It's not clear why CTCs appear to be linked to prognosis in some forms of cancer but not others, says Cristofanilli. Inflammatory breast cancer is already an aggressive disease, he says, so compared to other forms of breast cancer whether or not cells have broken off and entered the blood may say little more about an otherwise already aggressive disease.
Inflammatory breast tumors are typically fast-growing, and travel quickly to lymph nodes and the brain. During follow-up in the current study, which lasted more than 22 months for half of patients, more than 30% of the entire group had died.
Perhaps "the most important finding from the study," says Cristofanilli, is that more than three-quarters of women who just learned they have inflammatory breast cancer had CTCs that can be detected in the blood. In comparison, he adds, only 15% of women with non-inflammatory breast cancer typically have CTCs. "So there is a huge difference in inflammatory breast cancer and other forms of breast cancer." These stray tumor cells, therefore, may indicate something about inflammatory breast cancer, he reasons, perhaps serving as an early sign that it has already spread. Indeed, only approximately one-third of women with inflammatory breast cancer have detectable metastases at diagnosis, but 60% will eventually develop them.
Currently, says Cristofanilli, doctors primarily measure CTCs in women with metastatic disease, since a decrease in CTCs can signal that treatment is working. But given that most women with inflammatory breast cancer are likely metastatic at the time of diagnosis, this test could serve another purpose to guide doctors towards more aggressive and prolonged forms of treatment, says Cristofanilli. "If w
|Contact: Diana Quattrone|
Fox Chase Cancer Center