessment may provide evidence of active clonal evolution, minimal cellular residual disease (MCRD), and therapy sequencing. We assessed the presence of PD-L1-overexpressing CTCs and CTC clusters in patients with CA esophagus. Methods We retrospectively assessed 110 patients with CA esophagus using peripheral 1.5 mL blood samples collected at baseline (BL) (n=86; 78.2%) and follow-ups (FU) (n=24; 21.8%). CTC enumeration and PD-L1 expression analysis were performed using the CDSCO-approved OncoDiscover® platform. CTCs were identified based on EpCAM⁺, CK18⁺, DAPI⁺, CD45⁻, and PD-L1⁺ markers using a fluorescence automated microscope. Mean CTC distributions were calculated across multiple time points and longitudinal means were compared between BL and FU. Results Among 110 patients, 83 (75.5%) were CTC-positive. PD-L1 expression was detected in 63 patients (57.3%), while CTC clusters were observed in 14 patients (12.7%). Most patients (89/110; 80.9%) were aged 51–80 years, with a mean age of 59.7 years, and 67.3% were male. At baseline, 65/86 (75.6%) patients were CTC-positive, with 47 (54.7%) showing PD-L1 overexpression. At follow-up, 18/24 (75%) patients remained CTC-positive, of whom 16 (66.7%) demonstrated PD-L1 positivity. The mean CTC count was 1.37 at BL and 1.20 at FU, with a combined mean of 1.32. The mean distribution of PD-L1-positive CTCs was 0.83 at baseline, 0.91 at follow-up, and 0.85 overall. CTC clusters increased at follow-up compared with baseline (0.25 vs. 0.12). Conclusions We longitudinally monitored and assessed PD-L1-expressing CTCs and CTC clusters in esophageal cancer patients at baseline and follow-up. PD-L1-positive CTCs may have potential as a predictive biomarker for treatment outcomes and the detection of occult minimal cellular residual disease. Know more Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

CTC and PD-L1 detection reveals residual disease despite clear radiological scans. Publications | June 4, 2024 ASCO 2024: Effect of circulating tumor cells in clinically stable patients on the conundrum of recurrence with cellular residual disease. CTC detection with PD-L1 expression reveals residual disease despite negative radiological findings in treated cancer patients. Background Despite no evidence of disease by radiological imaging, up to 30% of breast cancer cases are known to relapse after treatment with curative intent. The presence of circulating tumor cells (CTCs) in stage I–II cancer patients signals the activation of extravasation and invasion processes leading to micro-metastasis and may result in poor outcomes. CTCs in blood circulation at any stage of cancer indicate detectable minimal cellular disease (MCD). Thus, the longitudinal investigation of patients with such biomarkers remains highly important for predicting recurrence, therapy escalation, and dose modifications. The expression of programmed death-ligand 1 (PD-L1) on CTCs is a dynamic biomarker, and these cells may escape elimination by the immune system, indicating progression toward a metastatic phenotype. Methods Retrospectively, a cohort of 20 cancer patients (including lung, colorectal, breast, stomach, etc.) who had recently undergone treatment were investigated for the presence of CTCs using the CDSCO-approved OncoDiscover platform. The platform contains multi-component systems conjugated with anti-EpCAM antibodies on magnetic nanoparticles. All patients clinically represented stable disease based on previous radiological findings. CTC enumeration was performed using CD45-, EpCAM+, and CK18+ markers, along with the evaluation of PD-L1 overexpression in 1.5 ml of peripheral blood using automated motorized Zeiss fluorescence microscopy. Results Despite no radiological evidence of disease and clinically stable status, 75% (n = 15) of the selected patients showed at least one CTC. Among them, 55% (n = 11) had one CTC, 5% (n = 1) had two CTCs, and 15% (n = 3) had three CTCs. In addition, 50% (n = 10) of patients demonstrated PD-L1 expression on CTCs, while one patient exhibited a CTC cluster. Conclusions Patients showed circulating residual disease (CRD) despite clinically stable disease, indicating possible progression from localized to secondary disease. Longitudinal monitoring of CTCs with PD-L1 expression may reveal real-time residual disease, progression, regression, and actual response to treatment. CRD monitoring can improve curative outcomes by potentially enhancing progression-free survival (PFS) and overall survival (OS) in solid cancers. Know more Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

Preventing Stage 4 Cancer: India’s Revolutionary Blood Test | Dr. Nirmal Raut Expert Insights | August 9, 2022 Preventing Stage 4 Cancer: India’s Revolutionary Blood Test | Dr. Nirmal Raut Leading oncologists discuss OncoDiscover, India's first indigenous CTC blood test. By detecting Circulating Tumor Cells post-treatment, this affordable "Made in India" innovation catches cancer relapse before it reaches incurable Stage 4, dramatically changing the landscape of cancer care. Cancer metastasis (Stage 4) is the deadliest and often incurable phase of the disease. While mass screening the entire population is practically impossible, preventing early-stage cancers from progressing is now a reality thanks to OncoDiscover. In this video, leading experts—Dr. Jayant Khandare, Dr. Pankaj Chaturvedi (Director, ACTREC), and Dr. Nirmal Raut (Sr. Medical Oncologist)—explain the life-saving impact of India's first indigenous medical device for detecting Circulating Tumor Cells (CTCs). Because CTCs evade traditional CT and MRI scans, this simple and highly affordable blood draw is used post-surgery or radiation to detect minimal residual disease. If CTCs are detected, oncologists can intervene with curative treatments before the disease reaches Stage 4. Clinically validated at Tata Memorial Hospital and approved by the Drug Controller General of India, this "Made in India" breakthrough drastically reduces patient costs while offering immense hope to families worldwide. Know more Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

Single CTC genomics reveals mutations and therapy resistance beyond ctDNA in CRC. Publications | September 17, 2024 ESMO 2024: True single-circulating tumor cell genomics reveals enriched therapy-resistance signatures in advanced colorectal cancer patients Single CTC genomics reveals actionable mutations and therapy resistance signatures not detected in paired ctDNA in advanced colorectal cancer. Background Plasma ctDNA (circulating tumor DNA) has emerged as a novel biomarker for detecting genomic alterations and for longitudinal monitoring of colorectal cancer (CRC) patients. However, nearly 30% of patients show no mutations detected, potentially missing opportunities for companion therapy. Single circulating tumor cell (sCTC) genomics can provide greater sensitivity in detecting actionable targets. We report comprehensive genomic profiling (CGP) of live sCTCs and paired ctDNA from an advanced CRC patient population. Methods Retrospectively, live sCTCs and CTC clusters were isolated from six patients with stage IV CRC using OncoRADAR technology. Whole genomes of sCTCs were amplified and target-enriched using hybridization capture with OncoIndx, a comprehensive 1080-gene panel, to generate sequencing libraries. These libraries were sequenced on the Illumina NextSeq 2000 platform in paired-end mode with a sequencing depth of 500×. Raw sequence alignment and variant calling were performed using iCare software. Paired ctDNA samples were processed similarly but sequenced at a higher depth of 5500×. Results A total of 22 sCTCs were isolated, including four CTC clusters. The combined mutational landscape revealed 142 clinically relevant mutations, including 65 missense (45.77%), 25 nonsense (17.61%), 16 frameshift (11.27%), 7 indels (4.93%), 10 splice variants (7.04%), and 19 structural variants (13.38%). NRAS was the most frequently mutated gene, occurring in 52% of samples, followed by SMO (47.6%), TAP1 (42.85%), and TP53 (42.5%). In paired ctDNA samples, TP53 (66%), KRAS (50%), and TAP1 (33.33%) were the most frequently mutated genes. At the individual gene level, a 40% concordance was observed between sCTC and ctDNA. The genomic profile of sCTCs was particularly enriched with mutations in proliferative and stemness-maintenance signaling pathways, including NRAS:p.A146T and SMO:p.V392G, suggesting potential therapy evasion mechanisms. CTCs also showed a higher accumulation of immunotherapy resistance signatures, including loss-of-function mutations in STK11 and STAT5B, which were not detected in paired ctDNA samples. Conclusions The genomic profile of sCTCs exhibited enriched mutations in proliferative and stemness-maintenance signaling pathways. Therapy resistance signatures were more prevalent in sCTCs compared to ctDNA and may provide important clinical insights, particularly for patients who cannot provide tissue biopsy samples or show negative ctDNA results. Know more Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

HER2 analysis on CTCs enables real-time monitoring in metastatic breast cancer. Publications | April 10, 2024 AACR 2024: Evaluation of HER-2 expression on circulating tumor cells as a real time biomarker in advanced breast cancer HER2 analysis on circulating tumor cells using the OncoDiscover® platform enables real-time, non-invasive profiling for improved metastatic breast cancer treatment decisions. Introduction: Breast cancer accounts for 12.5% of all new annual cancer cases worldwide. Cases classified as HER2-positive tend to proliferate, metastasize, and often lead to relapse. HER2 is one of the most valid tumor markers and is widely used as a diagnostic and prognostic biomarker in metastatic breast cancer (MBC). Thus, analyzing the expression of HER2 on circulating tumor cells (CTCs) can offer a real-time dynamic biomarker for guiding treatment options between endocrine therapy and chemotherapy in advanced breast cancer. Functional assays on CTCs with the HER2 biomarker offer evolving diagnostic opportunities, especially when tissue samples are not accessible or are inadequate. Methods: Retrospectively, blood samples from 179 breast cancer patients were analyzed for the presence of CTCs using the OncoDiscover® platform approved by the Drug Controller General of India (CDSCO). The platform consists of an immunomagnetic multi-component system mediated by anti-EpCAM antibodies. The isolated cells were immunostained using the nuclear dye DAPI along with CK18, CD45, and HER2 antibodies. CTCs were identified by the presence of HER2-positive, CK18-positive, DAPI-positive, and CD45-negative staining. Validation of HER2 expression on CTCs was analyzed based on the linear intensity gradients of fluorescence signals. CTCs were termed HER2-negative when weak or no detectable fluorescence signal was observed and HER2-positive when high fluorescence signals were detected. Results: Among the cohort of 179 patient samples, 63.68% of samples showed the presence of CTCs, with counts ranging from 1–7 CTCs. Among these, 47.84% of the detected CTCs showed HER2 expression. The mean fluorescence intensity value for HER2 expression in CTCs was found to be 3.23. The observed fluorescence intensity further emphasizes the robustness of CTCs as a viable source for molecular characterization. Conclusion: Integration of HER2 analysis on CTCs into the clinical assessment of metastatic breast cancer may offer a non-invasive, real-time strategy for tumor profiling and may help pave the way for more precise and tailored therapeutic interventions. Know more Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

CTCs in recurrent and metastatic head & neck squamous cell carcinoma. Publications | July 20, 2023 Manuscript: Role of circulating tumour cells (CTCs) in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) This study highlights the utility of CTCs as a disease progression monitoring tool in recurrent HNSCC patients. Our findings suggest the potential clinical utility of CTCs and the need for further exploration in upfront settings of the disease as well (NCT: CTRL/2020/02/023378). Background: Liquid biopsy is emerging as a non-invasive tool that provides a personalized snapshot of primary and metastatic tumors. It aids in detecting early metastasis, recurrence, or resistance to the disease. We aimed to assess the role of circulating tumour cells (CTCs) as a predictive biomarker in recurrent or metastatic head and neck cancer, specifically head and neck squamous cell carcinoma (HNSCC). Methodology: Thirty-five patients receiving palliative chemotherapy underwent blood sampling (2 mL in an ethylenediaminetetraacetic acid (EDTA) vial) at baseline and at 3-month intervals. The CTCs were isolated and evaluated using anti-epithelial cell adhesion molecule antibody-based enrichment with the OncoDiscover platform. Results: CTCs were isolated from 80% of patients (n = 28), showing sensitivity of cell detection at baseline and at 3-month intervals. The median CTC count was 1 per 1.5 mL of blood, and the concordance with clinicoradiological outcomes was 51.4%. The median CTC count declined at 3 months in responders (1 (range: 0–4) to 0 (range: 0–1)), while non-responders showed an increase in levels (0 (range: 0–2) to 1 (range: 0–3)). Although CTCs positively correlated with progression-free survival (PFS) and overall survival (OS), the association did not show a significant difference between CTC-positive and CTC-negative patients at 3 months (PFS: 6 months versus 4 months; hazard ratio: 0.68; 95% confidence interval (CI): 0.29–1.58, p = 0.323; OS: 10 months versus 8 months; hazard ratio: 0.54; 95% CI: 0.18–1.57; p = 0.216). Conclusion: This study highlights the utility of CTCs as a disease progression monitoring tool in recurrent HNSCC patients. Our findings suggest the potential clinical utility of CTCs and the need for further exploration in upfront settings of the disease as well (NCT: CTRL/2020/02/023378). View Manuscript Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe

Micropatterned surfaces enable selective cancer cell capture and real-time monitoring. Publications | January 17, 2018 Manuscript: Selective Cell Isolation by Transferrin Functionalized Silane– Carbon Soot Mediated Superhydrophobic Micropatterns Transferrin-functionalized wettability micropatterns enable selective cancer cell capture and real-time monitoring for diagnostics and recurrence detection. Surfaces that facilitate selective cell adhesion using specific targeting moieties have significant implications in diagnostics, tissue engineering, and high-throughput screening. However, designing robust and spatially confined micropatterns for selective cell isolation on portable platforms remains highly challenging. Here, wettable silane (Si) micropatterns with covalently attached transferrin (Tf) for targeting Tf-overexpressing cancer cells are reported. These micropatterns are separated by carbon soot–based superhydrophobic regions, which transform the targeting sites into surface tension–confined “microwells.” These microwells facilitate the capture of human colorectal carcinoma cells (HCT116) and human cervical adenocarcinoma cells (HeLa) by confining their attachment to the wettable regions, thereby making the isolation and spotting of targeted cells more efficient. In addition, owing to its transparent nature, the Tf-conjugated wettability-based patterned chip enables real-time optical monitoring of cell adhesion, cell growth, and cell behavior. The specific cell isolation enabled by such surfaces has potential applications in developing cancer recurrence monitoring tests. Advanced Material Interfaces View Manuscript Stay One Step Ahead of Cancer. Get the latest news and innovations from Actorius delivered straight to your inbox. Subscribe for regular updates Email* Yes, subscribe me for regular updates. * Subscribe