Objective: Published screening mammography performance measures vary across countries. An international study was undertaken to assess the comparability of two performance measures: the recall rate and positive predictive value (PPV). These measures were selected because they do not require identification of all cancers in the screening population, which is not always possible. Setting:The screening mammography programs or data registries in 25 member countries of the International Breast Cancer Screening Network (IBSN). Methods:In 1999 an assessment form was distributed to IBSN country representatives in order to obtain information on how screening mammography was performed and what specific data related to recall rates and PPV were collected. Participating countries were then asked to provide data to allow calculation of recall rates, PPV and cancer detection rates for screening mammography by age group for women screened in the period 1997-1999.Results: Twenty-two countries completed the assessment form and 14 countries provided performance data. Differences in screening mammography delivery and data collection were evident. For most countries, recall rates were higher for initial than for subsequent mammograms. There was no consistent relationship of initial to subsequent PPV, although PPV generally decreased as the recall rate increased. Recall rates decreased with increasing age, while PPV increased as age increased. Conclusion:Similar patterns for mammography performance measures were evident across countries.However, the development of a more standardized approach to defining and collecting data would allow more valid international comparisons, with the potential to optimize mammography performance. At present, international comparisons of performance should be made with caution due to differences in defining and collecting mammography data.

Purpose: Despite incidence rates that have been rising for decades, the molecular underpinnings that support the development of clear cell renal cell carcinoma (ccRCC) remain unclear. Herein, we evaluate expression levels of the hypoxia-induced autocrine survival factor endothelin-2 (EDN2) in patient-matched ccRCC and normal kidney samples.Methods: We identified 169 patients who underwent nephrectomy for histologically confirmed, localized ccRCC at our institution from 2000 to 2003 and had fresh-frozen tumor and normal kidney samples available. After mRNA was extracted from microdissected tissue, we conducted real time PCR to determine expression levels of EDN2. We normalized the expression data using four control genes and then fit linear mixed models to evaluate differential expression between tumor and normal samples. In addition, we explored potential interactions with relevant clinicopathologic characteristics including tumor stage and grade.Results: Of the 161 patients analyzed, 65% were male, 58% were stage pT1, and 43% were nuclear grade 1 or 2. Overall, EDN2 expression was higher in tumor samples compared to paired normal samples with an average fold change (FC) of 2.0 (P-value < 0.0001). This overexpression in tumor versus normal tissue was apparent in early stage (pT1) tumors but not later stage (pT2, pT3) tumors (FC of 2.9 v. 1.1 respectively; interaction P-value = 0.001). Similarly, over-expression was more pronounced in low grade (1, 2) tumors compared to high grade (3, 4) tumors (FC of 3.5 v. 1.3 respectively; interaction P-value = 0.0002).Conclusions: While independent validation is required, our patient-based data suggest that up-regulation of EDN2 is a common and early event in localized ccRCC. If confirmed in future studies, EDN2 could represent a target for the development of novel chemopreventive or neo-adjuvant therapeutics for ccRCC. Circulating 25-Hydroxyvitamin-D and Risk of Colorectal Adenomas and Hyperplastic PolypsAdams S, Newcomb P, Burnett-Hartman A, Mandelson M, Potter J Background: Colorectal adenomas are clear precursors of cancer; hyperplastic polyps have recently been hypothesized to also have malignant potential. However, these two distinct colorectal lesions are probably on different molecular pathways to neoplasia. An inverse association between vitamin D and adenoma risk has been reported, but this is the first study, to our knowledge, that examines circulating 25(OH)D in relation to risk of hyperplastic polyps.Methods: We conducted a colonoscopy-based casecontrol study of adenomas and hyperplastic polyps among 474 members of a large integrated health plan. Self-administered questionnaires provided data on demographics and colorectal polyp risk factors, and we as- Conclusions: There is no evidence in our study that the established inverse association between circulating 25(OH)D and colorectal adenoma applies to hyperplastic polyps.