Whether a patient’s breast cancer was detected through symptoms or routine screening mammography significantly affected their risk for advanced disease or death, according to a study published recently in Radiology: Imaging Cancer.
Patients with symptom-detected breast cancer had higher odds of developing advanced cancer, undergoing a mastectomy, and experiencing breast cancer–related death than those with screening-detected cancers. Only the odds for needing chemotherapy were similar for both detection methods.
Study Methods and Results
The investigators conducted a retrospective observational cohort study of 821 women (at least 40 years of age) who were diagnosed with breast cancer at a tertiary referral center between January and December 2016. These patients were followed for an average of 6.7 years.
About half of the patients had their cancer detected through a symptom, but this was noted more frequently in women who underwent screening less often, including women between the ages of 40 and 49 (72.9% of 133 patients) and those aged 75 or older (70.4% of 135 patients).
“I observed a marked difference in the way breast cancers were being detected in my clinical practice,” said lead study author Jean M. Seely, MD, FRCPC, Professor in the Department of Radiology at the University of Ottawa and Head of the Breast Imaging Section at Ottawa Hospital in Ontario, Canada. “I noted that many women under the age of 50 and older than 75 were diagnosed because of symptomatic presentation.”
The women with symptom-detected breast cancer had 6.60 times higher odds of developing breast cancer of stage IIA or greater compared with those who had screening-detected cancer (32.5% vs 10.2%; odds ratio [OR] = 6.60; 95% confidence interval [CI] = 4.96–8.77; P < .001). The hazard ratio for breast cancer–related death was 1.63 favoring screening-related detection (95% CI = 1.17–2.28; P = .004). The odds for undergoing mastectomy were also higher for the symptom detection group (OR = 2.20; 95% CI = 1.63–2.96; P < .001). The odds for chemotherapy were the same for both groups of women when adjusted for age and stage at diagnosis.
“Within only 6.7 years of follow-up, almost 20% of the 821 [patients with] breast cancer had died, half of them from breast cancer,” Dr. Seely said. “The patients whose breast cancers were detected because of symptoms had a 63% higher likelihood of dying.”
Multivariable analysis showed that higher tumor stage at diagnosis was associated with symptom detection (OR = 6.40; 95% CI = 4.74–8.70; P < .001), greater risk for needing chemotherapy (OR = 1.97; 95% CI = 1.39–2.78; P < .001), and age at diagnosis (OR = 1.02; 95% CI = 1.01–1.03; P = .001).
Conclusions
The study authors believe that fewer barriers to breast cancer screening and lower ages for beginning routine screenings will improve patient outcomes.
The U.S. Preventive Services Task Force updated its breast cancer screening guidelines in 2024 to suggest that women between the ages of 40 and 75 with an average risk undergo routine breast cancer screening every 2 years. The Canadian Task Force on Preventive Health Care recommends screening every 2 to 3 years for women between the ages of 50 and 74 who have an average risk.
“The results of this study will likely support the move to reduce the breast cancer screening age to 40 in the U.S. and Canada,” Dr. Seely said. “We have lowered the screening age in many provincial and territorial screening programs in Canada and are aiming to establish a single national policy for screening.”
Disclosure: For full disclosures of the study authors, visit pubs.rsna.org.
