Hypothesis: Core-needle biopsy (CNB) and fine-needle aspiration (FNA) play an important role in the initial diagnosis of breast cancer. However, CNB might alter the size of the tumor, which might subsequently change its pathologic stage and thus affect the decision about adjuvant chemotherapy.
Patients: Between January 2000 and May 2002, we studied 291 patients with invasive carcinoma lesion in a retrospective analysis. One hundred ninety-nine patients underwent ultrasonography-guided CNB. Ninety-two patients had FNA before surgical manipulation.
Main outcome measures: The clinically measured tumor size using ultrasonography was compared with the pathologic tumor size in both the CNB and FNA groups. The difference in each group was determined and analyzed using a t test. The mean +/- SD preoperative ultrasonographically measured size in the CNB group was 2.09 +/- 1.06 cm and in the FNA group, 2.16 +/- 0.92 cm (no significant difference). The pathologic measurement of the lesion on surgical specimens revealed that the mean pathologic tumor size was 2.09 +/- 0.90 cm in the CNB group and 2.36 +/- 0.92 cm in the FNA group. The changes in size from preoperative measurements by ultrasonography to pathologic measurements on surgical specimens were greater in the CNB group (0.003 +/- 0.65 cm) than in the FNA group (0.20 +/- 0.39 cm; P = .001).
Conclusions: Although the reduction in tumor size might be small with patients who undergo CNB, it must be considered when deciding adjuvant treatment, especially for tumor sizes on the "borderline" in establishing the indication for and the type of adjuvant treatment.