Do clinical and radiologic features help predict malignancy of B3 breast lesions without epithelial atypia (B3a)?

Apparent diffusion coefficient magnetic resonance imaging (ADC-MRI) in the axillary breast cancer lymph node metastasis detection: a narrative review

The presence of axillary lymph nodes metastases in breast cancer is the most significant prognostic factor, with a great impact on morbidity, disease-related survival and management of oncological therapies; for this reason, adequate imaging evaluation is strictly necessary. Physical examination is not enough sensitive to assess breast cancer nodal status; axillary ultrasonography (US) is commonly used to detect suspected or occult nodal metastasis, providing exclusively morphological evaluation, with low sensitivity and positive predictive value. Currently, sentinel lymph node biopsy (SLNB) and/or axillary dissection are the milestone for the diagnostic assessment of axillary lymph node metastases, although its related morbidity. The impact of magnetic resonance imaging (MRI) in the detection of nodal metastases has been widely investigated, as it continues to represent the most promising imaging modality in the breast cancer management. In particular, diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values represent additional reliable non-contrast sequences, able to improve the diagnostic accuracy of breast cancer MRI evaluation. Several studies largely demonstrated the usefulness of implementing DWI/ADC MRI in the characterization of breast lesions. Herein, in the light of our clinical experience, we perform a review of the literature regarding the diagnostic performance and accuracy of ADC value as potential pre-operative tool to define metastatic involvement of nodal structures in breast cancer patients. For the purpose of this review, PubMed, Web of Science, and SCOPUS electronic databases were searched with different combinations of "axillary lymph node", "breast cancer", "MRI/ADC", "breast MRI" keywords. All original articles, reviews and metanalyses were included.

External Validation of a Risk Stratification Score for B3 Breast Lesions Detected at Ultrasound Core Needle Biopsy

OBJECTIVE

The aim of this study was to externally validate the feasibility and robustness of a risk-stratification score for B3 lesions based on clinical, pathological, and radiological data for improved clinical decision making.

METHODS

129 consecutive histologically confirmed B3 lesions diagnosed at ultrasound-guided biopsy at our institution were included in this retrospective study. Patient- and lesion-related variables were independently assessed by two blinded breast radiologists (R1, R2), by assigning each feature a score from 0 to 2 (maximum sum-score of 5). Sensitivity, specificity, positive and negative predictive values were calculated at two different thresholds (≥1 and 2). Categorical variables were compared using Chi-squared and Fisher exact tests. The diagnostic accuracy of the score to distinguish benign from malignant B3 lesions was assessed by receiver operating characteristic (ROC) analysis.

RESULTS

Surgery was performed on 117/129 (90.6%) lesions and 11 of these 117 (9.4%) lesions were malignant. No cancers were found at follow-up of at least 24 months. Area under the ROC-curve was 0.736 (R1) to 0.747 (R2), with no significant difference between the two readers (p = 0.5015). Using a threshold of ≥1, a sensitivity, specificity, PPV, and NPV of 90%/90% (R1/R2), 39%/38% (R1/R2), 11%/12% (R1/R2) and 97%/98% (R1/R2) were identified. Both readers classified 47 lesions with a score ≤1 (low risk of associated malignancy). Of these, only one malignant lesion was underdiagnosed (Ductal carcinoma in situ-G1).

CONCLUSIONS

In our external validation, the score showed a high negative predictive value and has the potential to reduce unnecessary surgeries or re-biopsies for ultrasound-detected B3-lesions by up to 39%.

Apparent diffusion coefficient value in breast papillary lesions without atypia at core needle biopsy

PURPOSE

The main aim of the study was to assess if the mean apparent diffusion coefficient (ADC) value was significantly different between papillary lesions (PL) without atypia and PLs with atypical or malignant foci. A secondary objective was to evaluate if patients mean age, MRI BI-RADS® descriptors and assessment category were significantly different between these two PL groups.

METHODS

In this eight year retrospective study were included 122 patients (mean age, 51 years; range, 24-78) with 122 PLs without atypia at micro-histological examination after core needle biopsy (CNB) performed under sonographic guidance. All patients underwent surgical excision biopsy within 3 months after CNB. All patients underwent MRI examination before surgical excision, including STIR, DWI and Dynamic Contrast-Enhanced sequences.

RESULTS

Mean ADC value difference between PLs without and with atypia or malignant foci was statistically significant (p < 0.0001). Mean ADC value optimal threshold in order to distinguish the two groups was 1.418 × 10^-3 mm²/s. A mean ADC value ≤ 1.418 × 10^-3 mm²/s could predict atypical or malignant foci within a PL with 83.9% sensitivity and 75.8% specificity. No statistically significant difference was found with regard to patients mean age, MRI BI-RADS® descriptors and assessment category between these two PL groups.

CONCLUSIONS

Mean ADC value of PLs without atypia at CNB is an efficient tool in order to help distinguish between PLs without and with atypical or malignant foci at final pathology on surgical excision, and it could be used to help decide how to manage these lesions.