Standardized approach to extract candidate outcomes from literature for a standard outcome set: a case- and simulation study

AIMS

Standard outcome sets enable the value-based evaluation of health care delivery. Whereas the attainment of expert opinion has been structured using methods such as the modified-Delphi process, standardized guidelines for extraction of candidate outcomes from literature are lacking. As such, we aimed to describe an approach to obtain a comprehensive list of candidate outcomes for potential inclusion in standard outcome sets.

METHODS

This study describes an iterative saturation approach, using randomly selected batches from a systematic literature search to develop a long list of candidate outcomes to evaluate healthcare. This approach can be preceded with an optional benchmark review of relevant registries and Clinical Practice Guidelines and data visualization techniques (e.g. as a WordCloud) to potentially decrease the number of iterations. The development of the International Consortium of Health Outcome Measures Heart valve disease set is used to illustrate the approach. Batch cutoff choices of the iterative saturation approach were validated using data of 1000 simulated cases.

RESULTS

Simulation showed that on average 98% (range 92-100%) saturation is reached using a 100-article batch initially, with 25 articles in the subsequent batches. On average 4.7 repeating rounds (range 1-9) of 25 new articles were necessary to achieve saturation if no outcomes are first identified from a benchmark review or a data visualization.

CONCLUSION

In this paper a standardized approach is proposed to identify relevant candidate outcomes for a standard outcome set. This approach creates a balance between comprehensiveness and feasibility in conducting literature reviews for the identification of candidate outcomes.

Recurrent activating STAT5B N642H mutation in myeloid neoplasms with eosinophilia

Determining the underlying cause of persistent eosinophilia is important for effective clinical management but remains a diagnostic challenge in many cases. We identified STAT5B N642H, an established oncogenic mutation, in 27/1715 (1.6%) cases referred for investigation of eosinophilia. Of the 27 mutated cases, a working diagnosis of hypereosinophilic syndrome (HES; n = 7) or a myeloid neoplasm with eosinophilia (n = 20) had been made prior to the detection of STAT5B N642H. Myeloid panel analysis identified a median of 2 additional mutated genes (range 0–4) with 4 cases having STAT5B N642H as a sole abnormality. STAT5B N642H was absent in cultured T cells of 4/4 positive cases. Individuals with SF3B1 mutations (9/27; 33%) or STAT5B N642H as a sole abnormality had a markedly better overall survival compared to cases with other additional mutations (median 65 months vs. 14 months; hazard ratio = 8.1; P < 0.001). The overall survival of STAT5B-mutated HES cases was only 30 months, suggesting that these cases should be reclassified as chronic eosinophilic leukemia, not otherwise specified (CEL-NOS). The finding of STAT5B N642H as a recurrent mutation in myeloid neoplasia with eosinophilia provides a new diagnostic and prognostic marker as well as a potential target for therapy.

The role of extracorporeal photopheresis in the management of cutaneous T-cell lymphoma, graft-versus-host disease and organ transplant rejection: a consensus statement update from the UK Photopheresis Society

Extracorporeal photopheresis (ECP) has been used for over 35 years in the treatment of erythrodermic cutaneous T‐cell lymphoma (CTCL) and over 20 years for chronic and acute graft‐versus‐host disease (GvHD) and solid organ transplant rejection. ECP for CTCL and GvHD is available at specialised centres across the UK. The lack of prospective randomised trials in ECP led to the development of UK Consensus Statements for patient selection, treatment schedules, monitoring protocols and patient assessment criteria for ECP. The recent literature has been reviewed and considered when writing this update. Most notably, the national transition from the UVAR XTS^® machine to the new CELLEX machine for ECP with dual access and a shorter treatment time has led to relevant changes in these schedules. This consensus statement updates the previous statement from 2007 on the treatment of CTCL and GvHD with ECP using evidence based medicine and best medical practise and includes guidelines for both children and adults.

Extracorporeal photopheresis as second-line treatment for acute graft-versus-host disease: impact on six-month freedom from treatment failure

Second-line therapy for corticosteroid-refractory or -dependent acute graft-versus-host disease remains ill-defined, due to limited efficacy of drugs and evolving clinical trial endpoints. Six-month freedom from treatment failure has been proposed as a novel clinical trial endpoint and is defined by the absence of death, malignancy relapse/progression, or addition of a next line of systemic immunosuppressive therapy within 6 months of intervention and prior to diagnosis of chronic graft-versus-host disease. We analyzed the 6-month freedom from treatment failure endpoint in 128 patients enrolled from three centers who were treated with extracorporeal photopheresis as second-line therapy for acute graft-versus-host disease. The incidence of 6-month freedom from treatment failure was 77.3% with a 2-year survival rate of 56%. Corticosteroid dose or response status at onset of second-line therapy did not influence outcome. Higher grade of acute graft-versus-host disease (grade 2 versus grades 3-4) at onset of photopheresis predicted for poor outcome as measured by survival (hazard ratio 2.78, P<0.001), non-relapse mortality (hazard ratio 2.78, P=0.001) and 6-month freedom from treatment failure (hazard ratio 3.05, P<0.001). For the 91 patients who achieved 6-month freedom from treatment failure, 1-year, 2-year and 3-year survival rates were 78.9%, 70.8% and 69.5%, respectively. Six-month freedom from treatment failure is a reasonable early surrogate for outcome and should be considered as a clinical trial endpoint. This study demonstrates the durable effect of photopheresis as second-line therapy for corticosteroid-refractory or -dependent acute graft-versus-host disease using 6-month freedom from treatment failure as the primary endpoint.

Extracorporeal photopheresis for treatment of adults and children with acute GVHD: UK consensus statement and review of published literature

Extracorporeal photopheresis (ECP) has been used for over 20 years to treat acute GVHD (aGVHD) and chronic GVHD. Evidence on the efficacy of response in aGVHD has continued to accrue and data suggest that there is a good response and prolonged survival in both children and adults with grade II-IV aGVHD. Unlike chronic GVHD where treatment schedules are typically one or two times monthly for 12-18 months, patients with aGVHD respond rapidly to an intense weekly treatment schedule for 8 weeks, typically allowing steroids to be discontinued without flare-ups of aGVHD. Maintenance ECP therapy is generally not required. Many centres across Europe and United States treat aGVHD with ECP as second-line therapy and responses are excellent in a subset of patients. Unlike other second-line therapies, ECP is not immunosuppressive and has no reported drug interactions. Importantly, ECP does not have a negative impact on the graft-versus-malignancy effect of the transplant. This statement aims to select those patients most likely to respond to treatment and summarises treatment and monitoring schedules for the management of aGVHD in adult and paediatric patients to ensure the correct patients are treated with the optimal protocol for efficacy.

The acute impact of a hematopoietic allograft on lung function and inflammation: a prospective observational study

Background

No studies have investigated the immediate impact of receiving an allogeneic hematopoietic stem cell transplant (HSCT) on pulmonary inflammation or lung function.

Methods

Using a prospective study design, we quantified the changes in these outcome measures in eligible adult individuals in the first six months after receiving an allogeneic hematopoietic stem cell transplant.

Results

Between January 2007 and December 2008, 72 patients were eligible to participate in the cohort, and of these 68 (94%) were included in the study. Compared to baseline, pulmonary inflammation as measured by exhaled nitric oxide increased after receiving a HSCT with the largest increment seen at three months (+6.0ppb, 95%CI: +0.4 to +11.5), and this was sustained at six months. Percent predicted forced expiratory volume in one second decreased over the same period, with the largest decrease observed at six weeks (−5.9%, 95% CI: -8.9 to −2.9), and this was also sustained over a six month period. Similar associations were observed for FVC. A larger increase in exhaled nitric oxide from baseline at six weeks and three months may be associated with decreased mortality (p=0.06, p=0.04 respectively).

Conclusion

Our data demonstrate that recipients of an allogeneic HSCT experience an increase in biomarkers of pulmonary inflammation and a decrease in lung function in the first six months after the procedure. If independently validated in other study populations, these observations could have potential as a prognostic biomarker for this patient group.

Bone marrow transplantation in AML, and socioeconomic class: a UK population-based cohort study

Background

We have previously shown that in the UK mortality in people with Acute Myeloid Leukaemia (AML) was nearly 50% greater among the most socio-economically deprived. The aim of this study was to determine whether AML patients from lower socioeconomic classes had a lower chance of receiving a bone marrow transplant.

Methods

Using Hospital Episode Statistics (HES) data, we identified all incident cases of AML admitted to UK hospitals between 1998 and 2007. We calculated the number of bone marrow transplantations undertaken in AML patients, stratifying our results by gender, age at diagnosis, year of diagnosis, degree of socioeconomic deprivation and co-morbidity. We used logistic regression to calculate odds ratios for bone marrow transplantation, adjusting for gender, age at diagnosis, year of diagnosis, degree of socioeconomic deprivation and co-morbidity score.

Results

We identified a total of 23 910 incident cases of AML over this 10-year time period, of whom 1 140 (4.8%) underwent BMT. Bone marrow transplantation declined with increasing socioeconomic deprivation (p for trend < 0.001) such that people in the most deprived socioeconomic quintile were 40% less likely to have a transplant than those in the most advantaged group (Odds Ratio 0.60, 95% confidence interval 0.49, 0.73), even after adjusting for gender, age at diagnosis, year of diagnosis and co-morbidity.

Conclusion

This large cohort study demonstrates that AML patients from lower socioeconomic classes are less likely to undergo bone marrow transplantation than their better off counter-parts.

European development of clofarabine as treatment for older patients with acute myeloid leukemia considered unsuitable for intensive chemotherapy

PURPOSE

Treatment options for older patients with acute myeloid leukemia (AML) who are not considered suitable for intensive chemotherapy are limited. We assessed the second-generation purine nucleoside analog, clofarabine, in two similar phase II studies in this group of patients.

PATIENTS AND METHODS

Two consecutive studies, UWCM-001 and BIOV-121, recruited untreated older patients with AML to receive up to four or six 5-day courses of clofarabine. Patients in UWCM-001 were either older than 70 years or 60 to 69 years of age with poor performance status (WHO > 2) or with cardiac comorbidity. Patients in BIOV-121 were >or= 65 years of age and deemed unsuitable for intensive chemotherapy.

RESULTS

A total of 106 patients were treated in the two monotherapy studies. Median age was 71 years (range, 60 to 84 years), 30% had adverse-risk cytogenetics, and 36% had a WHO performance score >or= 2. Forty-eight percent had a complete response (32% complete remission, 16% complete remission with incomplete peripheral blood count recovery), and 18% died within 30 days. Interestingly, response and overall survival were not inferior in the adverse cytogenetic risk group. The safety profile of clofarabine in these elderly patients with AML who were unsuitable for intensive chemotherapy was manageable and typical of a cytotoxic agent in patients with acute leukemia. Patients had similar prognostic characteristics to matched patients treated with low-dose cytarabine in the United Kingdom AML14 trial, but had significantly superior response and overall survival.

CONCLUSION

Clofarabine is active and generally well tolerated in this patient group. It is worthy of further evaluation in comparative trials and might be of particular use in patients with adverse cytogenetics.

NSAID use and risk of leukaemia: a population-based case-control study

PURPOSE

The use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of developing colorectal and lung cancer. Studies suggesting similar associations in leukaemia have been small and underpowered. We have conducted a large population-based case-control study to determine whether the use of NSAIDs is associated with a reduced risk of acute and chronic leukaemias, and whether their use has any impact on survival in these patients.

METHODS

We identified all the incident cases of leukaemia in 'The Health Improvement Network' (THIN) general practice dataset, along with at least four matched controls per case. We used conditional logistic regression to determine odds ratios for NSAID prescription rates and the risk of developing several leukaemia sub-types. We then used Cox regression to determine the association between NSAID prescription rate and risk of death in leukaemia. Hazard ratios were adjusted for gender, age at diagnosis, smoking status and Townsend Score.

RESULTS

The risk of leukaemia overall appears to increase marginally with increased use of NSAIDs prior to diagnosis. This is not seen when individual leukaemia sub-types are examined, however, except perhaps in CLL where patients who had received 2-5 prescriptions/year are 34% more likely to be diagnosed with CLL than those who had not had any NSAID prescriptions (O.R. 1.34, p = 0.03, 95% C.I. 1.02-1.74). There was no statistically significant association between exposure to NSAIDs prior to leukaemia diagnosis and survival.

CONCLUSION

The use of NSAIDs does not reduce the risk of developing leukaemia, nor do they improve survival.

The incidence of and mortality from leukaemias in the UK: a general population-based study

Background

The acute and chronic leukaemias constitute about 2.5% of all newly diagnosed malignancies and kill over 4000 people/year in the UK, yet there is little accurate up-to-date data on how the incidence of and mortality from leukaemias vary with socio-economic status in the UK. We aimed to quantify the incidence of and mortality from leukaemias in the UK and their variation with gender, age, year of diagnosis as well as socio-economic status.

Methods

All incident cases of leukaemia were identified in 'The Health Improvement Network' (THIN) General Practice dataset. Crude incidence rates and incidence rate ratios (using Poisson Regression) stratified by age, gender, year of diagnosis and socio-economic status were calculated. Median survival and hazard ratios for risk of death (using Cox regression) were then calculated, and stratified in a similar manner.

Results

A total of 4162 cases of leukaemia were identified, 2314 (56%) of whom were male. The overall incidence of leukaemia was 11.25 per 100 000 person-years. The age and gender distributions of ALL, AML, CLL and CML were similar to UK cancer registry data. The incidence of leukaemias was independent of socio-economic class. Median survival from leukaemia was 6.58 years and mortality increased with increasing age at diagnosis. The prognosis in AML was dismal and worsened with increasing socio-economic deprivation. For other leukaemias mortality was independent of socio-economic status.

Conclusion

This is the first general population study to describe the incidence of and mortality from leukaemias in the UK by socio-economic status. Similar mortality across socio-economic gradients in the leukaemias studied suggests equal access to and uptake of services. The exception to this was in AML, where poorer survival in AML patients from lower socio-economic classes may represent a class bias in treatment offered and/or greater co-morbidity in these patients, and warrants further exploration.

The Impact of Chimerism Patterns and Predonor Leukocyte Infusion Lymphopenia on Survival following T Cell-Depleted Reduced Intensity Conditioned Transplants

Donor leukocyte infusions (DLI) are frequently required following reduced intensity conditioned (RIC) allografts to convert mixed chimerism (MC) to full donor chimerism (FDC). The rationale is to break tolerance and maximize the graft-versus-leukemia responses. We analyzed the impact of chimerism in 125 recipients of RIC (Alemtuzumab containing) transplants. Four patterns of chimerism were seen: (1) always 100% donor chimerism (54%), (2) persisting MC (22%), (3) MC with subsequent development of FDC (18%), (4) lost donor chimerism (6%). Forty-five (36%) patients received DLI. Chimerism patterns and pre-DLI lymphocyte counts (pDLI[Ly]) were significantly associated with DLI responsiveness. Complete disease responses were seen in 6 of 17 (35%) group A patients, 9 of 10 (90%) group C patients, and 0 of 6 group B patients (P = .027), supporting reports that chimerism response is a surrogate marker for disease response. In those with MC, pDLI(Ly) were significantly lower in DLI responsive than nonresponsive patients (P = .044). At 2 years, group C patients had a significant survival advantage (P = .009) compared to all other groups. In conclusion, the chimerism pattern was the best indicator of improved survival in this cohort (ie, MC later converting to FDC). In those with MC, response to DLI therapy was associated with a low lymphocyte count pre-DLI.

The impact of donor factors on primary non-engraftment in recipients of reduced intensity conditioned transplants from unrelated donors

BACKGROUND AND OBJECTIVES

Primary graft failure is a serious complication following hematopoietic cell transplants, particularly when using unrelated donors. We analyzed factors affecting primary graft failure in recipients of hematopoietic cell transplants from unrelated donors, which were performed using reduced intensity conditioning.

DESIGN AND METHODS

This was a retrospective analysis of 144 patients whose transplants took place between March 1998 and October 2004. The data were analyzed in January 2005.

RESULTS

The median age of the patients was 51 years. The diagnoses were varied. Conditioning regimens were fludarabine, melphalan, campath (n=80), fludarabine, busulphan, campath (n=38), fludarabine, BEAM, campath (n=9) and other (n=17). The donor was 10/10 allele matched in 95/144 (66%) cases; 94 donated bone marrow and 50 peripheral blood stem cells. The 3-year probability of overall survival was 43%. The median follow-up was 724 days (range: 91-1651 days). Of evaluable patients, 7/140 (5%) failed to achieve myeloid engraftment. Primary graft failure was significantly associated with the use of a mismatched donor (6/47,13% versus 1/93, 1%, p=0.006), as well as: bone marrow as the source of stem cells (p=0.046), chronic myeloid leukemia compared to other diagnoses (p=0.022), and a female rather than a male donor (p=0.019). In multivariate analysis chronic myeloid leukemia, HLA mismatched and/or female donors remained significantly associated with primary graft failure. Single HLA mismatches were tolerated, however in multiply mismatched grafts, overall survival was worse (p=0.005); transplanted-related mortality (p=0.005) and chronic graft-versus-host disease (p=0.025) were increased.

INTERPRETATION AND CONCLUSIONS

These data have implications for the choice of donor and stem cell source in transplants performed using reduced intensity conditioning regimens, suggesting that the use of bone marrow, female donors and HLA-mismatched grafts increase the risk of primary graft failure, and should be avoided in certain situations.

Flow cytometric measurement of functional and phenotypic P-glycoprotein

The measurement of functional and phenotypic P-glycoprotein by flow cytometry is suitable for cells in suspension, and is particularly appropriate for blood and bone marrow cells. We describe a functional assay for P-glycoprotein using rhodamine 123, an assay for daunorubicin accumulation, and an assay to measure P-glycoprotein levels using the MRK16 antibody. Our protocols include the use of an anti-CD45 antibody for the identification of leukemic blasts. The protocols described in this chapter were designed for use in studies accompanying UK Medical Research Council Trials of patients with Acute Myeloid Leukaemia and High Risk Myelodysplastic Syndrome (>10% blasts). These assays are performed in more than one UK Centre, and hence each assay has been subjected to rigorous reproducibility testing.

Polymorphisms in genes involved in homologous recombination repair interact to increase the risk of developing acute myeloid leukemia

PURPOSE

Double-strand break repair via homologous recombination is essential in maintaining genetic integrity. RAD51 and XRCC3 are involved in the repair of DNA by this pathway, and polymorphisms have been identified in both the RAD51 (RAD51-G135C) and XRCC3 (XRCC3-Thr241Met) genes. The object of this study was to examine whether these polymorphisms may modulate susceptibility to the development of acute myeloid leukemia (AML), a disease that is characterized by genetic instability.

EXPERIMENTAL DESIGN

We studied the distribution of polymorphisms in RAD51 and XRCC3 in 216 cases of de novo AML, 51 cases of therapy-related AML (t-AML), and 186 control subjects using PCR followed by restriction enzyme digestion. The polymorphic deletion of the detoxification gene glutathione S-transferase M1 (GSTM1) was also examined by PCR.

RESULTS

The risk of the development of AML was found to be significantly increased when both variant RAD51-135C and XRCC3-241Met alleles are present [odds ratio (OR), 3.77; 95% confidence interval (CI), 1.39-10.24], whereas the risk of t-AML development is even higher (OR, 8.11; 95% CI, 2.22-29.68), presumably because of the large genotoxic insult these patients receive after their exposure to radiotherapy or chemotherapy. If we further divide the AML group into patients in which the burden of DNA damage is increased, because of the deletion of the GSTM1 gene, the risk of development of AML is further increased (OR, 15.26; 95% CI, 1.83-127.27).

CONCLUSIONS

These results strongly suggest that DNA double-strand breaks and their repair are important in the pathogenesis of both de novo and t-AML.

The genotype distribution of the XRCC1 gene indicates a role for base excision repair in the development of therapy-related acute myeloblastic leukemia

Polymorphisms in several DNA repair genes have been described. These polymorphisms may affect DNA repair capacity and modulate cancer susceptibility by means of gene-environment interactions. We investigated DNA repair capacity and its association with acute myeloblastic leukemia (AML). We studied polymorphisms in 3 DNA repair genes: XRCC1, XRCC3, and XPD. We also assessed the incidence of a functional polymorphism in the NQO1 gene, which is involved in protection of cells from oxidative damage. We genotyped the polymorphisms by using polymerase chain reaction-restriction fragment-length polymorphism analysis in 134 patients with de novo AML, 34 with therapy-related AML (t-AML), and 178 controls. The distributions of the XRCC3 Thr241Met and NQO1 Pro187Ser genotypes were not significantly different in patients and controls. However, the distribution of the XRCC1 Arg399Gln genotypes was significantly different when comparing the t-AML and control groups (chi(2), P =.03). The presence of at least one XRCC1 399Gln allele indicated a protective effect for the allele in controls compared with patients with t-AML (odds ratio 0.44; 95% confidence interval, 0.20-0.93). We found no interactions between the XRCC1 or XRCC3 and NQO1 genotypes. We also found no differences in the distribution of the XPD Lys751Gln or XRCC1 Arg194Trp genotypes. Our data provide evidence of a protective effect against AML in individuals with at least one copy of the variant XRCC1 399Gln allele compared with those homozygous for the common allele.

Allogeneic haemopoietic stem cell transplantation for multiple myeloma or plasma cell leukaemia using fractionated total body radiation and high-dose melphalan conditioning

We have evaluated the outcome of allogeneic haemopoietic stem cell transplantation for multiple myeloma using a conditioning regimen comprising fractionated total body irradiation and high-dose melphalan (110 mg/m2). The study comprised 25 patients (median age 49 years) who had been transplanted by either bone marrow (n = 13) or G-CSF mobilized peripheral blood stem cells (n = 12). Overall transplant-related mortality was 30% but was lower for patients < 50 years of age at transplant (21%). The main cause of treatment-related mortality was viral infection. Of the 19 patients evaluable post-transplant, 17 have so far achieved complete remissions. Currently, with a median follow-up of 3.4 years, 18 out of 25 patients are alive, of whom 15 are in continuing complete remission (CR) and 2 in second remission after suffering localized relapses, which were treated with radiotherapy and donor leucocyte infusions. Patients transplanted after 1 line of previous therapy, < 50 years of age and receiving peripheral blood stem cells (PBSC) rather than bone marrow (BM) had a superior outcome, although there was no statistically significant factor. We conclude that allogeneic transplantation should be considered as a potentially curative option for younger patients with myeloma and that the regimen using fractionated total body irradiation and melphalan has a high CR rate and a relatively low risk of treatment-related mortality, particularly in younger patients.

Induction of remission after donor leucocyte infusion for the treatment of relapsed chronic idiopathic myelofibrosis following allogeneic transplantation: evidence for a 'graft vs. myelofibrosis' effect

A 54-year-old man showed evidence of disease progression and a reduction in donor chimaerism by molecular microsatellite analysis 6 months after an allogeneic peripheral blood stem cell transplant for chronic idiopathic myelofibrosis. He was treated with a single infusion of donor leucocyte infusions (DLI), which led to the development of mild acute graft versus host disease (GVHD) and the rapid restoration of full donor haemopoiesis. This subsequently led to a progressive reduction in marrow fibrosis from grade IV to grade I over the following 6 months. We believe that this is the first report to provide clear evidence for the efficacy of DLI in this setting, which also provides evidence for the existence of a T-cell-mediated 'graft vs. myelofibrosis' effect similar to that seen against other haematological malignancies.