Collagen analysis by second-harmonic generation microscopy predicts outcome of luminal breast cancer

Abstract

Second-harmonic generation microscopy represents an important tool to evaluate extracellular matrix collagen structure, which undergoes changes during cancer progression. Thus, it is potentially relevant to assess breast cancer development. We propose the use of second-harmonic generation images of tumor stroma selected on hematoxylin and eosin-stained slides to evaluate the prognostic value of collagen fibers analyses in peri and intratumoral areas in patients diagnosed with invasive ductal breast carcinoma. Quantitative analyses of collagen parameters were performed using ImageJ software. These parameters presented significantly higher values in peri than in intratumoral areas. Higher intratumoral collagen uniformity was associated with high pathological stages and with the presence of axillary lymph node metastasis. In patients with immunohistochemistry-based luminal subtype, higher intratumoral collagen uniformity and quantity were independently associated with poorer relapse-free and overall survival, respectively. A multivariate response recursive partitioning model determined 12.857 and 11.894 as the best cut-offs for intratumoral collagen quantity and uniformity, respectively. These values have shown high sensitivity and specificity to differentiate distinct outcomes. Values of intratumoral collagen quantity and uniformity exceeding the cut-offs were strongly associated with poorer relapse-free and overall survival. Our findings support a promising prognostic value of quantitative evaluation of intratumoral collagen by second-harmonic generation imaging mainly in the luminal subtype breast cancer.

Study on collagen parameters in vulvar cancer and preneoplastic lesions by Second Harmonic Generation microscopy

“…Additionally, patients with metastatic VSCC presented higher COL parameters than those without metastases. These findings agree with our previous study on luminal breast cancer, in which intratumoral COL parameters were reduced in comparison to peritumoral areas 14 . Similarly, patients with parameters associated with more aggressive disease, considered a rare cancer of elderly women, has been increasing in incidence in younger women over the last few decades [16][17][18] .…”

“…Slides stained with H&E were submitted to the identification and selection of collagen (COL) in the stromal areas adjacent to VIN, in intratumoral stroma, and in normal adjacent tissues. In each case, three areas were selected, and these areas were submitted to SHG analyses at the INFABiC -Unicamp 14 .…”

“…Scientific RepoRtS |(2020) 10:5568 | https://doi.org/10.1038/s41598-020-62346-8www.nature.com/scientificreports www.nature.com/scientificreports/ presented higher intratumoral COL values14 . Using another method to evaluate COL expression, it was recently found that higher values in VSCC were associated to superior aggressiveness12 .SHG microscopy has been used over the last few years to analyze COL in several types of cancer, due to its high sensitivity and specificity11,12,15 .…”

Method forin vivoassessment of cancer tissue inhomogeneity and accurate histology-like morphological segmentation based on Optical Coherence Elastography

“…In view of this, significant attention has been paid to the development of alternative fast and noninvasive ways of obtaining information about biological tissues similar to the results of histological image interpretation. In this context, various optical methods have been proposed, in particular the use of variations in auto-fluorescence properties to detect tumor cells 1,2 or the generation of higher harmonics, which can be used to detect the presence of collagen and elastin 3 . The use of Optical Coherence Tomography (OCT) for such purposes is also attracting much attention, because the characteristic scales of OCT scans occupy an intermediate place between macroscopic imaging (like medical ultrasound) and cell-resolution microscopy.…”

Second-harmonic generation directionality is associated with neoadjuvant chemotherapy response in breast cancer core needle biopsies

“…8,9 SHG imaging has been used to study collagen remodeling in BC using a number of analysis methods. [10][11][12] Provenzano et al 13 identified "tumor-associated collagen signatures" (TACS) by assessing fiber density and alignment relative to the tumor boundary during early disease, in-situ breast carcinomas, and invasive BC. Using a manual approach, TACS-3 (fiber alignment orthogonal to tumor boundary) was shown to be prognostic of disease-free survival by Conklin et al 9 Polarization-based SHG reflects the pitch angle of α-helices within the collagen triple helix, which change with BC progression and has been applied to mouse models and human samples.…”