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Sholom Wacholder

Publications and source records attributed to Sholom Wacholder.

At least 19 recordsLinked to original sources
PubMed2006

Human papillomavirus prevalence in women who have and have not undergone hysterectomies.

We compared human papillomavirus (HPV) prevalence in an age-stratified random sample of women who have undergone a hysterectomy (WH) (n=573) with the HPV prevalence in age-matched women with intact cervices (women who have not undergone a hysterectomy [WNH]) (n=581) participating in a study at Kaiser Permanente in Portland, Oregon. Testing cervicovaginal lavage fluids for >40 HPV genotypes using an MY09/11 L1 consensus primer polymerase chain reaction method, we found no statistical differences in the prevalence of HPV (16% for WNH vs. 13.9% for WH) or carcinogenic HPV (6.5% for WNH vs. 4.5% for WH) between the 2 groups of women. Although WH have a similar prevalence of carcinogenic HPV infection, compared with WNH without a cervix, they have minimal risk of HPV-induced cancer and are unlikely to benefit from HPV testing.

Adult↗
PubMed2006

Powerful multilocus tests of genetic association in the presence of gene-gene and gene-environment interactions.

In modern genetic epidemiology studies, the association between the disease and a genomic region, such as a candidate gene, is often investigated using multiple SNPs. We propose a multilocus test of genetic association that can account for genetic effects that might be modified by variants in other genes or by environmental factors. We consider use of the venerable and parsimonious Tukey's 1-degree-of-freedom model of interaction, which is natural when individual SNPs within a gene are associated with disease through a common biological mechanism; in contrast, many standard regression models are designed as if each SNP has unique functional significance. On the basis of Tukey's model, we propose a novel but computationally simple generalized test of association that can simultaneously capture both the main effects of the variants within a genomic region and their interactions with the variants in another region or with an environmental exposure. We compared performance of our method with that of two standard tests of association, one ignoring gene-gene/gene-environment interactions and the other based on a saturated model of interactions. We demonstrate major power advantages of our method both in analysis of data from a case-control study of the association between colorectal adenoma and DNA variants in the NAT2 genomic region, which are well known to be related to a common biological phenotype, and under different models of gene-gene interactions with use of simulated data.

Acetylation↗
PubMed2006

Relationships of human papillomavirus type, qualitative viral load, and age with cytologic abnormality.

Persistent cervical infections with carcinogenic human papillomaviruses (HPV) cause virtually all cervical cancer. Cytologic abnormalities are the manifestations of HPV infections used to identify women at risk. To compare the potential of the full range of anogenital HPV genotypes to induce cytopathic effects, we examined the influences of HPV type, viral load, and age on cytopathology among 1,222 women having a single HPV type at enrollment into a 10,000-woman population-based study in Costa Rica. Cervical specimens were tested for approximately 40 HPV types by MY09/MY11 L1 primer PCR and type-specific dot blot hybridization. Types were organized by phylogenetic species and cancer risk. PCR signal strength served as a qualitative surrogate for viral load. Overall, 24.8% [95% confidence interval (95% CI), 22.4-27.3] of single prevalent HPV infections had concurrent abnormalities (atypical squamous cells or worse) ranging from 0.0% to 80.0% based on HPV type. Noncarcinogenic alpha3/alpha15 types, although highly prevalent, uncommonly caused cytologic abnormalities (13.1%; 95% CI, 9.8-17.0). In contrast, one quarter to nearly one half of infections with a single major carcinogenic species type (alpha9/alpha11/alpha7/alpha5/alpha6) produced abnormalities. Greater abnormalities were observed with increasing qualitative viral load of carcinogenic types; fewer abnormalities were observed among older women (>54 years). A high percentage (46.2%) of detected abnormalities in women infected with HPV16 or related alpha9 types were high grade or worse, consistent with strong carcinogenicity, compared with 10.7% in women infected with alpha7 types, including HPV18, a major cause of adenocarcinoma. The lack of evident severe abnormalities associated with HPV18 and related HPV types might have implications for screening for poorly detected glandular and alpha7-related lesions.

Adult↗
PubMed2006

Risk of non-Hodgkin lymphoma (NHL) in relation to germline variation in DNA repair and related genes.

Chromosomal translocations, insertions, and deletions are common early events in non-Hodgkin lymphoma (NHL) carcinogenesis, and implicated in their formation are endogenous processes involved in antigen-receptor diversification, such as V(D)J recombination. DNA repair genes respond to the double- and single-strand breaks induced by these processes and may influence NHL etiology. We examined 34 genetic variants in 19 genes within or related to 5 DNA repair pathways among 1172 cases and 982 matched controls who participated in a population-based NHL study in Los Angeles, Seattle, Detroit, and Iowa from 1998 to 2000. Cases were more likely than controls to have the RAG1 820 R/R (odds ratio [OR] = 2.7; 95% confidence interval [CI] = 1.4 to 5.0) than Lys/Lys genotypes, with evidence of a gene dosage effect (P trend < .001), and less likely to have the LIG4 (DNA ligase IV) 9 Ile/Ile (OR = 0.5; 95% CI = 0.3 to 0.9) than T/T genotype (P trend = .03) in the nonhomologous end joining (NHEJ)/V(D)J pathway. These NHEJ/V(D)J-related gene variants represent promising candidates for further studies of NHL etiology and require replication in other studies.

DNA Repair↗
PubMed2006

Haplotype analysis of the HSD17B1 gene and risk of breast cancer: a comprehensive approach to multicenter analyses of prospective cohort studies.

The 17beta-hydroxysteroid dehydrogenase 1 gene (HSD17B1) encodes 17HSD1, which catalyzes the final step of estradiol biosynthesis. Despite the important role of HSD17B1 in hormone metabolism, few epidemiologic studies of HSD17B1 and breast cancer have been conducted. This study includes 5,370 breast cancer cases and 7,480 matched controls from five large cohorts in the Breast and Prostate Cancer Cohort Consortium. We characterized variation in HSD17B1 by resequencing and dense genotyping a multiethnic sample and identified haplotype-tagging single nucleotide polymorphisms (htSNP) that capture common variation within a 33.3-kb region around HSD17B1. Four htSNPs, including the previously studied SNP rs605059 (S312G), were genotyped to tag five common haplotypes in all cases and controls. Conditional logistic regression was used to estimate odds ratios (OR) for disease. We found no evidence of association between common HSD17B1 haplotypes or htSNPs and overall risk of breast cancer. The OR for each haplotype relative to the most common haplotype ranged from 0.98 to 1.07 (omnibus test for association: X2 = 3.77, P = 0.58, 5 degrees of freedom). When cases were subdivided by estrogen receptor (ER) status, two common haplotypes were associated with ER-negative tumors (test for trend, Ps = 0.0009 and 0.0076; n = 353 cases). HSD17B1 variants that are common in Caucasians are not associated with overall risk of breast cancer; however, there was an association among the subset of ER-negative tumors. Although the probability that these ER-negative findings are false-positive results is high, these findings were consistent across each cohort examined and warrant further study.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Age-related changes of the cervix influence human papillomavirus type distribution.

Approximately 15 human papillomavirus (HPV) types cause virtually all cervical cancer whereas other HPV types are unrelated to cancer. We were interested in whether some noncarcinogenic types differ from carcinogenic in their affinity for the cervical transformation zone, where nearly all HPV-induced cancers occur. To examine this possibility, we tested cervical specimens from 8,374 women without cervical precancer and cancer participating in a population-based study in Guanacaste for >40 HPV types using PCR. We compared age-group specific prevalences of HPV types of the alpha9 species, which are mainly carcinogenic and include HPV16, to the genetically distinct types of the alpha3/alpha15 species (e.g., HPV71), which are noncarcinogenic and common in vaginal specimens from hysterectomized women. We related HPV detection of each group to the location of the junction between the squamous epithelium of the ectocervix and vagina and the columnar epithelium of the endocervical canal. Models evaluated the independent effects of amount of exposed columnar epithelium (ectopy) and age on the presence of alpha9 or alpha3/alpha15 types. Prevalence of alpha9 types (7.6%) peaked in the youngest women, declined in middle-aged women, and then increased slightly in older women. By contrast, prevalence of alpha3/alpha15 types (7.6%) tended to remain invariant or to increase with increasing age. Detection of alpha9 infections increased (P(trend) < 0.0005) but alpha3/alpha15 infections decreased (P(trend) < 0.0005) with increasing exposure of the columnar epithelia. Older age and decreasing cervical ectopy were independently positively associated with having an alpha3/alpha15 infection compared with having an alpha9 infection. These patterns need to be confirmed in other studies and populations. We suggest that these genetically distinct groups of HPV types may differ in tissue preferences, which may contribute to their differences in carcinogenic potential.

Adult↗
PubMed2006

Genetic variations in CC chemokine receptors and hypertension.

BACKGROUND: CC-chemokine receptor 5 (CCR5) is a co-receptor for human immunodeficiency virus type 1 (HIV-1) infection. Homozygosity for a 32-base pair (bp) deletion (Delta32) in the CCR5 gene confers resistance to HIV-1. Previous studies found an increased prevalence of hypertension among CCR5-Delta32 homozygotes and among carriers of a polymorphism (CCR2-64I) found on the gene that codes a closely related chemokine receptor. The present study was carried out to verify these associations. METHODS: Subjects in this cross-sectional study were selected from the Global Repository at Genomics Collaborative, which includes patients and healthy control subjects enrolled at multiple clinical sites in the United States and other nations. The current study includes 2842 subjects with hypertension and 2893 nonhypertensive control subjects from white populations in the United States and Poland. Case and control subjects were frequency matched by age, gender, and birthplace. All subjects were genotyped for CCR5-Delta32 and CCR2-64I polymorphisms by established Taqman assays. RESULTS: The CCR5-Delta32 genotype was not found to be associated with hypertension (CCR5-Delta32 heterozygosity: odds ratio [OR] 0.99, 95% confidence interval [CI] 0.87 to 1.14; CCR5-Delta32 homozygosity: OR 1.07, 95% CI 0.68 to 1.67) among these subjects. There was also no association between CCR2-64I genotype and hypertension (CCR2-64I heterozygosity: OR 0.96, 95% CI 0.83 to 1.10; CCR2-64I homozygosity: OR 1.18, 95% CI 0.73 to 1.92). These results changed little after adjustment for potential confounding variables. CONCLUSION: The results of the present study, which is much larger than previously published studies, provide no evidence that either CCR5-Delta32 or CCR2-64I is associated with hypertension.

Adult↗
PubMed2006

Genetic variation in TNF and IL10 and risk of non-Hodgkin lymphoma: a report from the InterLymph Consortium.

BACKGROUND: Common genetic variants in immune and inflammatory response genes can affect the risk of developing non-Hodgkin lymphoma. We aimed to test this hypothesis using previously unpublished data from eight European, Canadian, and US case-control studies of the International Lymphoma Epidemiology Consortium (InterLymph). METHODS: We selected 12 single-nucleotide polymorphisms for analysis, on the basis of previous functional or association data, in nine genes that have important roles in lymphoid development, Th1/Th2 balance, and proinflammatory or anti-inflammatory pathways (IL1A, IL1RN, IL1B, IL2, IL6, IL10, TNF, LTA, and CARD15). Genotype data for one or more single-nucleotide polymorphisms were available for 3586 cases of non-Hodgkin lymphoma and for 4018 controls, and were assessed in a pooled analysis by use of a random-effects logistic regression model. FINDINGS: The tumour necrosis factor (TNF) -308G-->A polymorphism was associated with increased risk of non-Hodgkin lymphoma (p for trend=0.005), particularly for diffuse large B-cell lymphoma, the main histological subtype (odds ratio 1.29 [95% CI 1.10-1.51] for GA and 1.65 [1.16-2.34] for AA, p for trend <0.0001), but not for follicular lymphoma. The interleukin 10 (IL10) -3575T-->A polymorphism was also associated with increased risk of non-Hodgkin lymphoma (p for trend=0.02), again particularly for diffuse large B-cell lymphoma (p for trend=0.006). For individuals homozygous for the TNF -308A allele and carrying at least one IL10 -3575A allele, risk of diffuse large B-cell lymphoma doubled (2.13 [1.37-3.32], p=0.00083). INTERPRETATION: Common polymorphisms in TNF and IL10, key cytokines for the inflammatory response and Th1/Th2 balance, could be susceptibility loci for non-Hodgkin lymphoma. Moreover, our results underscore the importance of consortia for investigating the genetic basis of chronic diseases like cancer.

Case-Control Studies↗
PubMed2006

Human papillomavirus testing following loop electrosurgical excision procedure identifies women at risk for posttreatment cervical intraepithelial neoplasia grade 2 or 3 disease.

BACKGROUND: Loop electrosurgical excision procedure (LEEP) is the predominant treatment for cervical intraepithelial neoplasia grade 2 or 3 (CIN2+) in the United States, yet following treatment approximately 10% of women are diagnosed again with CIN2+, necessitating close follow-up of such patients. METHODS: Surveillance strategies using cytology and/or human papillomavirus (HPV) testing were compared among women who underwent LEEP (n = 610) in the Atypical Squamous Cells of Undetermined Significance (ASCUS) Low-Grade Squamous Intraepithelial Lesion (LSIL) Triage Study. Cervical specimens, collected at 6-month visits for 2 years, were used for cytology, Hybrid Capture 2 (HC2) detection of carcinogenic HPVs, and PCR for genotyping of carcinogenic and noncarcinogenic HPV types. At exit, women had colposcopy for safety and disease ascertainment. RESULTS: At the visit post-LEEP (median time: 4.5 months after LEEP), 36.9% [95% confidence interval (95% CI), 32.7-41.1%] of women were positive for carcinogenic HPV by PCR and 33.7% (95% CI, 29.7-37.9) had ASCUS or more severe (ASCUS+) cytology. The overall 2-year cumulative incidence of histologically confirmed posttreatment CIN2+ was 7.0%; this could be further stratified by the HPV risk category detected at the 6-month visit after LEEP. The 2-year risk associated with HPV16 positivity was 37.0%, significantly higher than for other carcinogenic HPV types (10.8%, P < 0.001), noncarcinogenic types (1.5%, P < 0.001), or testing HPV negative (0%). Post-LEEP cytology (using a positive threshold of ASCUS+) was 78.1% (95% CI, 60.0-90.7%) sensitive for detection of posttreatment CIN2+. By comparison, PCR for carcinogenic HPV and combination testing (using a positive result from carcinogenic HPV testing or cytology as the test threshold with HPV-negative ASCUS not referred) were significantly more sensitive (96.9% for each, P = 0.03); HC2 alone was nonsignificantly more sensitive (90.6%, P = 0.3). Specificity was similar for ASCUS+ cytology (69.1%, 95% CI, 64.6-73.3%) and PCR for carcinogenic HPV (67.1%, P = 0.5), yet was lower for HC2 (63.8%, P = 0.048) and combination testing (62.9%, P = 0.02). CONCLUSION: Women who tested positive after LEEP for carcinogenic HPV types, especially HPV16, had high risk of subsequent CIN2+. HPV-based detection methods, alone or in combination with cytology, may be useful to incorporate in post-LEEP management strategies.

Adult↗
PubMed2005

Genetic variation in the HSD17B1 gene and risk of prostate cancer.

Steroid hormones are believed to play an important role in prostate carcinogenesis, but epidemiological evidence linking prostate cancer and steroid hormone genes has been inconclusive, in part due to small sample sizes or incomplete characterization of genetic variation at the locus of interest. Here we report on the results of a comprehensive study of the association between HSD17B1 and prostate cancer by the Breast and Prostate Cancer Cohort Consortium, a large collaborative study. HSD17B1 encodes 17beta-hydroxysteroid dehydrogenase 1, an enzyme that converts dihydroepiandrosterone to the testosterone precursor Delta5-androsterone-3beta,17beta-diol and converts estrone to estradiol. The Breast and Prostate Cancer Cohort Consortium researchers systematically characterized variation in HSD17B1 by targeted resequencing and dense genotyping; selected haplotype-tagging single nucleotide polymorphisms (htSNPs) that efficiently predict common variants in U.S. and European whites, Latinos, Japanese Americans, and Native Hawaiians; and genotyped these htSNPs in 8,290 prostate cancer cases and 9,367 study-, age-, and ethnicity-matched controls. We found no evidence that HSD17B1 htSNPs (including the nonsynonymous coding SNP S312G) or htSNP haplotypes were associated with risk of prostate cancer or tumor stage in the pooled multiethnic sample or in U.S. and European whites. Analyses stratified by age, body mass index, and family history of disease found no subgroup-specific associations between these HSD17B1 htSNPs and prostate cancer. We found significant evidence of heterogeneity in associations between HSD17B1 haplotypes and prostate cancer across ethnicity: one haplotype had a significant (p < 0.002) inverse association with risk of prostate cancer in Latinos and Japanese Americans but showed no evidence of association in African Americans, Native Hawaiians, or whites. However, the smaller numbers of Latinos and Japanese Americans in this study makes these subgroup analyses less reliable. These results suggest that the germline variants in HSD17B1 characterized by these htSNPs do not substantially influence the risk of prostate cancer in U.S. and European whites.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

The elevated 10-year risk of cervical precancer and cancer in women with human papillomavirus (HPV) type 16 or 18 and the possible utility of type-specific HPV testing in clinical practice.

BACKGROUND: Human papillomavirus (HPV) types 16 and 18 cause 60%-70% of cervical cancer worldwide, and other HPV types cause virtually all remaining cases. Pooled HPV testing for 13 oncogenic types, including HPV16 and 18, is currently used in clinical practice for triage of equivocal cytology and, in conjunction with Pap tests, is an option for general screening among women 30 years of age and older. It is not clear to what extent individual identification of HPV16 or HPV18 as an adjunct to pooled oncogenic HPV testing might effectively identify women at particularly high risk of cervical cancer or its immediate precursor, cervical intraepithelial neoplasia 3 (CIN3). METHODS: From April 1, 1989, to November 2, 1990, a total of 20 810 women in the Kaiser Permanente health plan in Portland, OR, enrolled in a cohort study of HPV and cervical neoplasia. Women were tested for 13 oncogenic HPV types by Hybrid Capture 2 (HC2), and those women with a positive HC2 test were tested for HPV16 and 18. Enrollment Pap smear interpretation and HPV test results were linked to histologically confirmed CIN3 and cervical cancer (> or = CIN3) occurring during 10 years of cytologic follow-up. We calculated cumulative incidence rates with 95% confidence intervals for each interval up to 122 months using Kaplan-Meier methods. RESULTS: The 10-year cumulative incidence rates of > or = CIN3 were 17.2% (95% confidence interval [CI] = 11.5% to 22.9%) among HPV16+ women and 13.6% (95% CI = 3.6% to 23.7%) among HPV18+ (HPV16-) women, but only 3.0% (95% CI = 1.9% to 4.2%) among HC2+ women negative for HPV16 or HPV18. The 10-year cumulative incidence among HC2- women was 0.8% (95% CI = 0.6% to 1.1%). A subanalysis among women 30 years of age and older with normal cytology at enrollment strengthened the observed risk differences. CONCLUSIONS: HPV screening that distinguishes HPV16 and HPV18 from other oncogenic HPV types may identify women at the greatest risk of > or = CIN3 and may permit less aggressive management of other women with oncogenic HPV infections.

Adult↗
PubMed2005

The carcinogenicity of human papillomavirus types reflects viral evolution.

Persistent infections with carcinogenic human papillomaviruses (HPV) cause virtually all cervical cancers. Cervical HPV types (n > 40) also represent the most common sexually transmitted agents, and most infections clear in 1-2 years. The risks of persistence and neoplastic progression to cancer and its histologic precursor, cervical intraepithelial neoplasia grade 3 (CIN3), differ markedly by HPV type. To study type-specific HPV natural history, we conducted a 10,000-woman, population-based prospective study of HPV infections and CIN3/cancer in Guanacaste, Costa Rica. By studying large numbers of women, we wished to separate viral persistence from neoplastic progression. We observed a strong concordance of newly-revised HPV evolutionary groupings with the separate risks of persistence and progression to CIN3/cancer. HPV16 was uniquely likely both to persist and to cause neoplastic progression when it persisted, making it a remarkably powerful human carcinogen that merits separate clinical consideration. Specifically, 19.9% of HPV16-infected women were diagnosed with CIN3/cancer at enrollment or during the five-year follow-up. Other carcinogenic types, many related to HPV16, were not particularly persistent but could cause neoplastic progression, at lower rates than HPV16, if they did persist. Some low-risk types were persistent but, nevertheless, virtually never caused CIN3. Therefore, carcinogenicity is not strictly a function of persistence. Separately, we noted that the carcinogenic HPV types code for an E5 protein, whereas most low-risk types either lack a definable homologous E5 ORF and/or a translation start codon for E5. These results present several clear clues and research directions in our ongoing efforts to understand HPV carcinogenesis.

Cocarcinogenesis↗
PubMed2005

A prospective study of age trends in cervical human papillomavirus acquisition and persistence in Guanacaste, Costa Rica.

BACKGROUND: Cross-sectional human papillomavirus (HPV) DNA prevalence peaks at young ages, reflecting sexual acquisition and typically rapid clearance. In some populations, HPV prevalence demonstrates a second peak in older women. Longitudinal data may help to explain this second peak. METHODS: We followed a population-based cohort of 7237 women in Guanacaste, Costa Rica, in which we had previously observed a second peak in the baseline HPV prevalence in older women. We tested for >40 HPV types by polymerase chain reaction. We analyzed age-specific patterns of acquisition and persistence 5-7 years after enrollment for individual HPV types. RESULTS: At enrollment and follow-up, cross-sectional data revealed U-shaped age-specific HPV prevalence curves for virtually every type, with higher prevalences in the younger and older women than in the middle-aged women. Prospectively, acquisition of types decreased significantly as women aged (PTrend<.05, for both), with the highest peak in young women and a secondary minor peak in older women. Type-specific persistence of HPV increased with age (PTrend<.0001). Overall, HPV acquisition predominated at younger ages, whereas persistent infections gradually became more prominent with age (PTrend<.0001). CONCLUSIONS: Newly apparent infections decreased, whereas persistence increased, with age; this latter tendency supports the utility of HPV screening in older women.

Adult↗
PubMed2005

Epidemiologic profile of type-specific human papillomavirus infection and cervical neoplasia in Guanacaste, Costa Rica.

BACKGROUND: Detailed epidemiologic studies of cervical type-specific human papillomavirus (HPV) infection in large populations are scarce. METHODS: We recruited a population-based cohort in Guanacaste, Costa Rica. Participants were interviewed, screened for cervical neoplasia, and tested for >40 HPV types by use of MY09/11 L1 consensus primer polymerase chain reaction. We estimated the risk factors for infection and the associations between type-specific HPV infections and cervical intraepithelial neoplasia (CIN) and cancer in 8514 sexually active women who had not undergone a hysterectomy. RESULTS: The overall HPV prevalence was 26.5%. The most common type was HPV-16 (3.6% of the population). HPV prevalence showed a U-shaped age-specific curve. Sexual behaviors were the main determinants of oncogenic and nononcogenic infections; age at first sexual intercourse was not independently associated with infection. Barrier contraceptive use was somewhat protective against infection. Oncogenic infections were strongly associated with risk of all grades of CIN and of cancer. Types 16, 18, and 58 were the most common in women diagnosed with CIN3 and cancer. Except for those that included HPV-16, multiple-type infections were associated with an increased risk (compared with that for single-type infections) of all grades of CIN and of cancer. CONCLUSIONS: We confirmed the bimodal age pattern of HPV infection in Guanacaste and the sexually transmitted nature of both oncogenic and nononcogenic HPV types.

Adult↗
PubMed2005

A study of the impact of adding HPV types to cervical cancer screening and triage tests.

Use of human papillomavirus (HPV) testing in cervical cancer prevention is increasing rapidly. A DNA test for 13 HPV types that can cause cervical cancer is approved in the United States for co-screening with cytology of women >or=30 years old and for triage of women of all ages with equivocal cytology. However, most infections with HPV are benign. We evaluated trade-offs between specificity and sensitivity for approximately 40 HPV types in predicting cervical intraepithelial neoplasia 3 and cancer in two prospective studies: a population-based screening study that followed 6196 women aged 30-94 years from Costa Rica for 7 years and a triage study that followed 3363 women aged 18-90 years with equivocal cytology in four U.S. centers for 2 years. For both screening and triage, testing for more than about 10 HPV types decreased specificity more than it increased sensitivity. The minimal increases in sensitivity and in negative predictive value achieved by adding HPV types to DNA tests must be weighed against the projected burden to thousands of women falsely labeled as being at high risk of cervical cancer.

Adult↗
PubMed2005

Response rates in a case-control study: effect of disclosure of biologic sample collection in the initial contact letter.

PURPOSE: Participants in epidemiology studies are often asked to complete an interview and to provide biospecimens. In a population-based case-control study of kidney cancer involving an interview and optional biospecimens, we examined whether mentioning the biospecimens in the initial contact letter adversely affects willingness to be interviewed. METHODS: Eligible cases (n = 434) and controls (n = 775) in Detroit were alternately assigned to receive one of two versions of the contact letter. Both explained that the study involves an interview with 100 dollars compensation plus an optional component with additional compensation; only one disclosed that the optional component involved biospecimens. RESULTS: There were no meaningful differences between the groups in willingness to be interviewed. However, among 303 cases and 351 controls already interviewed, the proportion providing biospecimens was higher in the fully informed group: for blood, the differences were 10.8 (95% CI, 2.0, 19.5) for cases and 6.7% (95% CI, -1.7, 15.1) for controls. Findings were similar for saliva. CONCLUSIONS: In a study involving an interview and optional biospecimens, informing people about the samples in the contact letter seems preferable to a non-specific reference to a second study component. Both approaches yielded similar interview participation rates, but biospecimen participation rates were higher among those informed about the samples in the contact letter.

Adult↗
PubMed2005

The impact of a prevention effort on the community.

Commonly used measures of the impact of an exposure on disease are inadequate for assessing the potential benefit of community-based efforts to prevent disease caused by the exposure in question. Because relative measures of effect, including the risk ratio, odds ratio, and population attributable risk (PAR) do not account for the absolute risk of disease, they lack the most crucial element for evaluating the opportunity for prevention of disease caused by the exposure. Attributable community risk (ACR), defined as the difference between the crude risk (or overall risk in the population) and the risk in the unexposed, better captures the potential impact of a prevention effort. PAR can be expressed as the proportion of the disease incidence in a population that is attributable to the exposure. ACR, by contrast, is the proportion of the population that is affected with the disease due to the exposure. Therefore, unlike PAR, risk ratio or odds ratio, ACR is useful for comparing the potential benefit of programs aimed at the prevention of different diseases. For example, ACR provides a useful comparison of the potential benefits of efforts to prevent breast cancer and to prevent ovarian cancer among women with a BRCA1 or BRCA2 mutation.

BRCA1 Protein↗