Rapid fluorescence in situ hybridisation optimises induction therapy for acute myeloid leukaemia

Cancer cytogenetics in a genomics world: Wedding the old with the new

Since the discovery of the Philadelphia chromosome in 1960, cytogenetic studies have been instrumental in detecting chromosomal abnormalities that can inform cancer diagnosis, treatment, and risk assessment efforts. The initial expansion of cancer cytogenetics was with fluorescence in situ hybridization (FISH) to assess submicroscopic alterations in dividing or non-dividing cells and has grown into the incorporation of chromosomal microarrays (CMA), and next generation sequencing (NGS). These molecular technologies add additional dimensions to the genomic assessment of cancers by uncovering cytogenetically invisible molecular markers. Rapid technological and bioinformatic advances in NGS are so promising that the idea of performing whole genome sequencing as part of routine patient care may soon become economically and logistically feasible. However, for now cytogenetic studies continue to play a major role in the diagnostic testing and subsequent assessments in leukemia with other genomic studies serving as complementary testing options for detection of actionable genomic abnormalities. In this review, we discuss the role of conventional cytogenetics (karyotyping, chromosome analysis) and FISH studies in hematological malignancies, highlighting the continued clinical utility of these techniques, the subtleties and complexities that are relevant to treating physicians and the unique strengths of cytogenetics that cannot yet be paralleled by the current high-throughput molecular technologies. Additionally, we describe how CMA, optical genome mapping (OGM), and NGS detect abnormalities that were beyond the capacity of cytogenetic studies and how an integrated approach (broad molecular testing) can contribute to the detection of actionable targets and variants in malignancies. Finally, we discuss advances in the field of genomic testing that are bridging the advantages of individual (single) cell based cytogenetic testing and broad genomic testing.

Genomic profiling for clinical decision making in myeloid neoplasms and acute leukemia

Myeloid neoplasms and acute leukemias derive from the clonal expansion of hematopoietic cells driven by somatic gene mutations. Although assessment of morphology plays a crucial role in the diagnostic evaluation of patients with these malignancies, genomic characterization has become increasingly important for accurate diagnosis, risk assessment, and therapeutic decision making. Conventional cytogenetics, a comprehensive and unbiased method for assessing chromosomal abnormalities, has been the mainstay of genomic testing over the past several decades and remains relevant today. However, more recent advances in sequencing technology have increased our ability to detect somatic mutations through the use of targeted gene panels, whole-exome sequencing, whole-genome sequencing, and whole-transcriptome sequencing or RNA sequencing. In patients with myeloid neoplasms, whole-genome sequencing represents a potential replacement for both conventional cytogenetic and sequencing approaches, providing rapid and accurate comprehensive genomic profiling. DNA sequencing methods are used not only for detecting somatically acquired gene mutations but also for identifying germline gene mutations associated with inherited predisposition to hematologic neoplasms. The 2022 International Consensus Classification of myeloid neoplasms and acute leukemias makes extensive use of genomic data. The aim of this report is to help physicians and laboratorians implement genomic testing for diagnosis, risk stratification, and clinical decision making and illustrates the potential of genomic profiling for enabling personalized medicine in patients with hematologic neoplasms.

Dose intensity for induction in acute myeloid leukemia: what, when, and for whom?

Intensive chemotherapy has been the backbone of the treatment of acute myeloid leukemia (AML) for decades. However, an increase in novel targeted agents, which has been brought about in part by a deeper understanding of the genetic makeup of AML, has led to remission-inducing regimens that do not require traditional cytotoxic agents. Combinations of a hypomethylating agent (HMA) and venetoclax have doubled the chance of remission for patients considered unfit for induction chemotherapy who would have traditionally been offered singleagent HMA. In fact, this regimen may rival the complete remission rate achieved with induction chemotherapy for certain populations such as the very elderly and those with secondary AML, but equivalency has yet to be established. Further advances include the addition of gemtuzumab ozogamicin and FLT3 inhibitors to induction chemotherapy, which improves survival for patients with core-binding factor and FLT3-mutated AML, respectively. Still, much work is needed to improve the outcomes of the highest-risk subgroups: frail patients and those with high-risk cytogenetics and/or TP53 mutations. Promisingly, the landscape of AML therapy is shifting dramatically and no longer is intensity, when feasible, always the best answer for AML.