Prospective evaluation of skin surface electropotentials in Japanese patients with suspicious breast lesions

Review of electromagnetic techniques for breast cancer detection

Breast cancer is anticipated to be responsible for almost 40,000 deaths in the USA in 2011. The current clinical detection techniques suffer from limitations which motivated researchers to investigate alternative modalities for the early detection of breast cancer. This paper focuses on reviewing the main electromagnetic techniques for breast cancer detection. More specifically, this work reviews the cutting edge research in microwave imaging, electrical impedance tomography, diffuse optical tomography, microwave radiometry, biomagnetic detection, biopotential detection, and magnetic resonance imaging (MRI). The goal of this paper is to provide biomedical researchers with an in-depth review that includes all main electromagnetic techniques in the literature and the latest progress in each of these techniques.

A role for PP1/NIPP1 in steering migration of human cancer cells

Electrical gradients are present in many developing and regenerating tissues and around tumours. Mimicking endogenous electric fields in vitro has profound effects on the behaviour of many cell types. Intriguingly, specific cell types migrate cathodally, others anodally and some polarise with their long axis perpendicular to the electric vector. These striking phenomena are likely to have in vivo relevance since one of the determining factors during cancer metastasis is the ability to switch between attractive and repulsive migration in response to extracellular guidance stimuli. We present evidence that the cervical cancer cell line HeLa migrates cathodally in a direct current electric field of physiological intensity, while the strongly metastatic prostate cancer cell line PC-3-M migrates anodally. Notably, genetic disruption of protein serine/threonine phosphatase-1 (PP1) and its regulator NIPP1 decrease directional migration in these cell lines. Conversely, the inducible expression of NIPP1 switched the directional response of HeLa cells from cathodal to slightly anodal in a PP1-dependent manner. Remarkably, induction of a hyperactive PP1/NIPP1 holoenzyme, further shifted directional migration towards the anode. We show that PP1 association with NIPP1 upregulates signalling by the GTPase Cdc42 and demonstrate that pharmacological inhibition of Cdc42 in cells overexpressing NIPP1 recovered cathodal migration. Taken together, we provide the first evidence for regulation of directional cell migration by NIPP1. In addition, we identify PP1/NIPP1 as a novel molecular compass that controls directed cell migration via upregulation of Cdc42 signalling and suggest a way by which PP1/NIPP1 may contribute to the migratory properties of cancer cells.

Biopotential signals of breast cancer versus tumor types and proliferation stages

Clinical studies have shown compelling data of elevated biopotential signals recorded noninvasively from the breasts of women with breast cancer. While these data are compelling and show a strong potential for use in the noninvasive early detection of breast cancer, there remains significant knowledge gaps which must be addressed before this technology can be routinely used for breast cancer detection. A diffusion-drift model is developed to study the spatial and temporal characteristics of the biopotential signals of breast tumors taking into account the morphology and cell division stages. The electric signals of the most common tumor types-papillary, compact, and comedo-are also considered. The largest biopotential signal is observed from the compact tumor, while the smallest signal is observed from the papillary type. The results also show an increase in the time duration of the generated biopotential signals when cancer cells start their transitions at different time instants. The spatial and temporal variations of the biopotential signals are correlated with the tumor pattern which can have important implications for breast cancer detection.

Data mining approach to evaluating the use of skin surface electropotentials for breast cancer detection

The Biofield Diagnostic System (BDS) uses a score formed with measured skin surface electropotentials and a prior Level Of Suspicion (LOS) value (predicted by the physician based on the patient's ultrasound or mammography results) to calculate a revised Post-BDS LOS to indicate the presence of breast cancer. The demographic details, BDS test results, and the recorded electropotential values form a potentially useful dataset, which can be further explored with data mining tools to extract important information that can be used to improve the current predictive accuracy of the device. According to the proposed data mining framework, the BDS dataset with 291 cases was first pre-processed to remove outliers and then used to select relevant and informative features for classifier development and finally to evaluate the capability of the built classifiers in detecting the presence of the disease. Two popular feature selection techniques, namely, the filter and wrapper methods, were used in parallel for feature selection. A few statistical inference based classifiers and neural networks were used for classification. The proposed technique significantly improved the BDS prediction accuracy. Also, the use of prior LOS and, hence, the Post-BDS LOS, associates a mild subjective interpretation to the current prediction methodology used by BDS. However, the feature subset selected in our analysis that gave the best accuracy did not use either of these features. This result indicates the possibility of using BDS as a better objective assessment tool for breast cancer detection.

The use of skin surface electropotentials for breast cancer detection--preliminary clinical trial results obtained using the biofield diagnostic system

The purpose of this study is to evaluate the efficiency of the Biofield Diagnostic System (BDS) as an adjunct to established diagnostic techniques such as mammography and ultrasound in differentiating benign and malignant breast lesions. The clinical trial was conducted at the Tan Tock Seng hospital, Singapore. 103 women scheduled for mammography and/or ultrasound tests participated in the study. The BDS test recorded a sensitivity of 100%, specificity of 97.6%, and an accuracy of 98.1%. The area under the ROC curve was 0.988 which was slightly lower than that of ultrasound (0.994) and slightly higher than that of mammography (0.951). The BDS test has demonstrated high sensitivity and specificity values in the studied population. The accuracy is also comparable to that of diagnostic techniques like mammography and ultrasound. Thus, it is evident that BDS can be a fast and reliable adjunct tool for getting a secondary opinion on lesions with indeterminate mammographic and sonographic results.

The Use of Tissue Electrical Characteristics for Breast Cancer Detection: A Perspective Review

Breast cancer is the most frequently occurring malignancy in women. It is characterized by a high mortality rate. For the purpose of detecting this life threatening disease, research efforts are being made worldwide to exploit new technologies, to improve the detection accuracy of current devices and to develop new detection devices, comprehensive diagnostic procedures, and protocols. One such technology that is gaining popular attention over the recent years is the usage of electrical characteristics of the breast tissue to differentiate normal and cancerous tissues. Most of the devices using this technology are currently being used as adjunct diagnostic tools to improve the detection accuracy of established techniques like mammography and ultrasound. Also, early detection of breast cancer can help save many thousands of lives every year and can also reduce unnecessary healthcare expenditure caused by advanced stage treatment options. Hence, more research is also being done to adapt these devices into screening tools for early detection of breast cancer.

The main objective of this review is to highlight the features of the currently available commercial devices that use this technology for breast cancer detection. The electrical behavior of normal and cancerous breast tissues is first presented. The various commercial devices that utilize electrical impedance or electropotentials for breast cancer detection are then described. Finally, conclusions and potential areas of research are highlighted.

Statistical and fractal analyses of rat prostate cancer cell motility in a direct current electric field: comparison of strongly and weakly metastatic cells

The problems addressed here comprised (1) possible differences in galvanotactic properties of strongly versus weakly metastatic rat prostate cancer cells, with MAT-LyLu and AT-2 as examples, respectively; (2) quantitative description of the responses of the MAT-LyLu cells to direct current (dc) electric fields (EFs) of physiological strength (0.3-3 V/cm); and (3) voltage and time dependency of the cells' responses to the dcEFs. These issues were studied by application of statistical and fractal analyses of the cells' trajectories. The results showed that the MAT-LyLu cells responded strongly to the applied dcEFs by migrating towards the cathode. On the other hand, the galvanotactic response of the AT-2 cells was weak and towards the anode. Further studies of the MAT-LyLu cell motility in dcEFs of increasing strength showed that their response consisted of two voltage domains. Weaker fields (approximately 0.6 V/cm) induced "straightening" of the cells' trajectories without the cells showing a clear tendency to move along the applied field. Stronger fields (>0.6 V/cm) made the cells' movement oriented with respect to the direction of the applied field, without further changing the trajectories' structure. The results also showed that the cells do not perform a directed movement instantaneously after switching on a dcEF of 3 V/cm; approximately 30 min lapsed before the cells were able to fully follow the direction of the applied field. Possible biophysical bases and pathophysiological significance of the results obtained are discussed.