Positive Predictive Value of Mammographic Report BI-RADS Category 4 and 5 Correlating with Pathologic Results in Lampang Hospital
Somrat Thinyu · Lampang Medical Journal - ลำปางเวชสาร · 2013
Abstract Background : Mammography is a standard tool for detecting breast cancer. The Breast Imaging Reporting and Data System (BI-RADS) had been established for standardizing the terminology in mammographic reports on the level of suspicion. BI-RADS categories 4 and 5 indicate that biopsy and appropriate action should be taken. Its positive predictive value (PPV) has not been studied in Lampang Hospital. Objective: To determine PPV of mammographic reports according to the BI-RADS categories 4 and 5 for diagnosis of breast cancer. Material and method: A retrospective study was conducted on 398 patients whom reported with BI-RADS 4 and 5 in screening and diagnostic mammography between January 2008 and December 2010 in Lampang Hospital. The findings of mammogram accompany with ultrasound were reviewed and correlated with subsequent tissue pathology. The PPV were calculated. Results: The mean age was 52.3 ± 11.6 years (range, 24-92). Screening mammogram was performed in 31 cases and diagnostic study in 367 cases. The PPV of BI-RADS 4 was 47.8% (99/207 cases) and BI-RADS 5 was 84.8% (162/191 cases). Combined BI-RADS categories 4 and 5 yielded the PPV in screening and diagnostic groups for 58.1% and 66.2% respectively. Among 261 cases of malignancy, 77.0% was invasive ductal carcinoma and 11.9% was ductal carcinoma in situ. Fibrocystic change (41.6 %) and fibroadenoma (16.1%) were the most common findings in 137 patients with benign lesions. Conclusion: PPV of BI-RADS category 4 and 5 for detecting breast cancer in Lampang Hospital was comparable with other previous studies. However, preoperative biopsy should be obtained in all suspicious mammographic findings because of the overlap in radiological appearances of benign and malignant lesions.