Piecing together the story of how cancers spread is not just interesting research. It has future applications in finding new anti-cancer treatments. Right now, it can help with predicting the likely outcome, or prognosis, for a patient with cancer.
As an example, the aggressiveness of an individual tumour can be predicted by the measurement of genes, or products of genes, that are associated with the process of invasion and spreading described above. A cell where there are genes producing products involved in metastasising is likely to be more aggressive than one without. It would also be worth finding what proportion of a tumour’s cells has the ability to spread using probes for the markers associated with metastases. Some of the chemicals that we found to be associated with invasion may accumulate in the bloodstream and be measured there.
Many anti-cancer treatments are targeted at damaging the cell’s DNA, thereby stopping the cell dividing. Now, whereas there may be a greater percentage of a tumour’s cells in the growth phase when compared with the normal body’s tissues, both divide by thellame mechanism and both normal and cancer cells will be affected by the treatment. The ability to metastasise, however, sets a tumour apart from normal tissue. If we could target a treatment at some of the cascade of events that occur during the spread of cancers, we could expect better selectivity, sparing the normal tissues. This is where research into the mechanisms of metastasising holds such great promise for future treatments.
Anti-angiogenesis factors are already being tested. These may also stop tumour invasion since some of the mechanisms of the two are shared. Certainly, if new blood vessels cannot form, the size of the cancer is limited and the potential for spread beyond the primary site lessened.
Gene therapy, particularly inserting a gene to replace the function of a gene whose deletion is important in triggering the metastatic process, offers another possibility for treatment. Several of these approaches could be combined to help keep cancer cells under control.