Fate of patients with newly diagnosed acute myeloid leukemia who fail primary induction therapy.

The aim of this study was to describe the fate of patients with newly diagnosed acute myeloid leukemia (AML) who did not achieve an initial remission while being treated on a contemporary cooperative group trial. We analyzed the outcome of patients entered into S0106, a recently reported cooperative group trial for patients with newly diagnosed AML. A total of 589 eligible patients was treated, of whom 150 (25%) did not achieve a remission while on study and were available for further analysis. The 4-year survival rate for the entire cohort of 150 patients was 23%. Among the 64 patients who received an allogeneic hematopoietic cell transplant, the 4-year survival rate was 48% compared with 4% for the 86 patients who did not undergo transplantation. Among those transplanted, we could not detect a difference in outcome according to remission status, donor source, type of preparative regimen, or cytogenetic risk category. More than 20% of patients with newly diagnosed AML who fail induction therapy can still be cured, particularly if they are able to receive an allogeneic hematopoietic cell transplant. These results suggest that early HLA typing and donor identification are important components of the initial therapy of AML.

A phase 3 study of gemtuzumab ozogamicin during induction and postconsolidation therapy in younger patients with acute myeloid leukemia.

This randomized phase 3 clinical trial evaluated the potential benefit of the addition of gemtuzumab ozogamicin (GO) to standard induction and postconsolidation therapy in patients with acute myeloid leukemia. Patients were randomly assigned to receive daunorubicin (45 mg/m(2) per day on days 1, 2, and 3), cytarabine (100 mg/m(2) per day by continuous infusion on days 1-7), and GO (6 mg/m(2) on day 4; DA+GO) vs standard induction therapy with daunorubicin (60 mg/m(2) per day on days 1, 2, and 3) and cytarabine alone (DA). Patients who achieved complete remission (CR) received 3 courses of high-dose cytarabine. Those remaining in CR after consolidation were randomly assigned to receive either no additional therapy or 3 doses of GO (5 mg/m(2) every 28 days). From August 2004 until August 2009, 637 patients were registered for induction. The CR rate was 69% for DA+GO and 70% for DA (P = .59). Among those who achieved a CR, the 5-year relapse-free survival rate was 43% in the DA+GO group and 42% in the DA group (P = .40). The 5-year overall survival rate was 46% in the DA+GO group and 50% in the DA group (P = .85). One hundred seventy-four patients in CR after consolidation underwent the postconsolidation randomization. Disease-free survival was not improved with postconsolidation GO (HR, 1.48; P = .97). In this study, the addition of GO to induction or postconsolidation therapy failed to show improvement in CR rate, disease-free survival, or overall survival.

Cytokines in serum in relation to future non-Hodgkin lymphoma risk: evidence for associations by histologic subtype.

Specific associations for lymphoma in the general population suggest that chronic immune dysfunction/dysregulation may be associated with the development of B-cell non-Hodgkin lymphoma (NHL). Furthermore, polymorphisms in several cytokine genes have been associated with increased lymphoma risk, most consistently with genes for TNF and IL10. To evaluate the hypothesis that prediagnostic circulating cytokine levels would be associated with increased B-cell lymphoma risk, we conducted a nested case-control study within the Women's Health Initiative Observational Study cohort involving 491 B-cell NHL cases and 491 controls. Levels of eleven cytokines, including IL1ß, IL2, IL4, IL5, IL6, IL10, IL12, IL13, TNF, IFNγ and GM-CSF, were measured using a Luminex suspension bead-based multiplexed array in prediagnostic serum samples collected a median of 6 years prior to the lymphoma diagnosis. We observed a modestly increased risk of all B-cell NHL in women with increased levels of the cytokines TNF and IL10 (OR1.22, CI 1.07-1.38 and OR 1.09, CI 1.04-1.15, respectively, per doubling in the serum cytokine concentration) and this association showed some variation according to histologic subtype. The increased risk was strongest for those neoplasms diagnosed in close proximity to the blood draw for some histologic subtypes but not others, suggesting a component of reverse causation. Further study will be required to better understand how genetic polymorphisms in TNF and IL10 genes may interact with circulating cytokine levels and states of chronic immune dysfunction/stimulation to contribute to the risk of B-cell NHL.

Imatinib 800 mg daily induces deeper molecular responses than imatinib 400 mg daily: results of SWOG S0325, an intergroup randomized PHASE II trial in newly diagnosed chronic phase chronic myeloid leukaemia.

The standard dose of imatinib for newly diagnosed patients with chronic phase chronic myeloid leukaemia (CP-CML) is 400 mg daily (IM400), but the optimal dose is unknown. This randomized phase II study compared the rates of molecular, haematological and cytogenetic response to IM400 vs. imatinib 400 mg twice daily (IM800) in 153 adult patients with CP-CML. Dose adjustments for toxicity were flexible to maximize retention on study. Molecular response (MR) at 12 months was deeper in the IM800 arm (4-log reduction of BCR-ABL1 mRNA: 25% vs. 10% of patients, P = 0·038; 3-log reduction: 53% vs. 35%, P = 0·049). During the first 12 months BCR-ABL1 levels in the IM800 arm were an average 2·9-fold lower than in the IM400 arm (P = 0·010). Complete haematological response was similar, but complete cytogenetic response was higher with IM800 (85% vs. 67%, P = 0·040). Grade 3-4 toxicities were more common for IM800 (58% vs. 31%, P = 0·0007), and were most commonly haematological. Few patients have relapsed, progressed or died, but both progression-free (P = 0·048) and relapse-free (P = 0·031) survival were superior for IM800. In newly diagnosed CP-CML patients, IM800 induced deeper MRs than IM400, with a trend for improved progression-free and overall survival, but was associated with more severe toxicity.

Arsenic trioxide during consolidation for patients with previously untreated low/intermediate risk acute promyelocytic leukaemia may eliminate the need for maintenance therapy.

Aa total of 105 patients (age ≥18 years) with newly diagnosed low or intermediate risk acute promyelocytic leukaemia (APL) were treated with a standard induction and consolidation regimen including arsenic trioxide (ATO). Sixty-eight patients who were polymerase chain reaction (PCR) negative for PML-RARA post-consolidation were randomized to either 1 year of maintenance with tretinoin, mercaptopurine and methotrexate, or observation. Enrollment in this non-inferiority trial was stopped prematurely due to slow accrual. With a median follow up of 36·1 months, the overall survival of the 105 patients was 93%, and there have been no relapses in the patients randomized to maintenance or observation. These results demonstrate that cures can be expected in >90% of patients with low and intermediate risk APL and suggest that maintenance therapy may not be needed if patients are treated with an intensive post-remission regimen including ATO. This trial was registered at clinicaltrials.gov as #NCT00492856.

A randomized trial of dasatinib 100 mg versus imatinib 400 mg in newly diagnosed chronic-phase chronic myeloid leukemia.

Tyrosine kinase inhibitor therapy with imatinib (IM), dasatinib (DAS), or nilotinib is very effective in chronic-phase chronic myeloid leukemia. Two hundred fifty-three patients with newly diagnosed chronic-phase chronic myeloid leukemia were randomized to IM 400 mg/day or DAS 100 mg/day. The proportion of patients achieving a complete cytogenetic remission rate was superior with DAS (84% vs 69%), as was the 12-month molecular response by the proportions of patients achieving > 3-log, > 4-log, and > 4.5-log reduction in BCR-ABL transcript levels. Overall and progression-free survival was similar in the 2 arms. Among patients who achieved hematologic CR, 3-year relapse-free survival was 91% with DAS and 88% with IM 400 mg. Grade 3 and 4 toxicities were most commonly hematologic, including thrombocytopenia in 18% and 8% of DAS and IM patients, respectively. DAS induced more complete cytogenetic response and deeper molecular responses after 12 months, compared with IM 400 mg, and with a median follow-up of 3.0 years there have been very few deaths, relapses, or progressions in the 2 arms. In summary, DAS compared with IM appeared to have more short-term cytogenetic and molecular response, more hematologic toxicity, and similar overall survival. This trial is registered at www.clinicaltrials.gov as NCT00070499.

Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in the Life Span Study cohort of atomic bomb survivors.

PURPOSE: We examined colon cancer risk in atomic bomb survivors to investigate whether excess body weight after the bombings alters sensitivity to radiation effects. METHODS: Of the 56,064 Japanese atomic bomb survivors with follow-up through 2002 with self-reported anthropometric data obtained from periodic mail surveys, 1,142 were diagnosed with colon cancer. We evaluated the influence of body mass index (BMI) and height on radiation-associated colon cancer risk using Poisson regression. RESULTS: We observed a similar linear dose-response relationship for the 56,064 subjects included in our analysis and the entire cohort of Japanese atomic bomb survivors [excess relative risk (ERR) per Gray (Gy) = 0.53, 95 % confidence interval (CI) 0.25-0.86]. Elevation in earliest reported BMI, BMI reported closest to colon cancer diagnosis, and time-varying BMI were associated with an elevated risk of colon cancer [relative risk (RR) per 5 kg/m(2) increase in BMI = 1.14, 95 % CI 1.03-1.26; RR = 1.16, 95 % CI 1.05-1.27; and RR = 1.15, 95 % CI 1.04-1.27, respectively]. Height was not significantly related to colon cancer risk. Inclusion of anthropometric variables in models had little impact on radiation risk estimates, and there was no evidence that sensitivity to the effect of radiation on colon cancer risk depended on BMI. CONCLUSIONS: Radiation exposure and BMI are both risk factors for colon cancer. BMI at various times after exposure to the atomic bombings does not significantly influence the relationship between radiation dose and colon cancer risk, suggesting that BMI and radiation impact colon cancer risk independently of each other.

Prognostic implications of the IDH1 synonymous SNP rs11554137 in pediatric and adult AML: a report from the Children's Oncology Group and SWOG.

IDH1 SNP rs11554137 was recently reported in association with poor prognosis in normal karyotype adult acute myeloid leukemia (AML). We aimed to determine the prevalence, clinical associations, and prognostic significance of SNP rs11554137 in unselected pediatric and adult AML patients. Diagnostic marrow specimens from 527 AML patients treated on the pediatric trial Children's Oncology Group-AAML03P1 (N = 253) or adult SWOG trials (N = 274) were analyzed for the presence of the SNP. SNP rs11554137 was present in 11% of all patients. SNP status had no prognostic impact on survival in pediatric patients. In adult AML, overall survival for SNP-positive patients was 10% versus 18% for SNP-negative patients (P = .44). Among the 142 adults who achieved complete remission, 5-year relapse-free survival was significantly worse for SNP-positive patients (0% vs 25%, P = .0014). However, among adults with normal cytogenetics, FLT3/ITD was present in 90% of SNP-positive patients versus 59% of SNP-negative patients (P = .0053). In multivariate analysis, adjusting for the effects of age, cytogenetics, and FLT3/ITD, the independent prognostic effect of SNP positivity was not statistically significant (hazard ratio = 1.72, P = .18). The clinical profile of SNP-positive patients suggests that SNP rs11554137 may have biologic effects that bear further investigation. The clinical trials in this study are registered at http://www.clinicaltrials.gov as #NCT000707174 and #NCT00899171.

Very late antigen-4 function of myeloblasts correlates with improved overall survival for patients with acute myeloid leukemia.

Adhesion of acute myeloid leukemia (AML) blasts in the bone marrow microenvironment confers protection from chemotherapy-induced apoptosis. One mechanism for retention of blasts within the bone marrow is adhesion via very late antigen-4 (VLA-4), the alpha(4)beta(1) integrin heterodimer that binds to its main ligands, fibronectin, and vascular cell adhesion molecule-1 (VCAM-1). To examine the relationship of functional expression of VLA-4 to prognosis in AML, we studied marrow samples from 175 adult AML patients who underwent induction chemotherapy with anthracycline and cytarabine on Southwest Oncology Group trials. The studies included flow cytometry and functional in vitro assays for ligand binding and maximal beta(1) activation. VLA-4 expression varied widely, with mean expression 60.6% for alpha(4), and was not significantly associated with response to chemotherapy, relapse-free, or overall survival (OS). However, increased binding of soluble VCAM-1 via VLA-4 was significantly associated with longer OS, corrected for age (P = .033). Estimated 5-year OS was 31% (95% confidence interval, 14%-48%) in 30 patients with soluble VCAM-1 binding greater than or equal to 40%, compared with 10% (confidence interval, 3%-17%) in 72 patients with lower binding. Adhesion and migratory properties of AML blasts thus appear to influence chemosensitivity and therefore may be therapeutic targets.

Sequential phase II Southwest Oncology Group studies (S0112 and S0301) of daunorubicin and cytarabine by continuous infusion, without and with ciclosporin, in older patients with previously untreated acute myeloid leukaemia.

Attempts to overcome multi-drug resistance in acute myeloid leukaemia (AML) have been limited by toxicities. To investigate the effect of reducing peak drug levels, we performed sequential phase II studies using continuous infusion daunorubicin and cytarabine without (AD) and then with ciclosporin (ADC) in older patients with AML. Untreated patients (age 56+ years) received daunorubicin (45 mg/m2 per day for 3 d) and cytarabine (200 mg/m2 per day for 7 d), both by continuous infusion, without (S0112, 60 patients) and then with (S0301, 50 patients) the addition of ciclosporin. Complete response (CR) rates were 38% on S0112 and 44% on S0301. Fatal induction toxicities occurred in 17% and 12% respectively, arising primarily from infection and haemorrhage. Median overall and relapse-free survival was 7 and 8 months for AD respectively, and 6 and 14 months for ADC. Patients with phenotypic or functional P-glycoprotein had somewhat higher CR rates with ADC than AD, although confidence intervals overlapped. In these sequential trials, continuous infusion AD produced CR rates comparable to those with bolus daunorubicin. The addition of ciclosporin did not cause undue toxicities, produced a similar CR rate, and possibly improved relapse-free survival. Further correlate analyses did not identify a subpopulation specifically benefitting from the addition of ciclosporin.

Incidence of myelodysplastic syndromes within a nonprofit healthcare system in western Washington state, 2005-2006.

Myelodysplastic syndromes (MDS) incidence is unclear because of historical lack of population-based registration and possibly because of underdiagnosis. We conducted a study to evaluate completeness of MDS registration in the Seattle-Puget Sound region of the Surveillance, Epidemiology, and End Results (SEER) program-which has reported the highest rates among the SEER registries since mandatory reporting of MDS began in 2001. We identified incident MDS cases of any age that occurred within a nonprofit healthcare system in western Washington State in 2005 or 2006 through the local SEER registry or by relevant diagnostic code followed by medical chart review to classify these patients as unlikely, possible, or definite/probable MDS. We calculated age-standardized incidence rates for all identified MDS cases and for case groups based on identification method, and we summarized medical histories of the MDS patients. MDS incidence in our study population was estimated as 7.0 per 100,000 person-years in 2005-2006 when combining MDS cases identified by SEER and definite/probable cases identified by chart review, which was similar to the rate of 6.9 reported by our local SEER registry. The addition of possible MDS cases identified from chart review increased the rate to 10.2 per 100,000. MDS patients frequently had previous cancer diagnoses (25%) and comorbidities such as high blood pressure and diabetes. Our investigation suggests that although reporting of confirmed MDS diagnoses in our region appears complete, MDS incidence is likely underestimated because of omission of cases who are symptomatic but do not receive definitive diagnoses.

Female breast cancer risk in Bryansk Oblast, Russia, following prolonged low dose rate exposure to radiation from the Chernobyl power station accident.

BACKGROUND: Ionizing radiation is a known cause of female breast cancer, but there have been few studies of the risk after prolonged radiation exposure at low dose rates. METHODS: This population-based case-control study estimated breast cancer risk after ∼25 years' exposure to radiation from the Chernobyl accident. Cases (n = 468) were women ≤55 years old when first diagnosed with invasive breast cancer during October 2008 through February 2013, who lived in Bryansk Oblast, Russia at the time of the accident and their diagnoses. Controls, individually matched to cases on birth year, administrative district of residence and urban vs non-urban settlement during the accident, were women without breast cancer who lived in Bryansk Oblast at the time of the accident and on their cases' diagnosis dates (n = 468). Subjects were interviewed regarding residence, dietary and food source histories to support individualized estimation of their radiation doses to the breast, which ranged from 0.04 - 41 centigray (cGy) (mean 1.3 cGy). RESULTS: In multivariable analyses, the odds ratio for breast cancer risk was 3.0 [95% confidence interval (CI): 1.3, 7.0] and 2.7 (95% CI: 1.0, 7.3) in the seventh and eighth dose octiles, respectively, relative to the lowest octile. Analyses of dose effect modification suggested that radiation-related risk may have been higher in women who were younger at the time of the accident and/or at the time of diagnosis. CONCLUSIONS: This study suggests that prolonged exposure to ionizing radiation at low dose rates can increase risk of breast cancer.

AML risk stratification models utilizing ELN-2017 guidelines and additional prognostic factors: a SWOG report.

BACKGROUND: The recently updated European LeukemiaNet risk stratification guidelines combine cytogenetic abnormalities and genetic mutations to provide the means to triage patients with acute myeloid leukemia for optimal therapies. Despite the identification of many prognostic factors, relatively few have made their way into clinical practice. METHODS: In order to assess and improve the performance of the European LeukemiaNet guidelines, we developed novel prognostic models using the biomarkers from the guidelines, age, performance status and select transcript biomarkers. The models were developed separately for mononuclear cells and viable leukemic blasts from previously untreated acute myeloid leukemia patients (discovery cohort, N = 185) who received intensive chemotherapy. Models were validated in an independent set of similarly treated patients (validation cohort, N = 166). RESULTS: Models using European LeukemiaNet guidelines were significantly associated with clinical outcomes and, therefore, utilized as a baseline for comparisons. Models incorporating age and expression of select transcripts with biomarkers from European LeukemiaNet guidelines demonstrated higher area under the curve and C-statistics but did not show a substantial improvement in performance in the validation cohort. Subset analyses demonstrated that models using only the European LeukemiaNet guidelines were a better fit for younger patients (age < 55) than for older patients. Models integrating age and European LeukemiaNet guidelines visually showed more separation between risk groups in older patients. Models excluding results for ASXL1, CEBPA, RUNX1 and TP53, demonstrated that these mutations provide a limited overall contribution to risk stratification across the entire population, given the low frequency of mutations and confounding risk factors. CONCLUSIONS: While European LeukemiaNet guidelines remain a critical tool for triaging patients with acute myeloid leukemia, the findings illustrate the need for additional prognostic factors, including age, to improve risk stratification.

Basal cell skin cancer after total-body irradiation and hematopoietic cell transplantation.

Previous studies identified radiation therapy as a key modifier of basal cell carcinoma (BCC) risk in survivors of hematopoietic cell transplantation (HCT). In the present analysis, risk of BCC was analyzed in relation to age at transplant, attained age, race, total-body irradiation (TBI), and radiation fractionation in 6,306 patients who received HCT at ages 0-65 years after conditioning regimens with (n = 3870) or without (n = 2436) TBI, and who were followed from 100 days to 36.2 years after HCT. While age-specific BCC rates in the unirradiated patient population were higher than those reported for two non-patient populations, the general characteristics were similar; rates increased with attained age, were eightfold lower for non-white patients, and were higher in more recent birth cohorts. After adjusting for these effects, risk in unirradiated patients did not vary significantly with age at HCT. The additional BCC risk associated with radiation exposure was largest for the youngest ages at exposure to radiation, with relative risks exceeding 20 for those transplanted at ages less than 10 years, and decreased with increasing age at exposure until age 40 years, above which no excess risk was identified. Relative risk in the irradiated population did not vary significantly with attained age, dose fractionation or race. Risks per unit dose in HCT patients were similar to other populations exposed under clinical settings to similar radiation doses and were more than 10-fold lower than seen in the atomic bomb survivors, 97% of whom were exposed to doses <1 Sv.

Allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission: systematic review and meta-analysis of prospective clinical trials.

CONTEXT: The optimal treatment of acute myeloid leukemia (AML) in first complete remission (CR1) is uncertain. Current consensus, based on cytogenetic risk, recommends myeloablative allogeneic stem cell transplantation (SCT) for poor-risk but not for good-risk AML. Allogeneic SCT, autologous transplantation, and consolidation chemotherapy are considered of equivalent benefit for intermediate-risk AML. OBJECTIVE: To quantify relapse-free survival (RFS) and overall survival benefit of allogeneic SCT for AML in CR1 overall and also for good-, intermediate-, and poor-risk AML. METHODS: Systematic review and meta-analysis of prospective trials evaluating allogeneic SCT vs nonallogeneic SCT therapies for AML in CR1. The search used the combined search terms allogeneic; acut* and leukem*/leukaem*/leucem*/leucaem*/aml; myelo* or nonlympho* in the PubMed, Embase, and Cochrane Registry of Controlled Trials databases in March 2009. The search identified 1712 articles. STUDY SELECTION: Prospective trials assigning adult patients with AML in CR1 to undergo allogeneic SCT vs nonallogeneic SCT treatment(s) based on donor availability and trials reporting RFS and/or overall survival outcomes on an intention-to-treat, donor vs no-donor basis were identified. DATA EXTRACTION: Two reviewers independently extracted study characteristics, interventions, and outcomes. Hazard ratios (HRs) with 95% confidence intervals (CIs) were determined. DATA SYNTHESIS: Overall, 24 trials and 6007 patients were analyzed (5951 patients in RFS analyses and 5606 patients in overall survival analyses); 3638 patients were analyzed by cytogenetic risk (547, 2499, and 592 with good-, intermediate-, and poor-risk AML, respectively). Interstudy heterogeneity was not significant. Fixed-effects meta-analysis was performed. Compared with nonallogeneic SCT, the HR of relapse or death with allogeneic SCT for AML in CR1 was 0.80 (95% CI, 0.74-0.86). Significant RFS benefit of allogeneic SCT was documented for poor-risk (HR, 0.69; 95% CI, 0.57-0.84) and intermediate-risk AML (HR, 0.76; 95% CI, 0.68-0.85) but not for good-risk AML (HR, 1.06; 95% CI, 0.80-1.42). The HR of death with allogeneic SCT for AML in CR1 was 0.90 (95% CI, 0.82-0.97). Significant overall survival benefit with allogeneic SCT was documented for poor-risk (HR, 0.73; 95% CI, 0.59-0.90) and intermediate-risk AML (HR, 0.83; 95% CI, 0.74-0.93) but not for good-risk AML (HR, 1.07; 95% CI, 0.83-1.38). CONCLUSION: Compared with nonallogeneic SCT therapies, allogeneic SCT has significant RFS and overall survival benefit for intermediate- and poor-risk AML but not for good-risk AML in first complete remission.

Thyrotropin levels in a population with no clinical, autoantibody, or ultrasonographic evidence of thyroid disease: implications for the diagnosis of subclinical hypothyroidism.

CONTEXT: The current debate regarding whether to decrease the upper limit for the TSH reference range to 2.5 microIU/ml has considerable potential impact on the diagnosis and treatment of subclinical hypothyroidism worldwide. OBJECTIVE: We report an analysis of TSH distribution in a population with no evidence of thyroid disease, including a normal thyroid ultrasound. DESIGN: A subset of the Hanford Thyroid Disease Study cohort was used to examine the TSH distribution in a population having no evidence of thyroid disease, seronegative thyroid autoantibodies, no history of thyroid medications, and a normal thyroid ultrasound. The shape of the TSH distribution was compared with the Gaussian and lognormal distributions. SETTING: This study was performed in the general community. PARTICIPANTS: Of 1861 Hanford Thyroid Disease Study participants with TSH measured by ELISA who also had thyroid peroxidase antibody measurements, 766 comprised the normal reference group 3 (NRG-3) with no evidence of thyroid disease, including no positive antibodies and normal thyroid ultrasound. MAIN OUTCOME MEASURE: TSH was measured. RESULTS: The TSH distribution in the NRG (NRG-3) was right skewed and followed an approximate lognormal distribution. The best estimates of the 97.5th percentile, the percentage above 2.5 microIU/ml, and the percentage above 3.0 microIU/ml for TSH by 3rd generation immunochemiluminometric assay are 4.1 microIU/ml, 20% and 10.2%, respectively. CONCLUSION: These results indicate that the TSH reference range should be narrowed and support a value of approximately 4.0 as the upper-reference limit.

Locating members of a cohort identified retrospectively from limited data in 50-year-old records: successful approaches employed by the Hanford Thyroid Disease Study.

PURPOSE: Long-term follow-up studies sometimes rely on retrospective identification of the cohort to be followed. Few such studies have been conducted, however, that rely on very old source records, perhaps because of concern that identification and location of a cohort based on very old records would not be feasible. METHODS: The Hanford Thyroid Disease Study (HTDS), conducted in the 1990s, identified 5199 cohort members using Washington state birth records from 1940-1946. The limited information contained therein was used to trace cohort members to the present day, nearly 50 years later. RESULTS: We found the best strategy to locate individuals efficiently is to use a combination of methods and resources in a phased approach, beginning with readily available and easy-to-use sources of information before employing more time-intensive strategies that are costly and rely on information that is difficult to obtain. Motor vehicle licensing records and directories were the most useful individual sources of information. Using this approach, the HTDS successfully located 94% of the 5199 cohort members identified. CONCLUSIONS: It is feasible to successfully trace and locate a very high proportion of individuals identified from very old records that contain little information.

ret/PTC activation is not associated with individual radiation dose estimates in a pilot study of neoplastic thyroid nodules arising in Russian children and adults exposed to Chernobyl fallout.

BACKGROUND: Ionizing radiation is the strongest risk factor known for the development of thyroid neoplasia. While previous studies have demonstrated a high prevalence of ret/papillary thyroid cancer (PTC) activation in cohorts of patients developing thyroid nodules after childhood exposure to ionizing radiation, no study has directly compared ret/PTC activation with individual estimates of radiation dose to the thyroid. This study combines individual thyroid dosimetry data with molecular analysis of surgically removed thyroid nodules in order to determine if ret/PTC activation in thyroid nodules is associated with increasing estimated radiation dose from Chernobyl. METHODS: This pilot study included adults and children diagnosed with PTC (n = 76) and children diagnosed with follicular adenomas (n = 24) during May 1986 through December 1999, who were living in the Bryansk Oblast of the Russian Federation at the time of the Chernobyl accident, who had paraffin-embedded thyroid surgical samples available and for whom an individual dose to the thyroid could be estimated. The frequency of ret/PTC activation was determined using RT-PCR analysis. Individual radiation doses to the thyroid were estimated using a semiempirical model, and data were collected by detailed interview, primarily of the participant's mother. RESULTS: ret/PTC oncogene activation was detected in 23.8% (5/21) and 14.5% (8/55) of the childhood and adult PTC cases, respectively, and 8.3% (2/24) of the follicular adenoma cases. No statistically significant differences were noted in age at the time of exposure or diagnosis, gender, latency period, or estimated radiation dose between PTC patients with or without ret/PTC activation. Further, no significant dose-response relationship was detected among PTC patients with ret/PTC activation. CONCLUSIONS: Factors other than individual thyroid radiation doses may influence the development and subsequent detection of ret/PTC oncogene activation in radiation related PTC arising in the Bryansk Oblast of the Russian Federation in the aftermath of the Chernobyl accident.

Impact of Specimen Heterogeneity on Biomarkers in Repository Samples from Patients with Acute Myeloid Leukemia: A SWOG Report.

INTRODUCTION: Current prognostic models for acute myeloid leukemia (AML) are inconsistent at predicting clinical outcomes for individual patients. Variability in the quality of specimens utilized for biomarker discovery and validation may contribute to this prognostic inconsistency. METHODS: We evaluated the impact of sample heterogeneity on prognostic biomarkers and methods to mitigate any adverse effects of this heterogeneity in 240 cryopreserved bone marrow and peripheral blood specimens from AML patients enrolled on SWOG (Southwest Oncology Group) trials. RESULTS: Cryopreserved samples displayed a broad range in viability (37% with viabilities ≤60%) and nonleukemic cell contamination (13% with lymphocyte percentages >20%). Specimen viability was impacted by transport time, AML immunophenotype, and, potentially, patients' age. The viability and cellular heterogeneity in unsorted samples significantly altered biomarker results. Enriching for viable AML blasts improved the RNA quality from specimens with poor viability and refined results for both DNA and RNA biomarkers. For example, FLT3-ITD allelic ratio, which is currently utilized to risk-stratify AML patients, was on average 1.49-fold higher in the viable AML blasts than in the unsorted specimens. CONCLUSION: To our knowledge, this is the first study to provide evidence that using cryopreserved specimens can introduce uncontrollable variables that may impact biomarker results and enrichment for viable AML blasts may mitigate this impact.

Joint nonparametric correction estimator for excess relative risk regression in survival analysis with exposure measurement error.

Observational epidemiological studies often confront the problem of estimating exposure-disease relationships when the exposure is not measured exactly. In the paper, we investigate exposure measurement error in excess relative risk regression, which is a widely used model in radiation exposure effect research. In the study cohort, a surrogate variable is available for the true unobserved exposure variable. The surrogate variable satisfies a generalized version of the classical additive measurement error model, but it may or may not have repeated measurements. In addition, an instrumental variable is available for individuals in a subset of the whole cohort. We develop a nonparametric correction (NPC) estimator using data from the subcohort, and further propose a joint nonparametric correction (JNPC) estimator using all observed data to adjust for exposure measurement error. An optimal linear combination estimator of JNPC and NPC is further developed. The proposed estimators are nonparametric, which are consistent without imposing a covariate or error distribution, and are robust to heteroscedastic errors. Finite sample performance is examined via a simulation study. We apply the developed methods to data from the Radiation Effects Research Foundation, in which chromosome aberration is used to adjust for the effects of radiation dose measurement error on the estimation of radiation dose responses.