Abstract P4-03-06: Initial ex-vivo study of the ability of an in situ fluorescence spectroscopy probe to distinguish benign from malignant breast tissues

Abstract

Abstract Background: The native fluorescence spectra of human cancerous and normal breast tissues under the selected excitation of a 405 nm light should differ according to their different content of NAD(P)H, FAD, collagen or retinol and derived fluorophores. Nodea Medical has developed an in situ probe, Probea®, installed in a 25-Gauge needle, which is able to measure endogenous tissue fluorescence under 405 nm specific wavelength. Tissues are excited by this blue light; their back-production of fluorescence (around 480 nm) is caught and immediately analyzed. The objectives of the present preclinical study are to evaluate the ability of the Probea® probe to distinguish benign versus malignant breast lesions among freshly harvested ex-vivo surgical samples, and to evaluate the fluorescence behaviour of adjacent and remote normal tissues among cancer specimens. Methods: Fresh breast samples coming out of the operating room were harvested and analyzed prior to pathological fixation. Surgical specimens included mastectomies, lumpectomies, and plastic surgeries in different malignant or non-malignant situations. For each of them, the probe was placed within the main target surgical lesion, as well as within surrounding normal epithelial and fat tissues, and remote normal tissues where available (mastectomies or reduction mammoplasties). We aimed at measuring different parameters of the endogenous fluorescence at each measurement point: maximum intensity, peak wavelength, level of signal stability, growth or spontaneous decay in a fixed position. Fluorescence signals harvested were compared to the detailed pathological analyses of each area explored within the surgical samples. Results : 49 fresh breast samples were harvested and analyzed, of which 40 were from patients with cancer and 9 from patients without cancer. The presence of a fluorescence signal within the main lesion was overall strongly associated with a cancer diagnosis (N = 40/49 malignant lesions versus 0/9 benign lesions, p = 0.001). The positive predictive value of the test in this preliminary series is 98%, whereas the negative predictive value is 100% analyzing the maximum fluorescence intensity with a cut-off of 1000. Interestingly, normal adjacent fat tissues surrounding and remote from breast cancer lesions also produced fluorescence which could also be considered as criteria to define malignancy. Complete analyses of multiple parameters are ongoing. Conclusion: In this initial preclinical study, the Probea® probe has shown an elective ability to distinguish benign and malignant lesions. Particularly, its negative predictive value appears very promising. A clinical study to confirm these findings is planned. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-03-06.