Screening mammography in Minnesota cancer patients

Abstract 

Background:

Although a decrease in mortality due to breast cancer is the most definitive measure to assess the effectiveness of screening mammography, stage at diagnosis is an interim measure.

Objectives:

The objectives were to (1) examine the association between screening mammography and cancer stage at diagnosis and (2) provide information about mammography utilization in an insured population diagnosed with cancer.

Research design:

We utilized an existing data set of linked cancer registry–claims data. We computed an odds ratio for the association between screening mammography and breast cancer stage at diagnosis and examined mammography utilization patterns.

Subjects:

Women in Minnesota with available claims data who developed cancer in 1995.

Measures:

Mammography claims and breast cancer stage at diagnosis (grouped according to AJCC and summary stage).

Results:

Screening mammography was associated with significantly increased odds of an early (versus late) stage cancer diagnosis, consistent with the goal of screening. Mammography utilization was generally highest in the age group 50–64 and decreased in each successive age group.

Conclusions:

Linkage between insurance claims and cancer registry data provides useful information not available in either data set alone. The results contribute to the cohesiveness of the evidence that mammography prevents death due to breast cancer.

Keywords: Staging of breast cancer, Screening mammography, Odds ratio, Breast cancer prevention