Screening mammography for early detection of breast cancer.

From numerous studies on breast cancer it can be concluded that no single measure can lessen the burden of this frequent cancer in women in all developed countries. Complex strategies including primary prevention by identification of risk factors and their modification, secondary prevention by earlier detection and tertiary prevention by improving treatment outcome are needed to control the disease. Besides age, the established breast cancer risk factors include certain benign breast diseases, family history, ionising radiation, some reproductive factors and obesity. Primary prevention includes general recommendation for healthy lifestyle, e.g., avoidance of obesity, proper diet, physical activity and moderate alcohol consumption. Randomised controlled trials conducted in the USA, Canada, Scotland and Sweden have shown that regular mammography, alone or in combination with clinical examination, is effective in reducing mortality for about 30% in women over the age of 50, and much less in younger population. However, mammography screening has several drawbacks, the major being its tendency towards false positive and false negative results with all their potential psychosocial consequences. High quality assurance and control, as well as effective and readily available treatment, all of which demand high investments, are indispensable for good results. Even in the absence of organised screening, the availability of effective treatment may contribute to reduction in breast cancer mortality.