Clonal chromosomal aberrations in Philadelphia negative cells such as monosomy 7 and trisomy 8 may persist for years with no impact on the long term outcome in patients with chronic myeloid leukemia

Clinical Features of Clonal Cytogenetic Abnormalities in Philadelphia-negative Cells Developed During Tyrosine Kinase Inhibitor Treatment

Most clonal cytogenetic abnormalities of Philadelphia-negative cells (CCA/Ph-) occurring during tyrosine kinase inhibitor (TKI) treatment are transient, and the development of secondary myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) is rare, but the frequency and clinical significance in Japanese patients are still unknown. We herein report four patients who developed CCA/Ph- during TKI therapy and were diagnosed with secondary MDS/AML. The duration from TKI therapy initiation to MDS/AML onset ranged from 3 to 48 months, and the survival ranged from 5 to 84 months. The occurrence of CCA/Ph- with MDS/AML may be associated with a poor prognosis, and careful follow-up is recommended for patients who receive TKI therapy.

European LeukemiaNet laboratory recommendations for the diagnosis and management of chronic myeloid leukemia

From the laboratory perspective, effective management of patients with chronic myeloid leukemia (CML) requires accurate diagnosis, assessment of prognostic markers, sequential assessment of levels of residual disease and investigation of possible reasons for resistance, relapse or progression. Our scientific and clinical knowledge underpinning these requirements continues to evolve, as do laboratory methods and technologies. The European LeukemiaNet convened an expert panel to critically consider the current status of genetic laboratory approaches to help diagnose and manage CML patients. Our recommendations focus on current best practice and highlight the strengths and pitfalls of commonly used laboratory tests.

Clinical implications of clonal chromosomal abnormalities in Philadelphia negative cells in CML patients after treated with tyrosine kinase inhibitors

Emergence of clonal chromosomal abnormalities in Philadelphia chromosome-negative (CCA/Ph-) cells in chronic myeloid leukemia (CML) patients during the treatment with tyrosine kinase inhibitors (TKIs) is an interesting phenomenon. Although previous studies revealed some potential impact of CCA/Ph- on CML patients' outcome, clinical significance of CCA/Ph- in CML patients remains to be further elucidated. We retrospectively reviewed the patients with CML evaluated at Genoptix Medical Laboratory in Carlsbad, California from 2005 to 2015. Twenty-four CML patients with CCA/Ph- cells were identified. These include 18 patients with single chromosomal abnormality, 4 patients with double chromosomal abnormalities, and two patients with complex cytogenetic abnormalities. In addition to trisomy 8 and monosomy 7, we identified that 20q- was also a common abnormality in CCA/Ph- cells. Most of the patients with CCA/Ph- cells demonstrated no significant dysplasia or increased blasts with two exceptions: one patient with persistent 7q- exhibiting mild dysmegakaryopoiesis, suggestive of an early evolving myelodysplastic syndrome, and another patient with complex cytogenetic abnormalities who developed acute myeloid leukemia after gained MLL amplification. One patient with complex cytogenetic abnormalities showed optimal response to TKI treatment, no overt dysplasia, and no disease progression during almost 4-years of follow-up. More interestingly, FISH tests could identify more cases with double chromosomal abnormalities and these cases showed suboptimal responses to TKI treatments. Our observation indicates that 20q- was also a common abnormality in CCA/Ph- cells, further FISH tests revealed additional CCA/Ph-, and the majority of CML patients with two or more chromosomal abnormalities in Ph- cells showed inferior response to TKI treatments. The results of our study suggest that CML cases with CCA/Ph- may represent a group of patients with heterogeneous genetic alterations.

[Prognosis of clonal chromosomal abnormalities in Philadelphia negative metaphases cells in chronic myeloid leukemia with tyrosine kinase inhibitor therapy]

Objective: To investigate the characteristics and prognosis of clonal chromosomal abnormalities appearing in Philadelphia negative metaphases (CCA/Ph(-)) cells in chronic myeloid leukemia (CML) with tyrosine kinase inhibitor (TKI) therapy. Methods: The clinical data of 30 cases with CCA/Ph(-) during TKI treatment in Henan Cancer Hospital from August 2007 to July 2017 were retrospectively analyzed. The univariate factor was analyzed by Kaplan-Meier method. Multiple-factor was analyzed by Cox proportional risk model. Results: Of the 30 cases, 19 (63.3%) were males. At the first detection of CCA/Ph(-) the median age was 44 (rang 14-68) years old and the median treatment of TKI was 13 (rang 2-94) months. The clones proportion of first detected CCA/Ph(-)≥ 50% was found in 18 (60.0%) cases. TKI treatment for 3 months with BCR-ABL(IS) less than 10% was seen in 14 (46.7%) patients. 63.3% (19/30) of CCA/Ph(-) was transient (only one time) and 36.7% (11/30) was repeated (≥2 times) . Trisomy 8 dominant accounted for 60.0% (18/30) , -7/7q- for 13.3% (4/30) , loss of chromosome Y 6.7%. With a median of follow-up 50 months, 76.7% (23/30) cases were in complete cytogenetic response (CCyR) ; 63.3% (19/30) in major molecular response (MMR) , 43.3% (13/30) in undetectable minimal residual disease (UMRD) . The median event-free survival rate of (EFS) were 44 months, and 2-year and 5-year EFS were (82.1±7.3) % and (52.4±12.8) %, respectively. The median overall survival (OS) were 50 months, and 2-year and 5-year OS rates were (92.6±5.0) % and (77.2±14.7) %, respectively. Univariate analysis shows that the 2-year EFS of who in males, more than 2 times CCA/Ph(-), BCR-ABL(IS)>10% at 3 months after TKI were significantly lower than women, transient CCA/Ph(-), and BCR-ABL(IS)≤10% (P<0.05) . The 2-year OS rate in whom the occurrence frequency of CCA/Ph(-) more than twice was significantly lower than those with transient CCA/Ph(-) (P<0.05) . Multivariate analysis showed that CCA/Ph(-) was an independent risk factor (RR=4.741, 95%CI 1.21-18.571, P=0.018) for EFS in CML patients. Conclusion: Trisomy 8, -7/7q-, and -Y were the most common CCA/Ph(-) during TKI treatment, with high clones proportion of ≥50%. CCA/Ph(-) mainly occurred transiently or was permanent occasionally. CCA/Ph(-) recurrence (≥2 times) was an independent risk factor for EFS and OS in CML with TKI.

Poor prognosis of chromosome 7 clonal aberrations in Philadelphia-negative metaphases and relevance of potential underlying myelodysplastic features in chronic myeloid leukemia

Clonal chromosome abnormalities in Philadelphia-negative cells could concern chronic myeloid leukemia patients treated by tyrosine kinase inhibitors. The European LeukemiaNet distinguishes -7/del(7q) abnormalities as a “warning”. However, the impact of clonal chromosome abnormalities, and specifically those of -7/del(7q), in Philadelphia-negative cells on clinical outcomes is unclear and based on case-reports showing morphological dysplasia and increased risk of acute myeloid leukemia, suggesting the coexistence of chronic myeloid leukemia and high-risk myelodysplastic syndrome. The aim of this study was to determine whether the impact of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells on the clinical outcome is different from that of other types of abnormalities, and we argue for an underlying associated high-risk myelodysplastic syndrome. Among 102 chronic myeloid leukemia patients with clonal chromosome abnormalities in Philadelphia-negative cells with more than a median of 6 years of follow up, patients with -7/del(7q) more frequently had signs of dysplasia, a lower cumulative incidence of deep molecular response and often needed further treatment lines, with the consequent impact on event-free and progression-free survival. Morphological features of dysplasia are associated with myelodysplastic syndrome/acute myeloid leukemia mutations and compromise the optimal response to tyrosine kinase inhibitors, irrespectively of the type of clonal chromosome abnormalities in Philadelphia-negative cells. However, mutation patterns determined by next-generation sequencing could not clearly explain the underlying high-risk disease. We hereby confirm the pejorative prognostic value of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells and suggest that myelodysplastic features constitute a warning signal that response to tyrosine kinase inhibitors may be less than optimal.