What a New Mammography Study Reveals About Surveillance Imaging in Women Treated for Ductal Carcinoma In Situ

Consistent adherence with recommended annual surveillance breast cancer screening is a significant challenge for women who have been treated for ductal carcinoma in situ (DCIS), according to findings from a newly published study.

For the retrospective analysis, recently published in Radiology, researchers examined adherence over a median follow-up of 5.8 years to recommended annual breast cancer screening for 12,559 women (median age of 60 years) who had breast-conserving surgery for DCIS.

The study authors found that 52 percent of the women (6,469 out of 12,559) consistently adhered to annual surveillance imaging over the follow-up period with mammography, magnetic resonance imaging (MRI) or ultrasound. Thirty-three percent of the cohort (4,185) were inconsistent with surveillance imaging and 15 percent (1,905) did not have surveillance imaging during the follow-up period.

The researchers also noted lower adherence to annual surveillance screening among Black (adjusted odds ratio of 80 percent) and Hispanic women (adjusted odd ratio of 82 percent).

“Surveillance disparities by race and ethnicity are particularly concerning because they may reflect limited access to care, a long-standing and systemic inequity in the (United States) health care system,” wrote Marc D. Ryser, Ph.D, an assistant professor of Population Health Sciences and member of the Duke Cancer Institute at the Duke University School of Medicine, and colleagues. “ … The complicated landscape of inequitable access to care in the United States means that not all women diagnosed with DCIS will be able to adhere to recommended annual surveillance imaging.”

For the first follow-up period between six to 18 months after the original DCIS diagnosis, 75 percent of women had asymptomatic surveillance imaging with mammography alone being the predominant screening modality (65.6 percent). Adherence to surveillance imaging subsequently decreased to 68 percent adherence in the fourth follow-up period and 59 percent in the eighth follow-up period, according to the researchers.

(Editor’s note: For related content, see “What a New Study Reveals About Breast Density Awareness,” “Study Examines Racial Differences in Mammography and Ultrasound Imaging Characteristics of Breast Cancer” and “Medicare Mammography Study Shows Black Women Had Less Initial Access to Imaging Advances than White Women.”)

The study authors also found that of the 75 percent of women (9,373 women) who adhered to the first annual surveillance imaging, 69 percent (6,458 women) consistently adhered to surveillance imaging over the initial five follow-up periods. Ryser and colleagues also found that women who adhered to the first annual surveillance imaging had a lower rate of ipsilateral invasive cancer detection six years after the initial DCIS diagnosis.

“Our findings suggest that invasive in-breast recurrences may be found earlier in women who adhere to the guidelines. Indeed, thanks to successful balancing of cofounders, the differences in 6-year detection rates of ipsilateral invasive cancer were less likely due to differences in underlying risk factors and were more likely due to more intense surveillance, which in turn increases the chance of detecting an invasive recurrence earlier,” noted Ryser and colleagues.

Researchers also pointed out the use of adjunctive radiation treatment had a significant impact on adherence to surveillance imaging. According to the study, women who had radiation treatment and breast-conserving surgery were nearly 2.5 times more likely to have surveillance imaging screening in comparison to women who only had breast-conserving surgery.

In regard to study limitations, the study authors acknowledged they were not able to access data regarding the use of hormone replacement therapy, BRCA gene mutations and family history of breast cancer, factors that may have influenced the uptake of surveillance imaging. They also noted that full assessment of correlations between surveillance imaging and the diagnosis of ipsilateral invasive breast cancer is beyond the study’s scope.