No abstract

Our data show that axillary FNAC has moderate sensitivity (which varies according to selection criteria for the test) and consistently high specificity, is associated with low inadequacy and very few false positives. We estimate that its use would have improved triage to initial nodal procedure in about one quarter of our cases. If one accepts the premise that initial surgical staging of the axilla should be based on all information available through pre-operative diagnosis, then axillary FNAC should be adopted routinely into clinical practice.

Breast core needle biopsy (CNB) is used for sampling breast lesions in both the screening and diagnostic context. We present the accuracy of breast CNB from a consecutive series of 4035 core biopsies, using methods that minimise selection and verification bias. We calculate accuracy and underestimation of malignancy for both automated (14G) and directional vacuum-assisted (11G) CNB performed under stereotactic or sonographic guidance. Overall sensitivity of CNB is 94.2% (92.9-95.5%) and specificity is 88.1% (86.6-89.6%), positive and negative predictive values are 84.8% (82.9-86.7%) and 95.6% (94.6-96.6%), respectively. In sampling microcalcification, the overall underestimation of malignancy is 26.6% (22.9-30.3%): underestimation is significantly higher for automated CB relative to VAB (chi2 ((df = 1)) = 8.90 , P = 0.002), the absolute difference in underestimation being 14% (5-23%); sensitivity is higher for VAB than automated CB (chi2 ((df = 1)) = 3.28, P = 0.06) but specificity is significantly higher for automated CB (14G) relative to VAB (11G) (chi2 ((df = 1)) = 6.37, P = 0.01), and the overall accuracy of the two methods is similar. Sensitivity of CNB improved with experience (over time and in relation to caseload). Accuracy was not substantially affected by lesion palpability or image-guidance method, and was similar for both masses and calcification but lower for lesions depicted as distortions on mammography. Inadequacy was very low and decreased with greater operator caseload, and was not associated with core gauge or image-guidance method. False negatives occurred in 4.4% (3.4-5.4%) of cases, and where core histology was benign but discordant with (suspicious) imaging and/or clinical findings the likelihood of malignancy was 33.1% (18.5-47.7%), emphasising the importance of correlating all test information in breast diagnosis.

This study has analysed the generation of 3-(2-deoxy-β-D-erythro-pentafuranosyl) pyrimido [1,2-α] purin-10 (3H)-one deoxyguanosine adduct [M1dG], a biomarker of oxidative stress and lipid peroxidation, in breast fine-needle aspirate samples of 22 patients with breast cancer, at different clinical stages, in respect to 13 controls. The multivariate analysis show that M1dG adduct was higher in cases than in controls (Mean Ratio (MR) = 5.26, 95% CI = 3.16–8.77). Increased M1dG was observed in women with a tumour grade 3 and a pathological diameter 2 (MR = 7.61, 95% CI 3.91–14.80 and MR = 5.75, 95% CI = 3.13–10.59, respectively). A trend with increasing tumour grade and pathological diameter was present (MR = 1.98, 95% CI = 1.57–2.50 and MR = 2.44, 95% CI = 1.71–3.48, respectively). Not significant effects of age and smoking habit were found (MR = 1.58, 95% CI = 0.92–2.72 and MR = 1.68, 95% CI 0.88–3.20, respectively). An increment over the background frequency of M1dG can contribute to breast cancer development. Increasing severity of breast tumour can influence DNA damage level.

FNAC and CNB were generally performed in different patients, thus our study reported indirect comparisons of these tests. Although FNAC performed well (except for relatively high inadequacy), CNB had significantly better performance based on measures of sensitivity, but this was associated with lower specificity for CNB relative to FNAC. Overall, CNB is the more reliable biopsy method for sonographically-visible lesions; where FNAC is used as the first-line test, inadequate or inconclusive FNAC can be largely resolved by using repeat sampling with CNB.