Label-free multiphoton imaging to assess neoadjuvant therapy responses in breast carcinoma

Abstract

Neoadjuvant chemotherapy has been used increasingly in patients with early-stage or locally advanced breast carcinoma, and has been recommended as a general approach in locally advanced-stage diseases. Assessing therapy response could offer prognostic information to help determine subsequent nursing plan; particularly it is essential to identify responders and non-responders for the sake of helping develop follow-up treatment strategies. However, at present, diagnostic accuracy of preoperative clinical examination are still not satisfactory. Here we presented an alternate approach to monitor tumor and stroma changes associated with neoadjuvant therapy responses in breast carcinoma, with a great potential for becoming a new diagnostic tool-multiphoton microscopy. Imaging results showed that multiphoton imaging techniques have the ability to label-freely visualize tumor response such as tumor necrosis, and stromal response including fibrosis, mucinous response, inflammatory response as well as vascular hyperplasia in situ at cellular and subcellular levels. Moreover, using automated image analysis and a set of scoring methods, we found significant differences in the area of cell nucleus and in the content of collagen fibers between the pre-treatment and post-treatment breast carcinoma tissues. In summary, this study was conducted to pathologically evaluate the response of breast carcinoma to preoperative chemotherapy as well as to assess the efficacy of multiphoton microscopy in detecting these pathological changes, and experimental results demonstrated that this microscope may be a promising tool for label-free, real-time assessment of treatment response without the use of any exogenous contrast agents.

Second-Harmonic Generation Imaging Reveals Changes in Breast Tumor Collagen Induced by Neoadjuvant Chemotherapy

“…For example, cancer-associated fibroblasts (CAF) are stromal cells activated by tumor-secreted factors that play a role in ECM remodeling and tumor cell survival [ 46 ]. NACT is known to stimulate CAF recruitment, leading to increased tumor ECM density and stiffness through excess stromal protein and lysyl oxidase (LOX) production [ 47 , 48 ]. Blocking LOX-like 2, a member of the LOX enzyme family, alters collagen fibril thickness and organization, in turn disrupting human breast tumor cell motility, adhesion, and invasion [ 49 ].…”

Detection of pathological response of axillary lymph node metastasis after neoadjuvant chemotherapy in breast cancer using multiphoton microscopy

“…MPM also known as label-free histopathology, has been used for assessing breast pathologies [28,29], such as normal breast tissues, ductal carcinoma in situ (DCIS) as well as invasive carcinoma, and monitoring pathological changes in tumor microenvironment [30][31][32]. Recently, we have used MPM combining TPAF with SHG imaging to evaluate neoadjuvant therapy responses in breast carcinoma [14,17]. These studies suggest that MPM can be utilized for assessing the pathological response of axillary lymphatic metastasis induced by preoperative chemotherapy.…”

“…Due to its several advantages such as low damage, low photobleaching, high resolution and without the need for exogenous contrast agents, this imaging technique attracts a lot of attention and has been widely used for the diagnoses of cancer [11][12][13]. More importantly, MPM has been used for treatment evaluation, and imaging results show that this tool can instantly and label-free visualize pathologic changes in tumor microenvironment to detect residual tumors and stromal response [14,15], which may be helpful for the clinicians to rapidly and accurately make approximate treatment strategy after surgery. These researches suggest the utility of MPM for the detection of pathological response of axillary lymphatic metastasis after neoadjuvant treatment in breast cancer.…”

Evaluation of histopathological response to neoadjuvant therapy in rectal cancer using slide‐free, stain‐free multimodal multiphoton microscopy

“…Due to these advantages, in the past decade there has been an increasing number of studies that explored the application of MPM for biological tissue imaging and monitoring the changes during carcinogenesis, tumor progression, metastasis, and antitumor treatment in various types of cancers [3,[21][22][23][24][25][26]. Recently, several studies also explored MPM imaging for the evaluation of neoadjuvant responses in a variety of cancer types including breast and rectal cancer [3,25,27].…”

“…Due to these advantages, in the past decade there has been an increasing number of studies that explored the application of MPM for biological tissue imaging and monitoring the changes during carcinogenesis, tumor progression, metastasis, and antitumor treatment in various types of cancers [3,[21][22][23][24][25][26]. Recently, several studies also explored MPM imaging for the evaluation of neoadjuvant responses in a variety of cancer types including breast and rectal cancer [3,25,27]. These studies typically required frozen sectioning and focused mainly on the fibrotic reactions, in particular the changes to the fibrotic morphology including collagen fiber orientation, fibrosis density, and percentage areas of fibrosis.…”