[Value of drill-biopsy in breast cancer]

This study reports the results of 649 drill biopsies performed on breast tumors before any treatment. Diagnostic of malignancy was achieved with a drill biopsy in 89% cases (579/649 procedures). Pathological subtypes, i.e. common infiltrating types, special pathological types, were determined in 98% cases (566/579), while histo-prognostic grading, according to Scarff, Bloom and Richardson, was performed in 98% of the common infiltrating type carcinomas (498/507). Reliability of the technique was related to the tumor size 57%, 87.5%, 93.5% and 98.5% in T1, T2, T3 and T4 tumors (TNM classification), respectively. Comparative reliability of the three different operators was 86.5%, 88.5% and 92%, and was related to their technical experience. This study has demonstrated the diagnostic value of a "malignant" drill biopsy, which is independent of the results of the initial radiological and clinical work-up: suspicious or malignant (group A: 635 cases, or non-suspicious group B: 14 cases). However, "non malignant" drill biopsy has no value and should not be conclusive.