This article is more than 5 years old. Information may no longer be current.
Most breast cancer deaths occurred in unscreened women
Click Here to Manage Email Alerts
More than 70% of breast cancer deaths occurred in women who had not been screened, according to study results.
Some prior studies suggest statistically significant reductions in mortality among women who undergo breast cancer screening. However, individual trials and meta-analyses have produced varying results with regard to mortality reduction, according to background information provided by researchers. These conflicting results raise questions about the value of screening and whether advances in breast cancer therapy may have diminished the importance of detecting malignancy early, researchers wrote.
In the current study, researchers examined whether breast cancer mortality was more likely to occur in unscreened women.
The analysis included invasive tumors diagnosed between 1990 and 1999. Follow-up continued through 2007.
The investigators examined demographic and mammography data, as well as surgical and pathology reports, recurrence rates and mortality.
Mammograms were characterized as screening or diagnostic depending on whether patients demonstrated symptoms. Medical records were used to verify screening methods.
Mortality due to breast cancer was defined after previous distant metastases were documented. Mortality associated with other causes was defined as the absence of recurrent cancer or other lethal diseases.
The analysis included 7,301 patients with invasive breast cancer. Researchers documented 1,705 deaths, including 609 from breast cancer and 905 from other causes.
The investigators determined 29% of the confirmed breast cancer deaths occurred among women who had been screened (19% screen-detected cancers and 10% interval cancers). Seventy-one percent of the breast cancer deaths occurred in unscreened women (65% had never been screened, and 6% had not undergone a mammogram for more than 2 years).
Median age of breast cancer diagnosis was 49 years among those who died from the disease and 72 years among those who died from other causes.
“The biological nature of breast cancer in young women is more aggressive, while breast cancer in older women tends to be more indolent,” researcher Blake Cady, MD, professor of surgery (emeritus) at Harvard Medical School in Boston, said in a press release. “This suggests that less frequent screening in older women, but more frequent screening in younger women, may be more biologically based, practical and cost-effective.”
Disclosure: The researchers report no relevant disclosures.
Perspective
Back to TopKilian Salerno May, MD
The value of screening mammography for reduction of breast cancer mortality varies across trials and meta-analyses; however, screening mammography remains the most effective method for early detection of breast carcinomas. This study identified women diagnosed with breast cancer and then reviewed whether their cancers were detected on either screening mammography or diagnostic mammography (for those who were symptomatic). Among women who died of breast cancer, the rate of breast cancer mortality was significantly higher in those women who were unscreened (71% vs. 29%), especially those in those never screened.
Importantly, this failure analysis showed that half of breast cancer deaths occurred in women aged younger than 50 years. From this data, the authors infer that more frequent screening in this younger population would have a greater impact on breast cancer survival than screening women aged older than 60 years.
Despite limitations in cohort size and lack of treatment-specific variables, the study contributes important clinical data in further support of the reduction in breast cancer mortality conferred by screening mammography, particularly in younger patients.
Click Here to Manage Email Alerts