High-Grade DCIS Detection Rates Increase in Older Women

Total ductal carcinoma in situ (DCIS) detection rates increase with age, mostly because of an increase in high- and intermediate-grade DCIS, which are precursor lesions that carry a higher risk for transition to more aggressive invasive breast cancer than low-grade DCIS, new research shows.

In an article published online in Radiology, Stefanie Weigel, M.D., Ph.D., of the University of Muenster, Germany, and colleagues retrospectively studied 733,905 women aged 50–69 years who participated in a screening program for the first time from 2005 to 2008 (baseline examinations were performed with digital mammography). DCIS detection rates were determined for 5-year age groups (detection rates per 1,000 women screened) to distinguish high-, intermediate- and low-grade DCIS. Multivariable logistic regression was used to compare detection rates between age groups by adjusting for screening units (P < .05).

Results showed 989 graded DCIS diagnoses among the women (detection rate, 1.35 percent): 419 diagnoses of high-grade DCIS (detection rate, 0.57 percent), 388 diagnoses of intermediate-grade DCIS (detection rate, 0.53 percent) and 182 diagnoses of low-grade DCIS (detection rate, 0.25 percent). Detection rate for types of DCIS combined increased significantly across age groups (50–54 years, detection rate of 1.15 percent [254 of 220,985 women]; 55–59 years, detection rate of 1.23 percent [218 of 177,782 women]; 60–64 years, detection rate of 1.34 percent [201 of 150,415 women]; and 65–69 years, detection rate of 1.71 percent [316 of 184,723 women]; P < .001).

Of note, the detection rate for high-grade DCIS showed a significant increase with age (odds ratio, 1.18 per 5-year age group; P < .0001). The increase was lower for intermediate-grade DCIS (odds ratio, 1.11; P = .016) and not significant for low-grade DCIS (P = .10).

“The potential benefit of preventing aggressive invasive breast cancer through the diagnosis of a non–low-grade in situ lesion by means of digital mammography screening and subsequent treatment appears to apply significantly more frequently to older women than to younger women who are eligible for mammography screening. High-grade lesions are more likely than low-grade lesions to lead to symptoms during a patient’s remaining lifetime, even in older population groups,” the authors write.