Enhanced Risk Stratification for Children and Young Adults with B-Cell Acute Lymphoblastic Leukemia: A Children's Oncology Group Report

Current strategies to treat pediatric acute lymphoblastic leukemia rely on risk stratification algorithms using categorical data. We investigated whether using continuous variables assigned different weights would improve risk stratification. We developed and validated a multivariable Cox model for relapse-free survival (RFS) using information from 21199 patients. We constructed risk groups by identifying cutoffs of the COG Prognostic Index (PICOG) that maximized discrimination of the predictive model. Patients with higher PICOG have higher predicted relapse risk. The PICOG reliably discriminates patients with low vs. high relapse risk. For those with moderate relapse risk using current COG risk classification, the PICOG identifies subgroups with varying 5-year RFS. Among current COG standard-risk average patients, PICOG identifies low and intermediate risk groups with 96% and 90% RFS, respectively. Similarly, amongst current COG high-risk patients, PICOG identifies four groups ranging from 96% to 66% RFS, providing additional discrimination for future treatment stratification. When coupled with traditional algorithms, the novel PICOG can more accurately risk stratify patients, identifying groups with better outcomes who may benefit from less intensive therapy, and those who have high relapse risk needing innovative approaches for cure.

Mobile low-threshold buprenorphine integrated with infectious disease services

INTRODUCTION

In 2018, the Baltimore City Health Department launched a mobile clinic called Healthcare on The Spot, which offers low-threshold buprenorphine services integrated with health care services to meet the needs of people who use drugs. In addition to buprenorphine management, The Spot offers testing and treatment for hepatitis C, sexually transmitted infections, and HIV, as well as pre-exposure prophylaxis for HIV, wound care, vaccinations, naloxone distribution, and case management.

METHODS AND MATERIALS

This cohort analysis includes clinical service data from the first 15 months of The Spot mobile clinic, from September 4, 2018, to November 23, 2019. The Spot co-located with the Baltimore syringe services program in five locations across the city. Descriptive data are provided for patient demographics and services provided, as well as percent of patients retained in buprenorphine treatment at one and three months. Logistic regression identified factors associated with retention at three months.

RESULTS

The Spot mobile clinic provided services to 569 individuals from September 4, 2018, to November 23, 2019, including prescribing buprenorphine to 73.8% and testing to more than 70% for at least one infectious disease. Patients receiving a prescription for buprenorphine were more likely to be tested for HIV, hepatitis C, and sexually transmitted infections, as well as receive treatment for hepatitis C and preventive services including vaccination and naloxone distribution. The Spot initiated HIV treatment for four patients and HIV pre-exposure prophylaxis for twelve patients. More than 32% of patients had hepatitis C; nineteen of these patients initiated treatment for hepatitis C with eight having a documented cure. Buprenorphine treatment retention was 56.0% at one month and 26.2% at three months. Patients who were Black or receiving treatment for hepatitis C were more likely to be retained in buprenorphine treatment at three months.

CONCLUSIONS

Increasing access to integrated medical services and drug treatment through low-threshold, community-based models of care can be an effective tool for addressing the effects of drug use.

Utilizing telemedicine during COVID-19 pandemic for a low-threshold, street-based buprenorphine program

BACKGROUND

Changes in federal policy during the COVID-19 pandemic allowing for the use of telemedicine to treat opioid use disorder (OUD) have facilitated innovative strategies to engage and retain people in treatment. Since 2018, the Baltimore City Health Department has operated a mobile street medicine program called Healthcare on The Spot (The Spot) that provides treatment for OUD and infectious diseases. This study describes the transition of The Spot's buprenorphine service to telemedicine during the COVID-19 pandemic and one year treatment retention.

METHODS

Patients actively engaged in care at the time of transition to telemedicine and patients newly engaged in buprenorphine services through telemedicine were included in this descriptive analysis and assessed at one year for retention.

RESULTS

From March 16, 2020 to March 15, 2021, The Spot provided voice-only buprenorphine treatment services to 150 patients, 70.7% (n = 106) male and 80.0% (n = 120) Black; 131 were patients who transitioned from in person services and 19 were newly engaged via telemedicine. 80.7% (n = 121) of patients remained engaged in treatment at one year, 16.0% (n = 24) were lost to follow-up, and 3.3% (n = 5) were deceased. Patients newly engaged via telemedicine were more likely to be female and white than those retained from in person services.

CONCLUSION

The Spot's transition of patients from a street medicine program to telemedicine during the COVID-19 pandemic has implications for future practice. Increased flexibility of service delivery, extended prescription length, and decreased UDT likely contributed to high retention rates and should inform the future structure of low-threshold buprenorphine programs.

Prognostic significance of initial clinical and molecular genetic features of acute promyelocytic leukemia (APL): Results from the North American Intergroup Trial, C9710

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Background: The impact of previously defined prognostic variables can change with advances in treatment. Thus, the significance of initial clinical and molecular genetic features of APL were explored in the context of the first randomized trial designed to evaluate the potential benefit of adding As2O3 consolidation into front-line all-trans retinoic acid (ATRA)-based therapy of APL (Powell et al, ASCO 2007). Methods: We evaluated pre-treatment white blood cell (WBC) and platelet count, age, PML-RARA transcript level and isoform type in the first 180 untreated APL patients (pts) who underwent molecular analysis on C9710 and explored their relationship to disease- free (DFS) and overall survival (S). PML-RARA transcripts were measured using real-time quantitative RT-PCR and expressed as a normalized quotient (NQ) of PML-RARA/GAPDH. Results: Using a multivariate proportional hazard model, pre-treatment PML-RARA level and WBC count were independently associated with DFS; p = 0.0073 and p = 0.05, respectively. Pre-treatment WBC count was the only feature significantly associated with S; p<0.0001. With a median follow-up of 29 months, neither median DFS nor S have been reached and only 30 DFS events have been reported among these 180 pts. Pts with higher presenting WBC > 10K/μl had both shorter DFS and S with hazard ratios (HR) of 2.3 and 5.5, respectively. The relationships between treatment arm and pre-treatment WBC and PML-RARA transcript level were explored by categorical analyses. For non-As2O3-treated pts, a striking difference was observed in DFS at 2.5 years between those above or below cut-off values: WBC <10K, 78%; WBC >10K, 50%; NQ <median, 87%; NQ >median, 60%. For As2O3-treated pts smaller and the reverse differences were observed: WBC <10K, 94%; WBC >10K, no DFS events reported; NQ < median, 93%; NQ >median, no DFS events reported. Conclusion: These preliminary results (based on analysis of 31% of total C9710 pts) indicate that pre-treatment PML-RARA transcript level and WBC are prognostic variables for newly diagnosed APL pts in first remission treated with standard ATRA-based chemotherapy but suggest that they may not apply in pts receiving two 25-day courses of As2O3 as first consolidation.

No significant financial relationships to disclose.

Patient and tumor characteristics of colon cancers with microsatellite instability: a population-based study

Molecular screening for microsatellite instability (MSI) in colon cancers has been proposed to identify individuals with hereditary nonpolyposis colorectal cancer. To date, most reports of MSI in colorectal cancer have been based on studies of clinical case series or high-risk families. We examined the proportion of incident colon cancers in the general population that exhibit MSI by patient and tumor characteristics. We interviewed 201 colon cancer cases ascertained by the New Mexico Tumor Registry in the metropolitan Albuquerque area for demographic information, lifestyle factors, medical history, and family cancer history. Paired normal and tumor tissue specimens were obtained for each case. Three microsatellite markers were used; instability was defined as observed alteration at two or more loci. Overall, 37 of 201 (18%) colon cancers exhibited instability. MSI was more common among cases >70 years (26%) and most common among cases >80 years (38%). MSI was significantly associated with tumors in the proximal colon and with later stage and poor differentiation among cases >70 years. MSI was not associated with a history of polyps. Family history of colorectal cancer was associated with MSI only among cases <50 years. When all factors were analyzed jointly in a regression model, proximal subsite and poor differentiation remained significantly associated with MSI. One patient, whose tumor exhibited MSI, fulfilled the Amsterdam Criteria for hereditary nonpolyposis colorectal cancer. Our study provides a population-based estimate of MSI in colon tumors and a representative estimate of the proportion of colorectal cancer patients in the general population who consent to be interviewed for family cancer history and to have biological samples analyzed.

Three-color versus four-color multiparameter cell cycle analyses of primary acute myeloid leukemia samples

Checkpoint alterations that impact cell cycle and apoptosis responses to therapeutic treatments may produce drug resistance in acute myeloid leukemia (AML). To study these, we have developed flow cytometry assays of checkpoint function that also allow quantitation of key molecular regulators of apoptosis and cell cycle. We have used three-color (3C) assays, with FITC-labeled anti-BCL-2 and PE-labeled anti-proliferating cell nuclear antigen (PCNA) antibodies, and the DNA dye 7-aminoactinomycin, to characterize primary leukemia cells identified in DNA x side light scatter (SSC) histograms. We showed that 3C assays are accurate and reproducible in analyses of leukemia cell lines and of primary AML and normal bone marrow samples (Banker et al.: Blood 89: 243-255, 1997; Banker et al.: Leukemia Res 22: 221-239, 1998; Banker et al.: Clin Cancer Res 4: 3051-3062, 1998). To further confirm the validity of our SSC leukemia cell gating and to address whether immunophenotypic AML subsets might have different biologic properties, we have now designed four-color (4C) flow assays to characterize checkpoint status in leukemic blasts specifically identified by surface immunostaining. In modeling this assay strategy, PE/Cy5-labeled anti-CD34 antibody was used to detect blasts, with FITC-labeled anti-BCL-2, PE-labeled anti-PCNA antibodies, and Hoechst 33342 (H33342) DNA dye. Four-color CD34-gated data was concordant with 3C, SSC-gated data for leukemia cell lines and for most primary AML samples with high and intermediate blast counts. BCL-2 and PCNA immunopositivity and sub-G1 apoptosis determinations were different in the CD34-gated versus SSC-gated blasts in particular samples with smaller CD34(+) subsets, suggesting that leukemia samples can contain blast subsets with different biologic properties. On the other hand, PCNA-gated cell-cycle distributions in untreated cells and G1 versus S phase cell-cycle arrests after cytosine arabinoside treatments were completely concordant in 4C and 3C assays. We conclude that both 3C and 4C assays can be used to characterize protein expression and cell-cycle drug response patterns in leukemia blasts, but that 4C assays may additionally allow discrimination of these properties in immunophenotypic leukemia subsets.

Haploinsufficiency of CBFA2 causes familial thrombocytopenia with propensity to develop acute myelogenous leukaemia

Familial platelet disorder with predisposition to acute myelogenous leukaemia (FPD/AML, MIM 601399) is an autosomal dominant disorder characterized by qualitative and quantitative platelet defects, and propensity to develop acute myelogenous leukaemia (AML). Informative recombination events in 6 FPD/AML pedigrees with evidence of linkage to markers on chromosome 21q identified an 880-kb interval containing the disease gene. Mutational analysis of regional candidate genes showed nonsense mutations or intragenic deletion of one allele of the haematopoietic transcription factor CBFA2 (formerly AML1) that co-segregated with the disease in four FPD/AML pedigrees. We identified heterozygous CBFA2 missense mutations that co-segregated with the disease in the remaining two FPD/AML pedigrees at phylogenetically conserved amino acids R166 and R201, respectively. Analysis of bone marrow or peripheral blood cells from affected FPD/AML individuals showed a decrement in megakaryocyte colony formation, demonstrating that CBFA2 dosage affects megakaryopoiesis. Our findings support a model for FPD/AML in which haploinsufficiency of CBFA2 causes an autosomal dominant congenital platelet defect and predisposes to the acquisition of additional mutations that cause leukaemia.

Comparison of asynchronous versus synchronous arm crank ergometry

STUDY DESIGN

A direct comparison of synchronous versus asynchronous arm crank ergometry has not been carried out previously. Therefore, a comparative research design was employed.

OBJECTIVE

To assess the physiological responses of arm cranking when performed asynchronously (arms moving opposite to each other) versus synchronously (both arms moving in the same direction simultaneously).

SETTING

A university hospital setting in Galveston, Texas, USA.

METHODS

Seventeen individuals between the ages of 19 and 53 years were studied, 11 with paraplegia and six with no apparent disability. Two maximal arm crank graded exercise tests were performed with the subject seated in a wheelchair. Testing consisted of both arms (1) asynchronously (reciprocally) pushing and pulling the crank handles and (2) pushing and pulling the crank handles synchronously. Each test consisted of 2 min stages starting at 20 W and increasing 10 W per stage thereafter until exhaustion. Heart rate, oxygen consumption, and minute ventilation were measured and recorded during each stage. Blood lactate levels were monitored before and after each test. Statistical analysis was performed using the multivariate Hotelling's T2 followed by post hoc univariate tests.

RESULTS

Greater power and longer test times (both groups, P<0.05) and higher post test blood lactates (nondisabled P<0.01, paraplegic P<0.05) were achieved with asynchronous cranking versus synchronous cranking. While submaximal responses were similar between the two modes of cranking, there was a tendency for all variables to be lower with asynchronous. All subjects preferred asynchronous rather than synchronous cranking.

CONCLUSION

Despite few statistically significant differences, based on the subjective reports from all subjects, we believe there is a clinically significant difference between the two modes of cranking. The results suggest that the mode of cranking may have implications for arm crank testing, training, and functional locomotion in individuals with lower extremity impairments.

Chemotherapy compared with autologous or allogeneic bone marrow transplantation in the management of acute myeloid leukemia in first remission

BACKGROUND

In young adults with acute myeloid leukemia, intensive chemotherapy during the initial remission improves the long-term outcome, but the role of bone marrow transplantation is uncertain. We compared high-dose cytarabine with autologous or allogeneic marrow transplantation during the first remission of acute myeloid leukemia.

METHODS

Previously untreated adolescents and adults 16 to 55 years of age who had acute myeloid leukemia received standard induction chemotherapy. After complete remission had been achieved, idarubicin (two days) and cytarabine (five days) were administered. Patients with histocompatible siblings were offered allogeneic marrow transplantation, whereas the remaining patients were randomly assigned to receive a single course of high-dose cytarabine or transplantation of autologous marrow treated with perfosfamide (4-hydroperoxycyclophosphamide). Oral busulfan and intravenous cyclophosphamide were used as preparative regimens for both allogeneic and autologous marrow transplantation. The end points were survival from the time of complete remission and disease-free survival.

RESULTS

In an intention-to-treat analysis, we found no significant differences in disease-free survival among patients receiving high-dose chemotherapy, those undergoing autologous bone marrow transplantation, and those undergoing allogeneic marrow transplantation. The median follow-up was four years. Survival after complete remission was somewhat better after chemotherapy than after autologous marrow transplantation (P=0.05). There was a marginal advantage in terms of overall survival with chemotherapy as compared with allogeneic marrow transplantation (P=0.04).

CONCLUSIONS

A postinduction course of high-dose cytarabine can provide equivalent disease-free survival and somewhat better overall survival than autologous marrow transplantation in adults with acute myeloid leukemia.

The t(8;21) translocation is not consistently associated with high Bcl-2 expression in de novo acute myeloid leukemias of adults

Chromosomal translocations are commonly found in de novo acute myeloid leukemia (AML) cells, and the fusion proteins produced from these genetic abnormalities are assumed to contribute directly to leukemogenesis and/or progression. The AML1/ETO fusion protein, created by translocations between chromosomes 8 and 21 [t(8;21); G. Nucifora and J. D. Rowley, Leuk. Lymphoma, 14: 353-362, 1994; K. L. Rhoades et al., Proc. Natl. Acad. Sci. USA, 93: 11895-11900, 1996] can induce anti-apoptotic Bcl-2 expression in vitro and was proposed to thereby promote the survival of t(8;21)-bearing AML cells (L. Klampfer et al., Proc. Natl. Acad. Sci. USA, 93: 14059-14064, 1996). We confirm that cells of the t(8;21)-bearing Kasumi cell line do express high levels of Bcl-2 protein, as reported previously. However, we show that primary AML cells with (8;21) chromosomal translocations generally express low levels of Bcl-2 protein relative to normal bone marrow-derived myeloid cells and to AML samples with other simple karyotypic abnormalities. We note that p53 mutations are present in the myeloid cell lines expressing AML-ETO protein from chromosomal translocations (Kasumi and SKNO) or from transfected fusion genes (U937) but were undetected in our analyses of 28 primary t(8;21)-bearing AML cell samples from de novo AMLs. Because wild-type p53 can transcriptionally down-regulate bcl-2, we speculate that p53 mutations may contribute to the association of t(8;21) chromosomal abnormalities with higher Bcl-2 expression levels in leukemia cell lines. We also note that some t(8;21)-bearing samples from pediatric and older adult patients do express somewhat higher levels of Bcl-2 than t(8;21)-bearing samples from young adult patients. This suggests that Bcl-2 overexpression could occur in these AML cells by an as yet undefined, p53-independent mechanism and could contribute to the reported association of t(8;21) karyotypes with poor clinical outcomes in childhood AML patients and/or to typically poor clinical outcomes in elderly AML patients.

All-trans-retinoic acid in acute promyelocytic leukemia

BACKGROUND

All-trans-retinoic acid induces complete remission in acute promyelocytic leukemia. However, it is not clear whether induction therapy with all-trans-retinoic acid is superior to chemotherapy alone or whether maintenance treatment with all-trans-retinoic acid improves outcome.

METHODS

Three hundred forty-six patients with previously untreated acute promyelocytic leukemia were randomly assigned to receive all-trans-retinoic acid or daunorubicin plus cytarabine as induction treatment. Patients who had a complete remission received consolidation therapy consisting of one cycle of treatment identical to the induction chemotherapy, then high-dose cytarabine plus daunorubicin. Patients still in complete remission after two cycles of consolidation therapy were then randomly assigned to maintenance treatment with all-trans-retinoic acid or to observation.

RESULTS

Of the 174 patients treated with chemotherapy, 120 (69 percent) had a complete remission, as did 124 of the 172 (72 percent) given all-trans-retinoic acid (P=0.56). When both induction and maintenance treatments were taken into account, the estimated rates of disease-free survival at one, two, and three years were 77, 61, and 55 percent, respectively, for patients assigned to chemotherapy then all-trans-retinoic acid; 86, 75, and 75 percent for all-trans-retinoic acid then all-trans-retinoic acid; 75, 60, and 60 percent for all-trans-retinoic acid then observation; and 29, 18, and 18 percent for chemotherapy then observation. By intention-to-treat analysis, the rates of overall survival at one, two, and three years after entry into the study were 75, 57, and 50 percent, respectively, among patients assigned to chemotherapy, and 82, 72, and 67 percent among those assigned to all-trans-retinoic acid (P= 0.003).

CONCLUSIONS

All-trans-retinoic acid as induction or maintenance treatment improves disease-free and overall survival as compared with chemotherapy alone and should be included in the treatment of acute promyelocytic leukemia.

An expression based clonality assay at the human androgen receptor locus (HUMARA) on chromosome X

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An AML1/ETO fusion transcript is consistently detected by RNA-based polymerase chain reaction in acute myelogenous leukemia containing the (8;21)(q22;q22) translocation

The 8;21 translocation is one of the most common chromosomal translocations in acute myelogenous leukemia (AML), accounting for 40% of pediatric AML with French-American-British (FAB)-M2 morphology. The chromosomal breakpoints have recently been identified at the molecular level and shown to involve the AML1 gene on chromosome 21 and the ETO gene on chromosome 8. Translocation results in the consistent fusion of these genes on the der(8) chromosome, resulting in the production of a novel chimeric gene and message. Using oligonucleotide primers derived from the AML1 and ETO cDNAs, we were able to amplify a specific fusion transcript from 26 of 26 patients with t(8;21) by a reverse transcriptase polymerase chain reaction (PCR) approach. DNA fragments of identical size were generated from each case including two with complex translocations. Studies on the sensitivity and specificity of this approach show that PCR analysis can be used as a rapid, accurate, and sensitive means for detecting this chromosomal abnormality, and for following the patients' response to therapy.

Activation of the interleukin-3 gene by chromosome translocation in acute lymphocytic leukemia with eosinophilia

The t(5;14)(q31;q32) translocation from B-lineage acute lymphocytic leukemia with eosinophilia has been cloned from two leukemia samples. In both cases, this translocation joined the IgH gene and the interleukin-3 (IL-3) gene. In one patient, excess IL-3 mRNA was produced by the leukemic cells. In the second patient, serum IL-3 levels were measured and shown to correlate with disease activity. There was no evidence of excess granulocyte/macrophage colony stimulating factor (GM-CSF) or IL-5 expression. Our data support the formulation that this subtype of leukemia may arise in part because of a chromosome translocation that activates the IL-3 gene, resulting in autocrine and paracrine growth effects.

Cloning and characterization of the t(15;17) translocation breakpoint region in acute promyelocytic leukemia

A reciprocal chromosomal translocation, t(15;17)(q22;q11.2-12), is characteristic of acute promyelocytic leukemia (APL) of French-American-British (FAB) subtype M3, and is not associated with any other human malignancy. The non-random pattern of the APL translocations suggests that specific genes on chromosomes 15 and 17 are somehow altered or deregulated as a consequence of the rearrangement. Translocation breakpoints in APL patients provide physical landmarks that suggest an approach to isolating the APL gene(s). Genetic and physical maps constructed for the APL breakpoint region on chromosome 17 have indicated that two fully-linked DNA markers, defining loci for THRA1 and D17S80, map to opposite sides of an APL breakpoint yet reside on a common 350-kb Clal fragment. Cosmid-walking experiments to clone this APL breakpoint have revealed a 38-kilobase deletion on chromosome 17. Studies in additional APL patients have shown that the breakpoint region on chromosome 17 spans at least 80 kilobases.

Localization of preferential sites of rearrangement within the BCR gene in Philadelphia chromosome-positive acute lymphoblastic leukemia

The Philadelphia chromosome associated with acute lymphoblastic leukemia (ALL) has been linked to a hybrid BCR/ABL protein product that differs from that found in chronic myelogenous leukemia. This implies that the molecular structures of the two chromosomal translocations also differ. Localization of translocation breakpoints in Philadelphia chromosome-positive ALL has been impeded due to the only partial characterization of the BCR locus. We have isolated the entire 130-kilobase BCR genomic locus from a human cosmid library. A series of five single-copy genomic probes from the 70-kilobase first intron of BCR were used to localize rearrangements in 8 of 10 Philadelphia chromosome-positive ALLs. We have demonstrated that these breakpoints are all located at the 3' end of the intron around an unusual restriction fragment length polymorphism caused by deletion of a 1-kilobase fragment containing Alu family reiterated sequences. This clustering is unexpected in light of previous theories of rearrangement in Philadelphia chromosome-positive chronic myelogenous leukemia that would have predicted a random dispersion of breakpoints in the first intron in Philadelphia chromosome-positive ALL. The proximity of the translocation breakpoints to this constitutive deletion may indicate shared mechanisms of rearrangement or that such polymorphisms mark areas of the genome prone to recombination.

Nonleukemic granulocytic sarcoma of the heart: a report of a fatal case

We report the clinical and pathological features of a cardiac fatality caused by granulocytic sarcoma in a young adult man with no evidence of leukemia involving bone marrow or peripheral blood. At autopsy, walls of the four cardiac chambers were massively infiltrated by tumor, resulting in a cardiac weight of almost three times normal. Routine cytochemical stains plus immunoperoxidase staining for OKM1 confirmed the diagnosis. Although subclinical cardiac infiltrates are commonly detected at autopsy in patients with acute nonlymphoblastic leukemia (ANLL), massive cardiac granulocytic sarcoma in the absence of bone marrow disease has not been previously described. Cytochemical and immunological methods of diagnosing granulocytic sarcoma in fixed tissues are reviewed.

Endoscopic "salvage" cytology in neoplasms metastatic to the upper gastrointestional tract

Endoscopic "salvage" cytology was the only successful nonoperative diagnostic method in two patients with malignancy metastatic to the upper gastrointestinal tract. Smears and cell blocks of centrifuged material aspirated from the endoscope channel provided diagnoses of malignancies when other diagnostic techniques had been nonproductive. The results in these cases support the general utility of this technique and indicate its successful application in this specific clinical setting.