Massachusetts General Hospital (MGH) investigators have shown that an MGH-developed, microchip-based device that detects and analyzes tumor cells in the bloodstream can be used to determine the genetic signature of lung tumors, allowing identification of those appropriate for targeted treatment and monitoring genetic changes that occur during therapy. A pilot study of the device called the CTC-chip will appear in the July 24 New England Journal of Medicine and is receiving early online release.
“The CTC-chip opens up a whole new field of studying tumors in real time,” says Daniel Haber, MD, PhD, director of the MGH Cancer Center and the study’s senior author. “When the device is ready for larger clinical trials, it should give us new options for measuring treatment response, defining prognostic and predictive measures, and studying the biology of blood-borne metastasis, which is the primary method by which cancer spreads and becomes lethal.”
One can imagine a day when these sensors become cheap enough for routine blood testing for early diagnosis of cancer. Further out, implantable sensors could constantly watch for cancer cells and report to your cell phone when cancer is detected. "This text message is to inform you that you have very early stage liver cancer and should seek immediate treatment for a 99.99% chance of a cure."
Chips are the future of biotechnology. Smaller and more complex and powerful devices will slay many diseases.
The chip's ability to detect which drug resistance mutations each patient has can be used to guide choice of therapy.
Circulating tumor cells (CTCs) were identified in all cancer patients. Also, the chip identified which patients had genetic mutations in their tumors that made them resistant to certain forms of anti-cancer therapy.
The CTC-chip was used to analyze blood samples from 27 patients – 23 who had EGFR mutations and 4 who did not – and CTCs were identified in samples from all patients. Genetic analysis of CTCs from mutation-positive tumors detected those mutations 92 percent of the time. In addition to the primary mutation that leads to initial tumor development and TKI sensitivity, the CTC-chip also detected a secondary mutation associated with treatment resistance in some participants, including those whose tumors originally responded to treatment but later resumed growing.
The chip detected changes in concentrations of tumor cells. The chip will be able to detect a surge in cancer growth faster than X rays and with less harm and cost.
These visits were not timed for the purpose of the study, but Dr. Haber's group noted that in one case circulating tumor cell numbers dropped 50% within a week of staring therapy and continued to decline for three months.
Clinical progression was associated with an increase in the number of circulating tumor cells.
The researchers also reported "close concordance" between radiographic assessment of tumor volume and changes in the number of circulating tumor cells in patients followed throughout their course of therapy.
What I wonder: Will we ever get treated by something like a kidney dialysis machine but where the machine removes circulating cancer cells. One can imagine that upon diagnosis a patient could get hospitalized, hooked to a cancer cell catching machine, and then scheduled for surgery. During surgery the machine could continue to catch cancer cells that spill out into the blood as the surgeons cut into the tumor. Then the patient could remain on the machine for a few days after the surgery with the machine reporting the number of cancer cells getting caught per hour. If the count does not go down to 0 then the surgeons need to go looking for another pocket of cancer that they missed.
|Share |||Randall Parker, 2008 July 03 10:33 AM Biotech Cancer|