|1R03CA088834-01 Interpret this number
|University Of Iowa
|Meta Analysis of Timing of Sun Exposure and Melanoma
DESCRIPTION (Applicant's Description) The incidence of malignant melanoma of
the skin is increasing faster than any other cancer in the United States. Sun
exposure is the major etiologic risk factor implicated in the development of
melanoma. As the number of estimated new cases and deaths from melanoma
continue to rise, discerning the most important timing of sun exposure and the
magnitude of the effect is important. While not uncovering new hypotheses,
meta-analyses conducted on previous studies evaluating associations between
potential risk factors and melanoma may help to guide the search for the
etiologies of this disease in future case-control studies and prevention
efforts. For this, we need to have a better understanding of the current
information on sun exposure and possible confounding effects of the skin's
sensitivity to the sun.
The various techniques suggested by researchers for meta-analysis can be
generally summarized into two approaches: combination of significance levels
and combination of effect sizes. In this study, we plan to look at a
variation on combining effect sizes by combining relative risk estimates.
Relative risk estimates will be pooled using a weighted least square method
assuming a fixed effects model, a random effects model (when studies are
heterogeneous) and a linear dose-response model. The overall aims of this
proposal are to conduct research relevant to melanoma etiology by combining
relative risk estimates (RRs) and their variances from previously conducted
studies to examine both the strengths and consistency of the observed
The relationship between melanoma and 1) timing of sunburns, 2) sunscreen use,
3) tanning salon use, and 4) cumulative sun exposure will each be examined
separately by combining risk estimates from each study for an overall relative
risk estimate along with combined estimates by study design (e.g., cohort,
case-control, hospital controls, and population-based controls), and by method
of data abstraction. Studies will also be examined by whether or not they
are adjusted for sun-sensitivity (light complexion, tendency to burn,
inability to tan, etc.). When data is available, we will also examine the
possible effect modification of the relation between melanoma and 1) timing
of sunburns, 2) sunscreen use, 3) tanning salon use, and 4) cumulative sun
exposure by sun-sensitivity in an attempt to better understand this important
interaction. This potential interaction may explain some of the conflicting
results in the literature.
Sunburns and risk of cutaneous melanoma: does age matter? A comprehensive meta-analysis.
, Vanbeek M.J.
, Beane Freeman L.E.
, Smith B.J.
, Dawson D.V.
, Coughlin J.A.
Annals of epidemiology, 2008 Aug; 18(8), p. 614-27.
Sunscreen use and the risk for melanoma: a quantitative review.
, Beane Freeman L.E.
, VanBeek M.J.
Annals of internal medicine, 2003-12-16; 139(12), p. 966-78.