Changes in circulating tumor DNA and outcomes in solid tumors treated with immune checkpoint inhibitors: a systematic review

Prognostic significance of circulating tumor DNA in urothelial carcinoma: a systematic review and meta-analysis

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a noninvasive technique that provides valuable insights into molecular profiles and tumor disease management. This study aimed to evaluate the prognostic significance of circulating tumor DNA (ctDNA) in urothelial carcinoma (UC) through a systematic review and meta-analysis.

METHODS

A comprehensive search was conducted in MEDLINE, EMBASE, and the Cochrane Library from the inception to December 2023. Studies investigating the prognostic value of ctDNA in UC were included. Hazard ratios (HRs) of disease-free survival (DFS) and overall survival (OS) were extracted. Overall meta-analysis and subgroup exploration stratified by metastatic status, ctDNA sampling time, treatment type, and detection method was performed using the R software (version 4.2.2).

RESULTS

A total of 16 studies with 1725 patients were included. Fourteen studies assessed the association between baseline ctDNA status and patient outcomes. Patients with elevated ctDNA levels exhibited significantly worse DFS (HR=6.26; 95% CI: 3.71-10.58, P <0.001) and OS (HR=4.23; 95% CI: 2.72-6.57, P <0.001) regardless of metastatic status, ctDNA sampling time, treatment type, and detection methods. Six studies evaluated the prognostic value of ctDNA dynamics in UC. Patients who showed a decrease or clearance in ctDNA levels during treatment or observation demonstrated more favorable DFS (HR=0.26, 95% CI: 0.17-0.41, P <0.001) and OS (HR=0.21, 95% CI: 0.11-0.38, P <0.001) compared to those who did not. The association remained consistent across the subgroup analysis based on metastatic status and detection methods. In the immune checkpoint inhibitor-treated setting, both lower baseline ctDNA level and ctDNA decrease during the treatment were significantly associated with more favorable oncologic outcomes. Furthermore, specific gene mutations such as FGFR3 identified in ctDNA also demonstrated predictive value in UC patients.

CONCLUSION

This meta-analysis demonstrates a strong association of ctDNA status and its dynamic change with survival outcomes in UC, suggesting substantial clinical utility of ctDNA testing in prognosis prediction and decision making in this setting.

Circulating Cell-Free SHOX2 DNA Methylation Is a Predictive, Prognostic, and Monitoring Biomarker in Adjuvant and Palliative Anti-PD-1-Treated Melanoma

BACKGROUND

The majority of metastatic melanoma patients initially do not respond or acquire resistance to anti-programmed cell death 1 (PD-1) immunotherapy. Liquid biopsy biomarkers might provide useful early response information and allow for personalized treatment decisions.

METHODS

We prospectively assessed circulating cell-free SHOX2 DNA methylation (SHOX2 ccfDNAm) levels and their dynamic changes in blood plasma of melanoma patients by quantitative methylation-specific polymerase chain reaction. Patients were treated with either palliative (n = 42) or adjuvant (n = 55) anti-PD-1 immunotherapy. Moreover, we included n = 126 control patients without evidence of malignant disease. We analyzed SHOX2 ccfDNAm status prior to and 4 weeks after palliative treatment initiation with regard to outcome [objective response, progression-free survival (PFS), and overall survival (OS)]. In the adjuvant setting, we associated longitudinal SHOX2 ccfDNAm status with disease recurrence.

RESULTS

Sensitivity was 60% with 25/42 melanoma patients showing increased SHOX2 ccfDNAm levels, whereas specificity was 98% with 123/126 (P < 0.001) control patients having SHOX2 ccfDNAm levels below cut-off. Pretreatment SHOX2 ccfDNAm status did not correlate with outcome; however, SHOX2 ccfDNAm negativity 4 weeks after palliative treatment initiation was strongly associated with improved survival [PFS: hazard ratio (HR) = 0.25, P = 0.002; OS: HR = 0.12, P = 0.007]. Pretreatment positive patients who reached SHOX2 ccfDNAm clearance after 4 weeks of immunotherapy showed an exceptionally beneficial outcome. SHOX2 ccfDNAm testing allowed for an early detection of distant metastases in adjuvant-treated melanoma patients.

CONCLUSIONS

Our study suggests SHOX2 ccfDNAm to be an early predictor of outcome in anti-PD-1 treated melanoma patients. SHOX2 ccfDNAm testing may aid individualized treatment decision-making.

Sintilimab with two cycles of chemotherapy for the treatment of advanced squamous non-small cell lung cancer: a phase 2 clinical trial

This was a single-arm, multicenter phase 2 clinical trial (ChiCTR1900021726) involving advanced squamous non-small cell lung cancer (sq-NSCLC) patients undergoing 2 cycles of nab-paclitaxel/carboplatin and sintilimab (anti-PD-1), followed by sintilimab maintenance therapy. The median progression-free survival (PFS) was 11.4 months (95% CI: 6.7-18.1), which met the pre-specified primary endpoint. Secondary endpoints included objective response rate reaching 70.5% and a disease control rate of 93.2%, with a median duration of response of 13.6 months [95% CI: 7.0-not evaluable (NE)]. The median overall survival was 27.2 months (95% CI: 20.2-NE) with treatment-related adverse events grades ≥3 occurring in 10.9% of patients. Predefined exploratory endpoints comprised relationships between biomarkers and treatment efficacy, and the association between circulating tumor DNA (ctDNA) dynamics and PFS. Biomarker analysis revealed that the breast cancer gene 2, BMP/Retinoic Acid Inducible Neural Specific 3, F-box/WD repeat-containing protein 7, tyrosine-protein kinase KIT and retinoblastoma 1 abnormalities led to shorter PFS, while ctDNA negative at baseline or clearance at 2 cycles of treatment was associated with longer PFS (18.1 vs. 4.3 months). Taken together, sintilimab in combination with 2 cycles of nab-paclitaxel/carboplatin treatment produced encouraging PFS and better tolerability as first-line treatment for advanced sq-NSCLC.

Circulating tumor DNA (ctDNA) as a biomarker of response to therapy in advanced Hepatocellular carcinoma treated with Nivolumab

BACKGROUND

Circulating tumor DNA (ctDNA) is a promising non-invasive marker for detection, diagnosis, treatment selection, and prognosis of hepatocellular carcinoma (HCC).

OBJECTIVE

This study aimed to examine the utility of ctDNA as a prognostic and predictive tool in HCC patients treated with nivolumab.

METHODS

We analyzed pre-treatment ctDNA from 44 HCC patients using comprehensive genomic testing on a commercially available platform. We utilized log rank test and univariate Cox models to correlate overall survival (OS) and progression-free survival (PFS) with ctDNA expressions.

RESULTS

Of 44 patients, 77.3% were men with median age of 67 years. All but 3 patients had at least one alteration identified, and TP53 was the most commonly altered gene (52.3%). Median OS was 17.5 months (95% CI: 12.7, NA). Mutations involving PIK3CA, BRCA1, and CCND1 amplification were associated with shorter OS (P 0.0001, 0.0001 and 0.01, respectively). Median PFS time was 4.01 months (95% CI: 3.06, 9.33). Mutations involving KIT and PIK3CA were associated with shorter PFS (P 0.0001 and 0.0004, respectively), while mutation involving CTNNB1 were associated with longer PFS (p= 0.04).

CONCLUSIONS

ctDNA profiling may provide a benefit for prediction of survival and progression of HCC patients treated with nivolumab. Future studies are needed for confirmation.

Promising and Minimally Invasive Biomarkers: Targeting Melanoma

The therapeutic landscape of malignant melanoma has been radically reformed in recent years, with novel treatments emerging in both the field of cancer immunotherapy and signalling pathway inhibition. Large-scale tumour genomic characterization has accurately classified malignant melanoma into four different genomic subtypes so far. Despite this, only somatic mutations in BRAF oncogene, as assessed in tumour biopsies, has so far become a validated predictive biomarker of treatment with small molecule inhibitors. The biology of tumour evolution and heterogeneity has uncovered the current limitations associated with decoding genomic drivers based only on a single-site tumour biopsy. There is an urgent need to develop minimally invasive biomarkers that accurately reflect the real-time evolution of melanoma and that allow for streamlined collection, analysis, and interpretation. These will enable us to face challenges with tumour tissue attainment and process and will fulfil the vision of utilizing "liquid biopsy" to guide clinical decisions, in a manner akin to how it is used in the management of haematological malignancies. In this review, we will summarize the most recent published evidence on the role of minimally invasive biomarkers in melanoma, commenting on their future potential to lead to practice-changing discoveries.

It is time to improve the diagnostic workup of oropharyngeal cancer with circulating tumor HPV DNA: Systematic review and meta-analysis

The possibility of detecting circulating tumor HPV DNA (ctHPVDNA) in plasma in patients with oropharyngeal cancer has been demonstrated in several reports. However, these data are from small cohorts and available tests for detection of ctHPVDNA are not fully validated. The aim is to evaluate sensitivity, specificity, and accuracy of ctHPVDNA by ddPCR to define its efficacy in the clinical setting for the diagnosis of HPV + OPSCC. A comprehensive search of three different databases: MEDLINE, Embase, and Cochrane Library databases. A total of 998 patients were evaluated from the 13 studies. OPSSC p16+ were 729, while controls p16- were 269. The meta-analytic study estimated the diagnostic performance of ctHPVDNA as follows: pooled sensitivity and specificity of 0.90 (95% CI: 0.82-0.94) and 0.94 (95% CI: 0.85-0.98), respectively; positive and negative likelihood ratios of 12.6 (95% CI: 4.9-32.1) and 0.05 (95% CI: 0.02-0.13), respectively. ddPCR for ctHPVDNA has good accuracy, sensitivity, and specificity for diagnosis of HPV + OPSCC. ctHPVDNA kinetic represents a great reliable opportunity to improve diagnostic and therapeutic management of cancer patients and could open new perspectives for understanding tumor biology.

Prognostic significance of blood-based PD-L1 analysis in patients with non-small cell lung cancer undergoing immune checkpoint inhibitor therapy: a systematic review and meta-analysis

BACKGROUND

The main types of PD-L1 in the blood include soluble PD-L1 (sPD-L1), exosomal PD-L1 (exoPD-L1), and PD-L1 in circulating tumor cells (CTCs). However, the predictive and prognostic values of these three indicators in patients with non-small cell lung cancer (NSCLC) undergoing immune checkpoint inhibitor (ICI) therapy are unclear, warranting a systematic meta-analysis.

METHODS

A systematic literature search was performed in the PubMed, Cochrane Library, and Embase databases. The pooled hazard ratio (HR) and 95% confidence interval (CI) values were extracted from the included studies to investigate the correlation between the three PD-L1 indicators and overall survival (OS) or progression-free survival (PFS). The Newcastle-Ottawa Scale (NOS) was used to examine the quality of the included studies. Subgroup analyses were employed to investigate the heterogeneity. The publication bias of the included studies was assessed using Begg's and Egger's tests. P < 0.05 was regarded as significantly different.

RESULTS

The pooled results revealed that high pre-treatment sPD-L1 levels were significantly associated with inferior OS (HR = 2.32, 95% CI = 1.68-3.18, P < 0.001) and PFS (HR = 2.52, 95% CI = 1.72-3.68, P < 0.001). However, dynamic changes in sPD-L1 after immunotherapy were not statistically significant for OS (HR = 1.46, 95% CI = 0.65-3.26, P > 0.05) or PFS (HR = 1.62, 95% CI = 0.92-2.86, P > 0.05). Meanwhile, the upregulated pre-treatment exoPD-L1 levels were significantly associated with poor PFS (HR = 4.44, 95% CI = 2.87-6.89, P < 0.001), whereas the post-treatment dynamic upregulation of exoPD-L1 was significantly correlated with superior PFS (HR = 0.36, 95% CI = 0.24-0.54, P < 0.001) and OS (HR = 0.20, 95% CI = 0.07-0.53, P < 0.001). For PD-L1 in CTCs, the pooled results indicated that PD-L1 expression in CTCs was not significantly correlated with OS (HR = 0.75, 95% CI = 0.49-1.13, P = 0.170) and PFS (HR = 0.79, 95% CI = 0.59-1.06, P = 0.12).

CONCLUSIONS

Blood-based PD-L1 analysis is a potential strategy for predicting treatment efficacy and prognosis in patients with cancer.

Progresses in biomarkers for cancer immunotherapy

Currently, checkpoint inhibitor-based immunotherapy has emerged as prevailing treatment modality for diverse cancers. However, immunotherapy as a first-line therapy has not consistently yielded durable responses. Moreover, the risk of immune-related adverse events increases with combination regimens. Thus, the development of predictive biomarkers is needed to optimize individuals benefit, minimize risk of toxicities, and guide combination approaches. The greatest focus has been on tumor programmed cell death-ligand 1 (PD-L1), microsatellite instability (MSI), and tumor mutational burden (TMB). However, there remains a subject of debate due to thresholds variability and significant heterogeneity. Major unmet challenges in immunotherapy are the discovery and validation of predictive biomarkers. Here, we show the status of tumor PD-L1, MSI, TMB, and emerging data on novel biomarker strategies with oncogenic signaling and epigenetic regulation. Considering the exploration of peripheral and intestinal immunity has served as noninvasive alternative in predicting immunotherapy, this review also summarizes current data in systemic immunity, encompassing solute PD-L1 and TMB, circulating tumor DNA and infiltrating lymphocytes, routine emerging inflammatory markers and cytokines, as well as gut microbiota. This review provides up-to-date information on the evolving field of currently available biomarkers in predicting immunotherapy. Future exploration of novel biomarkers is warranted.

Fluorometric Quantification of Total Cell-Free DNA as a Prognostic Biomarker in Non-Small-Cell Lung Cancer Patients Treated with Immune Checkpoint Blockade

The present study aimed to investigate the potential of basal cell-free fluorometric DNA (cfDNA) quantification as a prognostic biomarker in advanced non-small cell lung cancer (NSCLC) patients treated with an Immune Checkpoint Blockade (ICB). A discovery and validation cohort of 61 and 31 advanced lung cancer patients treated with ICB were included in this study. Quantification of cfDNA concentration was performed before the start of the treatment and patients were followed up for a median of 34 (30-40) months. The prognostic predicted value of cfDNA was evaluated based on ROC, and Cox regression was conducted via univariate and multivariate analyses to estimate the hazard ratio. We observed that a cfDNA cut-off of 0.55 ng/µL before the ICB determines the overall survival of patients with a log rank p-value of 3.3 × 10^-4. That represents median survivals of 3.8 vs. 17.5 months. Similar results were obtained in the validation cohort being the log rank p-value 3.8 × 10^-2 with median survivals of 5.9 vs. 24.3. The univariate and multivariate analysis revealed that the cut-off of 0.55 ng/µL before ICB treatment was an independent predictive factor and was significantly associated with a better survival outcome. High cfDNA concentrations identify patients with advanced NSCLC who do not benefit from the ICB. The determination of cfDNA is a simple test that could select a group of patients in whom new therapeutic strategies are needed.