Large Michigan Study Suggests Continued Importance of Self-Exams, Annual Mammography in Breast Cancer Detection, Even in Younger Women
An analysis of breast cancer diagnosis data from nearly 6,000 women in Michigan suggests that mammography and self-breast exams remain important tools for detecting breast cancer, even among women aged 40 to 49 for whom routine mammography has been questioned by the U.S. Preventive Services Task Force (USPSTF).
Researchers found that women under the age of 50 who have breast cancer were more likely to be diagnosed based on a palpable mass (detectable by feel) rather than through mammography. Those women diagnosed because of a palpable mass had a more advanced stage of cancer and were more likely to undergo mastectomy as opposed to breast conservation surgery.
Using a statewide breast cancer registry compiled from 14 institutions through the Michigan Breast Oncology Quality Initiative, Jamie Caughran, MD, Medical Director of the Comprehensive Breast Center at the Lacks Cancer Center in Grand Rapids, Michigan, and her research team examined data on breast cancer diagnosis and treatment gathered on 5,903 women between 2006 and 2009 to determine how the 2009 USPSTF breast cancer screening recommendations might affect future breast cancer detection, particularly in women age 40 to 49. The study examined data on the method of detection, cancer stage, age at detection, treatment type and patient demographics.
In 2009, the USPSTF recommended that mammograms should only be conducted biennially after 50 years of age, and those women aged 40 to 49 should not be offered routine mammography but should discuss the risks and benefits with their physicians. The recommendations also discouraged teaching breast self-examinations, citing a high number of benign biopsies performed after a palpable breast mass is found. The previous recommendations stated that women aged 40 to 49 should undergo routine mammography every year. The new recommendations were controversial because in many cases they were in conflict with more established approaches, which included annual screening mammograms for women between ages 40 and 49, and encouraged regular self-exams.
In their review, the investigators in this study found that overall, 65.5 percent of breast cancers were detected by mammography, 29.8 percent were detected by palpation and 4.7 percent by other methods. The majority of women whose tumors were detected by mammography (3,869) were over 50 (81 percent). Of women whose tumors were found by palpation (1,759), 40 percent were under 50. In women under 50, cancers were detected by mammography in 48.3 percent of women compared to 46.1 percent detected by palpation.
Women with palpable tumors had more advanced cancers; 50 percent and 17 percent were diagnosed at stage II and III, respectively, compared to 18 percent and 4 percent found through mammography. As a result, the researchers found that patients whose tumors were detected through palpation were more likely to undergo mastectomy (46 percent) than those found by mammography (27 percent). Women whose tumors were diagnosed by palpation were also more likely to undergo chemotherapy (22.7 percent) than those diagnosed by mammography (15.7 percent).
“While there has been ongoing debate about when and how breast cancer screening should occur, this study validates that women who undergo regular mammography screening present at earlier stages and often require less aggressive treatment than those who do not. This is true for women older than 50 years, as well as women aged 40 to 49 years for whom routine mammography is questioned by the USPSTF,” said Dr. Caughran. “In addition, women of all ages presented with palpable tumors, highlighting the use of self-breast exam as an important public health measure.”Abstract #1
Title: Clinical presentation of breast cancer: Age, stage, and treatment modalities in a contemporary cohort of Michigan women. Authors: D. R. Smith, J. Caughran, J. L. Kreinbrink, G. K. Parish, S. M. Silver, T. M. Breslin, J. E. Pettinga, A. M. Mehringer, C. A. Wesen, H. Yin, D. Share, A. T. Davis, F. T. Pleban, T. A. Bacon-Baguley; Grand Valley State University, Grand Rapids, MI; Richard J. Lacks Sr. Cancer Center, St. Mary's Health Care, Grand Rapids, MI; University of Michigan, Ann Arbor, MI; University of Michigan Comprehensive Cancer Center, Ann Arbor, MI; Spectrum Health, Grand Rapids, MI; MiBOQI, University of Michigan, Ann Arbor, MI; Michigan Breast Specialists, Grosse Pointe Woods, MI; BlueCross BlueShield of Michigan, Southfield, MI; Grand Rapids Medical Education Partners, Grand Rapids, MI; Health Sciences Consultant and Freelance Medical/Health Writer, Macomb, MI 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 biennial 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. Disclosures: Nothing to disclose.