Summary of the published Indian data on chronic myeloid leukemia

Evaluation of visual evoked potential in chronic myeloid leukemias

BACKGROUND

Visual complaint is not very uncommon in chronic myeloid leukemia (CML) patients. Our study aims to evaluate the visual pathway using visual evoked potential (VEP) in cases of CML at the time of diagnosis and 6 weeks after tyrosine kinase therapy, to find out treatment impact in asymptomatic as well as symptomatic individuals and compare it with the general population.

MATERIALS AND METHODS

This is an analytical cross-sectional study. The study group comprised 20 newly diagnosed cases of CML and 20 age- and sex-matched healthy control population. A thorough history and clinical examination with detailed ophthalmological studies, including VEP, were done. Cases who had VEP abnormalities were then followed-up after 6 weeks post-Imatinib therapy and underwent repeat investigations, including VEP.

RESULTS

VEP in cases was significantly deranged (P < 0.001), where 15 patients (75%) had abnormalities in VEP compared to 3 (15%) in control. Post 6 weeks chemotherapy, Out of 10 cases that were followed up, 7 patients had achieved hematological remission with normal VEP finding (P = 0.02). Simultaneously, an increase in hemoglobin (P = 0.002) and reduction in total leukocyte count (TLC) (P = 0.004) were observed.

CONCLUSION

Considerable evidence appear to support the notion that CML patients have a higher prevalence of ophthalmic manifestations as compared to the general population, which can be screened earlier with objective tests like VEP. Concurrently, hematological parameters and VEP showed derangement at the time of diagnosis. After 6 weeks of Imatinib treatment, the improvement in VEP can then be attributed to a reduction in TLC. Hence it can be deduced that VEP has paramount importance in the early identification of ophthalmic manifestations, which are reversible with timely treatment.

Deep sequencing reveals the spectrum of BCR-ABL1 mutations upon front-line therapy resistance in chronic myeloid leukemia: An Eastern-Indian cohort study

The course of clinical management in chronic myeloid leukemia (CML) often faces a road-block in the form of front-line (imatinib) therapy resistance. Subsequently, several hotspot mutations were clinically validated in the kinase domain (KD) of BCR-ABL1, in deterring imatinib sensitivity and further, made targeted by next-generation tyrosine-kinase-inhibitor (TKI) drugs. Identifying KD mutations, occurring even at low frequencies, became pertinent here. Globally, cohorts from different origins were tested and the mutational spectra were mapped to categorize clinical management as well as related pathological features of CML. Moreover, targeted deep sequencing could reveal the mutational landscape more efficiently than the less sensitive Sanger sequencing method. However, no such efforts were reported from Eastern Indian cohorts of imatinib-resistant CML-sufferers. This study assessed a prospective study cohort of imatinib-resistant CML cases from Eastern India. Following dissecting the molecular and clinical parameters, the mutational spectrum was comparatively examined using conventional Sanger and next-generation deep sequencing method. This cohort showed a prevalence of e14a2-p210 variant of BCR-ABL1 and acquired resistance against imatinib, while the disease was mostly confined in its chronic phase. Together with a few common hotspot mutations identified in this cohort, deep sequencing revealed cases with a candidate mutation, otherwise undetermined by Sanger method. Also, cases with a second low frequency mutation were identified upon applying deep sequencing. Along with highlighting a few aspects of CML biology employing an Eastern-Indian cohort, this data could mark the immense importance of deep sequencing to contribute in the clinical management of CML upon front-line therapy resistance.

Atypical activation of signaling downstream of inactivated Bcr-Abl mediates chemoresistance in chronic myeloid leukemia

Chronic myeloid leukemia (CML) epitomises successful targeted therapy, where inhibition of tyrosine kinase activity of oncoprotein Bcr-Abl1 by imatinib, induces remission in 86% patients in initial chronic phase (CP). However, in acute phase of blast crisis, 80% patients show resistance, 40% among them despite inhibition of Bcr-Abl1 activity. This implies activation of either Bcr-Abl1- independent signalling pathways or restoration of signalling downstream of inactive Bcr-Abl1. In the present study, mass spectrometry and subsequent in silico pathway analysis of differentiators in resistant CML-CP cells identified key differentiators, 14-3-3ε and p38 MAPK, which belong to Bcr-Abl1 pathway. Their levels and activity respectively, indicated active Bcr-Abl1 pathway in CML-BC resistant cells, though Bcr-Abl1 is inhibited by imatinib. Further, contribution of these components to resistance was demonstrated by inhibition of Bcr-Abl1 down-stream signalling by knocking-out of 14-3-3ε and inhibition of p38 MAPK activity. The observations merit clinical validation to explore their translational potential.

Long-Term Outcome of Philadelphia Chromosome Positive Leukemia From Eastern Indian Subcontinent: An Experience in the Era of Tyrosine Kinase Inhibitor (TKI) Therapy

INTRODUCTION

Philadelphia chromosome (Ph) marks a group of leukemia with almost all cases of chronic myeloid leukemia (CML), a subset of acute lymphoid leukemia (ALL) and rare cases of acute myeloid leukemia (AML). In the era of precision medicine, such cases are successfully managed with tyrosine kinase inhibitor (TKI) drugs. This study examined the features and long-term outcome of Ph+ve cases from a tertiary cancer care center from Eastern Indian subcontinent.

MATERIALS AND METHODS

Reviewing retrospective case-records registered between 2005 and 2015, cases of CML and ALL were documented under Ph+ve category; while no instance of Ph+ve AML was found.

RESULTS

In CML cohort, adult and juvenile incidences were 95.2% and 4.8% respectively; in ALL cohort, the same was found for 66.67% and 33.33% cases. Among the CML cases, 10-year overall survival (OS) and progression-free survival (PFS) were significantly affected upon the phase of disease at time of detection. Furthermore, both OS and PFS significantly dropped whenever non-TKI-based treatment was applied prior to TKI-commencement. Long-term (10-year) sensitivity to 1st generation TKI, imatinib, was noted 88.51% and 83.33% for adult and juvenile CML cohorts, respectively. For Ph+ ALL cohort, the OS was benefitted upon combinatorial TKI and chemotherapy. However, large fractions of affected individual from CML as well as ALL cohorts were found to discontinue follow-up.

CONCLUSION

Together with differences in outcome on the basis of drug-use from onset, age (juvenile versus adult) and stage at diagnosis, our analyses bring forward the real-world scenario of Ph+ve leukemia managed with precision medicine.

Molecular, Cytogenetic, and Hematological Analysis of Chronic Myeloid Leukemia Patients and Discovery of Two Novel Translocations

Chronic myeloid leukemia (CML) is a disease of hematopoietic stem cells and is caused by the balanced translocations among the long arms of chromosomes 9 and 22, which are called the Philadelphia (Ph) chromosome. In this study, 131 CML patients were enrolled. Complete blood cell count was performed at the time of diagnosis for all the patients. Cytogenetic (karyotyping) examination using bone marrow samples was conducted on 76 CML patients for the confirmation of Ph-positive (9;22)(q34;q11) standard translocation, complex variant translocation, and additional chromosome abnormalities. FISH was performed on 38 patients for diagnostic purposes and on 39 patients for monitoring purposes. Twenty-two samples of CML patients were evaluated by reverse transcriptase PCR and real-time PCR for the patients who failed to respond against imatinib mesylate. In this study, 72 (54.96%) were males and 59 (45.03%) were females with a median age of 38.5 years. CBC values in the diagnosis process showed that 75 patients had high values of WBC being >100 × 103/μl, while 71 (58.01) patients exhibited reduced values of hemoglobin, i.e., <10.00 mg/dl, and high values of PLTs > 100 were observed in 40 (30.53%) patients. Cytogenetic results show that standard translocation was developed in 63 (82.89%), development of complex variant translocations in 4 (5.32%), additional chromosomal abnormalities (ACAs) in 3 (3.94%), and ACAs together with complex variant translocations in 1 (1.31%) patient. At the time of diagnosis, 61 (92.95%) patients were in the chronic phase, 4 (5.63%) were in the accelerated phase, and only 1 (1.40%) was in the blast crisis. Out of twenty-two patients, only 6 CML patients who were shifted from imatinib mesylate to nilotinib showed BCR-ABL-positive amplification. However, only 7 out of twenty-one patients exhibit BCR-ABL gene values ≥ 1 after three months of follow-up when analyzed by the quantitative real-time PCR. In conclusion, we found a novel five-way translocation 46XX,t(1;2;2;17;9;22)(p36.3,q21;q11.2,q21,q34,q11.2) and a novel four-way complex variant translocation 48XY,+8(8;17)(9;22),+der(22)(q11.2;q23)(q34;q11.2) in the accelerated phase.

Prospective evaluation of variables affecting platelet function in patients with newly diagnosed chronic myeloid leukemia

: Platelet function in chronic myeloid leukemia (CML) could be affected by either hyperleucocytosis, clonal megakaryopoiesis, or tyrosine kinase inhibitors. However, these variables have never been prospectively evaluated. We conducted a prospective study over a period of 1.5 years in a tertiary care center of north India. Patients with CML in chronic phase, more than 18 years, and treated with imatinib were enrolled (n = 32). Age, and sex-matched controls were also included. Platelet function test was performed using two-channel Chrono-Log aggregometer 490 at four time-points: first, at diagnosis; second, after leucoreduction (total leucocyte count, <10 × 10/l) achieved with hydroxycarbamide; third, on-imatinib at BCR-ABL less than 1%; and fourth, in an independent cohort (off-imatinib) at deep molecular response (DMR) (BCR-ABL < 0.01%). Statistical analysis was performed using IBM SPSS statistics (version 22.0). Median age of patients was 42 years (15-65), and M : F ratio was 1 : 1. At diagnosis, platelet function correlated negatively with total leucocyte count, but not with platelet count. As compared with baseline, platelet aggregation with ADP (2.5 μl), and collagen (2.5 μl) improved significantly after leucoreduction (P = 0.05 and 0.009, respectively). Imatinib further caused significant impairment of aggregation with ADP (2.5 μl), collagen (2.5 μl), and collagen (1 μl) (P = 0.04, 0.008, and 0.02, respectively). Patients in DMR also demonstrated a significant impairment of platelet aggregation with all the agonists as compared with controls. While leucoreduction alone can improve the baseline platelet function derangement in CML, imatinib further impairs it. Residual CML stem cells, or effect of imatinib on normal common myeloid progenitors might account for platelet function derangement at DMR.

Exovesicular-Shh confers Imatinib resistance by upregulating Bcl2 expression in chronic myeloid leukemia with variant chromosomes

Chronic myeloid leukemia (CML) patients with complex chromosomal translocations as well as non-compliant CML patients often demonstrate short-lived responses and poor outcomes on the current therapeutic regimes using Imatinib and its variants. It has been derived so far that leukemic stem cells (LSCs) are responsible for Imatinib resistance and CML progression. Sonic hedgehog (Shh) signaling has been implicated in proliferation of this Imatinib-resistant CD34(+) LSCs. Our work here identifies the molecular mechanism of Shh-mediated mutation-independent Imatinib resistance that is most relevant for treating CML-variants and non-compliant patients. Our results elucidate that while Shh can impart stemness, it also upregulates expression of anti-apoptotic protein—Bcl2. It is the upregulation of Bcl2 that is involved in conferring Imatinib resistance to the CD34(+) LSCs. Sub-toxic doses of Bcl2 inhibitor or Shh inhibitor (<<IC50), when used as adjuvants along with Imatinib, can re-sensitize Shh signaling cells to Imatinib. Our work here highlights the need to molecularly stratify CML patients and implement combinatorial therapy to overcome the current limitations and improve outcomes in CML.

Efficacy and safety profile of generic imatinib in patients with newly diagnosed chronic myeloid leukemia-chronic phase: sharing experience of a hemato-oncology center from eastern India

In India, CML is the commonest adult leukemia. Imatinib is the gold standard for frontline treatment of newly diagnosed CML-CP patients. The present study was conducted to assess the efficacy and safety of generic imatinib in newly diagnosed CML-CP patients. In this prospective study, 76 newly diagnosed CML-CP patients received generic imatinib. They were monitored as per the ELN2013 recommendation. Karyotyping and BCR-ABL transcript level were done at specified time points. Adverse effects, if any, were documented as per the NCI-CTCAE criteria v4.03. Statistical analysis was done using standard methods. A total of 76 patients included in the study; median age was 36 years. The most common (71%) presenting symptom was fatigue; splenomegaly was found in all patients. CHR was achieved in 97% cases. At 3 months, 64.5% patients achieved ERM. At 6 months, CCyR and MCyR had seen in 65% and 68% cases, respectively. MMR achieved at 12 months in 44% cases. Most common hematological and non-hematological toxicity were anemia and skin changes seen in 89.5% and 71% cases, respectively. With generic imatinib therapy, the results of treatment outcome and safety profile were comparable with original imatinib. The added advantage was gross reduction in cost of therapy meeting unmet needs in CML patients in countries with resource constraints.

A study to determine the clinical, hematological, cytogenetic, and molecular profile in CML patient in and around Eastern UP, India

Introduction:

Myeloproliferative disorders are characterized by proliferation of one or more myeloid lineages cells. In order to assess the burden of these illness for public health planning, it is important to know their frequency.

Objectives:

A study to determine the clinical, hematological, cytogenetic, and molecular profile in chronic myeloid leukemia (CML) patient in and around Eastern UP, India.

Materials and Methods:

Newly diagnosed and follow-up adult and pediatric cases of myeloproliferative disorder were taken into study. Detailed history, physical, and systemic examination was done with informed consent. Investigations like complete blood count including hemoglobin level, platelet count, total and differential leucocyte count, general blood picture, and bone marrow aspiration/biopsy were done. Molecular and cytogenetic studies were also done whenever required.

Results:

In total, 90 patients were enrolled in the study. The median age of presentation of CML was 37 years and the mean age was 38.6 years. M: F ratio of 1.4:1.75 patients (83%) were in CML-chronic phase (CP), 11 patients (12%) in CML-accelerated phase (AP) phase, and 4 patients (5%) were found in CML-blast crisis (BC) phase. The common symptoms of the patients were fullness of the abdomen (66.6%). Among these 69 cases, Philadelphia chromosome was present in 65 (94.2%) cases. Revers transcriptase polymerase chain reaction (RT–PCR) was done in 40 out of 90 cases, breakpoint cluster region (BCR)-Abelson oncogene (ABL) gene came out to be positive in all the 40 cases.

Conclusion:

Most CML patients in eastern UP (India) are relatively young (31–40 years). In addition, males were more commonly affected.

Adolescent and Young Adult Chronic Myeloid Leukemia in Real-World Settings: Experience from a Tertiary Care Institute in Northern India

The data on adolescent and young adult chronic myeloid leukemia (AYA-CML) from the Indian subcontinent are scarce. We studied characteristics of AYA-CML through a retrospective analysis of 1950 CML patients registered to a tertiary care hospital in Northern India. AYA-CML represented 22.1% of all CML patients, with cumulative overall survival (OS) of 84%, and 1 and 8 years OS of 94.2% and 74.2%, respectively. Of all cases, 8.91% patients had advanced disease at the time of diagnosis, and 13.95% had myelofibrosis in the diagnostic marrow, 79.6% had complete cytogenetic response (CCyR), and 84.5% had major molecular response (MMR). Loss of CCyR and MMR was noted in 37.2% and 28.4%, respectively. The cumulative OS was significantly better in patients on patient assistance program, and they were initiated on therapy within 3 months of symptom onset.

Outcome of Chronic Myeloid Leukemia-Chronic Phase Patients Treated With Imatinib: A Local Experience

BACKGROUND

Imatinib was the first tyrosine kinase inhibitor that has revolutionized the therapy of chronic myeloid leukemia. It binds breakpoint cluster region-Abelson kinase domain inducing apoptosis of the leukemic cells. In this study, we assessed the efficacy and toxicity of imatinib therapy in patients with chronic myeloid leukemia in chronic phase (CML-CP) in our hospital.

PATIENTS AND METHODS

We retrospectively analyzed the outcome of 17 patients with CML-CP treated with imatinib.

RESULTS

The median age at the time of presentation was 35 years with male preponderance. The most common presenting clinical features were fatigue, abdominal distention, and discomfort. Forty-seven percent of patients had fever at presentation whereas 35.29% were referred to our hospital because of incidental findings of high blood cell counts. With a median follow-up of 8 years (range, 2-16 years) the overall survival is 100% and progression-free survival 85%. Two patients had acceptable adverse effects.

CONCLUSION

After a median follow-up of 8 years, imatinib was found to induce long survival with manageable side effect in adult Saudi patients with CML-CP.

Atypical Presentation of Chronic Myelogenous Leukemia

Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disorder characterized by the presence of the Philadelphia chromosome, t(9;22), which is a constitutively active tyrosine kinase that causes excessive proliferation and differentiation of myeloid cells in the bone marrow. Most patients are either asymptomatic or present with fatigue, abdominal fullness, and splenomegaly. This is a case in which a 72-year-old Caucasian male’s initial presentation of CML was new-onset atrial fibrillation, chronic obstructive pulmonary disease (COPD) exacerbation, and pneumonia. The severity of his symptoms of atrial fibrillation and dyspnea complicated his stabilization, which delayed his diagnosis of CML and initiation of tyrosine kinase inhibitor for treatment. Unregulated proliferation of leukemic cells increases blood viscosity and results in aberrations in blood circulation that may result in atypical presenting symptoms in myeloproliferative disease. Thus, it is important to have a high clinical index of suspicion for CML in patients with leukocytosis and concurrent symptomatology that is unusual for leukemia.