Presentation

Estudio multi-caso control poblacional, incluyendo tumores de alta incidencia en España

In late 2007, the IS Carlos III and the CIBER Epidemiology and Public Health (CIBERESP) signed a collaboration agreement for the development of a special research action on cancer following an agreement by the Council of Ministers of 11 October 2007. The CIBERESP undertook to develop and implement an operational plan for research in cancer epidemiology.

In 2008, 7 groups of CIBERESP launched a population-based multicase-control study (MCC-SPAIN) to evaluate the influence of environmental factors and their interaction with genetic factors in common tumours or tumours with peculiar epidemiological characteristics in our country, for which the environmental factors involved were not well investigated. At present, the MCC-Spain study includes 17 CIBERSP research groups.

The selected tumours are colorectal cancer, breast cancer, gastroesophageal cancer and prostate cancer. Chronic lymphocytic leukaemia (CLL) has been recently included in the study. Colorectal cancer was selected for its high incidence and mortality in both sexes. Breast cancer is the most common cancer in women and its prevention is a major problem of public health. Identified risk factors explain around 50% of the incidence of breast cancer and an even lower percentage refers to preventable factors. Prostate cancer was included for its frequency and its hormonal nature, sharing with breast cancer the etiological hypotheses of endocrine disruption. Gastroesophageal cancer was due to its characteristic geographic pattern and the environmental hypotheses suggested. CLL was selected later, in collaboration with the sequencing study of CLL cases included in the framework of the International Cancer Genome Consortium.

This study involves the recruitment of cases of various types of cancer compared with the same control group. Exposure information is collected by trained interviewers through face-to-face interviews using a structured electronic questionnaire, which includes detailed information on demographic factors, occupation, personal and family history, lifestyle and diet. Blood and other biological samples are collected and different types of biomarkers are used. Information from clinical records is abstracted for al patients. Population controls are selected at random from lists of people attending primary care health centres within the catchment areas of the hospitals where cases are recruited. Controls are interviewed at their primary care facility by the same interviewers as those contacting the cases, and at that time, biological samples are collected.

MCC-Spain study is funded by the CIBERESP and receives funding from the Health Research Fund (FIS) and other funding agencies in certain areas.

Objectives

The general objective of the study is to assess environmental and genetic factors associated with the cancers examined in MCC-Sp: colorectal, breast, stomach/oesophageal, prostate and CLL.
The specific objectives are:

  1. To assess the cancer risk of every tumour site in relation to environmental and occupational exposures including drinking water contaminants (arsenic, nitrates, chrome, chlorination by-products), hormonal disruptors and other persistent organic contaminants, disruption of the circadian rhythm through night shift work, and other factors.
  2. To assess cancer risks related to the consumption of specific medicaments including statins and analgesics.
  3. To assess cancer risks related to several lifestyle factors, nutrition and physical activity, medical and family history and other factors.
  4. To assess the risk of breast and prostate cancer related to hormonal factors, infections and permanent phenotypes (digit ratio 2d:4d; anogenital distance) related with environmental exposures in early stages of life.
  5. To validate the assessment of exposure to environmental chemical agents by means of exposure models using exposure biomarkers, individual information and environmental exposure measurements.
  6. To assess, at a first phase, a limited series of genes in relation both to primary effects and to their interaction with environmental factors.
  7. To store sufficient biologic material for its use in future GWAS (genome wide association studies) studies and others.

Organization

MCC-Spain is coordinated by Manolis Kogevinas (CREAL, Barcelona, manolis.kogevinas@isglobal.org) and Marina Pollan (ISCIII, Madrid, mpollan@isciii.es) and has a steering committee that includes representatives of all MCC-Sp groups that collect cases and controls.

Researchers in MCC-Spain, participate in working groups that address the main research areas of the study including: clinical and pathological characteristics of tumours, contaminants in drinking water, occupation, hormonal factors and endocrine disrupters, medication, infections, nutrition and physical activity, exposure to heavy metals, and genomics.

Researchers from the CIBERESP in 11 autonomous communities of Spain (Andalusia, Asturias, Basque Country, Cantabria, Castilla y Leon, Catalonia, Madrid, Murcia, Navarra, Valencia,) are participating in the study. Up until December 2010 information and biologic samples were obtained from approximately 2300 population controls, 1,600 colon and rectum cases, 1200 breast cancer cases, 850 prostate cancer cases, 350 stomach cancer cases, and 200 CLL cases.