(HealthDay News) – A variation measure, estimated from an automated algorithm of the grayscale variation within a mammogram, correlates with the risk of breast cancer as strongly or more so than percent density (PD), according to a study published online July 3 in the Journal of the National Cancer Institute.
John J. Heine, PhD, from the H. Lee Moffitt Cancer Center & Research Institute in Tampa, FL, and colleagues developed an automated, objective measure of grayscale value variation within a mammogram, examined its correlation with breast cancer, and compared its performance with PD. Data were utilized from 3 studies: a case-cohort study involving 217 cases and 2,094 non-case individuals, and two case-control studies involving 928 and 246 cases matched with 1,039 and 516 controls, respectively.
The researchers found that, in all 3 studies, the variation measure correlated significantly with the risk of breast cancer (highest vs lowest quartile: hazard ratio, 7.0; odds ratio, 10.7; odds ratio, 2.6; all Ptrend<0.001). The risk estimates and area under the receiver operating characteristic curves were greater for the variation measure than PD in 2 studies (0.71 and 0.76 vs 0.65 and 0.65); in the third study, the estimates were similar (0.60 and 0.61). In a meta-analysis of the 3 studies, there was a stronger correlation observed between variation and breast cancer than PD and breast cancer (highest vs lowest quartile: relative risk, 3.6 and 2.3, respectively).
“These results suggest that the variation measure is a viable automated mammographic density measure that is consistent across film and digital imaging platforms and may be useful in the clinical setting for risk assessment,” the authors write.