Impact of cancer screening on women's health.

Worldwide, 31% of cancers in women are in the breast or uterine cervix. Prevention of cervical cancer is effective with the use of the cervical Pap smear test if applied in an organized and continuous fashion, including treatment of precancerous lesions. At best such programs have led to a 60% decrease in cervical cancer incidence and mortality in the Nordic countries. Early detection of breast cancer in a population based screening may lead to a 30% reduction of mortality from this disease in the screened population. Measures to guarantee high coverage and attendance, adequate field facilities, organized program for quality control and adequate facilities for diagnosis and treatment are prerequisites of successful programs. In absolute terms the contribution of screening to the total mortality reduction among middle-aged populations is small, much smaller than the potential gains from cancer prevention.