Diagnostic accuracy of clinical breast examination for breast cancer in patients with palpable breast lump in a middle income country

Abstract

Background: Breast cancer assessment using breast self-examination (BSE), clinical breast examination (CBE) and mammography are secondary measures that aid in early detection of breast cancer and better management.
Objective: The aim of this study is to evaluate the sensitivity, specificity, false positive and false negative rates of clinical breast examination for palpable breast masses at Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria.
Methodology: This is a one-year prospective study from February 2009 to January 2010. All the consecutive patients with palpable breast lesions presenting at the general surgery out-patient clinics were recruited and evaluated clinically. Biopsy was performed on all the patients (open or core needle) and histology reports obtained. Data collected were recorded in a proforma and subsequently analyzed.
Results: The age range of the patients was 16-73years (mean=36.9 SD 14.5). Out of the 110 patients, 109 were females and one was male, giving a male to female ratio of 1:109. Clinical breast examination achieved true positive value of 47(42.7%); true negative value 52(47.3%); false positive and false negative values 6(5.5%) and 5(4.5%), respectively. It also achieved the following diagnostic validities: sensitivity of 90.4%; specificity 89.7%; false positive rate 11.3%; false negative rate 8.8%; positive predictive value 88.7%; negative predictive value 91.2% and overall diagnostic accuracy of 90%.
Conclusion: Clinical breast examination in trained hands is a useful tool for assessing breast cancer especially in resource poor countries where mammography is still largely unavailable. We recommend this examination to all women from the age of 20years especially in people with positive family history of breast cancer.

Keywords: Biopsy, false-negatives, false-positives, family history,
mammography