However, new research by a WEHI scientific team has shown that the growth of at least some tumours is instead sustained by the majority of cells within the cancer.
According to the “stem cell” theory, only a minute number of cells within each tumour can multiply enough to keep the tumour growing and spreading, while the vast majority of the cells cannot do so and hence are largely passengers. The WEHI team’s research, however, suggests that the proportion of cells that can propagate tumours was previously grossly underestimated. They find that many tumours can be propagated by a substantial fraction of the tumour cells – sometimes the majority.
Determining whether most cells in a tumour, or only a rare population, can maintain its growth has important implications for therapy. On the “stem cell theory”, the treatment must be tailored to eliminate the stem cells; otherwise, the surviving stem cells will regenerate the tumour and cause a relapse. The WEHI research suggests instead that all the tumour cells should be targeted.
The research team included Priscilla Kelly, Aleksandar Dakic, Stephen Nutt, Jerry Adams and Andreas Strasser.
The team was generously funded by the Cancer Council Victoria; the NHMRC; the NIH; and the Leukemia and Lymphoma Society.