Response prediction by mutation- or methylation-specific detection of ctDNA dynamics in pretreated metastatic colorectal cancer.

Background: Serial analysis of circulating tumor DNA (ctDNA) levels is a promising tool for both relapse prediction in the curative setting, as well as predicting clinical benefit from systemic treatment in metastasic colorectal cancer (mCRC). Most data in this context are derived from treatment naive patients. Objective: To predict progressive disease (PD) as early as possible through monitoring of changes in ctDNA levels during systemic treatment in pretreated patients with mCRC. Design: A prospective, single-center, observational study. Methods: Patients treated beyond first-line were prospectively included between February 2020 and September 2021. Blood for ctDNA detection was taken before every treatment cycle from start of treatment until first restaging by CT-scan. ctDNA was detected by mutation- (mut-ctDNA) and methylation-specific ddPCR. Receiver Operating Characteristic (ROC)-analysis was used to describe sensitivity and specificity for prediction of PD at restaging for all time points. Results: A total of 42 patients were included who all carried a mutation in tumor tissue. Detection rate of mut-ctDNA was 88.1% and 74.4% for meth-ctDNA. Absolute ctDNA levels before treatment were prognostic in terms of overall survival. Levels of ctDNA were significantly higher in patients with PD at restaging. Median time from start of treatment to restaging was 93 days (95% CI 88.8-96). After a median of 19 days of treatment (95% CI 16.1-20.2), a decline of either mutation- or methylation-specific ctDNA levels of ⩽58% predicted PD at restaging with a sensitivity/specificity of 92.9/85.7% and 85.7/100%, respectively. Median time to restaging was 66 days (95% CI 56.8-75.2). There was no significant increase of sensitivity/specificity at later time points of ctDNA measurements. Conclusion: Monitoring early changes of ctDNA levels either by mut- or meth-ctDNA allows for early prediction of PD in pretreated patients with mCRC. This has the potential to complement RECIST-based treatment assessment with the aim to switch potentially insufficient treatments as early as possible, which is of particular interest in higher treatment lines.

Amp(1q) and tetraploidy are commonly acquired chromosomal abnormalities in relapsed multiple myeloma.

Long-term disease control in multiple myeloma (MM) is typically an unmet medical need, and most patients experience multiple relapses. Fluorescence in situ hybridization (FISH) is the standard technique to detect chromosomal abnormalities (CAs), which are important to estimate the prognosis of MM and the allocation of risk adapted therapies. In advanced stages, the importance of CAs needs further investigation. From 148 MM patients, two or more paired samples, at least one of which was collected at relapse, were analyzed by FISH. Using targeted next-generation sequencing, we molecularly investigated samples harboring relapse-associated CAs. Sixty-one percent of the patients showed a change in the cytogenetic profile during the disease course, including 10% who acquired high-risk cytogenetics. Amp(1q) (≥4 copies of 1q21), driven by an additional increase in copy number in patients who already had 3 copies of 1q21, was the most common acquired CA with 16% affected patients. Tetraploidy, found in 10% of the samples collected at the last time-point, was unstable over the course of the disease and was associated with TP53 lesions. Our results indicate that cytogenetic progression is common in relapsed patients. The relatively high frequency of amp(1q) suggests an active role for this CA in disease progression.

Prediction of response to systemic treatment by kinetics of circulating tumor DNA in metastatic pancreatic cancer.

Introduction: Pretherapeutic detectable circulating tumor DNA (ctDNA) represents a promising prognostic biomarker for predicting relapse and overall survival in patients with metastatic pancreatic cancer. However, the prognostic value of ctDNA dynamics during treatment has not been studied thus far. We aimed to investigate the correlation between the change of ctDNA levels and response to treatment in patients treated by systemic therapy. Material and methods: CtDNA detection using liquid biopsy (droplet digital PCR (ddPCR) utilizing KRAS G12/13 and, if negative, Q61 commercial test kits) was prospectively performed on patients with stage IV pancreatic cancer i) prior to initiation of systemic chemotherapy and ii) serially every 2 weeks until restaging. Detection rates, levels of ctDNA, and the course of the relative ctDNA change (ctDNA kinetics) were correlated to treatment response and clinical outcome. Results: The detection rate at baseline was 64.3% (45/70), and complete serial measurement records were available for 32 ctDNA-positive patients. Reduction of ctDNA levels below 57.9% of its baseline value at week 2 after treatment initiation was significantly predictive of response to treatment (area under the curve (AUC) = 0.918, sensitivity 91.67%, and specificity 100%) and was associated with prolonged overall survival (OS) (5.7 vs. 11.4 months, p = 0.006) and progression-free survival (PFS) (2.5 vs. 7.7 months, p < 0.000) regardless of treatment line. Pretherapeutic ctDNA detection was independently associated with worse OS in patients receiving a first-line regimen (7 vs. 11.3 months, p = 0.046) and regardless of treatment line (11.4 vs. 15.9 months, p = 0.045) as well as worse PFS (3.4 vs. 10.8 months, p = 0.018). Conclusion: The change in magnitude of ctDNA during systemic treatment allows the prediction of treatment response and is associated with both OS and PFS. This finding adds significant clinical potential to the already established prognostic value of ctDNA positivity in metastatic pancreatic cancer.

Clonal Hematopoiesis of Indeterminate Potential and Diabetic Kidney Disease: A Nested Case-Control Study.

Introduction: The disease trajectory of diabetic kidney disease (DKD) shows a high interindividual variability not sufficiently explained by conventional risk factors. Clonal hematopoiesis of indeterminate potential (CHIP) is a proposed novel cardiovascular risk factor. Increased kidney fibrosis and glomerulosclerosis were described in mouse models of CHIP. Here, we aim to analyze whether CHIP affects the incidence or progression of DKD. Methods: A total of 1419 eligible participants of the PROVALID Study were the basis for a nested case-control (NCC) design. A total of 64 participants who reached a prespecified composite endpoint within the observation period (initiation of kidney replacement therapy, death from kidney failure, sustained 40% decline in estimated glomerular filtration rate or sustained progression to macroalbuminuria) were identified and matched to 4 controls resulting in an NCC sample of 294 individuals. CHIP was assessed via targeted amplicon sequencing of 46 genes in peripheral blood. Furthermore, inflammatory cytokines were analyzed in plasma via a multiplex assay. Results: The estimated prevalence of CHIP was 28.91% (95% CI 22.91%-34.91%). In contrast to other known risk factors (albuminuria, hemoglobin A1c, heart failure, and smoking) and elevated microinflammation, CHIP was not associated with incident or progressive DKD (hazard ratio [HR] 1.06 [95% CI 0.57-1.96]). Conclusions: In this NCC study, common risk factors as well as elevated microinflammation but not CHIP were associated with kidney function decline in type 2 diabetes mellitus.

Data of 'Circulating tumor DNA correlates with tumor burden and predicts outcome in pancreatic cancer irrespective of tumor stage'.

This data article subsumes the data acquiration process, analysis and results of 'Circulating tumor DNA correlates with tumor burden and predicts outcome in pancreatic cancer irrespective of tumor stage' published in European Journal of Surgical Oncology (Eur J Surg Oncol. 2021 Dec 1:S0748-7983(21)00947-1. doi:10.1016/j.ejso.2021.11.138. PMID: 34876329) (Kirchweger et al., 2021). 28.5 mL of blood was obtained from 60 patients with localized pancreatic cancer directly prior to curative intended surgery as well as from 47 patients with metastasized pancreatic cancer (PDAC) directly prior to palliative intended systemic treatment initiation. Cell-free DNA preparation was done on the Chemagic 360 (Perkin Elmer, Waltham, Massachusetts, USA) using the kits CMG-1304 and CMG-844 from the same provider and quantified using the Quantus fluorometer (Promega, Madison, Wisconsin, USA). Screening for most common KRAS alterations (KRAS G12/G13 screening kit and additionally for KRAS Q61 if screening was negative) was performed utilizing the QX200™ Droplet Digital™ PCR System from Bio-Rad (Bio-Rad Laboratories, Hercules, CA, USA). Volumetric analysis was performed on contrast enhanced dual-energy CT scans in the arterial and portal venous phase prior to treatment initiation using Syngo.via (Siemens Healthcare, Forchheim, Germany) on MM Oncology Workflow adhering to RECIST 1.1 criteria (Eisenhauer et al., 2009). CtDNA predicts outcome in localized and disseminated disease. Moreover, it correlates with distant metastasis volume and positive lymph nodes but not primary tumor volume and therefore could indicate subclinical synchronous distant metastases in localized PDAC undetectable by current gold standard (computed tomography).

Circulating tumor DNA correlates with tumor burden and predicts outcome in pancreatic cancer irrespective of tumor stage.

INTRODUCTION: Circulating tumor DNA (ctDNA) represents a promising tool for diagnosis, prognosis and treatment monitoring of several malignancies. Its association with tumor burden in pancreatic ductal cancer (PDAC), especially in localized disease, is not fully explored yet. We aimed to investigate the association of pretherapeutic ctDNA levels in localized and metastatic PDAC with tumor volume and clinical outcomes. MATERIAL AND METHODS: Liquid biopsy for ctDNA detection was prospectively obtained from patients with localized or disseminated PDAC prior to either resection or systemic treatment. Detection rates and levels of ctDNA (digital droplet PCR) were correlated to tumor volume, relapse rate and survival. RESULTS: 60 patients with localized and 47 patients with metastatic PDAC were included. ctDNA was detected in 10% of localized and 57.4% of metastasized PDAC samples. In localized disease, ctDNA detection significantly correlated with the numbers of involved locoregional lymph nodes (p = 0.030). Primary tumor volume did not correlate with ctDNA levels in neither localized (p = 0.573) nor metastasized disease (p = 0.878). In disseminated disease, ctDNA levels correlated with total tumor volume (p = 0.026) and especially with liver metastases volume (p = 0.004), but not with other metastases. Detection of pretherapeutic ctDNA was associated with shorter DFS in localized (3.3 vs. 18.1 months, p = 0.000), whereas ctDNA levels were associated with worse survival in metastatic PDAC (5.7 vs. 7.8 months, p = 0.036). CONCLUSION: ctDNA positivity indicates major nodal involvement or even presence of undetected distant metastases associated with early recurrence in localized PDAC. Moreover, it predicts worse clinical outcome in both localized and metastatic disease.

Clonal dynamics in a composite chronic lymphocytic leukemia and hairy cell leukemia-variant.

Composite lymphoma is the rare simultaneous manifestation of two distinct lymphomas. Chronic lymphocytic leukemia (CLL) has a propensity for occurring in composite lymphomas, a phenomenon that remains to be elucidated. We applied cytogenetics, droplet digital polymerase chain reaction, and massively parallel sequencing to analyze longitudinally a patient with CLL, who 3 years later showed transformation to a hairy cell leukemia-variant (HCL-V). Outgrowth of the IGHV4-34-positive HCL-V clone at the expense of the initially dominant CLL clone with trisomy 12 and MED12 mutation started before CLL-guided treatment and was accompanied by a TP53 mutation, which was already detectable at diagnosis of CLL. Furthermore, deep sequencing of IGH showed a composite lymphoma with presence of both disease components at all analyzed timepoints (down to a minor clone: major clone ratio of ~1:1000). Overall, our analyses showed a disease course that resembled clonal dynamics reported for malignancies with intratumoral heterogeneity and illustrate the utility of deep sequencing of IGH to detect distinct clonal populations at diagnosis, monitor clonal response to therapy, and possibly improve clinical outcomes.