Relative benefit of mammography reduces with age

Kerlikowske, Karla MD
Smith-Bindman, Rebecca MD

Department of Medicine and Epidemiology and Biostatistics; University of California, San Francisco, USA (Kerlikowske)
Department of Radiology and Epidemiology and Biostatistics; University of California, San Francisco, USA (Smith-Bindman)

Abstracted from:Barratt A, Irwig L, Glasziou P, Salkeld G, Houssami N. Benefits, harms and costs of screening mammography in women 70 years and over: a systematic review. Med J Aust 2002; 176: 266-272 .

Evidence-based Healthcare 6(4):p 156-157, December 2002.

BACKGROUND

Women over the age of 50 benefit from regular mammographic screening. There is little information about the age at which screening should stop. Although breast cancer mortality rises with age, for older women the benefits of mammography may be offset by competing causes of death and discomfort from screening.

OBJECTIVE

To examine the benefits, harms and costs of breast cancer screening in women over 70 years old.

METHOD

Systematic review.

SEARCH STRATEGY

MEDLINE search for models estimating life expectancy gains from mammography in older women (to July 2000). Studies were eligible if they reported decision-analytic or cost-effectiveness models of mammography, provided age-specific results for older and younger women and presented results as estimated gains in life expectancy per woman screened. Five studies were included.

DATA SYNTHESIS

Models were used to estimate the relative benefit of mammography for women of different ages. A validated model estimated the marginal cost-effectiveness of extending screening to women aged over 70. Data from Australia's mammographic screening programme were used to identify the consequences of screening women of different ages.

OUTCOMES

Benefit of mammography in older women relative to benefit for women aged 50 to 69 years.

MAIN RESULTS

For women aged 70 to 79 years, the relative benefit of mammography was 40% to 72% of the benefit for younger women. For women over 80 years, the relative benefit was about one-third. Cost-effectiveness estimates for extending the upper screening age from 69 to 79 years ranged from $8119 to $27,751 per quality-adjusted life year gained (Australian dollars).

AUTHORS' CONCLUSIONS

The relative benefit of breast cancer screening reduces with age. Educational materials are needed to help older women and their physicians decide whether to continue with screening.