So these articles were saying, you know, Skeletal metastasis to skeletal muscle is very rare.

And what metastases are is when the tumor when a piece breaks off and travels through the blood stream and goes to a different organ. That's what a metastasis is.

The answers to these questions will require research, and research into metastasis and tumor dormancy is difficult. It requires patience, development of models, and willingness to undertake long term studies.

The challenge today is thus to understand the processes of tumor dormancy and metastasis better, in order to determine more accurately which patients will benefit from long term therapy. We have much to learn, and at this stage don t even know all of the questions to ask.

In some ways, the success of cancer research is fueling pressure to cure cancer quickly, steering clinical and laboratory researchers away from the tricky problems of metastasis and long term tumor dormancy. This focus ultimately may be shortsighted, as the increasing number of cancer survivors leads to an increase in late recurrences.

We do know that metastasis is a very inefficient process, with most cancer cells that escape into the blood stream failing to form metastatic tumors in distant organs. Recent studies from both the laboratory and the clinic suggest that many cancer cells that leave the primary tumor may lodge themselves in new organs and go into a dormant state.

With a growing number of cancer survivors, we need to understand better the twin processes of tumor dormancy and metastatic cancer recurrence. While remarkable progress has been made in understanding the biology of cancer leading in part to the development of new, less toxic drugs our understanding of the biology of tumor metastasis, and especially the development of metastases after a long period of tumor dormancy, has lagged.