Quality-oriented mass mammography screening.

PURPOSE

To demonstrate the ability of a mass mammography screening program to provide consistently high-quality mammography screening, while at the same time sustain a large volume of patients to keep the cost of mammography low.

MATERIALS AND METHODS

A public-funded, mass mammography screening program, begun in 1988, is currently being conducted in five Canadian provinces. For the Screening Mammography Program of British Columbia, complete follow-up data are available for the first 57 months of operation. During that time, the program expanded from one center with five radiologist screeners to 14 centers with 30 radiologist screeners. There were 201,937 examinations performed on 128,325 women, 35% of whom were younger than 50 years.

RESULTS

There were 802 cancers detected at an overall rate of 6.2 per 1,000 women (2.8 per 1,000 in women younger than 50 years and 8.1 per 1,000 in women older than 50 years). In the women younger than 50 years, 90 (72%) of the cancers were stage 0 or stage I, and the axillary lymph nodes were involved in 14 (11%). In the women 50 years or older, 496 (73%) of the cancers were stage 0 or stage 1, and the axillary lymph nodes were involved in 97 (14%).

CONCLUSION

If quality is carefully controlled, the results of a mass screening program can be either maintained or improved. For both age groups, the prognostic characteristics are similar.