The purpose of this project is to investigate, in analytic studies, the etiologies of selected cancers. Specific cancer sites and hypotheses are selected for which the need for investigation is clear but which have been difficult to study elsewhere. Studies focus either on tumors that have not been studied analytically before (e.g., because of the rarity of the tumor) or on hypotheses that are difficult to assess (e.g., because of the prevalence of the exposure or the need to detect an effect at low levels of exposure). Since these studies are often the first or most through to date, they collect data on a wide range of exposures, usually through interviews and medical records. A major emphasis within this project area has been on defining the etiology of female tumors. In many of these studies, as well as in selected others, attempts have been made to assess, more precisely, exposures through interdisciplinary approaches.