As reported in The Lancet by Harada-Shoji et al, the Japanese J-START trial showed that adjunctive ultrasonography was associated with a reduced cumulative incidence of advanced breast cancer vs mammography alone in screening of asymptomatic women aged 40 to 49 years.
Initial reports from the trial showed that adjunctive ultrasonography was associated with significantly higher rates of breast cancer detection than mammography alone.
Study Details
In the multicenter trial, 72,661 women were randomly assigned between August 2007 and March 2011 to receive screening ultrasonography and mammography (n = 36,723) or mammography alone (n = 35,938) twice during a 2-year screening period. The current report evaluated the long-term effect of adjunctive ultrasonography on the cumulative incidence of advanced breast cancer (stage II or higher on TNM classification).
Key Findings
Median follow-up for the secondary analysis was 11.4 years (interquartile range [IQR] = 9.3–12.9 years) in the ultrasonography group and 11.3 years (IQR = 8.9–12.9 years) in the control group.
Among 894 breast cancers detected in the ultrasonography group, 234 (26%) were advanced cancers vs 277 (33%) of 843 breast cancers detected in the control group (hazard ratio [HR] = 0.83, 95.6% confidence interval [CI] = 0.70–0.98, P = .026).
Kaplan-Meier analysis suggested a violation of the proportional hazards assumption, with a significant difference in advanced cancer incidence observed only between 48 and 96 months; the divergence between groups emerged at approximately year 4, widened until year 8, and remained stable thereafter.
The investigators concluded: “Adjunctive ultrasonography reduced the cumulative incidence of advanced breast cancer in women aged 40–49 years. These findings highlight the potential value of integrating adjunctive ultrasonography into screening programmes for women with dense breast tissue, particularly in Asian populations, and could inform future breast cancer screening guidelines.”
Narumi Harada-Shoji, MD, PhD, of the Department of Breast and Endocrine Surgical Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan, is the corresponding author for The Lancet article.
DISCLOSURE: The study was funded by The Ministry of Health, Labor, and Welfare and Japan Agency for Medical Research and Development. For full disclosures of the study authors, visit thelancet.com.
