Analysing prostate cancer using the CTC-chip, which measures the level of circulating tumour cells in blood, provides important insights into prognosis and potential rates of recurrent disease, according to data from a developing study at Massachusetts General Hospital, which was presented at the American Association for Cancer Research 101st Annual Meeting 2010.

Sunitha Nagrath, Ph.D., an instructor of surgery and bioengineering at Harvard Medical School and Massachusetts General Hospital, said her research team found circulating tumour cells in patients with localized cancers, low-grade cancers and in those who had undergone surgery three months prior.

“These are patient groups in whom we would normally not expect to see circulating tumour cells, so it gives us a tremendous amount of information about their risk,” said Nagrath.

Circulating tumour cells are the root cause of metastasis in a number of cancers, which occurs when the cancer spreads beyond its tumour site. The identification of these circulating tumour cells can help identify patients at risk for metastasis early on, but, unfortunately, circulating tumour cells are extremely rare - scientists estimate one per one billion normal cells - and identifying them is a challenge.

One method of identification that shows promise is the CTC-chip, which in May 2009 received a Stand Up To Cancer Dream Team grant for scientists to continue its development. Stand Up To Cancer, the charitable initiative supporting groundbreaking research aimed at getting new cancer treatments to patients in an accelerated timeframe, awarded five Dream Team grants to investigators conducting promising research in a variety of areas. The American Association for Cancer Research is the sole scientific partner of Stand Up To Cancer.

The CTC-chip can capture approximately 200 circulating tumour cells from a teaspoon of blood taken from a cancer patient, according to researchers.

Nagrath and colleagues performed their analysis on 20 patients with early-stage prostate cancer and found circulating tumour cells in 42 percent of the patients. In patients with advanced prostate cancer, circulating tumour cells were found in 64 percent of the patients.

The research team was also able to identify circulating tumour cells nine days after surgery and also more than three months post-surgery. Nagrath and colleagues plan to continue this research and these circulating tumour cells would provide important prognostic information.

“The field is still emerging because while circulating tumour cells have been studied in patients with metastatic cancer, the idea of localised cancer is still new,” said Nagrath. “We haven’t had the right tools before; with the CTC-chip we potentially have the necessary tool.”