Prediction of Sentinel Lymph Node Biopsy Status in Breast Cancers with PET/CT Negative Axilla

Lighthouses illuminating tumor metastasis: The application of fluorescent probes in the localization and imaging metastatic lymph nodes across various tumors

The significance of metastatic lymph nodes in tumor diagnosis and prognosis is self-evident. With the deepening of research on the lymphatic system and the advancement of imaging technology, an increasing number of near-infrared fluorescent probes targeting tumor metastatic lymph nodes have been developed. These probes can identify tumors while further detecting lymph nodes (LNs), showcasing great potential in image-guided surgery. In this review, we comprehensively outline the design strategies and applications of near-infrared fluorescent probes for cancers with a high propensity for lymph node metastasis during disease progression. Particular emphasis is placed on two targeting mechanisms: tumor-directed probes capable of identifying metastatic lymph nodes and lymph node-specific probes utilizing passive targeting of metastatic lymph nodes or active targeting of lymph nodes directly. Additionally, we discuss current issues and future prospects in this field, which will facilitate the development of new fluorescent probes and their further clinical translation.

Investigating the role of tumour-to-skin proximity in predicting nodal metastasis in breast cancer

BACKGROUND

Understanding the factors influencing nodal status in breast cancer is vital for axillary staging, therapy, and patient survival. The nodal stage remains a crucial factor in prognostication indices. This study investigates the relationship between tumour-to-skin distance (in T1-T3 tumours where the skin is not clinically involved) and the risk of nodal metastasis.

METHODS

We retrospectively reviewed data from 100 patients who underwent neoadjuvant chemotherapy (NACT). Besides patient demographics and tumour variables, a radiologist retrospectively reviewed pre-operative MRI to measure tumour-to-skin distance. R core packages were used for univariate (χ2 and T-Wilcoxon tests) and bivariate logistic regression statistical analysis.

RESULTS

Of 95 analysable datasets, patients' median age was 51 years (IQR: 42-61), 97% were symptomatic (rest screen detected), and the median tumour size was 43 mm (IQR, 26-52). On multivariate analysis, increasing invasive tumour size (p = 0.02), ER positivity (p = 0.007) and shorter tumour-to-skin distance (p = 0.05) correlated with nodal metastasis.  HER2 was not included in multivariate analysis as there was no association with nodal status on univariate analysis. In node-positive tumours, as tumour size increased, the tumour-to-skin distance decreased (r = - 0.34, p = 0.026). In node-negative tumours, there was no correlation (r = + 0.18, p = 0.23).

CONCLUSION

This study shows that non-locally advanced cancers closer to the skin (and consequent proximity to subdermal lymphatics) are associated with a greater risk of nodal metastasis. Pre-operative identification of those more likely to be node positive may suggest the need for a second-look USS since a higher nodal stage may lead to a change in therapeutic strategies, such as upfront systemic therapy, node marking, and axillary clearance without the need to return to theatre following sentinel node biopsy.