Clinical presentation of breast cancer: Age, stage, and treatment modalities in a contemporary cohort of Michigan women.

Abstract

1 Background: The U.S. Preventative Services Task Force (USPSTF) revised their breast cancer screening recommendations in 2009 changing their stance on age and frequency of mammography screening to biannual exams starting at age 50. The purpose of this study is to analyze data from a statewide breast cancer registry managed by the Michigan Breast Oncology Quality Initiative (MiBOQI) to determine the impact of these new recommendations on diagnosing and treating breast cancer. Methods: De-identified data were collected on women participating in the MiBOQI registry at seventeen statewide institutions from 2006-2009. Data included method of detection, cancer stage, age at detection, treatment type, and patient demographics. Participants were stratified based on age, and data analyzed using NCSS software (chi-square and t-tests). Results:5903 women with breast cancer with an average age at diagnosis of 59.4 years were included. 65.5% of breast cancers were detected via mammography, 29.8% by palpation, and 4.7% by other methods. In women under 50 years of age, cancers were detected by mammography in 48.3% (69.3% >50yr) and by palpation in 46.1% (24.1% >50yr). Patients with palpable presentations were younger (55.8 yr vs. 61.2 yr; p <0.001). Cancers with a palpable presentation were diagnosed at higher stages (50.0% stage II) than with mammography (52.5% stage I; p<0.001). Breast conservation surgery occurred more frequently than mastectomy (palpation 54.2%; mammography 72.9%, p<0.001) but cancers detected through palpation were more likely to undergo mastectomy procedures. Conclusions: Results of this study validate the importance of annual screening mammography in women older than 50 years, and women aged 40 to 49 years recently omitted from screening guidelines. There was an increased prevalence of palpation for the method of detection in women less than 50 years of age. If screening mammography is omitted in this group, cancers when detected may be of a more advanced stage and result in more mastectomies. This study also supports the use of palpation as a method of detection despite recent recommendations against teaching self breast exams by USPSTF.