Interval breast cancer has its own risk factors, mortality patterns
Women with dense breast tissue are less likely than normal-density peers to develop breast cancer between screening mammography exams.
Meanwhile such “interval breast cancers” are more likely among women who have lower body mass indexes, drink alcohol, have had hormone replacement therapy after menopause and lack a family history of breast cancer.
The unusual risk profile emerged from a study conducted in 2023 at Hanyang University in South Korea. JAMA Network Open published the work this week.
The authors compared outcomes data on 8,700 women in their country who had interval breast cancer and 9,500 women whose cancer was discovered at screening. The team calculated mortality outcomes from the date of diagnosis until either the date of death or the record of survival as of end-of-year 2020.
They found women with interval breast cancer had no higher mortality than those whose cancer was detected during a normal screening exam.
Other key findings:
- When stratified by detection time, younger age at breast cancer diagnosis and family history of breast cancer were associated with an increased likelihood of interval breast cancer diagnosed at 6 to 12 months but a decreased likelihood of interval breast cancer diagnosed at 12 to 24 months.
- Overall mortality of interval breast cancer was comparable with screening-detected breast cancer, but total mortality and cancer-related mortality of interval cancers diagnosed between 6 and 12 months was higher than that of screening-detected cancer.
The authors also report that interval breast cancers diagnosed six to 12 months after negative screenings showed higher all-cause, breast cancer-related and cancer-related mortality than screening-detected cancers, “suggesting the more aggressive nature of interval cancers diagnosed earlier after negative screening.”
More:
‘The lower likelihood of interval breast cancer as a breast density category increased and the different associations observed between a family history of breast cancer and interval breast cancer by diagnostic period might reflect the wide application of breast ultrasonography for breast cancer screening.’
The study is available in full for free.
Dave P. has worked in journalism, marketing and public relations for more than 30 years, frequently concentrating on hospitals, healthcare technology and Catholic communications. He has also specialized in fundraising communications, ghostwriting for CEOs of local, national and global charities, nonprofits and foundations.