How the screening method impacts survival outcomes for patients with DCIS

Patients with screening-detected ductal carcinoma in situ (DCIS) who were screened with mammography and ultrasound (US) have similar disease-free survival (DFS) rates, according to a new study published in Radiology. In patients with screening mammography-detected DCIS, an association was observed between dense breasts and second breast cancer.

“Several studies have reported that screening-detected DCIS shows better DFS than does symptomatic DCIS,” wrote lead author Seung Hee Choi of the Sungkyunkwan University School of Medicine in Seoul, Korea, and colleagues. “To our knowledge, however, no studies have evaluated the association between the screening method (mammography or US) and survival outcome after treatment of DCIS.”

The researchers explored data from 814 women who underwent surgery to treat DCIS first detected by either screening mammography or screening US. All patients were treated from July 2004 to December 2011 at a single institution. The median patient age was 47 years old, and the median follow-up time was seven years. A majority (627) of patients were treated for screening mammography-detected DCIS.

Overall, the five-year overall survival (OS) and DFS rates for the patients were 100% and 95.3%, respectively. No significant differences in OS or DFS rates were detected between the two groups. In the mammography-detected DCIS group, dense breasts and a higher nuclear grade were both associated with second breast cancer. In the US-detected DCIS group, on the other hand, human epidermal growth factor 2 positivity was associated with second breast cancer.

“Our underlying hypothesis was that survival outcomes would differ according to the screening method,” the authors wrote. “However, in our study, DFS rates did not differ according to screening method. Meanwhile, survival outcomes in overall patients who underwent treatment for DCIS detected with screening mammography or US were favorable in our study.”

Notably, the team added, larger tumor size and close surgical margin were not associated with second breast cancer, though they are “known as predictive factors for local recurrence in patients who underwent treatment for DCIS.”

The authors explained that their research did have certain limitations. It was a single-center retrospective study, for example, and patients were followed for “a relatively short period, which might account for the high OS and DFS rates.”