Accuracy of ultrasound-guided versus palpation-guided biopsy of palpable breast masses in women at Kenyatta National Hospital: a randomized controlled trial

Abstract

Background: Breast cancer is one of the most common cancers in women. More than 90 percent of patients presenting to Kenyatta National Hospital with complaints of breast disease have a palpable breast mass. The American Society of Breast Surgeons has a consensus guideline stating that image guided biopsy of palpable and non-palpable breast lesions is the standard procedure for obtaining a histological diagnosis of a breast mass. At KNH, biopsies are currently performed using predominantly the palpation guidance method; however, the accuracy of the said method at KNH is not documented. Objectives: To determine the accuracy of ultrasound-guided versus palpation-guided biopsy of palpable breast masses at KNH Methodology: This was a single-blind randomized controlled trial carried out at Kenyatta National Hospital from January 2019 to January 2020, among women who were 18 year and above presenting with palpable breast masses, which were from T1-T3 and from BIRADS 3-5. Seventy-nine women who met the inclusion criteria were randomized into one of two arms, palpation guided or ultrasound guided biopsy. Demographic data, and appropriate physical examination carried out. Biopsy results determined further management as per standard guidelines. Biopsy results were compared with the final histology following surgical excision of the tumours. Data was entered into SPSS and analyzed for means, proportions. Inferential data on sensitivity, specificity, negative predictive value, and positive predictive value was determined from 4 by 4 table and means compared using student-t test. Statistically significant results were taken at p<0.05 with a confidence interval of 95%. Results: There was no statistically significant difference in demographic data and other baseline characteristics. The sensitivity for ultrasound-guided biopsy was 95.7% compared to 87% for palpation-guided biopsy. The specificity and positive predictive values for the two methods was similar at 100%. The false negative rate was 18.8% for palpation-guided biopsy and 5.9% for image-guided biopsy. Conclusion: This study has demonstrated that, in terms of accuracy, ultrasound guided biopsy is superior to palpation guided biopsy, with a higher sensitivity and a lower false negative rate.