Complex cytogenetic abnormalities in chronic myeloid leukemia resulting in early progression to blast crisis: a case report

Does presence of complex translocations involving BCR::ABL1 in chronic myeloid leukemia affect the response rate to tyrosine kinase inhibitors? A systematic review of the literature

Philadelphia (Ph) chromosome (9;22)(q34;q11) comprises 90-95 % of chronic myeloid leukemia (CML), while 5-10 % of CML have translocations involving three or more chromosomes. The outcome of treating patients harbouring complex Ph-positive cytogenetics with tyrosine kinase inhibitors (TKI) is unclear. In the present systematic review, we aim to summarise the response of patients with complex Ph-positive cytogenetics to treatment with TKI therapy. We collated all available literature from databases such as PubMed, Google Scholar, Web of Science database, Cochrane library, Scopus and Embase (up until January 31st, 2024), which describe cases of patients with CML, harbouring complex Ph-positive variations (three and four-way translocations), and summarised their response to TKI therapy. The studies were screened for the following criteria: documented TKI intervention and outcome (whether CR was achieved). Studies that did not report the same, were excluded. Additionally, we report a case from our center of a 55-year-old patient with CML, positive for the Ph-chromosome, harbouring a three-way translocation involving chromosome 15 i.e. 46XX, t(9;15;22) (q34;p11;q11). Identification of BCR::ABL and involvement of chromosome 15 was carried out using conventional cytogenetics, fluorescence in situ hybridization (FISH), and quantitative PCR (qPCR). Based on the inclusion criteria, a total of 15 studies were included from which a total of 87 cases were covered. Overall, we identified 38 unique complex three- and four-way translocations across 87 Ph-positive cases and found that 85 patients with complex Ph-positive cytogenetics achieved complete remission upon treatment and did not appear to have a lesser response to TKI therapy.

Impact of additional cytogenetic aberrations at diagnosis on prognosis of adults patients with Philadelphia chromosome positive acute lymphoblastic leukemia undergoing allogeneic hematopoietic cell transplantation: a retrospective analysis

Additional chromosomal abnormalities(ACAs) at diagnosis are associated with inferior prognosis in chronic myeloid leukemia. However, the prognostic significance of ACAs in adult patients with Philadelphia Chromosome Positive acute lymphoblastic leukemia (Ph + ALL) receiving TKI-targeted drugs and allogeneic hematopoietic stem cell transplantation(HSCT) is unknown. One hundred thirty-six adult patients with Ph + ALL were included in the study and retrospectively analysed, evaluating the effect of ACAs on outcomes of transplantation. ACAs are observed in 60 cases (44%). ACAs detected in more than 5% of cases were defined as major-route and encompass: +der(22), +der(9), + 8, -7 and complex karyotype. The median follow-up was 26.4 months. In the subgroup analyses of major route ACAs, three-year cumulative incidence of relapse (CIR) and progression-free survival(PFS) are statistically significant in + 8[66.7% vs.23.7%, P = 0.024; 77.8% vs. 23.7%, P = 0.0087], -7[53.8% vs. 23.7%, P = 0.035%; 61.5% vs. 32.9%, P = 0.033], and complex karyotypes[42.9% vs. 23.7%, P = 0.027; 47.6% vs. 23.7%] compared with t(9;22) sole. Additionally, the 3-year CIR for Ph + ALL with + der(22) is 44% vs. 23.7% for t(9;22) sole(P = 0.045). The 3-year overall survival (OS) in the - 7 group is 46.5%, which is statistically significant compared with the other groups(P = 0.001). In multivariate analyses, three years CIR and PFS are statistically significant in + der(22), + 8, -7 and complex karyotype compared with t(9;22) sole(P < 0.05). More importantly, Ph + ALL with - 7 was negatively associated with the rate of 3-year OS(P = 0.012). Thus, ACAs at diagnosis appear to have a significant prognostic impact on transplantation outcomes in patients with Ph + ALL.

Cytogenetic abnormalities in patients with hematological malignancies in Lahore city, Pakistan

Hematological and hematopoietic cells malignancies of the genes and hematopoietic cells are associated with the genetic mutation, often at the chromosomal level. The standard cytogenetic study is widely accepted as one of the main diagnostics and prognostic determinants in patients. Therefore, the current descriptive and cross-sectional study sought to determine the cytogenetic analysis of frequent hematological malignancies in Pakistan. A total of 202 peripheral bone marrow or blood samples from patients with benign and malignant hematological malignancy were taken using a conventional G-banding technique. Among enrolled patients, the mean age was 21.5 years ± 23.4, and gender-wise distribution showed a marked predominance of the male 147 (73%) population compared to the female 55 (27%). Patients in the age group (2-10 years) had the highest frequency, 48 (24%), of hematological neoplasms, followed by age (11-20 years) with 40 (20%). Normal karyotypes (46, XX/46, XY) was found in 51% (n=103) patients. Furthermore, the frequency of complex karyotype was 30 (15%), while normal was seen in 171 (85%) patients. Pre-B Acute Lymphoblastic Leukemia (Pre-B ALL) was the most prevalent malignancy of 66 (33%), followed by Chronic Myelogenous Leukemia (CML) of 41 (20%) and Acute Lymphocytic Leukemia of 29 (14%). Translocation was the most prevalent 50 (25%), followed by hypotriploidy 14 (7%) and monosomy 8 (4%) on chromosome aberration analysis. In addition, t(9:22) translocation was found to be 20 (10%) in CML, with the majority in the age group (31-40 years). This study recommends that karyotyping should be tested frequently in hematological conditions because it may provide insight into the relative chromosomal changes associated with particular malignancies.

Sudden Blast Crisis After Excellent Initial Response in Chronic Myeloid Leukemia

Sudden blast crisis is an uncommon phenomenon in chronic myeloid leukemia (CML) patients who are being treated with tyrosine kinase inhibitors (TKIs). Despite well-defined guidelines to treat and monitor the disease, it is difficult to predict the occurrence of a sudden blast crisis. Research directed towards improving guidelines in choosing the appropriate TKIs and better monitoring protocols could help prevent such unfortunate outcomes. We present a case of a 46-year-old man diagnosed with CML who responded well to imatinib as evidenced by a downtrend in quantitative BCR-ABL mutation to less than 1. He quickly transformed into a blast crisis phase after five months of therapy with imatinib regardless of achieving an excellent initial optimal response. In conclusion, it is possible to transform into a blast phase despite achieving an initial optimal response. Therefore, attention should be focused on the selection of proper tyrosine kinase inhibitors and careful monitoring to allow the early detection of sudden blast crisis.

Philadelphia chromosome positive chronic myeloid leukemia with 5q deletion at diagnosis

Background

Although, molecular genetic analyses became more and more important to guide therapy decisions in leukemia, banding cytogenetic analysis has retained its vital role in diagnosis and monitoring of chronic myeloid leukemia (CML), by quick and easy enabling identification of pathognomonic Philadelphia chromosome (Ph).

Case presentation

A 45 year old female presented with characteristic hematological features of CML in chronic phase; cytogenetic studies revealed the presence of the typical Ph and a deletion of almost entire long arm of a chromosome 5.

Conclusion

5q deletions have rarely been reported in CML. Those seen yet were either associated with tyrosine kinase inhibitor therapy or detected post allogeneic stem cell transplantation. To our knowledge, this is the first case of Ph positive CML accompanied by a 5q deletion.