Therapy-related myeloid neoplasms in 109 patients after radiation monotherapy

Therapy-Related Myeloid Neoplasms: Predisposition and Clonal Evolution

Therapy-related Myeloid Neoplasm (t-MN) represents one of the worst long-term consequences of cytotoxic therapy for primary tumors and autoimmune disease. Poor survival and refractoriness to current treatment strategies characterize affected patients from a clinical point of view. In our aging societies, where newer therapies and ameliorated cancer management protocols are improving the life expectancy of cancer patients, therapy-related Myeloid Neoplasms are an emerging problem. Although several research groups have contributed to characterizing the main risk factors in t-MN development, the multiplicity of primary tumors, in association with the different therapeutic strategies available and the new drugs in development, make interpreting the current data still complex. The main risk factors involved in t-MN pathogenesis can be subgrouped into patient-specific, inherited, and acquired predispositions. Although t-MN can occur at any age, the risk tends to increase with advancing age, and older patients, characterized by a higher number of comorbidities, are more likely to develop the disease. Thanks to the availability of deep sequencing techniques, germline variants have been reported in 15-20% of t-MN patients, highlighting their role in cancer predisposition. It is becoming increasingly evident that t-MN with driver gene mutations may arise in the background of Clonal Hematopoiesis of Indeterminate Potential (CHIP) under the positive selective pressure of chemo and/or radiation therapies. Although CHIP is generally considered benign, it has been associated with an increased risk of t-MN. In this context, the phenomenon of clonal evolution may be described as a dynamic process of expansion of preexisting clones, with or without acquisition of additional genetic alterations, that, by favoring the proliferation of more aggressive and/or resistant clones, may play a crucial role in the progression from preleukemic states to t-MN.

Stagnation in quality of next-generation sequencing assays for the diagnosis of hereditary hematopoietic malignancies

Hereditary hematopoietic malignancies (HHMs) are inherited syndromes that confer the risk of blood cancer development. With the rapid acceleration of next-generation sequencing (NGS) into commercial biotechnology markets, HHMs are increasingly recognized by genetic counselors and clinicians. In 2020, it was demonstrated that most diagnostic test offerings for HHMs were insufficient for accurate diagnosis, failing to sequence the full spectrum of genetic events known to cause HHMs. We hypothesized the number of genes on commercially available HHM assay increased from 2020 to 2022, consistent with a more comprehensive sequencing approach. Here, we analyzed assays from eight commercial laboratories to determine the HHM-related genes sequenced by these assays. We compared these assays with panels from 2020 to determine trends in sequencing quality. Most HHM diagnostic assays did not change and remain insensitive for the detection of all HHM-related variants. Most (75%) HHM assays do not sequence CHEK2, the gene most frequently mutated in HHMs, and 25% of HHM assays does not sequence DDX41, the second most frequent HHM driver. The quality of HHM diagnostic assays stagnated despite the discovery of novel HHM-related genes and prior work demonstrating heterogeneity in the quality of HHM testing. Most commercially available HHM tests remain insufficient.

Therapy-related MDS dissected based on primary disease and treatment-a nationwide perspective

In this population-based study, we aimed to characterize and compare subgroups of therapy-related Myelodysplastic syndromes (t-MDS) and define the implications of type of previous treatment and primary disease. We combined data from MDS patients, diagnosed between 2009 and 2017 (n = 2705), in the nationwide Swedish MDS register, with several health registers. Furthermore, using matched population controls, we investigated the prevalence of antecedent malignancies in MDS patients in comparison with the general population. This first ever nationwide study on t-MDS confirms a shorter median survival for t-MDS compared to de novo MDS (15.8 months vs 31.1 months, p < 0.001). T-MDS patients previously treated with radiation only had disease characteristics with a striking resemblance to de novo-MDS, in sharp contrast to patients treated with chemotherapy who had a significantly higher risk profile. IPSS-R and the WHO classification differentiated t-MDS into different risk groups. As compared with controls, MDS patients had a six-fold increased prevalence of a previous hematological malignancy but only a 34% increased prevalence of a previous solid tumor. T-MDS patients with a previous hematological malignancy had a dismal prognosis, due both to mortality related to their primary disease and to high-risk MDS.

Clinically relevant germline variants in allogeneic hematopoietic stem cell transplant recipients

Allogeneic hematopoietic stem cell transplantation (HSCT) provides patients with severe hematologic disease a well-established potential for curation. Incorporation of germline analyses in the workup of HSCT patients is not a common practice. Recognizing rare harmful germline variants may however affect patients' pre-transplantation care, choice of the stem cell donor, and complication risks. We analyzed a population-based series of germline exome data of 432 patients who had undergone HSCT. Our aim was to identify clinically relevant variants that may challenge the outcome of the HSCT. We focused on genes predisposing to hematological diseases, or solid tumors, and genes included in the American College of Medical Genetics secondary findings list v3.0. As population-specific controls, we used GnomAD non-cancer Finns (n = 10,816). We identified in our population-based analysis rare harmful germline variants in disease-predisposing or actionable toxicity-increasing genes in 17.8% of adult and pediatric patients that have undergone HSCT (15.1% and 22.9%, respectively). More than half of the patients with a family member as a donor had not received genetic diagnosis prior to the HSCT. Our results encourage clinicians to incorporate germline genetic testing in the HSCT protocol in the future in order to reach optimal long-term outcome for the patients.