TUESDAY, March 22, 2016 (HealthDay News) -- Interpretation of a single breast biopsy slide per case predicts low likelihood of verification for diagnosis of atypia or ductal carcinoma in situ (DCIS), according to a study published online March 22 in the Annals of Internal Medicine.
Joann G. Elmore, M.D., M.P.H., from the University of Washington School of Medicine and Fred Hutchinson Cancer Research Center in Seattle, and colleagues used Bayes' theorem to examine how diagnostic variability affects accuracy from the perspective of a U.S. woman aged 50 to 59 years having a breast biopsy. Data were included for 115 practicing pathologists, with 240 distinct cases. The authors estimated the proportion of biopsies with a diagnosis that would be verified if the same slide were interpreted by a reference group of three expert pathologists.
The researchers found that if one representative slide were used per case, 92.3 percent of breast biopsy diagnoses would be verified by reference consensus diagnosis, with 4.6 and 3.2 percent overinterpreted and underinterpreted, respectively. For invasive breast cancer and benign without atypia diagnoses, verification was highly probable, with estimated predictive values of 97.7 and 97.1 percent, respectively. For atypia (53.6 and 8.6 percent over- and underinterpreted, respectively) and DCIS (18.5 and 11.8 percent over- and underinterpreted, respectively) verification was less probable.
"This diagnostic grey zone should be considered in clinical management decisions in patients with these diagnoses," the authors write.