Massachusetts General HospitalTechnical enhancements to a microchip-based device for identifying and examining tumor cells in the bloodstream are said to be disclosing cellular differences that could expose a tumor’s aggressiveness and long-term response to treatment.

A report from the Massachusetts General Hospital (MGH) Center for Engineering in Medicine apparently defines alterations to the MGH-developed CTC-chip, which could gauge levels of circulating tumor cells (CTCs) in the blood stream. This could enable improved evaluation of how CTC levels respond to treatment for prostate cancer and divulge key biological properties of the cells.

CTCs are claimed to be living solid-tumor cells discovered at exceedingly low levels in the bloodstream. Until the 2007 development of the CTC-chip by researchers from the MGH Cancer Center and Center for Engineering in Medicine, it may not be feasible to receive details from CTCs that could be helpful for clinical decision making. The updated system defined in the present report appears to include enhanced imaging technology, thereby enabling more absolute visualization of cells arrested by the device. The new software appears to automate the recognition of CTCs by means of criteria definite to the specific kind of tumor.

Shannon Stott, PhD, of the MGH Center for Engineering in Medicine, the study’s lead author, commented, “The earlier versions of the CTC-chip required hand-counting of thousands of microscopic images, which was sufficient for the initial proof-of-principle studies but far too time-intensive for handling high volumes of patient samples. We also were limited in our ability to analyze cellular factors that could be markers for important properties of the tumors.”

The MGH team applied the automated system to examine CTCs from roughly two groups of prostate cancer patients. After the cells were primarily arrested on the CTC-chip, which is enclosed with microscopic posts encrusted with antibody to a general tumor protein, the cells were believed to be tagged by means of an antibody to prostate-specific antigen. This may enable swift scanning and more inclusive visualization of the CTCs.

Samples taken from a group of men with localized prostate cancer before and at numerous intervals following surgical elimination illustrated that while CTCs vanished instantly post surgery in a few patients, CTC levels appeared to decline only moderately in others. Examining CTCs from a group of patients being treated for metastatic prostate cancer disclosed that, among patients whose tumors were reacting to treatment, only some CTCs could exhibit a marker discovered on proliferating cells. But in patients whose tumors were not responding, most of the CTCs apparently showed the proliferation marker.

The findings were published in Science Translational Medicine.