Interlaboratory performance of a microarray-based gene expression test to determine tissue of origin in poorly differentiated and undifferentiated cancers.

Clinical workup of metastatic malignancies of unknown origin is often arduous and expensive and is reported to be unsuccessful in 30 to 60% of cases. Accurate classification of uncertain primary cancers may improve with microarray-based gene expression testing. We evaluated the analytical performance characteristics of the Pathwork tissue of origin test, which uses expression signals from 1668 probe sets in a gene expression microarray, to quantify the similarity of tumor specimens to 15 known tissues of origin. Sixty archived tissue specimens from poorly and undifferentiated tumors (metastatic and primary) were analyzed at four laboratories representing a wide range of preanalytical conditions (eg, personnel, reagents, instrumentation, and protocols). Cross-laboratory comparisons showed highly reproducible results between laboratories, with correlation coefficients between 0.95 to 0.97 for measurements of similarity scores, and an average 93.8% overall concordance between laboratories in terms of final tissue calls. Bland-Altman plots (mean coefficients of reproducibility of 32.48+/-3.97) and kappa statistics (kappa >0.86) also indicated a high level of agreement between laboratories. We conclude that the Pathwork tissue of origin test is a robust assay that produces consistent results in diverse laboratory conditions reflecting the preanalytical variations found in the everyday clinical practice of molecular diagnostics laboratories.

Federally-Assisted Healthcare Coverage among Male State Prisoners with Chronic Health Problems.

Prisoners have higher rates of chronic diseases such as substance dependence, mental health conditions and infectious disease, as compared to the general population. We projected the number of male state prisoners with a chronic health condition who at release would be eligible or ineligible for healthcare coverage under the Affordable Care Act (ACA). We used ACA income guidelines in conjunction with reported pre-arrest social security benefits and income from a nationally representative sample of prisoners to estimate the number eligible for healthcare coverage at release. There were 643,290 US male prisoners aged 18-64 with a chronic health condition. At release, 73% in Medicaid-expansion states would qualify for Medicaid or tax credits. In non-expansion states, 54% would qualify for tax credits, but 22% (n = 69,827) had incomes of ≤ 100% the federal poverty limit and thus would be ineligible for ACA-mediated healthcare coverage. These prisoners comprise 11% of all male prisoners with a chronic condition. The ACA was projected to provide coverage to most male state prisoners with a chronic health condition; however, roughly 70,000 fall in the "coverage gap" and may require non-routine care at emergency departments. Mechanisms are needed to secure coverage for this at risk group and address barriers to routine utilization of health services.