Real Index of Refraction of Normal and Cancerous Axillary Lymph Nodes in Breast Cancer Patients: Results from an Experimental Study

<b>Background:</b> Breast malignancy is the most common cancer type and the second leading cause of cancer-related death for women all ages. Axillary surgery provides prognostic and predictive information, but carries significant morbidity. Imaging techniques are a promising field, providing the characterization of biological tissues using the interaction between the light and a medium, and may offer an accurate cancerous diagnosis without the need for formal histopathological examination. <b>Methods:</b> In this study, using a prism couple refractometer, we sought to determine tissues' reflection profiles in freshly excised human lymph nodes from female patients with breast cancer, in whom axillary lymph node dissection was performed. <b>Results:</b> Thirty-four patients were included, contributing a total number of 90 lymph nodes and, according to our results, the median refractive indices were significantly higher in cancerous lymph nodes compared to normal lymph nodes in 450 nm, 964 nm, and 1551 nm wavelengths (<i>p</i> < 0.05). <b>Conclusions:</b> Results from this small experimental study imply that the use of a prism couple refractometer may aid in the discrimination between benign and malignant axillary lymph nodes in female patients with breast cancer.