Night-shift Work and Breast Cancer

All cases and controls will be contacted by telephone or e-mail and invited to participate in the study. Female workers who decide to join the study will be asked to go to their company's occupational health clinic where they will undergo administration of a questionnaire to investigate possible known and unknown risk factors for breast cancer

Women who give consent to undergo this phase of the study will be called back to the center and will be asked to provide a blood sample