A historical cohort study on glycemic-control and cancer-risk among patients with diabetes.

AIMS: This population-based historical cohort study examined whether poor glycemic-control (i.e., high glucose and HbA1c blood levels) in patients with diabetes is associated with cancer-risk. METHODS: From a large healthcare database, patients aged 21-89 years, diagnosed with diabetes before January 2002 (prevalent) or during 2002-2010 (incident), were followed for cancer during 2004-2012 (excluding cancers diagnosed within the first 2 years since diabetes diagnosis). Risks of selected cancers (all-sites, colon, breast, lung, prostate, pancreas and liver) were estimated according to glycemic-control in a Cox regression model with time-dependent covariates, adjusted for age, sex, ethnic origin, socioeconomic status, smoking and parity. Missing glucose or HbA1c values were imputed. RESULTS: Among 440,000 patients included in our analysis, cancer was detected more than 2 years after diabetes diagnosis in 26,887 patients (6%) during the follow-up period. Associations of poor glycemic-control with all-sites cancer and most specific cancers were either null or only weak (hazard ratios (HRs) for a 1% HbA1c or a 30 mg/dl glucose increase between 0.94 and 1.09). Exceptions were pancreatic cancer, for which there was a strong positive association (HRs: 1.26-1.51), and prostate cancer, for which there was a moderate negative association (HRs: 0.85-0.96). CONCLUSION: Overall, poor glycemic-control appears to be only weakly associated with cancer-risk, if at all. A substantial part of the positive association with pancreatic cancer is attributable to reverse causation, with the cancer causing poorer glycemic-control prior to its diagnosis. The negative association with prostate cancer may be related to lower PSA levels in those with poor control.

Checking for completeness of 24-h urine collection using para-amino benzoic acid not necessary in the Observing Protein and Energy Nutrition study.

BACKGROUND/OBJECTIVES: The orally administered para-amino benzoic acid (PABA) is known to have near 100% excretion in urine and is used as a measure of 24-h urine collection completeness (referred to as PABAcheck). The purpose was to examine the effect of including urine collections deemed incomplete based on PABAcheck in a dietary measurement error study. SUBJECTS/METHODS: The Observing Protein and Energy Nutrition (OPEN) study was conducted in 1999-2000 and included 484 men and women aged 40-69 years. A food frequency questionnaire and 24-h dietary recalls were evaluated using recovery biomarkers that included urinary nitrogen and potassium from two 24-h urine collections. Statistical modeling determined the measurement error properties of dietary assessment instruments. In the original analyses, PABAcheck was used as a measure of complete urine collection; incomplete collections were either excluded or adjusted to acceptable levels. The OPEN data were reanalyzed including all urine collections and by using criteria based on self-reported missing voids to assess the differences. RESULTS: Means and coefficients of variation for biomarker-based protein and potassium intakes, and measurement error model-based correlations and attenuation factors were similar regardless of whether PABAcheck or missed voids were considered. CONCLUSION: PABAcheck may not be required in large population-based biomarker studies. However, until there are more analyses evaluating the necessity of a PABAcheck, it is recommended that PABA be given to all participants, but not necessarily analyzed. Then, PABAcheck could be used selectively as a marker of completeness among the collections in which low levels of biomarker are detected or for which noncompliance is suspected.

Traumeel S in preventing and treating mucositis in young patients undergoing SCT: a report of the Children's Oncology Group.

Mucositis can be a serious complication of hematopoietic SCT (HSCT). A previous phase II trial in 32 children undergoing HSCT reported a beneficial effect of the homeopathic remedy Traumeel S. The Children's Oncology Group sought to replicate the results in a multi-institutional trial. The study was an international multi-center, double-blind, randomized trial comparing Traumeel with placebo in patients aged 3-25 years undergoing myeloablative HSCT. Traumeel/placebo was started on Day -1 as a five-time daily mouth rinse. Efficacy of the treatment was assessed using the modified Walsh scale for mucositis, scored daily from Day -1 to 20 days after HCST. The main outcome was the sum of Walsh scale scores (area-under-the-curve (AUC)) over this period. Other outcomes included narcotic use, days of total parenteral feeding, days of nasogastric feeding and adverse events. In 181 evaluable patients, there was no statistical difference in mucositis (AUC) in the Traumeel group (76.7) compared with placebo (67.3) (P=0.13). There was a trend towards less narcotic usage in the Traumeel patients. No statistically beneficial effect from Traumeel was demonstrated for mucositis. We could not confirm that Traumeel is an effective treatment for mucositis in children undergoing HSCT.

Factors affecting mortality following myeloablative cord blood transplantation in adults: a pooled analysis of three international registries.

A retrospective analysis was conducted to examine factors affecting early mortality after myeloablative, single-unit cord blood transplantation (CBT) for hematological malignancies in adolescents and adults. Data were collected from the three main CBT registries pooling 514 records of unrelated, single, unmanipulated, first myeloablative allogeneic CBTs conducted in North America or Europe from 1995 to 2005, with an HLA match ≥ 4/6 loci, in patients aged 12-55. Overall 100-day, 180-day and 1-year survival (Kaplan-Meier method) were 56, 46 and 37%, respectively, with no significant heterogeneity across registries. Multivariate analysis showed cell dose < 2.5 × 107/kg (odds ratio (OR) 2.76, P < 0.0001), older age (P = 0.002), advanced disease (P = 0.02), positive CMV sero-status (OR 1.37 P = 0.11), female gender (OR 1.43, P = 0.07) and limited CBT center experience (< 10 records contributed, OR 2.08, P = 0.0003) to be associated with higher 100-day mortality. A multivariate model predictive of 1-year mortality included similar prognostic factors except female gender. Transplant year did not appear as a significant independent predictor. This is the first analysis to pool records from three major CBT registries in the United States and Europe. In spite of some differences in practice patterns, survival was remarkably homogeneous. The resulting model may contribute to better understanding factors affecting CBT outcomes.

Prediction of nonSVR to therapy with pegylated interferon-alpha2a and ribavirin in chronic hepatitis C genotype 1 patients after 4, 8 and 12 weeks of treatment.

In patients with chronic hepatitis C genotype 1, the current algorithm for treatment discontinuation is based on no early virological response (<2 log decline in hepatitis C virus (HCV)-RNA) at 12 weeks. It is important to determine whether prediction of nonsustained virological response (NR) before 12 weeks can be robustly obtained by statistical methods. We used longitudinal discriminant analysis (LDA) to build and cross-validate models including baseline patient characteristics and measurements of serum HCV-RNA in the first 4, 8 or 12 weeks of treatment. The performance of each model was evaluated by the partial AUC (PA) index, exploring the accuracy of prediction in the range of high negative predictive values. Models were compared by computing 95% confidence intervals for the difference in PA indices. NR was best predicted before week 12 by a single HCV-RNA measurement at week 8 taken together with gender, BMI and age (W8 model, PA index = 0.857). This model was not inferior to models that included a measurement at week 12 (PA index = 0.831). The best model obtained with LDA within the first 4 weeks, which included measurements at days 4, 8 and at week 4, was found to be inferior to the week 8 model (PA index = 0.796). These results indicate that lack of sustained viral response is best predicted after 8 weeks of treatment and that waiting until 12 weeks does not improve the prediction.

Functional variant of KLOTHO: a breast cancer risk modifier among BRCA1 mutation carriers of Ashkenazi origin.

Klotho is a transmembrane protein that can be shed and act as a circulating hormone and is a putative tumor suppressor in breast cancer. A functional variant of KLOTHO (KL-VS) contains two amino acid substitutions F352V and C370S and shows reduced activity. Germ-line mutations in BRCA1 and BRCA2 substantially increase lifetime risk of breast and ovarian cancers. Yet, penetrance of deleterious BRCA1 and BRCA2 mutations is incomplete even among carriers of identical mutations. We examined the association between KL-VS and cancer risk among 1115 Ashkenazi Jewish women: 236 non-carriers, 631 BRCA1 (185delAG, 5382insC) carriers and 248 BRCA2 (6174delT) carriers. Among BRCA1 carriers, heterozygosity for the KL-VS allele was associated with increased breast and ovarian cancer risk (hazard ratio 1.40, 95% confidence intervals 1.08-1.83, P=0.01) and younger age at breast cancer diagnosis (median age 48 vs 43 P=0.04). KLOTHO and BRCA2 are located on 13q12, and we identified linkage disequilibrium between KL-VS and BRCA2 6174delT mutation. Studies in breast cancer cells showed reduced growth inhibitory activity and reduced secretion of klotho F352V compared with wild-type klotho. These data suggest KL-VS as a breast and ovarian cancer risk modifier among BRCA1 mutation carriers. If validated in additional cohorts, the presence of KL-VS may serve as a predictor of cancer risk among BRCA1 mutation carriers.

A modified approach to estimating sample size for simple logistic regression with one continuous covariate.

Different methods for the calculation of sample size for simple logistic regression (LR) with one normally distributed continuous covariate give different results. Sometimes the difference can be large. Furthermore, some methods require the user to specify the prevalence of cases when the covariate equals its population mean, rather than the more natural population prevalence. We focus on two commonly used methods and show through simulations that the power for a given sample size may differ substantially from the nominal value for one method, especially when the covariate effect is large, while the other method performs poorly if the user provides the population prevalence instead of the required parameter. We propose a modification of the method of Hsieh et al. that requires specification of the population prevalence and that employs Schouten's sample size formula for a t-test with unequal variances and group sizes. This approach appears to increase the accuracy of the sample size estimates for LR with one continuous covariate.

A statistical comparison of different family history scores.

Family history (FH) scores are used for estimating the familial risk (FR), i.e. the level of risk for a particular disease among members of that family. An FH score is created from reports about the disease status of the relatives in each family. The most commonly used score is the dichotomous score (positive when at least one relative is affected), which does not consider the family size, number of affected relatives nor each relative's risk factor profile. Authors have proposed many other FH scores that overcome these deficiencies by using external expected risks adjusted for important risk factors. We consider the use of FH scores in studies, which investigate risk factors for a disease and where family risk is considered as a confounder, and examine through simulations the performance of a variety of FH scores in controlling the FR status. We also examine performance in predicting true FR status. For both criteria, only small differences were found between most of the FH scores, although the dichotomous score performed the poorest. Since the proportion score (the proportion of first-degree relatives of the index who have the disease) is the simplest to calculate, use of this score seems to be justified.

A comparison of population-based cancer incidence rates in Israel and Jordan.

Reliable information about comparative cancer incidence in the Middle East has been lacking. The Middle East Cancer Consortium (MECC) has formed a network of population-based registries with standardized basic data. Here the age-adjusted cancer incidences are compared for four populations: Israeli Jews, Israeli non-Jews, Jordanians and the US Surveillance Epidemiology and End Results (SEER) population, for the years 1996-1997 (Israel) and 1996-1998 (other populations). The all-sites rate of cancer is approximately twice as high in Israeli Jews and SEER, compared with Israeli non-Jews and Jordanians. Rates of lung cancer are similar among Israeli Jews and non-Jews and about twice as high as in Jordanians. Childhood leukaemia rates in Jordan are higher than in Israeli Jews, but lower than SEER. Hodgkin lymphoma rates in Israeli non-Jews and Jordanians are similar to SEER, but non-Hodgkin lymphoma rates are lower than SEER. The previous suspicion of higher overall leukaemia and lymphoma rates in Jordan is thus not confirmed.

Body mass index at age 18 years and during adult life and ovarian cancer risk.

During the years 1994-1999, a nationwide ovarian cancer case-control study was conducted in Israel. The present analysis addresses the question: Is epithelial ovarian cancer associated with body mass index at age 18 years and/or with weight changes in body mass index between adolescence and adult life? The study is based on 1,269 women with epithelial ovarian cancer and 2,111 matched controls. A significant decrease in risk of ovarian cancer was observed with parity, oral contraceptive use, and postmenopausal status. A significant increase in risk with family history of ovarian/breast cancer was also found. No significant association with age at menarche or infertility was found. For body mass index at age 18 years, the odds ratio of the highest versus lowest body mass index quartile was 1.42 (95% confidence interval: 1.08, 1.85) and after adjusting for confounders was 1.54 (95% confidence interval: 1.17, 2.02). However, no statistically significant risk associated with change in weight from age 18 years to adult life was found. The authors conclude that, in their population, body mass index at age 18 years is an independent risk factor for ovarian cancer.

Design and serendipity in establishing a large cohort with wide dietary intake distributions : the National Institutes of Health-American Association of Retired Persons Diet and Health Study.

In 1995-1996, the authors mailed a food frequency questionnaire to 3.5 million American Association of Retired Persons members who were aged 50-69 years and who resided in one of six states or two metropolitan areas with high-quality cancer registries. In establishing a cohort of 567,169 persons (340,148 men and 227,021 women), the authors were fortunate in that a less-than-anticipated baseline response rate (threatening inadequate numbers of respondents in the intake extremes) was offset by both a shifting and a widening of the intake distributions among those who provided satisfactory data. Reported median intakes for the first and fifth intake quintiles, respectively, were 20.4 and 40.1 (men) and 20.1 and 40.0 (women) percent calories from fat, 10.3 and 32.0 (men) and 8.7 and 28.7 (women) g per day of dietary fiber, 3.1 and 11.6 (men) and 2.8 and 11.3 (women) servings per day of fruits and vegetables, and 20.7 and 156.8 (men) and 10.5 and 97.0 (women) g per day of red meat. After 5 years of follow-up, the cohort is expected to yield nearly 4,000 breast cancers, more than 10,000 prostate cancers, more than 4,000 colorectal cancers, and more than 900 pancreatic cancers. The large size and wide intake range of the cohort will provide ample power for examining a number of important diet and cancer hypotheses.

A randomized, controlled clinical trial of the homeopathic medication TRAUMEEL S in the treatment of chemotherapy-induced stomatitis in children undergoing stem cell transplantation.

BACKGROUND: Stomatitis is a common consequence of chemotherapy and a condition for which there is little effective treatment. Although the management of patients with other chemotherapy-related toxicities has improved in recent years, the incidence of stomatitis is increasing because of more intensive treatment and is often a dose limiting factor in chemotherapy. The authors assessed the efficacy of a homeopathic remedy, TRAUMEEL S(R), in the management of chemotherapy-induced stomatitis in children undergoing bone marrow transplantation. METHODS: A randomized, placebo-controlled, double-blind clinical trial was conducted in 32 patients ages 3-25 years who had undergone allogeneic (16 patients) or autologous (16 patients) stem cell transplantation. Of the 30 evaluable patients, 15 were assigned placebo, and 15 were assigned TRAUMEEL S both as a mouth rinse, administered five times daily from 2 days after transplantation for a minimum of 14 days, or until at least 2 days after all signs of stomatitis were absent. Stomatitis scores were evaluated according to the World Health Organization grading system for mucositis. RESULTS: A total of five patients (33%) in the TRAUMEEL S treatment group did not develop stomatitis compared with only one patient (7%) in the placebo group. Stomatitis worsened in only 7 patients (47%) in the TRAUMEEL S treatment group compared with 14 patients (93%) in the placebo group. The mean area under the curve stomatitis scores were 10.4 in the TRAUMEEL S treatment group and 24.3 in the placebo group. This difference was statistically significant (P < 0.01). CONCLUSIONS: This study indicates that TRAUMEEL S may reduce significantly the severity and duration of chemotherapy-induced stomatitis in children undergoing bone marrow transplantation.

Bayesian monitoring of a phase 2 chemoprevention trial in high-risk cohorts for prostate cancer.

The objective of phase 2 cancer chemoprevention trials is to evaluate whether a chemopreventive agent will cause significant modulation of intermediate endpoint biomarkers (IEB) in patients at high risk for the disease. A phase 2 chemoprevention trial of 4-hydroxyphenyl retinamide (4-HPR) versus placebo was conducted in men with a histologic diagnosis of early prostate cancer and scheduled to have radical prostatectomy. A Bayesian monitoring method was used to sequentially monitor this trial for evidence of biological activity or ineffectiveness based on a single IEB variable. Different prior distributions were used and posterior distributions were obtained to calculate the probability that treatment differences are greater than or less than a predetermined clinically significant effect. The interim analysis of transforming growth factor-alpha expression indicated a high probability of insufficient biological activity of 4-HPR on this IEB. This study demonstrates the potential utility of Bayesian methods in the decision-making process in the conduct of phase 2 chemoprevention trials.

Covariate measurement error adjustment for matched case-control studies.

We propose a conditional scores procedure for obtaining bias-corrected estimates of log odds ratios from matched case-control data in which one or more covariates are subject to measurement error. The approach involves conditioning on sufficient statistics for the unobservable true covariates that are treated as fixed unknown parameters. For the case of Gaussian nondifferential measurement error, we derive a set of unbiased score equations that can then be solved to estimate the log odds ratio parameters of interest. The procedure successfully removes the bias in naive estimates, and standard error estimates are obtained by resampling methods. We present an example of the procedure applied to data from a matched case-control study of prostate cancer and serum hormone levels, and we compare its performance to that of regression calibration procedures.

Empirical evidence of correlated biases in dietary assessment instruments and its implications.

Multiple-day food records or 24-hour recalls are currently used as "reference" instruments to calibrate food frequency questionnaires (FFQs) and to adjust findings from nutritional epidemiologic studies for measurement error. The common adjustment is based on the critical requirements that errors in the reference instrument be independent of those in the FFQ and of true intake. When data on urinary nitrogen level, a valid reference biomarker for nitrogen intake, are used, evidence suggests that a dietary report reference instrument does not meet these requirements. In this paper, the authors introduce a new model that includes, for both the FFQ and the dietary report reference instrument, group-specific biases related to true intake and correlated person-specific biases. Data were obtained from a dietary assessment validation study carried out among 160 women at the Dunn Clinical Nutrition Center, Cambridge, United Kingdom, in 1988-1990. Using the biomarker measurements and dietary report measurements from this study, the authors compare the new model with alternative measurement error models proposed in the literature and demonstrate that it provides the best fit to the data. The new model suggests that, for these data, measurement error in the FFQ could lead to a 51% greater attenuation of true nutrient effect and the need for a 2.3 times larger study than would be estimated by the standard approach. The implications of the results for the ability of FFQ-based epidemiologic studies to detect important diet-disease associations are discussed.

Cancer registration in the Middle East.

This project signals an advance in cancer registration in the Middle East region. While it is too early to declare a major breakthrough, significant strides have been made toward establishing a basis for reliable information on the cancer burden at a population level and future collaborative efforts in cancer epidemiologic research and prevention.

Seroprevalence of Kaposi's sarcoma-associated herpesvirus in healthy adults in Israel.

To determine if Kaposi's sarcoma-associated herpesvirus (KSHV) prevalence is correlated with the 9-fold difference in the incidence of classic Kaposi's sarcoma observed among Israeli Jewish populations, we conducted a cross-sectional KSHV seroprevalence survey in a population of 166 HIV-seronegative healthy subjects from the general population (26 women, 140 men). Eight individuals (4.8%) (all men) were seropositive for KSHV; differences between men and women were not statistically significant. If we consider the sensitivity and specificity of the assays, the corrected prevalence would be 6.1% (95% confidence interval 2.0-10.1). We noticed a non-statistically 5.5-fold difference between individuals above and below 40 years of age, but did not find an association with the incidence of classic KS among the Israeli Jewish sub-population, according to their origin. This suggests that KSHV is only necessary, albeit not sufficient, cause of classic Kaposi's sarcoma.