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Leslie K Dennis

Publications and source records attributed to Leslie K Dennis.

8 recordsLinked to original sources
PubMed2005

Test-retest of self-reported exposure to artificial tanning devices, self-tanning creams, and sun sensitivity showed consistency.

OBJECTIVE: Exposure to ultraviolet radiation has consistently been linked to an increased risk of melanoma. Epidemiologic studies are susceptible to measurement error, which can distort the magnitude of observed effects. Although the reliability of self-report of many sun exposure factors has been previously described in several studies, self-report of use of artificial tanning devices and self-tanning creams has been less well characterized. STUDY DESIGN AND METHODS: A mailed survey was re-administered 2-4 weeks after completion of the initial survey to 76 randomly selected participants in a case-control study of melanoma. Cases and controls were individuals diagnosed in 1999 and 2000 who were ascertained from the Iowa Cancer Registry in 2002. We assessed the consistency of self-reported use of sunlamps and self-tanning creams, sun sensitivity, and history of sunburns. RESULTS: There was substantial reliability in reporting the use of sunlamps or self-tanning creams (cases: Kappa (kappa)=1.0 for both exposures; controls: kappa=0.71 and 0.87, respectively). kappa estimates of 0.62-0.78 were found for overall reliability of several sun sensitivity factors. CONCLUSION: Overall, the survey instrument demonstrated substantial reproducibility for factors related to the use of sunlamps or tanning beds, self-tanning creams, and sun sensitivity factors.

Adult↗
PubMed2004

Toenail arsenic content and cutaneous melanoma in Iowa.

Cutaneous melanoma has the lowest survival rate of all forms of skin cancer. There has been little research investigating the link between arsenic and cutaneous melanoma, although arsenic has been associated with increased risk of nonmelanoma skin cancer. The authors performed a case-control study examining the association between cutaneous melanoma and environmental arsenic exposure among Iowans aged 40 years or older. Participants included 368 cutaneous melanoma cases and 373 colorectal cancer controls diagnosed in 1999 or 2000, frequency matched on gender and age. Participants completed a mailed survey and submitted toenail clippings for analysis of arsenic content by graphite furnace atomic absorption spectrophotometry. The authors found an increased risk of melanoma for participants with elevated toenail arsenic concentrations (odds ratio = 2.1, 95 percent confidence interval: 1.4, 3.3; p-trend = 0.001) and effect modification by prior skin cancer diagnosis (p-interaction = 0.03). The arsenic-melanoma findings in this study are not known to have been previously reported in observational epidemiologic studies involving incident cutaneous melanoma. Therefore, the findings warrant confirmation.

Adult↗
PubMed2004

Problems with the assessment of dietary fat in prostate cancer studies.

The authors conducted a detailed review of studies on the association between prostate cancer and total dietary fat along with specific fatty acids. Overall, the 29 studies reporting actual dietary fat levels in grams of fat were heterogeneous, suggesting that pooling of the relative risks may be inappropriate. Heterogeneity was also seen by study design. More specifically, although the pooled estimate for prostate cancer and an increase of 45 g in total fat consumption per day was small (relative risk = 1.2), heterogeneity between studies was large, and the association was not supported by specific fatty acids. The strongest association was found among the five extremely inconsistent studies of alpha-linolenic fatty acid. The associations with advanced prostate cancer were more homogeneous and suggest a relation with total and saturated fat but none with specific fatty acids. This review highlights the inconsistent way in which total dietary fat and specific fatty acids have been measured and reported across epidemiologic studies of prostate cancer. The heterogeneity between studies was large, possibly because of the variation in the dietary instruments used and the corresponding databases (nondifferential misclassification), recall bias, differing case definitions, residual confounding, or potential selection bias in different studies.

Dietary Fats↗
PubMed2003

Sunscreen use and the risk for melanoma: a quantitative review.

BACKGROUND: Originally developed to protect against sunburn, sunscreen has been assumed to prevent skin cancer. However, conflicting reports include claims that sunscreen increases risk for melanoma. OBJECTIVE: To examine the strength and consistency of associations between melanoma and sunscreen use in the published literature. DATA SOURCES: A comprehensive MEDLINE search of articles published from 1966 to 2003 that reported information on sunscreen use and melanoma in humans. STUDY SELECTION: Analytic studies reporting data on sunscreen use before diagnosis of melanoma. DATA EXTRACTION: Two independent reviewers extracted data. Inconsistencies were rereviewed until agreement was achieved. When necessary, a third party resolved discrepancies. DATA SYNTHESIS: Odds ratios were pooled across studies by using standard meta-analytic techniques. Pooled odds ratios for ever use among 18 heterogeneous studies did not support an association between melanoma and sunscreen use. Variation among odds ratios was explained by studies that did not adjust for confounding effects of sun sensitivity. The lack of a dose-response effect with frequency of use (never, sometimes, or always) or years of use provided further evidence of a null association. CONCLUSIONS: No association was seen between melanoma and sunscreen use. Failure to control for confounding factors may explain previous reports of positive associations linking melanoma to sunscreen use. In addition, it may take decades to detect a protective association between melanoma and use of the newer formulations of sunscreens.

Confounding Factors, Epidemiologic↗
PubMed2003

Developing a scoring method for evaluating dietary methodology in reviews of epidemiologic studies.

We examined the quality of dietary assessment used by studies of prostate cancer and dietary fat in an attempt to explain the heterogeneity of their relative risk (RR) estimates. We reviewed the dietary assessment of 39 studies published in English that reported RRs for the association between prostate cancer and dietary fat intake derived from food frequency questionnaires (FFQs). We scored studies based on several objective measures of quality dietary assessment. Studies received no points for characteristics with unclear information. Studies scored 2 points for interviewer-completed FFQs, along with 2 points for quantitative assessments. They were scored 4 points for FFQs with more than 150 items, with an additional point for pretesting and 2 points for validated FFQs. Studies were given 1 point for describing each of the following characteristics: specifying the nutrient database used to convert foods to grams of fat, specifying quality control, attempting to measure dietary intake prior to diagnosis (recalled dietary period), and reporting the time needed to complete the FFQ. We then ranked studies based on their overall score: "high" for a score of 7 or greater out of 15 and "low" for lower scores. Two of the 39 studies that used quantitative methods other than a FFQ were excluded. Of the remaining 37 studies reviewed that used FFQs, only 16 were judged to have a high quality assessment of dietary fat. This review highlights the inconsistency of FFQ used in epidemiologic studies of dietary fat. Such variations in dietary measurement may be reflected in the variation in the magnitude of RRs reported for prostate cancer and dietary fat. The problems identified here include insufficient reporting of the details of dietary assessment, in addition to use of questionnaires with only a few food items to estimate a subject's dietary fat intake. It is imperative that journals include experts in the field of nutrition as reviewers of epidemiologic papers describing diet.

Dietary Fats↗
PubMed2002

Epidemiologic association between prostatitis and prostate cancer.

OBJECTIVES: To quantify the relationship between prostatitis and prostate cancer by pooling previous epidemiologic studies of this association. METHODS: A comprehensive search for articles published through 2000 was performed, blinded reviews of each study were conducted, data were abstracted, and all such studies were pooled. RESULTS: In this meta-analysis, an increased risk was seen among men with a history of prostatitis (odds ratio = 1.6), particularly with population-based case-control studies (odds ratio = 1.8). Increased relative risk estimates were also seen among men with a history of syphilis and a history of gonorrhea. CONCLUSIONS: These associations with prostate cancer suggest that infections may represent one mechanism through which prostate cancer develops. However, causality is unclear, because recall bias and detection bias cannot be ruled out. Future cohort studies of prostate cancer should examine sexually transmitted infections, as well as other infections, as potential risk factors.

Adult↗
PubMed2002

Meta-analysis of measures of sexual activity and prostate cancer.

We conducted a meta-analysis of the association between prostate cancer and aspects of sexual activity. The data suggest an elevated relative risk (RR) of prostate cancer among men with a history of sexually transmitted infections. This was observed with both random- and fixed-effects models (RR = 1.4; 95% CI = 1.2-1.7; N = 17 studies; heterogeneity P = 0.14), especially for syphilis (RR = 2.3; 95% CI = 1.3-3.9; N = 6; heterogeneity P = 0.47). Risk of prostate cancer is also associated with increasing frequency of sexual activity (RR = 1.2 for an increase of three times per week; 95% CI = 1.1-1.3; N = 12). However, these studies are heterogeneous (P < 0.001). Increasing number of sexual partners is also associated with prostate cancer (RR = 1.2 for an increase of 20 partners; 95% CI = 1.1-1.3; N = 16; heterogeneity P = 0.11). The data do not support associations with multiple marriages, age at first intercourse, or age at first marriage. These results indicate an association between prostate cancer and sexually transmitted infections, suggesting that infections may represent one mechanism through which prostate cancer develops. The mechanism through which frequency of sexual activity may be related to prostate cancer is unclear.

Adult↗