The only widely applied cancer screening programmes are those for cancers of the cervix and female breast. Participation in breast cancer screening has been shown to depend on income and education, health insurance and type of health service. Women in low social classes tend to have lower screening participation rates than those in higher classes. Socioeconomic differences in screening practices tend to decrease when participation is promoted, cultural and economic barriers are removed, and social support is offered. In both developed and developing countries, women of low socioeconomic status have a higher than average risk of cervical cancer, and a lower than average participation in Pap smear screening.