Using Tumor-Informed Circulating Tumor DNA (ctDNA)-Based Testing for Patients with Anal Squamous Cell Carcinoma.

BACKGROUND: Anal squamous cell carcinoma (SCCA) is an uncommon malignancy with a rising incidence that has a high cure rate in its early stages. There is an unmet need for a reliable method to monitor response to treatment and assist in surveillance. Circulating tumor DNA (ctDNA) testing has shown great promise in other solid tumors for monitoring disease progression and detecting relapse in real time. This study aimed to determine the feasibility and use of personalized and tumor-informed ctDNA testing in SCCA. PATIENTS AND METHODS: We analyzed real-world data from 251 patients (817 plasma samples) with stages I-IV SCCA, collected between 11/5/19 and 5/31/22. The tumor genomic landscape and feasibility of ctDNA testing was examined for all patients. The prognostic value of longitudinal ctDNA testing was assessed in patients with clinical follow-up (N = 37). RESULTS: Whole-exome sequencing analysis revealed PIK3CA as the most commonly mutated gene, and no associations between mutations and stage. Anytime ctDNA positivity and higher ctDNA levels (MTM/mL) were associated with metastatic disease (P = .004). For 37 patients with clinical follow-up, median follow-up time was 21.0 months (range: 4.1-67.3) post-diagnosis. For patients with stages I-III disease, anytime ctDNA-positivity after definitive treatment was associated with reduced DFS (HR: 28.0; P = .005). CONCLUSIONS: Our study demonstrates the feasibility of personalized and tumor-informed ctDNA testing as an adjunctive tool in patients with SCCA as well as potential use for detection of molecular/minuteimal residual disease, and relapse during surveillance. Prospective studies are needed to better evaluate the use of ctDNA testing in this indication.

Detection of microsatellite instability high (MSI-H) status by targeted plasma-based genotyping in metastatic breast cancer.

We evaluate microsatellite instability-high (MSI-H) status with cell-free DNA (cfDNA) in metastatic breast cancer (MBC) and the association with clinico-genomic characteristics. Patients with MSI-H in cfDNA (Guardant360®, 74 gene next-generation sequencing (NGS) with MBC are identified. We conduct a retrospective review. The median number of alterations and a median maximum mutant allelic fraction (MAF) in MSI-H and non-MSI-H cohorts are compared with Mann-Whitney U-test. Of 6718 patients with breast cancer with ≥1 plasma NGS alteration, 42 (0.63%) have MSI-H. A median number of genomic alterations per sample is 11 in MSI-H vs. 3 in non-MSI-H (Mann-Whitney U-test p < 0.0001) and the median maximum MAF is 16.8% in MSI-H vs. 2.6% in non-MSI-H (Mann-Whitney U-test p < 0.0001). The co-existing genomic landscape is heterogeneous. The median response duration for seven patients receiving immunotherapy is 92 days (range 29-273 days). CfDNA can identify MSI-H in MBC. Research is needed to validate immunotherapy usage in cfDNA-detected MSI-H MBC.

Treatment Response Monitoring Using a Tumor-Informed Circulating Tumor DNA Test in an Advanced Triple-Negative Breast Cancer Patient: A Case Report.

Triple-negative breast cancer (TNBC) is highly aggressive disease that is often refractory to surgery and multiple lines of therapy. Although the repertoire of FDA-approved treatments has expanded, there is an unmet need for biomarkers that can aid in appropriate selection and timing of therapy. We present a case of highly aggressive treatment-resistant TNBC that employed a comprehensive genomic profiling (CGP)-based assay to identify therapeutic targets, followed by longitudinal circulating tumor DNA (ctDNA) testing. For this, a tumor-naïve next-generation sequencing-based targeted panel was used to aid in therapy selection, along with longitudinal personalized and tumor-informed ctDNA testing to monitor tumor response to treatment. Longitudinal ctDNA testing using the tumor-informed assay detected post-surgical molecular residual disease, and rise in ctDNA levels during the surveillance period provided rationale for switching between four lines of therapy. Overall, the combined use of CGP assay with longitudinal ctDNA testing resulted in a potential prolonged survival in this highly aggressive case of TNBC.

Validation of Microsatellite Instability Detection Using a Comprehensive Plasma-Based Genotyping Panel.

PURPOSE: To analytically and clinically validate microsatellite instability (MSI) detection using cell-free DNA (cfDNA) sequencing. EXPERIMENTAL DESIGN: Pan-cancer MSI detection using Guardant360 was analytically validated according to established guidelines and clinically validated using 1,145 cfDNA samples for which tissue MSI status based on standard-of-care tissue testing was available. The landscape of cfDNA-based MSI across solid tumor types was investigated in a cohort of 28,459 clinical plasma samples. Clinical outcomes for 16 patients with cfDNA MSI-H gastric cancer treated with immunotherapy were evaluated. RESULTS: cfDNA MSI evaluation was shown to have high specificity, precision, and sensitivity, with a limit of detection of 0.1% tumor content. In evaluable patients, cfDNA testing accurately detected 87% (71/82) of tissue MSI-H and 99.5% of tissue microsatellite stable (863/867) for an overall accuracy of 98.4% (934/949) and a positive predictive value of 95% (71/75). Concordance of cfDNA MSI with tissue PCR and next-generation sequencing was significantly higher than IHC. Prevalence of cfDNA MSI for major cancer types was consistent with those reported for tissue. Finally, robust clinical activity of immunotherapy treatment was seen in patients with advanced gastric cancer positive for MSI by cfDNA, with 63% (10/16) of patients achieving complete or partial remission with sustained clinical benefit. CONCLUSIONS: cfDNA-based MSI detection using Guardant360 is highly concordant with tissue-based testing, enabling highly accurate detection of MSI status concurrent with comprehensive genomic profiling and expanding access to immunotherapy for patients with advanced cancer for whom current testing practices are inadequate.See related commentary by Wang and Ajani, p. 6887.

A phase III randomized controlled trial of tiotropium add-on therapy in children with severe symptomatic asthma.

BACKGROUND: Studies in adults and adolescents have demonstrated that tiotropium is efficacious as an add-on therapy to inhaled corticosteroids (ICSs) with or without other maintenance therapies in patients with moderate or severe symptomatic asthma. OBJECTIVE: We sought to assess the efficacy and safety of once-daily tiotropium Respimat add-on therapy to high-dose ICS with 1 or more controller medications, or medium-dose ICS with 2 or more controller medications, in the first phase III trial of tiotropium in children with severe symptomatic asthma. METHODS: In this 12-week, double-blind, placebo-controlled, parallel-group trial, 401 participants aged 6 to 11 years were randomized to receive once-daily tiotropium 5 µg (2 puffs of 2.5 µg) or 2.5 µg (2 puffs of 1.25 µg), or placebo (2 puffs), administered through the Respimat device as add-on to background therapy. RESULTS: Compared with placebo, tiotropium 5 µg, but not 2.5 µg, add-on therapy improved the primary end point, peak FEV1 within 3 hours after dosing (5 µg, 139 mL [95% CI, 75-203; P < .001]; 2.5 µg, 35 mL [95% CI, -28 to 99; P = .27]), and the key secondary end point, trough FEV1 (5 µg, 87 mL [95% CI, 19-154; P = .01]; 2.5 µg, 18 mL [95% CI, -48 to 85; P = .59]). The safety and tolerability of tiotropium were comparable with those of placebo. CONCLUSIONS: Once-daily tiotropium Respimat 5 µg improved lung function and was well tolerated as add-on therapy to ICS with other maintenance therapies in children with severe symptomatic asthma.

Isocitrate dehydrogenase mutations in chondrosarcoma: the crossroads between cellular metabolism and oncogenesis.

PURPOSE OF REVIEW: This article reviews the most recent developments and implications in regard to isocitrate dehydrogenase mutations in chondrosarcoma, a disease in which currently available systemic therapies have proven inefficacious, with an emphasis on how disruption in normal cellular metabolism plays a role in oncogenesis. RECENT FINDINGS: The development of acquired isocitrate dehydrogenase-1/isocitrate dehydrogenase-2 mutations has been described in multiple tumors and more recently in chondrosarcomas. The impact of these mutations has been the focus of multiple research efforts during the last years, allowing us to better understand the impact of the mutation, including its interaction with other proteins, changes in expression of genes involved in tumor genesis, the oncogenic potential of 2-hydroxyglutarate, the impact on cellular proliferation and differentiation, and the influence on the epigenetic state of cells owing to changes in DNA and histone methylation patterns. New compounds targeting the mutation have been developed. SUMMARY: This mutation is the first of its kind described in chondrosarcoma, serving as an identifying marker of chondroid differentiation, and becoming the first molecular target with potential anticancer effect, translating into the development of therapies targeting these mutations currently being tested further in preclinical models and clinical trials.

Congestive heart failure risk in patients with breast cancer treated with bevacizumab.

PURPOSE: Bevacizumab is a treatment option in patients with metastatic breast cancer. Congestive heart failure (CHF) has been reported, although the overall incidence and relative risk (RR) of this complication remains unclear. We performed an up-to-date, comprehensive meta-analysis to determine the risk of serious CHF in patients with breast cancer receiving bevacizumab. METHODS: The databases of Medline were searched for articles from 1966 to March 2010. Abstracts presented at the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium meetings were also searched for relevant clinical trials. Eligible studies include randomized trials with bevacizumab in patients with breast cancer. Adequate reporting of safety profile data was required for inclusion. Statistical analyses were conducted to calculate the summary incidence, RR, and 95% CIs by using random-effects models. RESULTS: A total of 3,784 patients were included. Overall incidence results for high-grade CHF in bevacizumab- and placebo-treated patients were 1.6% (95% CI, 1.0% to 2.6%) and 0.4% (95% CI, 0.2% to 1.0%), respectively. The RR of CHF in bevacizumab-treated patients was 4.74 (95% CI, 1.66 to 11.18; P = .001) compared with placebo-treated ones. In subgroup analyses, there were no significant differences in CHF incidence or risk between patients treated with low-dose (2.5 mg/kg) versus high-dose (5 mg/kg) bevacizumab or among patients treated with different chemotherapy regimens. No evidence of publication bias was observed. CONCLUSION: This is the first comprehensive report to show that bevacizumab is associated with an increased risk of significant heart failure in patients with breast cancer.