\title{studies on the association between the casp8 -652 6n del promoter polymorphism and breast cancer risk}
\description{results from 4 case-control studies examining the association between the casp8 -652 6n del promoter polymorphism and breast cancer risk.}
\bold{study}      \tab \code{character} \tab study identifier \cr
\bold{bc.ins.ins} \tab \code{numeric}   \tab number of cases who have a homozygous insertion polymorphism \cr
\bold{bc.ins.del} \tab \code{numeric}   \tab number of cases who have a heterozygous insertion/deletion polymorphism \cr
\bold{bc.del.del} \tab \code{numeric}   \tab number of cases who have a homozygous deletion polymorphism \cr
\bold{ct.ins.ins} \tab \code{numeric}   \tab number of controls who have a homozygous insertion polymorphism \cr
\bold{ct.ins.del} \tab \code{numeric}   \tab number of controls who are heterozygous insertion/deletion polymorphism \cr
\bold{ct.del.del} \tab \code{numeric}   \tab number of controls who have a homozygous deletion polymorphism
the 4 studies included in this dataset are case-control studies that have examined the association between the casp8 -652 6n del promoter polymorphism and breast cancer risk. breast cancer cases and controls were genotyped and either had a homozygous insertion, a heterozygous insertion/deletion, or a homozygous deletion polymorphism.
ziegler et al. (2011) used the same dataset to illustrate the use of meta-analytic methods to examine deviations from hardy-weinberg equilibrium across multiple studies. the relative excess heterozygosity (reh) is the proposed measure for such a meta-analysis, which can be computed by setting \code{measure="reh"}.
frank, b., rigas, s. h., bermejo, j. l., wiestler, m., wagner, k., hemminki, k., reed, m. w., sutter, c., wappenschmidt, b., balasubramanian, s. p., meindl, a., kiechle, m., bugert, p., schmutzler, r. k., bartram, c. r., justenhoven, c., ko, y.-d., brüning, t., brauch, h., hamann, u., pharoah, p. p. d., dunning, a. m., pooley, k. a., easton, d. f., cox, a. & burwinkel, b. (2008). the casp8 -652 6n del promoter polymorphism and breast cancer risk: a multicenter study. \emph{breast cancer research and treatment}, \bold{111}(1), 139--144. \verb{https://doi.org/10.1007/s10549-007-9752-z}
ziegler, a., steen, k. v. & wellek, s. (2011). investigating hardy-weinberg equilibrium in case-control or cohort studies or meta-analysis. \emph{breast cancer research and treatment}, \bold{128}(1), 197--201. \verb{https://doi.org/10.1007/s10549-010-1295-z}
### calculate log odds ratios comparing ins/del versus ins/ins
dat <- escalc(measure="or", ai=bc.ins.del, bi=bc.ins.ins,
### fit random-effects model and get the pooled odds ratio (with 95\% ci)
### calculate log odds ratios comparing del/del versus ins/ins
dat <- escalc(measure="or", ai=bc.del.del, bi=bc.ins.ins,
### calculate log odds ratios comparing ins/del+del/del versus ins/ins
dat <- escalc(measure="or", ai=bc.ins.del+bc.del.del, bi=bc.ins.ins,
### compute the relative excess heterozygosity in the controls
dat <- escalc(measure="reh", ai=ct.ins.ins, bi=ct.ins.del, ci=ct.del.del,
### fit random-effects model and get the pooled reh value (with 90\% ci)
segments(log(5/7), -2, log(5/7), res$k+1, lty="dotted")
segments(log(7/5), -2, log(7/5), res$k+1, lty="dotted")
medicine, oncology, genetics, odds ratios