Preoperative Assessment of Small Tumours in Women with Breast Cancer

BACKGROUND AND OBJECTIVES: In patients with breast cancer, planning of the surgical strategy may rely on preoperative tumour size. The optimal method for assessment of small tumours has not been established. We compared findings from preoperative mammography and ultrasonography with histopathological tumour size in patients treated with breast-conserving surgery. MATERIAL AND METHODS: The study was retrospective and the setting a single institution clinic with free referral of patients. The patients were examined before the operation with mammography, ultrasonography, and findings were compared with postoperative histopathological tumour size. RESULTS: The study included 131 patients (median age was 59) years with grade I, II, and III cancers in 47, 71 and in 13 patients, respectively. The medium histological tumour size was 14 mm, range 4-45 mm. A wide 95% confidence interval between histopathological tumour size and preoperative mammography (standard deviation 4.8 mm) and ultrasonography (standard deviation 4.8 mm) was found. The combination of mammography and ultrasonography did not improve the results (standard deviation 4.3 mm). Preoperative mammography tended to over estimate the tumour size compared with histological tumour size whereas preoperative ultrasonography tended to underestimate the tumour size. CONCLUSION: In this retrospective study with preoperative evaluation of small breast cancers by mammography and ultrasonography, wide 95% confidence intervals for the methods were found and they should therefore be used with caution in the planning of the surgical strategy.