Population-based multicase-control study in common tumors in Spain (MCC-Spain): Rationale and study design = Estudio multicaso-control de base poblacional de tumores comunes en España (MCC-Spain): razón y diseño del estudio

Abstract

We present the protocol of a large population-based case-control study of 5 common tumorsin Spain (MCC-Spain) that evaluates environmental exposures and genetic factors.Methods: Between 2008-2013, 10,183 persons aged 20-85 years were enrolled in 23 hospitals and pri-mary care centres in 12 Spanish provinces including 1,115 cases of a new diagnosis of prostate cancer,1,750 of breast cancer, 2,171 of colorectal cancer, 492 of gastro-oesophageal cancer, 554 cases of chroniclymphocytic leukaemia (CLL) and 4,101 population-based controls matched by frequency to cases by age,sex and region of residence. Participation rates ranged from 57% (stomach cancer) to 87% (CLL cases) andfrom 30% to 77% in controls. Participants completed a face-to-face computerized interview on sociode-mographic factors, environmental exposures, occupation, medication, lifestyle, and personal and familymedical history. In addition, participants completed a self-administered food-frequency questionnaireand telephone interviews. Blood samples were collected from 76% of participants while saliva sampleswere collected in CLL cases and participants refusing blood extractions. Clinical information was recordedfor cases and paraffin blocks and/or fresh tumor samples are available in most collaborating hospitals.Genotyping was done through an exome array enriched with genetic markers in specific pathways. Mul-tiple analyses are planned to assess the association of environmental, personal and genetic risk factorsfor each tumor and to identify pleiotropic effects.Discussion: This study, conducted within the Spanish Consortium for Biomedical Research in Epidemiol-ogy & Public Health (CIBERESP), is a unique initiative to evaluate etiological factors for common cancersand will promote cancer research and prevention in Spain