Cancer stem cells: advances in biology and clinical translation-a Keystone Symposia report

The test for the cancer stem cell (CSC) hypothesis is to find a target expressed on all, and only CSCs in a patient tumor, then eliminate all cells with that target that eliminates the cancer. That test has not yet been achieved, but CSC diagnostics and targets found on CSCs and some other cells have resulted in a few clinically relevant therapies. However, it has become apparent that eliminating the subset of tumor cells characterized by self-renewal properties is essential for long-term tumor control. CSCs are able to regenerate and initiate tumor growth, recapitulating the heterogeneity present in the tumor before treatment. As great progress has been made in identifying and elucidating the biology of CSCs as well as their interactions with the tumor microenvironment, the time seems ripe for novel therapeutic strategies that target CSCs to find clinical applicability. On May 19-21, 2021, researchers in cancer stem cells met virtually for the Keystone eSymposium "Cancer Stem Cells: Advances in Biology and Clinical Translation" to discuss recent advances in the understanding of CSCs as well as clinical efforts to target these populations.

[Efficacy and side effect analysis of paclitaxel liposome for neoadjuvant chemotherapy in locally advanced cervical cancer]

Objective: To investigate the efficacy and side effect of paclitaxel liposome for neoadjuvant chemotherapy (NACT) in locally advanced cervical cancer. Methods: This study were included 265 cervical cancer patients staging Ⅰb2 and Ⅱa2 who underwent paclitaxel-platinum NACT followed by radical surgery from June 2008 to December 2016 in the Cancer Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences. All patients were classified into two groups with 106 patients in paclitaxel liposome group and 159 patients in traditional paclitaxel group. The difference in clinicopathologic characteristics, efficacy and side effect were analyzed retrospectively between the two groups. Results: (1) Clinicopathologic characteristics: there were no significant difference in clinicopathologic characteristics between the two groups, including age, body mass index, clinical stage, pathological histology, cycles of NACT, combined platinum regimen, lymph-vascular space invasion, lymph node metastasis, deep stromal invasion, and postoperative adjuvant therapy (all P>0.05). (2) Efficacy: after NACT, the overall response occurred in 90 (15 complete response plus 75 partial response) of 106 cases in the paclitaxel liposome group versus 131 (21 complete response plus 110 partial response) of 159 cases in the traditional paclitaxel group without statistical significance (84.9% vs 82.4%; χ(2)=0.291, P=0.590). A total of 248 patients received surgery after NACT and were evaluable in survival. The 5-year recurrence-free survival (RFS) rate and 5-year overall survival (OS) rate of these patients was 85.1% and 88.2%. The 5-year RFS rate in the paclitaxel liposome group was 85.9% compared with 85.2% in the traditional paclitaxel group, while the corresponding 5-year OS rate was 88.5% and 88.7%, respectively. There was no statistically significant difference in efficacy between the two groups (P=0.968, P=0.797). (3) Side effect: the incidence of allergic reaction between the paclitaxel liposome group and the traditional paclitaxel group was 0 versus 1.9% (3/159) without statistical significance (P=0.277). But the incidence of neurotoxicity in the paclitaxel liposome group significantly decreased compared with the traditional paclitaxel group (6.6% vs 15.7%, P<0.05), as well as the incidence of alopecia (67.9% vs 79.2%, P<0.05) and myalgia (17.9% vs 28.9%, P<0.05). However, significant differences were not found in terms of hematological toxicity, gastrointestinal reaction, and hepatic function damage (P>0.05). Conclusion: In paclitaxel-platinum NACT of local advanced cervical cancer, paclitaxel liposome can achieve similar efficacy compared with traditional paclitaxel, but paclitaxel liposome is helpful in decreasing the toxicity of neurotoxicity, alopecia and myalgia.

Systemic lupus erythematosus is a risk factor for cancer: a nationwide population-based study in Korea

OBJECTIVE

Specific differences in cancer risk have been observed between systemic lupus erythematosus patients and the general population. Although meta-analyses have estimated cancer incidence in systemic lupus erythematosus patients, results have been inconclusive. Hence, we aimed to assess malignancy risk in systemic lupus erythematosus patients, compared to the risk in the general population.

METHODS

Systemic lupus erythematosus patients ( n = 21,016; mean age 41.67 ± 13.14 years; female 90.22%) were selected from the Korean National Health Insurance Service database between 2008 and 2014. Age- and sex-matched controls were randomly sampled in a 5:1 ratio ( n = 105,080).

RESULTS

During the 7 years of follow up, malignancy was detected in 763 (3.63%) systemic lupus erythematosus patients and 2667 (2.54%) controls. Systemic lupus erythematosus patients had a higher risk of malignancy than controls (odds ratio 1.44; 95% confidence interval 1.327-1.559), after multivariate adjustment. Systemic lupus erythematosus patients had a higher odds ratio for developing cervical, thyroid, ovarian, and oral cancer, as well as lymphoma, leukemia, and multiple myeloma than controls. Based on subgroup analysis, male systemic lupus erythematosus patients and patients younger than 40 years showed the highest lymphoma risk.

CONCLUSIONS

Systemic lupus erythematosus might be an independent risk factor for cancer. Therefore, the importance of cancer screening programs should be emphasized in systemic lupus erythematosus patients. Our study is the first large nationwide cohort study for evaluating the risk of cancer in systemic lupus erythematosus patients.

Systemic lupus erythematosus is a risk factor for cardiovascular disease: a nationwide, population-based study in Korea

OBJECTIVE

To investigate the incidence and clinical significance of cardiovascular disease in systemic lupus erythematosus patients.

METHODS

We included systemic lupus erythematosus patients ( n = 18,575) without previous cardiovascular disease and age- and sex-matched individuals without systemic lupus erythematosus (controls; n = 92,875) from the Korean National Health Insurance Service database (2008-2014). Both cohorts were followed up for incident cardiovascular disease and death until 2015.

RESULTS

During follow up, myocardial infarction occurred in 203 systemic lupus erythematosus patients and 325 controls (incidence rate: 1.76 and 0.56 per 1000 person-years, respectively), stroke occurred in 289 patients and 403 controls (incidence rate: 2.51 and 0.70 per 1000 person-years, respectively), heart failure occurred in 358 patients and 354 controls (incidence rate 3.11 and 0.61 per 1000 person-years, respectively), and death occurred in 744 patients and 948 controls (incidence rate 6.54 and 1.64 per 1000 person-years, respectively). Patients with systemic lupus erythematosus had higher risks for myocardial infarction (hazard ratio: 2.74, 95% confidence interval: 2.28-3.37), stroke (hazard ratio: 3.31, 95% confidence interval: 2.84-3.86), heart failure (hazard ratio: 4.60, 95% confidence interval: 3.96-5.35), and cardiac death (hazard ratio: 3.98, 95% confidence interval: 3.61-4.39).

CONCLUSIONS

Here, systemic lupus erythematosus was an independent risk factor for cardiovascular disease, thus cardiac assessment and management are critical in systemic lupus erythematosus patients.

Prognostic impact of hyponatraemia in patients with colorectal cancer

AIM

Hyponatraemia is a common in surgical practice, but its clinical impact in patients with colorectal cancer has not been evaluated.

METHOD

We retrospectively assessed 2944 patients who had been admitted to Chonnam National University Hwasun Hospital, Korea with a diagnosis of colorectal cancer. In order to determine the relationship between the serum sodium level and 3-year mortality, we categorized the patients as having normonatraemia (135-147 mEq/l), or mild (130-134 mEq/l), moderate (125-129 mEq/l) or severe hyponatraemia (< 125 mEq/l).

RESULTS

Hyponatraemia, defined as a serum sodium level of < 135 mEq/l, was evident in 27.6% of patients during hospitalization. Declining serum sodium levels were associated with increasing age, a higher number of comorbidities, a more advanced TNM stage and worsening biochemical parameters. In a multivariate Cox-proportional regression analysis, the mortality risk was correlated with the severity of hyponatraemia [hazard ratio (HR) 1.65, 95% CI 1.38-1.96; HR 2.24, 95% CI 1.69-2.98; HR 2.20, 95% CI 1.25-3.90, for patients with mild, moderate, and severe hyponatraemia, respectively, compared with patients with normonatraemia]. An independent association between hyponatraemia and long-term mortality was sustained among various subpopulations and patients with persistent hyponatraemia had a worse prognosis than those with hyponatraemia that resolved.

CONCLUSION

A substantial proportion of patients developed hyponatraemia during hospitalization, and the long-term mortality risk increased even in mild cases of hyponatraemia. Hyponatraemia should be considered as an important prognostic factor in colorectal cancer.

Chronic Myeloid Leukemia in an Adolescent with Ollier's Disease after Intensive X-Ray Exposure

We report a 19-year-old man with Ollier's disease with multiple orthopedic procedures performed for leg length discrepancy; who developed chronic myeloid leukemia presenting with intramuscular hematoma. His symptoms resolved with cytoreductive treatment by hydroxyurea. Cytogenetic and molecular investigations showed a complex Philadelphia translocation t(9;22;13) (q34;q11.2;q12), with predominance of ela2 BCR/ABL splicing and deletion of reciprocal der(9) ABL/BCR locus, all suggesting poor prognosis. The cumulative X-ray exposure from repeated operations from the age of 7 to 12 years was estimated to be around 16 mSv, approximately the dose of 720 chest X rays. Literature review showed two other cases of leukemia occurring in patients with multiple enchondromatosis. Although the development of CML in this young patient might be related partly to genetic defects, the repeated radiation exposure, especially at young age and directly on the marrow tissue in the long bones, might also be an important pathogenetic factor.

Eosinophilic Leukemic Transformation in Polycythemia Rubra Vera (PRV)

We report a rare case of eosinophilic leukemia transformation in a patient with polycythemia rubra vera on hydroxycarbamide (hydroxyurea) therapy only. Cytogenetic study showed complex abnormalities including -5, -7, +8, suggestive of a secondary leukemia. The leukemogenic risk of hydroxycarbamide, a ribonucleoside reductase, and the risk of natural leukemic transformation of polycythemia rubra vera is discussed in the context of previous PVSG studies.

Glucose-6-phosphate-dehydrogenase deficiency and haematopoietic stem cell transplantation in Chinese patients

Deficiency in glucose-6-phosphate dehydrogenase (G6PD), an X-linked recessive red cell enzymopathy, is endemic in Southern Chinese. Universal screening of newborn is done in Hong Kong, Taiwan and Singapore, among other places. In Hong Kong, 4.8% of males are affected and seven common G6PD alleles account for over 99% of all defects. Male hemizygotes suffer from severe deficiency, while female heterozygotes may also be affected. Deficiency of G6PD may affect haematopoietic stem cell transplantation (HSCT) recipients and donors, before and after HSCT. Female patients with clonal erythropoiesis (eg myelodysplasia/myeloproliferative diseases) will have the male population incidence of G6PD. Quantitative enzyme level screening is prudent for donors and recipients, and should be repeated after engraftment. Cotrimoxazole prophylaxis should be avoided in known male and female carriers, including those with low-normal G6PD enzyme levels. Our experience suggested that G6PD-deficient marrow, stem cell and cord blood donor units have no engraftment problems. Post-engraftment G6PD levels correlate with those in donors. An acquired change in G6PD status may serve as a surrogate marker for engraftment. For female heterozygote donors with normal G6PD levels, skewing of lyonized X-chromosome ratio during engraftment may result in over-expression of the deficient allele. This can result in unexpected significant G6PD deficiency. Hence, a repeat G6PD screening at stable engraftment is recommended, especially before commencement of oxidative medications.

Use of antibody avidity assays for diagnosis of severe acute respiratory syndrome coronavirus infection

An indirect immunofluorescent assay (Euroimmun AG, Luebeck, Germany) was used to investigate the avidity of immunoglobulin G (IgG), IgM, IgA, and total Ig (IgGAM) antibody responses to severe acute respiratory syndrome coronavirus (SARS CoV) infections. Serial serum samples from eight patients collected during the first, third, and ninth months after the onset of infection were evaluated. It was found that low-avidity IgG antibodies were detected in 15/15 (100%), 1/5 (20%), and 0/8 (0%) serum samples collected during the first, third, and ninth months after the onset of symptoms, respectively. Low-avidity antibodies of IgA and IgM subclasses were detected in 14/14 (100%) and 3/14 (21%) serum samples, respectively, collected in the first month after the onset of infection. However, IgA antibodies remained low in avidity in a proportion of patients even during late convalescence. As a consequence, IgG antibody avidity assays gave better discrimination between acute-phase and late-convalescent-phase serum samples than IgM, IgA, or IgGAM assays. In two of these patients, sequential serum samples were also tested for IgG avidity against human CoV strains OC43 and 229E in parallel. While SARS CoV infections induced an anamnestic IgG antibody response to the 229E and OC43 viruses, these cross-reactive antibodies remained of high avidity from early (the first month) postinfection. The results showed that assays to detect low-avidity antibody may be useful for discriminating early from late antibody responses and also for distinguishing anamnestic cross-reactive antibody responses from primary specific responses. This may be useful in some clinical situations.

Serial analysis of JAK2 mutation in a patient who developed essential thrombocythemia after orthotopic liver transplantation

A 52-year-old man developed essential thrombocythemia (ET) with JAK2 V617F mutation after orthotopic liver transplantation (OLT). Retrospective analysis showed that, despite a low platelet count, the JAK2 mutation was already found at presentation 14 months before OLT. The high platelet count that would have been typical of ET might be masked by the cirrhosis-related hypersplenism. Thrombocythemia became obvious after OLT. The patient subsequently developed blastic transformation 12 months afterward, a process probably accelerated by the immunosuppression required for the OLT.

Der(8)t(1;8) in myeloblastic transformation of ET with hydroxyurea as the sole prior treatment

We described a patient with ET that evolved into MF and then subsequently developed myeloblastic transformation. A novel derivative chromosome der(8)t(1;8) was identified in the AML phase. The only prior treatment had been hydroxyurea. We hypothesized that AML in this case resulted from a complex pre-disposition by the natural progression of ET, prolonged use of HU, and the prior evolution into MF. The leukemogenic risk of HU is critically appraised.

The distribution of inhibitory and excitatory synapses on single, reconstructed jaw-opening motoneurons in the cat

In a previous study, we reported that the distribution of inhibitory input, in contrast to excitatory input, decreased somatofugally along dendrites of cat jaw-closing alpha-motoneurons [J Comp Neurol 414 (1999) 454]. The present study examined the distribution of GABA, glycine, and glutamate immunopositive boutons covering horseradish peroxidase-labeled cat jaw-opening motoneurons. The motoneurons were divided into four compartments: the soma, and primary, intermediate, and distal dendrites. Ninety-seven percent of the total number of studied boutons had immunoreactivity for at least one of the three amino acids. The proportion of boutons immunoreactive for GABA and/or glycine was lower than the proportion of boutons immunoreactive for glutamate. Boutons immunoreactive to glycine alone were more numerous than boutons double-labeled for GABA and glycine, which, in turn, occurred more frequently than boutons immunoreactive to GABA alone. The percentage synaptic covering (proportion of membrane covered by synaptic boutons) of the putatively excitatory (glutamate containing) and putatively inhibitory (GABA and/or glycine containing) boutons decreased somatofugally along the dendrites. Such systematic variations were not seen in the packing density (number of boutons per 100 microm(2)); the packing density showed a distinct drop between the soma and primary dendrites but did not differ significantly among the three dendritic compartments. Overall, the packing density was slightly higher for the putatively excitatory boutons than for the inhibitory ones. When taken together with previous analyses of jaw-closing alpha-motoneurons the present data on jaw-opening alpha-motoneurons indicate that the two types of neuron differ in regard to the nature of synaptic integration in the dendritic tree.

Hyperbilirubinemia and cholelithiasis in Chinese patients with hemoglobin H disease

Hemoglobin H disease (HbH) is a hemoglobinopathy peculiar to parts of the world with high incidence alpha-thalassemia mutations. Among 90 HbH cases, 50 cases suffered from clinically significant jaundice (bilirubin >30 mmol/l), including 14 with severe jaundice (bilirubin >60 mmol/l). Cholelithiasis was found in 38 cases. The incidence is roughly eight times higher than that in background control population but 50% lower than that in beta-thalassemia. The risk of gallstones was related to higher bilirubin levels but not alpha-globin genotype, sex, ferritin, and hemoglobin levels. Homozygotes or double heterozygotes for Gilbert alleles (17.2%), but not heterozgyotes (42.2%), were found to have a significantly increased risk of gallstones and jaundice. However, common Chinese Gilbert syndrome alleles do not completely explain the variable risks.

Pathogenesis of jumping translocations: a molecular cytogenetics study

BACKGROUND/AIMS

Jumping translocations are rare cytogenetic aberrations in haematological malignancies, the pathogenesis of which remains to be fully characterised. We investigated the mechanism of formation of jumping translocations in a case of adult common acute lymphoblastic leukaemia (ALL) positive for the Ph translocation.

METHODS

Interphase and metaphase fluorescence in situ hybridisation (FISH) was performed using several probe systems. Results were correlated with findings on conventional cytogenetics. Granulocytes, T-cells and leukaemic B-cells in peripheral blood were sorted by immunomagnetic method and the terminal restriction fragment (TRF) length of these cellular populations was determined by Southern blot analysis.

RESULTS

Duplicated BCR-ABL fusion signals were found on a dic(14;22)der(22)t(9;22) chromosome. Clonal jumping translocations, existing as evolutionary changes, involved the donor chromosomal segment distal to 1q12 jumping onto the telomere ends of 11q, 15p, 19p and 20p. Telomere length was decreased in the neoplastic B-cell population and contributed to the formation of the dicentric chromosome that showed absence of telomere repeats at fusion ends. Subsequent pericentromeric heterochromatin decondensation of chromosome 1q occurred, and this donor segment was randomly fused to the shortened telomere ends of non-homologous chromosomes.

CONCLUSIONS

Both telomere shortening and pericentromeric heterochromatin decondensation contribute to the formation of jumping translocations, which is most probably a multi-stage process.

Bone marrow transplantation for therapy-related acute myeloid leukemia in congenital retinoblastoma associated with 13q deletion syndrome

Children with constitutional deletion of the long arm of chromosome 13 are at risk for retinoblastoma (RB) due to loss of the RB tumor suppressor gene. The prognosis is poor since the tumors are often bilateral, aggressive, and recurrent and the patients often harbor other congenital abnormalities. One further complication is that of therapy-related malignancies later in life. We report a case of allogeneic stem cell transplantation for therapy-related acute myeloid leukemia in an 8-year-old girl after multimodality treatment for refractory bilateral relapsing RB, with excellent outcome in both the ophthalmic and marrow disease.

Transformation of diffuse large B-cell lymphoma into pre-B acute lymphoblastic leukemia: clinicopathologic features and clonal relationship

A patient with fibrosing alveolitis developed a diffuse large B-cell (DLBC) lymphoma that expressed CD20 and CD30. After an initial response, the lymphoma relapsed and was salvaged with further chemotherapy. After another remission of 3 years, a pre-B-cell acute lymphoblastic leukemia (ALL), which expressed CD10, CD19, CD22, CD79a, CD34 and terminal deoxyribonucleotidyl transferase, developed and led to death. Molecular analysis of the immunoglobulin heavy-chain gene showed that the initial lymphoma and its relapse were clonally related. At leukemic relapse, 2 clones related to the initial and relapsed lymphoma clones were present. DLBC lymphomas arise from post-follicle center B cells, whereas ALL arises from pregerminal B cells. Therefore, a direct transformation of DLBC lymphoma to ALL appears unlikely. The overall features suggest instead separate lymphoma and leukemic evolution from a common mutated B-cell precursor rather than transformation of DLBC lymphoma to ALL.

Potential role for platelet apheresis for post-liver transplant thrombocytosis complicating portal vein thrombosis

Except for patients with underlying myeloproliferative diseases (MPD), thrombocytosis is rarely encountered in cirrhotic patients after liver transplantation. Although the long-term control of primary thrombocytosis is important for the prevention of graft thrombosis in MPD patients, the threshold for intervention and best mode for the control of persistent reactive thrombocytosis after liver transplantation is unclear. We present two patients with extreme reactive thrombocytosis (over 1,000 x 10(9)/l) due to intra-abdominal sepsis after liver transplantation. Furthermore, both patients suffered from bleeding problems as well as ongoing venous thrombosis of the graft. Rapid control of the platelet count was achieved using platelet apheresis. The use of cell separation procedures may be a relatively rapid, reversible, and reasonably safe way to control platelet counts peri-operatively in liver transplant recipients.

Treatment of postrenal transplantation lymphoproliferative disease manifesting as plasmacytoma with nonmyeloablative hematopoietic stem cell transplantation from the same kidney donor

Posttransplantation lymphoproliferative disease (PTLD) presenting as an Epstein-Barr-virus (EBV)-related nasal plasmacytoma developed in a renal-allograft recipient 13 years after transplantation. Systemic dissemination occurred despite immunosuppression withdrawal, surgery, irradiation, and chemotherapy. A nonmyeloablative hematopoietic-stem-cell-transplantation (HSCT) with peripheral blood HSC from the kidney donor was performed. With the onset of graft-versus-host disease, resolution of the systemic disease was demonstrated clinically and molecularly by serial quantification of plasma EBV-DNA. Isolated relapse occurred in the central nervous system (CNS), a known tumour sanctuary site, ultimately leading to death. Nonmyeloablative HSCT might be considered a cellular therapy for PTLD, but possible CNS relapse must be effectively tackled.

The occurrence of Philadelphia chromosome (Ph) negative leukemia after hematopoietic stem cell transplantation for Ph positive chronic myeloid leukemia: implications for disease monitoring and treatment

Chronic myeloid leukemia (CML) is a clonal neoplastic disorder, characterized by t(9;22)(q34;q11) that results in the formation of the Philadelphia chromosome (Ph) and the BCR/ABL fusion gene. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for CML. Much of its therapeutic efficacy is attributed to a graft-versus-leukemia (GVL) effect exerted by donor-derived lymphoid cells against the Ph positive (Ph+) clone. Post-HSCT monitoring by cytogenetic and molecular detection of the Ph+ clone is necessary, so that pre-emptive immunologic or pharmacologic treatment may be administered at an early stage of relapse. However, under rare circumstances a second Ph negative (Ph-) leukemia may evolve post-HSCT. The pathogenetic possibilities included leukemia arising from donor-derived hematopoietic stem cells (HSCs), or transformation of residual recipient-derived Ph- HSCs that have survived the conditioning chemotherapy and radiotherapy. Recipient-derived Ph- leukemia may be related to genetic alterations that precede the onset of CML, or myelotoxic effects of the HSCT conditioning regimen. The diagnosis of Ph- relapses requires detailed investigations by conventional karyotyping, fluorescence in-situ hybridization (FISH), and molecular analysis; as well as chimerism studies that help to document the donor or recipient origin of the leukemia. Although uncommonly reported in the past, Ph- relapses may in fact be more frequent if leukemic relapses post-HSCT are more thoroughly evaluated with these investigations. The recognition of Ph- relapses are important in several ways. Ph- relapses cannot be identified by monitoring investigations targeting the Ph+ clone, so that the early detection of Ph- leukemia is usually not possible. Furthermore, Ph- relapses will not respond to therapeutic strategies effective against the Ph+ CML clone.

Poor engraftment after allogeneic bone marrow transplantation: role of chimerism analysis in treatment and outcome

We analyzed the clinical course and risk factors of 18 patients with poor engraftment after allogeneic bone marrow transplantation (BMT), defined as absolute neutrophil count below 0.1 x 10(9)/l 28 days post-BMT. Significant risks associated with non-engraftment included HLA one antigen mismatch, BMT from matched unrelated donor, and a low dose of colony-forming units-granulocyte-macrophage (<10(4)/kg). Examined by a semiquantitative analysis of polymorphic microsatellite markers, donor DNA chimerism on day 28 was found to be predictive of treatment outcome. Seven patients had detectable donor DNA, varying from 43 to 100%. Five of them responded to granulocyte colony-stimulating factor (G-CSF) and achieved engraftment. Two were given further infusions of peripheral blood hematopoietic stem cells (PBSC) from the same donors, resulting in engraftment in one of them. Eleven patients had no detectable donor DNA, and none responded to G-CSF. Autologous regeneration occurred in six of these patients, four after infusion of backup marrow and two spontaneously. The remaining five patients died despite the administration of PBSC from the same or different donors. Regular monitoring of donor DNA chimerism is useful in the management of patients at high risk of poor engraftment.

Derivative chromosome 9 deletions in chronic myeloid leukaemia: interpretation of atypical D-FISH pattern

BACKGROUND/AIMS

New molecular cytogenetic techniques are increasingly applied as a routine investigative tool in haematological malignancies, both at diagnosis and subsequent monitoring. This report describes the interpretation of atypical signal patterns encountered using BCR-ABL dual colour dual fusion fluorescence in situ hybridisation (D-FISH) translocation probes in chronic myeloid leukaemia (CML).

METHODS

Interphase FISH experiments were carried out using BCR-ABL D-FISH probes in 46 patients with CML at diagnosis and during subsequent disease monitoring. Atypical hybridisation signal patterns were characterised by molecular cytogenetic techniques and correlated with conventional karyotyping.

RESULTS

Two patients showed atypical interphase D-FISH patterns with one orange, one green, and one fusion (1O1G1F) signal. The presence of BCR-ABL gene fusion was documented by a dual colour single fusion (S-FISH) probe. The submicroscopic deletion of the ABL-BCR fusion gene on the derivative chromosome 9 in these cases was subsequently characterised by metaphase FISH on relocated G banded metaphases.

CONCLUSIONS

Atypical interphase D-FISH patterns should not be interpreted in isolation and should be considered in conjunction with other cytogenetic or molecular genetic investigations.

Arsenic trioxide in comparison with chemotherapy and bone marrow transplantation for the treatment of relapsed acute promyelocytic leukaemia

BACKGROUND

The best overall treatment strategy for patients with acute promyelocytic leukaemia (APL) in relapse with chemotherapy, bone marrow transplantation (BMT) or arsenic trioxide (As(2)O(3)) based therapy remains undefined.

PATIENTS AND METHODS

We reviewed the clinical course and treatment outcome of 143 APL cases seen in four major hospitals in Hong Kong over a 10-year period.

RESULTS

Complete remission (CR) was attained in 113 cases (79%) with all-trans retinoic acid (ATRA) and chemotherapy. Relapse occurred at a median of 16 months in 54 cases, with a 3-year disease free survival of 56%. Post-relapse treatment was successful in 41 cases (76%), giving an actuarial 3-year overall survival (OS) of 81% from CR1. Three different protocols were used: chemotherapy alone (n = 19), allogeneic BMT (n = 14) and an As(2)O(3)-based regimen (n = 21). Chemotherapy was associated with the highest treatment-related mortality (TRM) at 53%, giving a CR2 rate of 47%. TRM was 36% for BMT. The CR2 rate for the As(2)O(3)-based regimen was 100%, with no TRM. However, 38% of As(2)O(3) treated patients had subsequent relapses, which were further salvaged in 75% by combined As(2)O(3) plus ATRA. The actuarial OS for the three protocols leveled off by 2 years at 82% for As(2)O(3), 43% for BMT and 23% for chemotherapy (P = 0.0004).

CONCLUSIONS

Our results suggest that As(2)O(3) may be superior to chemotherapy and BMT for the treatment of APL in relapse.

Aberrant p15 gene promoter methylation in therapy-related myelodysplastic syndrome and acute myeloid leukaemia: clinicopathological and karyotypic associations

Seventeen patients with therapy-related myelodysplastic syndrome/acute myeloid leukaemia (t-MDS/AML) were examined for aberrant p15 gene methylation by methylation-specific polymerase chain reaction. Ten patients (58%) showed p15 methylation, which was significantly related to monosomy/deletion of chromosome 7q, but not to antecedent chemotherapy, blast count, leukaemic evolution or survival. In three of six patients with marrow samples obtained prior to the diagnosis of t-MDS/AML, p15 methylation predated disease development by up to 2 years. Bone marrow transplantation led to the disappearance of p15 methylation in one patient. These results showed that p15 methylation was an early event in the evolution of some t-MDS/AML patients.

Concurrent mediastinal B cell lymphoma and chronic myeloid leukemia with an unusually favorable response to chemotherapy

A 67-year-old Chinese woman presented with mediastinal B cell lymphoma in 1992 with incidental leukocytosis. Bone marrow and peripheral blood findings confirmed the diagnosis of chronic myeloid leukemia (CML). After combination chemotherapy and radiotherapy for lymphoma, her peripheral blood counts remained normal, and she refused further treatment for nearly six years. Frank hematologic relapse occurred in 1998 and low dose hydroxyurea was used, which was stopped after six months owing to cytopenia. She remained well without treatment at 12-year follow up. Retrospective Southern blot analysis confirmed BCR gene rearrangement in marrow in 1992 and 1998, but not in the lymphoma or the latest peripheral blood. Fluorescence in-situ hybridzation analysis showed no Philadelphia chromosome positive (Ph+) cells in the peripheral blood at last (FISH) follow-up, but BCR/ABL remained detectable. The relevance of the concomitant occurrence of CML and lymphoma and the unusually favorable response of CML to chemotherapy to the pathogenesis of CML is discussed.

Trisomy 21 and other chromosomal abnormalities in acute promyelocytic leukemia

We describe a case of acute promyelocytic leukemia (APL) with t(15;17)(q22;q12) and trisomy 21 as an additional change in a patient who died at relapse after achieving complete remission (CR) for the duration of 20 months. A survey of 42 cases of APL with cytogenetic study performed at our institutionover the past 10 years showed 12 cases (28.6%) having chromosomal changes in addition to t(15;17). Trisomy 8 and trisomy 21 as additional changes were noted in 4 and 2 cases, respectively, with one patient showing both trisomies simultaneously. Two cases showed t(15;17) in hyperdiploid clones. Among the 10 patients with follow-up data, all eventually relapsed and none achieved continuous complete remission 1. Survival analysis performed in APL patients with adequate follow-up data showed no significant difference in overall and disease free survival between those with and without additional cytogenetic changes. After excluding cases with one induction death, the overall survival was significantly in favor of the group without additional cytogenetic abnormalities (P = 0.022). Late relapses may therefore be significantly more common in APL patients with additional cytogenetic abnormalities, and may not be reflected by analysis focused at three-year survival only. As APL is now considered a curable disease, any confirmed long-term survival impact of additional cytogenetic changes is expected to have important management implications.

Leukaemic relapse of donor origin after allogeneic bone marrow transplantation from a donor who later developed bronchogenic carcinoma

Donor-derived leukaemia is exceptional after allogeneic bone marrow transplantation (BMT). A woman with chronic myeloid leukaemia received an allogeneic BMT from a human leucocyte antigen-identical brother. The donor, a 50-year-old non-smoker, died of squamous cell bronchogenic carcinoma 1 year later. At 4 years post BMT, the patient became BCR/ABL positive and relapsed with acute myeloid leukaemia, which was shown to be donor-derived cytogenetically and molecularly. Retrospective analysis showed that the donor-leukaemic clone had started to evolve as early as 6 months post BMT. Sequencing of p53 ruled out Li-Fraumeni syndrome. Predisposition to malignancy might be an underlying mechanism of donor-cell leukaemia.

Two balanced and novel chromosomal translocations in myeloid malignancies. characterization by multiplex fluorescence in situ hybridization

We describe two novel chromosomal translocations in two cases of leukemia in which these translocations were further characterized as the sole acquired karyotypic abnormality by mutliplex fluorescence in situ hybridization (M-FISH). They comprised a case of acute myeloid leukemia with t(6;10)(q21;p12) and a case of chronic myelomonocytic leukemia with t(5;12)(q34;q24). To the best of our knowledge, these two balanced translocations are novel and are hitherto unrecognized in hematologic malignancies. While the clinical and pathogenic significance of these translocations remains to be defined, the present report illustrates that M-FISH technology contributes to the exclusion of subtle or cryptic translocations in sole karyotypic aberrations and the confirmation of novel chromosomal arrangements in neoplastic disorders.

Two cases of therapy-related acute promyelocytic leukemia (t-APL) after mantle cell lymphoma and gestational trophoblastic disease

We report two cases of secondary acute promyelocytic leukemia (APL). One patient presented with concurrent APL and missed abortion 1 year after etoposide-based chemotherapy for gestational trophoblastic disease. A prolonged complete remission was achieved with standard chemotherapy. An elderly man developed APL 1 year after alkylator-based chemotherapy for mantle cell lymphoma (MCL). A complete clinical and molecular remission was obtained with chemotherapy and all- trans retinoic acid, followed by arsenic consolidation. Concomitant molecular relapse of APL and MCL clones was detected at 1 year, both of which responded to oral arsenic therapy. High-dose epipodophyllin is a dose risk for secondary APL, but alkylating agents may also be implicated. For patients with a history of active malignancy and heavy previous chemotherapy exposure, the use of nontoxic arsenic therapy appeared to be effective and prudent.

Tyrosine kinase inhibitor STI571 in the treatment of Philadelphia chromosome-positive leukaemia failing myeloablative stem cell transplantation

Eight patients with Philadelphia chromosome-positive (Ph(+)) leukaemia relapsing from stem cell transplantation (SCT) (one syngeneic and seven allogeneic) were treated with the tyrosine kinase inhibitor STI571. Five patients relapsing as chronic myeloid leukaemia (CML) in chronic phase achieved a complete haematological response, with complete and major cytogenetic responses occurring in four and one cases, respectively. One patient became negative for BCR/ABL in the bone marrow. Three patients relapsed as acute leukaemia (two CML in myeloblastic crisis and one Ph(+) acute lymphoblastic leukaemia), all of whom achieved haematological and cytogenetic responses. One patient also became BCR/ABL negative. However, pancytopenia and graft-versus-host disease led to cessation of treatment in the remaining two cases, which was followed by disease recurrence refractory to further STI treatment. Our results showed that Ph(+) leukaemic relapses after SCT might respond well to STI571 therapy.

Routine screening of (--(SEA)) alpha-thalassemia deletion by an enzyme-linked immunosorbent assay for embryonic zeta-globin chains

We evaluated an enzyme-linked immunosorbent assay (ELISA) for embryonic zeta-globin chains as a routine screening test for (--(SEA)) alpha-thalassemia deletion (SEA deletion). A total of 174 consecutive patient samples with a request for Hb analysis were recruited. The ELISA method was evaluated against a polymerase chain reaction (PCR)-based technique that was taken as the standard. Among 56 simple carriers of SEA deletion diagnosed by PCR and 112 subjects without the SEA deletion, the sensitivity and specificity of the ELISA method was 89.3-96.4 and 98.2-100%, respectively, depending on the cutoff value for optical density that was adopted. The ELISA method was able to detect both subjects with SEA deletion and concurrent beta-thalassemia trait in this series, but only 1 out of 4 patients (25%) with Hb H disease. We speculate that incomplete lysis of hypochromic microcytic red cells together with the low red cell count in Hb H disease might account for the false-negative results. We showed that the ELISA method for embryonic zeta-chains was a sensitive method of screening for SEA deletion carriers at our locality, and should be easily adopted in a routine diagnostic laboratory. The method was rapid and also amendable to automation. In areas with a high prevalence of alpha-thalassemia, improved detection of SEA deletion carriers would ultimately facilitate the identification of pregnancies at risk of hydrops fetalis and its prevention through prenatal diagnosis.

Clonal marrow abnormalities after azathioprine and sulfasalazine exposure in Crohn's disease: a cautionary tale

We report a patient with longstanding Crohn's disease (CD) developing recurrent sepsis and impaired neutrophil function tests. His inflammatory bowel disease was controlled with local steroids and sulfasalazine with only short exposure to azathioprine. His blood counts remained within normal range, but the marrow showed mild dysplasia. Repeated cytogenetic examinations revealed trisomies 8 and 9, which are typical for therapy related myelodysplasia. Fluorescent in situ hybridization (FISH) study showed stable persistent trisomies, confined to the myeloid lineage, one year after discontinuation of sulfasalazine. The long-term use of immunodulating agents in patients with CD is not without risks, and early therapy related myelodysplasia might not be easily detected by blood count and morphology assessment alone.

Subvalvular pulmonary stenosis, demyelination and myelodysplasia with monosomy 7

We report a 23-year-old male with subvalvular pulmonary stenosis (PS) presenting with concurrent acute demyelinating neuropathy and myelodysplasia with monosomy 7. There was no stigmata of Noonan syndrome or neurofibromatosis, nor any family history of cardiac or hematologic disorders. There are 40 reported pediatric cases of Noonan syndrome with subvalvular PS that developed leukemia, over two-thirds with monosomy 7. There is also a genetic overlap between Noonan syndrome and neurofibromatosis, which is also closely associated with demyelination and leukemia. The importance of recognition of rare clinical syndromes that may predispose to leukemia is discussed.

Fatal diffuse alveolar damage complicating acute myeloid leukemia with abnormal eosinophils and trisomy X

We describe a case of acute myeloid leukemia (AML) with abnormal eosinophils in a 44-year-old Chinese woman that was complicated by diffuse alveolar damage (DAD) and pulmonary hemorrhage (PH) shortly after induction chemotherapy. Cytogenetic study of bone marrow cells at diagnosis showed a rare aberration of trisomy X (+X) as the sole acquired karyotypic abnormality. We speculate that tissue damage by cellular constituents of the abnormal eosinophils that were released on cell lysis after chemotherapy might be etiologically linked to the occurrence of fatal pulmonary complications.

Glucose-6-phosphate dehydrogenase deficiency and hematopoietic stem cell transplantation

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked hemolytic enzymopathy affecting 3% of Southern Chinese males. Among 275 adult allogeneic hematopoietic stem cell transplantations (SCT), five cases (1.8%) each of donors and recipients were G6PD deficient. Among 107 autologous SCT, four patients (3.7%) were G6PD deficient. All subjects were male, except for two female patients with chronic myeloid leukemia (CML). The incidence of G6PD deficiency in female CML patients was significantly higher than the background female incidence (P = 0.004), but comparable with that in the males (P = 0.664). There was no significant hemolysis or delay in red cell engraftment, and all but one patient converted to donor G6PD screening status. One female patient achieved partial correction of her G6PD status and relapsed at 10 months. We suggest that G6PD deficiency should be tested for in all marrow donors and recipients in susceptible populations. From our data, there is a suggestion of increased clinical incidence of G6PD deficiency in female patients with multi-lineage clonal marrow disorders.

Percutaneous catheterization of the internal jugular vein for hemodialysis

OBJECTIVES

The present study was aimed at evaluating the clinical experiences in the internal jugular venous catheterization for hemodialysis.

METHODS

We retrospectively analyzed the data on internal jugular venous catheterization at Chonnam National University Hospital from May 2000 to February 2001.

RESULTS

There were 132 uremic patients with a total of 150 attempts of internal jugular cannulation. Overall success rate was 90.9% with average puncture trials of 2.3 +/- 2.1. 124 (82.7%) of the catheterization attempts were made on the right side and 26 (17.3%) were made on the left. The catheters were left in place from 2 to 87 days with an average of 19.5 +/- 15.3 days per catheter. The dialysis sessions per catheter were from 2 to 58 with an average of 11.3 +/- 6.8. The mean blood flow during hemodialysis immediately after catheterization was 213.4 +/- 42.2 ml/min. Thirty two (21.3%) patients had early complications. These included carotid artery puncture (11.3%), local bleeding (4.7%), local pain (3.3%), neck hematoma (0.7%) and malposition of the catheter (1.3%). Seventeen (11.3%) patients had late complications. These included fever or infection (11.3%), inadequate blood flow rate (3.3%) and inadvertent withdrawal (2.0%). There was no catheter-related mortality.

CONCLUSIONS

Our experiences revealed that the internal jugular vein catheterization is relatively safe and efficient for temporary vascular access for hemodialysis.

Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat

The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

Haemoglobin H disease due to (--SEA) alpha-globin gene deletion and alpha2-codon 30 (DeltaGAG) mutation: a family study

A Chinese family in which two siblings suffer from haemogloblin (Hb) H disease due to (--SEA) alpha-globin gene deletion and alpha2-codon 30 (DeltaGAG) mutation is described. Both siblings are transfusion-independent and have survived to adulthood. In contrast to previous report of hydrops fetalis associated with zeta-alpha-thal-1 and alpha2-codon 30 (DeltaGAG) mutation, the zeta-globin genes are intact in the two siblings, which most probably alleviates the gamma-chain excess and protects the fetus from severe anaemia. Correlation of genotype with phenotype in Hb H disease is important for genetic counselling, especially in the antenatal setting.

Characterization of additional genetic events in childhood acute lymphoblastic leukemia with TEL/AML1 gene fusion: a molecular cytogenetics study

TEL/AML1 gene fusion that results from a cryptic t(12;21) is the most common genetic aberration in childhood B-lineage acute lymphoblastic leukemia (ALL). While the translocation may initiate the leukemic process, critical secondary genetic events are currently believed to be pivotal for leukemogenesis. We investigated 12 cases of childhood ALL with TEL/AML1 gene fusion by fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) and documented additional or secondary genetic changes in seven patients (58%). Three patients showed extra copies of chromosome 21 including a case in which the trisomy 21 (+21) clone was distinct from the one harboring TEL/AML1 gene fusion. Interestingly, one patient without +21 showed amplification of the AML1 gene on chromosome 21q, supporting the contention that AML1 amplification may be an important additional genetic event. Gene expression study by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) in two of these four patients showed an increase in AML1 transcripts that paralleled the increase in gene copy number. Deletion of the normal TEL allele was detected in two patients, with one of them showing loss of chromosome 12 together with duplication of the der(12)t(12;21). Finally, one patient showed duplication of the fusion signal. Our findings confirm that additional or secondary genetic changes including AML1 amplification are commonly encountered in childhood ALL with TEL/AML1 gene fusion, which are envisaged to play significant roles in disease progression.