RATE OF INSUFFICIENT SAMPLES FOR FINE-NEEDLE ASPIRATION FOR NONPALPABLE BREAST-LESIONS IN A MULTICENTER CLINICAL-TRIAL - THE RADIOLOGIC DIAGNOSTIC ONCOLOGY GROUP-5 STUDY

BACKGROUND. Radiologic Diagnostic Oncology Group 5 is a multicenter cl inical trial designed to evaluate fine-needle aspiration (FNA) of nonp alpable breast lesions performed by multiple operators using the same protocol. METHODS. Four hundred and nineteen women with mammographical ly detected nonpalpable breast lesions were enrolled on the trial at 1 8 institutions. Group A institutions randomized women to stereotactica lly guided FNA (SFNA) followed by stereotactically guided core needle biopsy (SCNB), or SCNB only. Group B institutions randomized women to SFNA and SCNB, SCNB, or ultrasonographically guided FNA followed by ul trasonographically guided core needle biopsy (USCNB), or USCNB only. A total of 377 women were eligible for analysis. RESULTS. FNA yielded 1 28 insufficient samples for the 377 patients (33.95%; 95% confidence i nterval, 29.2-38.7%). The rate of insufficient samples varied by type of lesion with calcified lesions associated with a significantly highe r rate of insufficient sampling than masses (P < 0.001). The radiologi st's level of suspicion of the lesion was not a statistically signific ant predictor of insufficient samples for mass lesions, but was a pred ictor for calcified lesions. For the 336 lesions for which histologic information was available, insufficient samples occurred in significan tly more benign than malignant lesions. CONCLUSIONS. The high rate of insufficient samples for FNA of nonpalpable breast lesions in this mul ticenter trial makes its use impractical in this setting. Because of t his factor, the study was terminated early. (C) 1998 American Cancer S ociety.