Circulating Tumor Cells - Article about them as an indicator of metastatic disease

This study was mentioned in the Uroalert email I get periodically. The link here is for the free full-text version of the article. It explores the idea of using Circulating Tumor Cells (CTCs) as indicators of metastatic disease status. They find various cancers are better or worse about releasing CTCs. Prostate cancer is more prone to exhibiting CTCs, according to this.

From the article:
In a disease-to-disease comparison when reviewing the percentage of patients exhibiting CTCs, CTCs are seen in a higher percentage of breast and prostate cancer patients than in colorectal cancer patients. Pancreatic and ovarian cancers, regardless of their stage and aggressiveness, rarely reveal CTCs.

The smart guys can comment on this, I'm sure. It's at least an interesting research avenue, and may one day be good enough to help people make better treatment choices up front. This is one aspect of the "liquid biopsy" idea we sometimes hear about.

Also from the article (cfDNA is "cell free DNA"):
Can CTCs and cfDNA be combined in such a manner to aid in the cure of metastatic disease? Yes, and used in combination and including a control of whole blood to detect somatic mutations, CTCs—the “silent” predictor of metastatic disease—and cfDNA can serve to monitor the progression of primary disease to a metastatic state and this combination can be used for every tumor type.

Circulating tumor cells: silent predictors of metastasis

Another article on the "liquid biopsy" topic. It would appear they're working on distinguishing simply circulating cells from those that are actually related to the cancer. The example used in this article is actually for colorectal, a type specifically identified in the first study as not having many circulating cells. They're even looking at how the tumors change over time, how the DNA "evolves".

Obviously they'll need to be able to identify circulating tumor cells, not just circulating prostate cells.

From the article:
Panels that are capable of tracking tumor evolution, for instance, can help determine when a patient may need to change treatments and what the next option should be.

Cancer’s Circulating Secrets

CTCs are addressed in the New Yorker article I posted the other day. (And was re-posted in another thread today as well.) As part of the author's premise that certain patients have host tissue that is more conducive to picking up mets, he talks about the large quantity of CTCs that some cancers can produce. Yet for many people, the cancer doesn't spread, while for some it does.

His point is that we need to understand why that is to more effectively design treatments.