Burden and Morbidity of Breast Screening and Diagnostic Work Up: Results from a Community Based Approach

The work in this thesis focused on addressing the limitations of breast screening and diagnostic work up using a cohort of women from a single large healthcare organization. For all three studies that were conducted, a probabilistic linkage between the examinations dataset (included all screening and diagnostic procedures) and the Illinois State Cancer Registry (included all incident breast cancer cases between 2001 and 2011) was performed to define the outcomes of interest. The first study was designed to compare the false positive rate (FPR), false positive burden (work-up rate including additional mammography, ultrasound or Magnetic resonance imaging (MRI) imaging) and false positive morbidity (risk of receipt of a biopsy) between full field digital mammography (FFDM) and screen-film mammography (SFM). Compared to SFM, FFDM had slightly lower FPR (12.8% vs 12.3%, P=0.02), lower FP burden (225 per 1000 FFDM screens vs 233 per 1000 SFM screens, P=0.001) but slightly higher risk of receipt of biopsy (1.24% vs 1.04%, P=0.05). The second study examined whether the experience of a FP mammogram delays the return to the subsequent round of screening. The results suggest that there was a compelling evidence that the women who received a true negative mammogram had significantly higher chance of returning to their next screening mammogram compared to women with a FP mammogram HR=1.35 (95% CI: 1.34-1.36). The third study estimated the risk of a false negative (FN) finding, defined as the percentage of cancers with a benign biopsy finding, and risk of complete false negative rate, defined as the percentage of cancers with a benign or high risk benign biopsy finding, for core-needle biopsy (CNB), vacuum-assisted ultrasound CNB and non-vacuum assisted ultrasound CNB. In this study, the FN rates for image-guided CNBs were 5.4% for stereotactic-guided, 4.8% for vacuum-assisted ultrasound-guided and 3.8% for non-vacuum-assisted ultrasound-guided biopsies. The complete FN rate was 11.3% for stereotactic-guided, 7% for vacuum-assisted ultrasound-guided and 5.1% for non-vacuum-assisted ultrasound-guided biopsies. Additionally, this study found an increased FN rate and complete FN rate in minority women, younger women and women with denser breasts

Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR (12.5mg/day) 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07 (hi vs lo) 95% CI: 0.98-1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.National Institutes of Health [5U54CA91431-01]; Egyptian Ministry of Higher Education [GM842]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Validation of the breast cancer surveillance consortium model of breast cancer risk.

PurposeIn order to use a breast cancer prediction model in clinical practice to guide screening and prevention, it must be well calibrated and validated in samples independent from the one used for development. We assessed the accuracy of the breast cancer surveillance consortium (BCSC) model in a racially diverse population followed for up to 10 years.MethodsThe BCSC model combines breast density with other risk factors to estimate a woman's 5- and 10-year risk of invasive breast cancer. We validated the model in an independent cohort of 252,997 women in the Chicago area. We evaluated calibration using the ratio of expected to observed (E/O) invasive breast cancers in the cohort and discrimination using the area under the receiver operating characteristic curve (AUROC).ResultsIn an independent cohort of 252,997 women (median age 50 years, 26% non-Hispanic Black), the BCSC model was well calibrated (E/O = 0.94, 95% confidence interval [CI] 0.90-0.98), but underestimated the incidence of invasive breast cancer in younger women and in women with low mammographic density. The AUROC was 0.633, similar to that observed in prior validation studies.ConclusionsThe BCSC model is a well-validated risk assessment tool for breast cancer that may be particularly useful when assessing the utility of supplemental screening in women with dense breasts

Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

<div><p>Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR _{<6.5 vs 6.5–12.5mg/day} 1.8, 95% CI: 0.6,5.6; OR _{<6.5 vs >12.5mg/day} 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07_{hi vs lo} 95% CI: 0.98–1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.</p></div

Flow diagram of systematic literature search on zinc and the risk of prostate cancer.

<p>Flow diagram of systematic literature search on zinc and the risk of prostate cancer.</p

Characteristics of papers included in the meta-analysis.

<p>Characteristics of papers included in the meta-analysis.</p

Dose-response relations between zinc intake and RR of prostate cancer (P for nonlinearity = 0.0022).

<p>The fitted nonlinear trend is represented by the solid line with the 95% confidence intervals line in long dashes. Lines with short dashes represent the linear trend.</p

Demographic and health-related characteristics of the Washington D.C. prostate cancer study by outcome.

<p>Demographic and health-related characteristics of the Washington D.C. prostate cancer study by outcome.</p