Liquid biopsy approaches to capture tumor evolution and clinical outcomes during cancer immunotherapy.

Circulating cell-free tumor DNA (ctDNA) can serve as a real-time biomarker of tumor burden and provide unique insights into the evolving molecular landscape of cancers under the selective pressure of immunotherapy. Tracking the landscape of genomic alterations detected in ctDNA may reveal the clonal architecture of the metastatic cascade and thus improve our understanding of the molecular wiring of therapeutic responses. While liquid biopsies may provide a rapid and accurate evaluation of tumor burden dynamics during immunotherapy, the complexity of antitumor immune responses is not fully captured through single-feature ctDNA analyses. This underscores a need for integrative studies modeling the tumor and the immune compartment to understand the kinetics of tumor clearance in association with the quality of antitumor immune responses. Clinical applications of ctDNA testing in patients treated with immune checkpoint inhibitors have shown both predictive and prognostic value through the detection of genomic biomarkers, such as tumor mutational burden and microsatellite instability, as well as allowing for real-time monitoring of circulating tumor burden and the assessment of early on-therapy responses. These efforts highlight the emerging role of liquid biopsies in selecting patients for cancer immunotherapy, monitoring therapeutic efficacy, determining the optimal duration of treatment and ultimately guiding treatment selection and sequencing. The clinical translation of liquid biopsies is propelled by the increasing number of ctDNA-directed interventional clinical trials in the immuno-oncology space, signifying a critical step towards implementation of liquid biopsies in precision immuno-oncology.

Peripheral blood immune cell dynamics reflect antitumor immune responses and predict clinical response to immunotherapy.

BACKGROUND: Despite treatment advancements with immunotherapy, our understanding of response relies on tissue-based, static tumor features such as tumor mutation burden (TMB) and programmed death-ligand 1 (PD-L1) expression. These approaches are limited in capturing the plasticity of tumor-immune system interactions under selective pressure of immune checkpoint blockade and predicting therapeutic response and long-term outcomes. Here, we investigate the relationship between serial assessment of peripheral blood cell counts and tumor burden dynamics in the context of an evolving tumor ecosystem during immune checkpoint blockade. METHODS: Using machine learning, we integrated dynamics in peripheral blood immune cell subsets, including neutrophil-lymphocyte ratio (NLR), from 239 patients with metastatic non-small cell lung cancer (NSCLC) and predicted clinical outcome with immune checkpoint blockade. We then sought to interpret NLR dynamics in the context of transcriptomic and T cell repertoire trajectories for 26 patients with early stage NSCLC who received neoadjuvant immune checkpoint blockade. We further determined the relationship between NLR dynamics, pathologic response and circulating tumor DNA (ctDNA) clearance. RESULTS: Integrated dynamics of peripheral blood cell counts, predominantly NLR dynamics and changes in eosinophil levels, predicted clinical outcome, outperforming both TMB and PD-L1 expression. As early changes in NLR were a key predictor of response, we linked NLR dynamics with serial RNA sequencing deconvolution and T cell receptor sequencing to investigate differential tumor microenvironment reshaping during therapy for patients with reduction in peripheral NLR. Reductions in NLR were associated with induction of interferon-γ responses driving the expression of antigen presentation and proinflammatory gene sets coupled with reshaping of the intratumoral T cell repertoire. In addition, NLR dynamics reflected tumor regression assessed by pathological responses and complemented ctDNA kinetics in predicting long-term outcome. Elevated peripheral eosinophil levels during immune checkpoint blockade were correlated with therapeutic response in both metastatic and early stage cohorts. CONCLUSIONS: Our findings suggest that early dynamics in peripheral blood immune cell subsets reflect changes in the tumor microenvironment and capture antitumor immune responses, ultimately reflecting clinical outcomes with immune checkpoint blockade.

A novel bedside cardiopulmonary physical diagnosis curriculum for internal medicine postgraduate training.

BACKGROUND: Physicians spend less time at the bedside in the modern hospital setting which has contributed to a decline in physical diagnosis, and in particular, cardiopulmonary examination skills. This trend may be a source of diagnostic error and threatens to erode the patient-physician relationship. We created a new bedside cardiopulmonary physical diagnosis curriculum and assessed its effects on post-graduate year-1 (PGY-1; interns) attitudes, confidence and skill. METHODS: One hundred five internal medicine interns in a large U.S. internal medicine residency program participated in the Advancing Bedside Cardiopulmonary Examination Skills (ACE) curriculum while rotating on a general medicine inpatient service between 2015 and 2017. Teaching sessions included exam demonstrations using healthy volunteers and real patients, imaging didactics, computer learning/high-fidelity simulation, and bedside teaching with experienced clinicians. Primary outcomes were attitudes, confidence and skill in the cardiopulmonary physical exam as determined by a self-assessment survey, and a validated online cardiovascular examination (CE). RESULTS: Interns who participated in ACE (ACE interns) by mid-year more strongly agreed they had received adequate training in the cardiopulmonary exam compared with non-ACE interns. ACE interns were more confident than non-ACE interns in performing a cardiac exam, assessing the jugular venous pressure, distinguishing 'a' from 'v' waves, and classifying systolic murmurs as crescendo-decrescendo or holosystolic. Only ACE interns had a significant improvement in score on the mid-year CE. CONCLUSIONS: A comprehensive bedside cardiopulmonary physical diagnosis curriculum improved trainee attitudes, confidence and skill in the cardiopulmonary examination. These results provide an opportunity to re-examine the way physical examination is taught and assessed in residency training programs.

Use of cell free DNA in breast oncology.

Cell free DNA (cfDNA) are short fragments of nucleic acids present in circulation outside of cells. In patients with cancer, some portion of cfDNA is derived from tumor cells, termed circulating tumor DNA (ctDNA), and contains the same mutations and genetic changes as the cancer. The development of new, more effective methods to detect these changes has led to increased interest in developing ctDNA as a biomarker for cancer. Here we will review current literature on the use of ctDNA, with an emphasis on breast cancer, for cancer detection, prognosis, monitoring response to therapy, and tracking the rise of new mutant subclones.

Upfront therapy of acute myeloid leukemia.

Acute myeloid leukemia is a clinically and biologically heterogeneous disease. Standard induction chemotherapy, consisting of cytarabine and an anthracycline, has not changed substantially over several decades, and outcomes remain suboptimal, particularly in older patients. Many genetic and molecular changes have been identified that guide selection of post-remission therapy and for which targeted therapies are beginning to be developed and tested. These research efforts are resulting in gradual improvement in outcomes. We will review here recent advances in induction chemotherapy, including anthracycline dose intensification in younger patients, treatment selection and use of novel agents in upfront therapy for older patients, and risk-adapted post-remission therapy.