Accuracy of Mammography in the Diagnosis of Breast Cancer

Background: Breast cancer is one of the leading causes of cancer-related deaths among women worldwide. Mammography was recently introduced at the Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria for breast cancer screening and diagnosis at the institution. Objective: The objective of this study is to determine the diagnostic accuracy of mammography in the assessment of palpable malignant breast lump among adult females referred from the NAUTH outpatient clinics using histopathology as gold standard. Materials and Methods: This prospective cross sectional study involved recruitment of consenting adult females with palpable breast lump referred for mammography between October 2017 and November 2019 at NAUTH, Nnewi, Nigeria. Two standard views—cranio-caudal (CC) and medio-lateral oblique (MLO)—were done for each patient. Spot magnification or other supplementary views were only done when indicated. Data analysis was done using Statistical Package for the Social Sciences (SPSS) version 21.0 for Windows software. Results: The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of malignant breast lesions were 41.4%, 98%, 96.7%, 54.4%, and 65%, respectively. The most common features of malignancy were mammographic opacity with an irregular outline (86.7%) and architectural distortion (80%), whereas asymmetric density (10%) was the least common feature. Conclusion: Mammography has a fairly high overall diagnostic accuracy in breast cancer diagnosis. However, an alternative imaging modality is required for dense breasts. This study’s reported specificity (98%) suggests that the test has a very high ability to correctly identify non-cancerous breast lumps. This is particularly relevant in breast cancer screening with an objective to rule out the presence of the disease among adult females in the population.