Longitudinal assessment of air conduction audiograms in a phase III clinical trial of difluoromethylornithine and sulindac for prevention of sporadic colorectal adenomas.

A phase III clinical trial assessed the recurrence of adenomatous polyps after treatment for 36 months with difluoromethylornithine (DFMO) plus sulindac or matched placebos. Temporary hearing loss is a known toxicity of treatment with DFMO, thus a comprehensive approach was developed to analyze serial air conduction audiograms. The generalized estimating equation method estimated the mean difference between treatment arms with regard to change in air conduction pure tone thresholds while accounting for within-subject correlation due to repeated measurements at frequencies. Based on 290 subjects, there was an average difference of 0.50 dB between subjects treated with DFMO plus sulindac compared with those treated with placebo (95% confidence interval, -0.64 to 1.63 dB; P = 0.39), adjusted for baseline values, age, and frequencies. In the normal speech range of 500 to 3,000 Hz, an estimated difference of 0.99 dB (-0.17 to 2.14 dB; P = 0.09) was detected. Dose intensity did not add information to models. There were 14 of 151 (9.3%) in the DFMO plus sulindac group and 4 of 139 (2.9%) in the placebo group who experienced at least 15 dB hearing reduction from baseline in 2 or more consecutive frequencies across the entire range tested (P = 0.02). Follow-up air conduction done at least 6 months after end of treatment showed an adjusted mean difference in hearing thresholds of 1.08 dB (-0.81 to 2.96 dB; P = 0.26) between treatment arms. There was no significant difference in the proportion of subjects in the DFMO plus sulindac group who experienced clinically significant hearing loss compared with the placebo group. The estimated attributable risk of ototoxicity from exposure to the drug is 8.4% (95% confidence interval, -2.0% to 18.8%; P = 0.12). There is a <2 dB difference in mean threshold for patients treated with DFMO plus sulindac compared with those treated with placebo.

Genetic screening for iron overload: No evidence of discrimination at 1 year.

PURPOSE: This study measured the extent of insurance and employment problems associated with population screening for hereditary hemochromatosis and iron overload. METHODS: 101,168 primary care patients from the US and Canada were screened for iron phenotypes and HFE genotypes associated with hemochromatosis. Those identified to be at risk (2253) were offered a clinical examination, which 1677 (74%) accepted, and the 1154 of these who responded to an initial questionnaire about psychosocial issues were surveyed 1 year later about whether they had experienced problems with insurance or employment that they attributed to hereditary hemochromatosis and iron overload. RESULTS: 832 (72.1%) of the 1154 participants surveyed after 1 year responded to the second survey. Three (0.4%) had verified problems with insurance or employment that they believed were related to hereditary hemochromatosis and iron overload. Two had problems with life insurance, and one with long-term care insurance. All 3 had elevated iron levels but not a relevant HFE genotype. One of the life insurance problems was resolved; the second one was not serious. The participant who was denied long-term care insurance had other health conditions unrelated to hereditary hemochromatosis and iron overload that could have contributed to the denial. No problems were verified for health insurance or employment, or from any of the comparison group participants (controls and those with inconclusive screening results). CONCLUSIONS: The risk of insurance or employment problems 1 year after phenotype and genotype screening for hereditary hemochromatosis and iron overload is very low.

Correlation of dynamic contrast enhancement MRI parameters with microvessel density and VEGF for assessment of angiogenesis in breast cancer.

PURPOSE: To investigate the association between parameters obtained from dynamic contrast enhanced MRI (DCE-MRI) of breast cancer using different analysis approaches, as well as their correlation with angiogenesis biomarkers (vascular endothelial growth factor and vessel density). MATERIALS AND METHODS: DCE-MRI results were obtained from 105 patients with breast cancer (108 lesions). Three analysis methods were applied: 1) whole tumor analysis, 2) regional hot-spot analysis, and 3) intratumor pixel-by-pixel analysis. Early enhancement intensities and fitted pharmacokinetic parameters were studied. Paraffin blocks of 71 surgically resected specimens were analyzed by immunohistochemical staining to measure microvessel counts (with CD31) and vascular endothelial growth factor (VEGF) expression levels. RESULTS: MRI parameters obtained from the three analysis methods showed significant correlations (P < 0.0001), but a substantial dispersion from the linear regression line was noted (r = 0.72-0.97). The entire region of interest (ROI) vs. pixel population analyses had a significantly higher association compared to the entire ROI vs. hot-spot analyses. Cancer specimens with high VEGF expression had significantly higher CD31 microvessel densities than did specimens with low VEGF levels (P < 0.005). No significant association was found between MRI parameters obtained from the three analysis strategies and IHC based measurements of angiogenesis. CONCLUSION: A consistent analysis strategy was important in the DCE-MRI study. In this series, none of these strategies yielded results for MRI based quantitation of tumor vascularity that were associated with IHC based measurements. Therefore, different analyses could not account for the lack of association.