Patterns and predictors of the breast cancer detection methods in women under 45 years of age (United States)

Objectives: Few studies have examined methods by which breast cancers are d etected, and only one study has been published on predictors of those metho ds. This study examined patterns and predictors of breast cancer detection methods during 1990-1992 among women age 20-44. Methods: In-person interview and medical record data were obtained during a population-based case-control study of 1619 women newly diagnosed with bre ast cancer in three areas of the United States (US). Results: Seventy-one percent of the cancers were identified by self-detecti on, 9% by routine clinical breast exam (CBE), and 20% by routine mammograph y. Cancers detected by mammography and CBE, but not those detected by breas t self-exam, were much more likely to be early-stage. Detection by mammogra phy increased with age, and a history of mammography use was associated wit h detection by mammography or CBE. Several commonly studied predictors of s creening utilization in the US population were associated with CBE detectio n, but were less clearly related to or unrelated to mammography detection. Conclusion: Findings suggest that, during the 1990s in the US, most breast cancers among women under age 45, including those age 40-44, were self-dete cted. Few factors other than age and prior screening are verified predictor s of method of breast cancer detection.