Can Radiologists Predict the Presence of Ductal Carcinoma In Situ and Invasive Breast Cancer?

OBJECTIVE: We hypothesize that radiologists' estimated percentage likelihood assessments for the presence of ductal carcinoma in situ (DCIS) and invasive cancer may predict histologic outcomes. MATERIALS AND METHODS: Two hundred fifty cases categorized as BI-RADS category 4 or 5 at four University of California Medical Centers were retrospectively reviewed by 10 academic radiologists with a range of 1-39 years in practice. Readers assigned BI-RADS category (1, 2, 3, 4a, 4b, 4c, or 5), estimated percentage likelihood of DCIS or invasive cancer (0-100%), and confidence rating (1 = low, 5 = high) after reviewing screening and diagnostic mammograms and ultrasound images. ROC curves were generated. RESULTS: Sixty-two percent (156/250) of lesions were benign and 38% (94/250) were malignant. There were 26 (10%) DCIS, 20 (8%) invasive cancers, and 48 (19%) cases of DCIS and invasive cancer. AUC values were 0.830-0.907 for invasive cancer and 0.731-0.837 for DCIS alone. Sensitivity of 82% (56/68), specificity of 84% (153/182), positive predictive value (PPV) of 66% (56/85), negative predictive value (NPV) of 93% (153/165), and accuracy of 84% ([56 + 153]/250) were calculated using an estimated percentage likelihood of 20% or higher as the prediction threshold for invasive cancer for the radiologist with the highest AUC (0.907; 95% CI, 0.864-0.951). Every 20% increase in the estimated percentage likelihood of invasive cancer increased the odds of invasive cancer by approximately two times (odds ratio, 2.4). For DCIS, using a threshold of 40% or higher, sensitivity of 81% (21/26), specificity of 79% (178/224), PPV of 31% (21/67), NPV of 97% (178/183), and accuracy of 80% ([21 + 178]/250) were calculated. Similarly, these values were calculated at thresholds of 2% or higher (BI-RADS category 4) and 95% or higher (BI-RADS category 5) to predict the presence of malignancy. CONCLUSION: Using likelihood estimates, radiologists may predict the presence of invasive cancer with fairly high accuracy. Radiologist-assigned estimated percentage likelihood can predict the presence of DCIS, albeit with lower accuracy than that for invasive cancer.

Inter-reader Variability in the Use of BI-RADS Descriptors for Suspicious Findings on Diagnostic Mammography: A Multi-institution Study of 10 Academic Radiologists.

RATIONALE AND OBJECTIVES: The study aimed to determine the inter-observer agreement among academic breast radiologists when using the Breast Imaging Reporting and Data System (BI-RADS) lesion descriptors for suspicious findings on diagnostic mammography. MATERIALS AND METHODS: Ten experienced academic breast radiologists across five medical centers independently reviewed 250 de-identified diagnostic mammographic cases that were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. Each radiologist assessed the presence of the following suspicious mammographic findings: mass, asymmetry (one view), focal asymmetry (two views), architectural distortion, and calcifications. For any identified calcifications, the radiologist also described the morphology and distribution. Inter-observer agreement was determined with Fleiss kappa statistic. Agreement was also calculated by years of experience. RESULTS: Of the 250 lesions, 156 (62%) were benign and 94 (38%) were malignant. Agreement among the 10 readers was strongest for recognizing the presence of calcifications (k = 0.82). There was substantial agreement among the readers for the identification of a mass (k = 0.67), whereas agreement was fair for the presence of a focal asymmetry (k = 0.21) or architectural distortion (k = 0.28). Agreement for asymmetries (one view) was slight (k = 0.09). Among the categories of calcification morphology and distribution, reader agreement was moderate (k = 0.51 and k = 0.60, respectively). Readers with more experience (10 or more years in clinical practice) did not demonstrate higher levels of agreement compared to those with less experience. CONCLUSIONS: Strength of agreement varies widely for different types of mammographic findings, even among dedicated academic breast radiologists. More subtle findings such as asymmetries and architectural distortion demonstrated the weakest agreement. Studies that seek to evaluate the predictive value of certain mammographic features for malignancy should take into consideration the inherent interpretive variability for these findings.

Evolving paradigm for imaging, diagnosis, and management of DCIS.

Our understanding of the biology of breast cancer has dramatically expanded over the past decade, revealing that breast cancer is a heterogeneous group of diseases. This new knowledge can generate insights to improve screening performance and the management of ductal carcinoma in situ. In this article, the authors review the current state of the science of breast cancer and tools that can be used to improve screening and risk assessment. They describe several opportunities to improve clinical screening: (1) radiologists interpreting mammograms should aim to differentiate between the risk for invasive cancer and ductal carcinoma in situ to better assess the time frame for disease progression and the need for and optimal timing of biopsy; (2) imaging features associated with low risk, slow-growing cancer versus high risk, fast-growing cancer should be better defined and taught; and (3) as we learn more about assessing an individual's risk for developing breast cancer, we should incorporate these factors into a strategy for personalized screening to maximize benefit and minimize harm.

Cost minimization analysis of ultrasound-guided diagnostic evaluation of probably benign breast lesions.

The objective of this study was to compare direct health care costs for two competing diagnostic strategies for probably benign breast lesions detected by ultrasound in young women. We developed a decision analytic model and performed a cost minimization analysis comparing ultrasound-guided vacuum-assisted core biopsy and conservative short-term diagnostic ultrasound follow-up. Relative probabilities for diagnostic outcomes were derived from pooled analysis of the medical literature. Direct health care costs were estimated using United States national average figures from calendar year 2010. Deterministic sensitivity analyses were conducted, as well as a first-order Monte Carlo simulation to confirm cost differences between the two strategies. The conservative short-term imaging follow-up strategy ($639.55 average cost per patient) was the most economical strategy compared to immediate vacuum-assisted core biopsy ($879.55 average cost per patient). Sensitivity analyses demonstrated that the preferred strategy is most dependent on the probabilities of detecting change in appearance on follow-up ultrasound, having a benign finding on immediate core biopsy, and finding cancer on a biopsy triggered by an interval change in ultrasound appearance. The model was also sensitive to the costs of vacuum-assisted core biopsy and diagnostic ultrasound. Conservative imaging follow-up of BIRADS 3 breast masses by ultrasound is cost saving compared to immediate vacuum-assisted core biopsy, with a potential of saving more than one-third of overall costs associated with the diagnostic work-up of such lesions. Watchful waiting with short-term interval follow-up ultrasounds will spare women from unnecessary procedures and spare the United States health care system from unnecessary direct health care costs.

Patients' willingness to participate in a breast cancer biobank at screening mammogram.

To characterize patients' willingness to donate a biospecimen for future research as part of a breast cancer-related biobank involving a general screening population. We performed a prospective cross-sectional study of 4,217 women aged 21-89 years presenting to our facilities for screening mammogram between December 2010 and October 2011. This HIPAA-compliant study was approved by our institutional review board. We collected data on patients' interest in and actual donation of a biospecimen, motivators and barriers to donating, demographic information, and personal breast cancer risk factors. A multivariate logistic regression analysis was performed to identify patient-level characteristics associated with an increased likelihood to donate. Mean patient age was 57.8 years (SD 11.1 years). While 66.0 % (2,785/4,217) of patients were willing to donate blood or saliva during their visit, only 56.4 % (2,378/4,217) actually donated. Women with a college education (OR = 1.27, p = 0.003), older age (OR = 1.02, p < 0.001), previous breast biopsy (OR = 1.23, p = 0.012), family history of breast cancer (OR = 1.23, p = 0.004), or a comorbidity (OR = 1.22, p = 0.014) were more likely to donate. Asian-American women were significantly less likely to donate (OR = 0.74, p = 0.005). The major reason for donating was to help all future patients (42.3 %) and the major reason for declining donation was privacy concerns (22.3 %). A large proportion of women participating in a breast cancer screening registry are willing to donate blood or saliva to a biobank. Among minority participants, Asian-American women are less likely to donate and further qualitative research is required to identify novel active recruitment strategies to insure their involvement.