Hasmukh Jain

Characteristics of BCR-ABL kinase domain mutations in chronic myeloid leukemia from India: not just missense mutations but insertions and deletions are also associated with TKI resistance

Abstract We document the characteristics of BCR-ABL kinase domain mutations (KDM) in the largest study from India comprising of 385 patients and demonstrate that more than half (51.9%) of these patients have detectable abnormalities in the KD both in adult and in pediatric chronic myelogenous leukemia (CML). These comprise singly occurring missense mutations (25.5%), polyclonal/compound point mutations (4.9%), and insertions/deletions (29.6%). Missense mutations were most commonly seen in the imatinib-binding region followed by the P-loop. The commonest mutation in our dataset was T315I. Other common missense mutations were Y253H, M244V, and F317L. A high prevalence of BCR-ABL exon7 deletion (p.R362fs*) was also seen (25.5% of the entire cohort), whereas the 35bpintron-derived insertion/truncation mutation detected in 12 patients. In the pediatric age group, 58.8% of patients harbored missense mutations, polyclonal/compound mutations as well as insertions and deletions. We detected 11 novel mutations (seven missense mutations and four insertions/deletions).

Immunogenetics of chronic lymphocytic leukemia

Introduction: Cytogenetic aberrations as well as presence of IGVH mutations are the underlying reason for clinical heterogeneity in Chronic Lymphocytic Leukemia (CLL). The presence of IGVH mutations as well as the predominant gene usage shows geographical variations. However, there is no study from India addressing immunogenetics of CLL. In a first Indian study we document the immunogenetics of CLL in a large tertiary hospital. Methods: We analyzed IGVH mutation status, VH gene usage, cytogenetic abnormalities using FISH, immunophenotyping data and correlated them with standard clinical variables in 84 patients of CLL. Results: Advanced Rai stage (Stage 3/4) was seen in 45% of our patients, where as 13q deletion was the commonest clonal cytogenetic abnormality detected in 48.4% of the cases. IGVH unmutated cases (55.2%) showed higher proportion expressing CD38 and CD49d, a preferential usage for VH1 and VH3 families (55.2%), presentation at an advanced Rai stage (52.8%) as well as more frequent presence of p53 deletions. As compared to the IGVH mutated cases greater proportion of IGVH unmutated patients (70%) required treatment. However, there was no significant difference in the time to treatment between mutated and unmutated cases which can be attributed to relatively short median follow up of 10 months. Conclusion: To summarize, we have seen a higher proportion of IGVH unmutated patients in our cohort (55.2%). The commonly used VH genes in the Indian population are IGVH 2-5, IGVH 1-2 and IGVH 1-69. Longer clinical follow up and a larger cohort is necessary to confirm the prognostic value of IGVH mutation analysis in Indian Patients with CLL.

Carcinomatous meningitis in non-small cell lung cancer: Palliation with intrathecal treatment

Carcinomatous meningitis or meningeal carcinomatosis is seen in up to 5% of patients of metastatic non-small cell lung cancer. However, isolated carcinomatous meningitis without brain parenchymal metastasis is less common. Patients with carcinomatous meningitis have limited treatment options. However, intrathecal therapy if used optimally along with targeted therapy when indicated result in good palliation with improvement in survival.

Frequency of bacterial isolates and pattern of antimicrobial resistance in patients with hematological malignancies: A snapshot from tertiary cancer center.

BACKGROUND Infections are the most important cause of mortality in patients with high-risk febrile neutropenia. Emergence of multi-drug resistant organisms (MDROs) has become a major challenge for hemato-oncologists. Knowledge of the prevalent organisms and their antimicrobial sensitivity can help deciding the empirical therapy at individual centers and allows timely measures to reduce the risk of antimicrobial resistance. AIMS To evaluate the frequency of bacterial isolates from all the samples and the pattern of bacterial bloodstream infections and incidence of MDROs. SETTINGS AND DESIGN This is a retrospective analysis from a tertiary care cancer center. MATERIALS AND METHODS From January to June 2014 information on all the samples received in Department of Microbiology was collected retrospectively. The data from samples collected from patients with hematological cancers were analyzed for types of bacterial isolates and antimicrobial sensitivity. RESULTS A total of 739 isolates were identified with 67.9% of isolates being Gram-negative. The predominant Gram-negative organisms were Escherichia coli, Psuedomonas spp. and Klebsiella spp. Among the bacterial bloodstream infections, 66% were Gram-negative isolates. MDROs constituted 22% of all isolates in blood cultures. Incidence of resistant Gram-positive organisms was low in the present dataset (methicillin resistant Staphylococcus aureus and vancomycin-resistant enterococci-1.3%). CONCLUSIONS The analysis reconfirms the Gram-negative organisms as the predominant pathogens in bacteremia seen in patients with hematological cancers. The high frequency of multi-drug resistance in the dataset calls for the need of emergency measures to curtail further development and propagation of resistant organisms.

Outcomes of Patients with Splenic Marginal Zone Lymphoma Treated with Rituximab or Splenectomy: Report from Tertiary Cancer Center in India

S282 Context: Castleman ’s Disease (CD) is the rare lymphoproliferative disease masking a number of hematologic, oncological and autoimmune diseases. Objective: To determine the frequency of occurrence of the diseases which are followed by Castleman-like similar changes in lymph nodes. Materials and methods: Medical records of the 48 patients with preliminary diagnosis CD directed in outpatient department from 2016 to 2017. All patients were examined according to the recommendations of the international working group on the study of CD. Morphological study of lymph node tissue biopsies included the assessment of regressed or hyperplastic germinal centers, follicular dendritic cell prominence, vascularization and polytypic plasmacytosis in the interfollicular spaces by the point system from 0 to 3 grades. Results: Morphological picture in 24 lymph node tissue biopsies, from 24 of 48 patients corresponded to the first large criterion of diagnosis of CD. In these cases, comparison of clinical and laboratory data allowed to confirm the diagnosis of C D. The greatest divergence was observed in cases with a generalized lymphadenopathy. From 15 patients with the preliminary diagnosis multicentric CD the diagnosis has been confirmed in 20%. Diagnosis CD was changed to the Hodgkin’s lymphoma (HL) in three cases, to NHL in three cases, to the connective tissue disease and solid tumors in two cases respectively, to primary amyloidosis in one patient, and to multiple myeloma in one patient. In cases with local specific involvement the diagnosis of CD has been confirmed in 63.6%. The range of the revealed diseases included: a reactive lymphadenopathy in 6 cases, a tumor not of the lymphoid nature in two cases, HL at the one patient and NHL at the three patients. Conclusion: Inspection of patients with suspected diagnosis of CD according to the recommendations of the international working group has shown that the frequency of occurrence of the diseases which are followed by Castleman-like similar changes in lymph nodes varies from 36,4 to 80% and depends on prevalence of process. The range of the diseases demanding an exception includes HL and NHL, connective tissue disease, other neoplastic processes and reactive conditions.

A rare case of hepatosplenic γδ T-cell lymphoma expressing CD19 with ring chromosome 7 and trisomy 8

Hepatosplenic T-cell lymphoma (HSTL) is a rare subtype of peripheral T-cell lymphoma predominantly seen in young males. This disease presents with isolated hepatosplenomegaly and thrombocytopenia with sinusoidal infiltration of liver and sinusal infiltration of spleen. Immunophenotype shows positivity for CD3, CD7, TCRγδ or TCRαβ, CD38 and double negative for CD4, CD8, TdT, CD5, and CD56. Isochromosome 7q with or without trisomy 8 is seen in HSTL. Recently, ring chromosome 7 has also been identified as a new abnormality. We describe the clinical, immunophenotypic and cytogenetic analysis in a 24-year-old woman. We present an unusual case of TCRγδ positive T-cell lymphoma with aberrant expression of CD19, which is a B-cell lymphoid marker, with amplification of 7q region and subsequent formation of ring chromosome 7 and trisomy 8. This is the second case of HSTL, positive for CD19 and first case presenting with ring chromosome 7 and trisomy 8 in a CD19 positive HSTL which is a rare finding in T-cell lymphoma and needs to be explored further.

B acute lymphoblastic leukemia/lymphoma involving pre-existing fibroadenoma of the breast

A 32-year-old lady presented with bilateral multiple breast lumps of 4 months duration and low grade fever of 2 months duration. Patient had multiple lumps in both breasts which were hypoechoic on ultrasound and isodense on mammography. Radiological impression was of a benign lesion likely to be a fibroadenoma (FA). One of the enucleated lesions, on gross examination showed a tan colored, multilobulated tumor, measuring 5.5 9 2.5 x 1.5 cm. Microscopic examination revealed typical morphology of intracanalicular FA (Figure 1). In addition, stroma showed infiltration by small atypical cells which were present as loose clusters and singly scattered throughout the lesion (Figure 2). On immunohistochemistry (IHC), the atypical cells were positive for LCA (Figure 3), CD20, and TdT (Figure 4). They were negative for CD3, MPO, and c-kit. They were also negative for CK7 and E-cadherin thus ruling out carcinoma. Based on histomorphology and IHC, a diagnosis of B lymphoblastic leukemia/lymphoma (BLL) infiltrating the pre-existing FA was offered. Subsequently bone marrow aspiration and biopsy with flowcytometry confirmed the diagnosis of BLL. PET scan revealed involvement of bilateral breasts, kidneys, spleen, pancreas, skeleton, and cervical and mesenteric nodes. Patient was started with treatment regimen for BLL.

Blastic plasmacytoid dendritic cell neoplasm: A rare subtype of myeloid leukemia

A34-year-old male presented with a 2-month history of fever, backache, and generalized rash. Clinical examination revealed generalized lymphadenopathy along with maculopapular, erythematous, confluent rash involving the face, trunk, and extremities. Complete blood counts showed pancytopenia (hemoglobin 8.1 g/dL, platelet count 7000/mm, and white blood cell count 2000/mm). Bone marrow examination revealed intermediate to large sized blasts. The blast population expressed CD4, CD56, HLA-DR, dim to negative CD38 and CD45 and variable CD123. Blasts did not express CD 303, markers of myeloid, B-cell or T-cell lineage. The morphological and immunophenotypic findings were consistent with a diagnosis of blastic plasmacytoid dendritic cell neoplasm (BPDCN). BPDCN is a rare malignancy, and belongs to the category of acute myeloid leukemia and related precursor neoplasms. It commonly affects elderly males and involves skin, bone marrow and lymph nodes. The

978PCORRELATION OF PHARMACOKINETICS OF 6MP AND ITS METABOLITES WITH HAEMATOLOGICAL TOXICITY: STEP TOWARDS DEVELOPMENT OF PHARMACOKINETICS BASED MODEL FOR OPTIMAL 6 MP DOSING IN ADULT ALL

ABSTRACT Aim: Dosing of 6MP has remained empirical in acute lymphoblastic leukemia (ALL) with leucocyte count and thiopurine methyl transferase (TPMT) being the main determinants. However, TPMT alone cannot predict for marked inter-individual differences. In our experience, adult ALL patients tolerate standard 6- MP doses poorly, resulting in frequent dose interruptions or subtherapeutic doses. To address this issue we are conducting a study to develop pharmacokinetic model (PK) for optimal 6 MP dosing. Herein we report the preliminary data for correlationof PK parameters of 6 MP and its metabolites with toxicity (dose interruptions and dose reduction). Methods: Adult ALL patients (18 years or more) who were receiving 6 MP during interim maintenance (IM)or maintenance (M) phase of MCP841 protocol were enrolled after informed consent. Plasma samples were collected on day 1 for measuring 6-mercaptopurine levels using HPLC. TPMT activity was calculated by measuring 6-mMP (6-methylmercaptopurine) and 6-methyl thioguanine nucleotides (6-mTGN) levels in erythrocytes on day 1.Levels for 6-mMP and 6-TGN were also measured in erythrocytes using HPLC on day 8 and day 22 of the IM and on day 1 of M phase upto 6 months post enrollment. Statistical analysis was performed with receiver operating characteristic curve to assess the discrimination potential of level of 6-mp, 6-mMP (day 8 and day 22), 6-TGN (day 8 and day 22), 6-mMP and 6-mTGN levels (day 1-IM) for toxicity. Mean AUC has been compared for the above parameters using Mann-Whitney test. Binomial logistic regression was performed to assess correlation of various covariates with the toxicity. Results: 29 patients (males-24, females-5) with median age of 28 years (range,16-50) were enrolled.14 patients experienced dose interruptions (median-1, range1-2)) and 10 required dose reduction due to grade 4 cytopenias. OnDay 22 levels, a concentration of 0.315 ug/ml for 6-mMP (AUC = 0.73, p = 0.2) and 0.17 ug/ml for 6-TGN (AUC = 0.92,p value =0.01)in erythrocytes could successfully discriminate between patients who suffered from toxicity. Day 8 levels were not discriminatory. Hemoglobin (p= 0.05) and TPMT activity (p = 0.08) were found to be significant covariates for toxicity. Conclusions: Preliminary data does suggest the value of PK variables on 6 MP toxicity. Disclosure: All authors have declared no conflicts of interest.