Chemotherapy drugs are usually administered to cancer patients every few weeks at a high “maximum tolerated” dose. Though this approach kills the majority of tumor cells, it often spares a small number of tumor-initiating cells (TICs) that subsequently give rise to new tumors. Moreover, these recurring tumors are often more aggressive and able to metastasize to other tissues, in part because high doses of chemotherapy drugs also affect cells in the stromal tissue that surrounds tumors, including immune cells and blood vessel endothelial cells. Read more . . .
Conventional, high-dose chemotherapy treatments can cause the fibroblast cells surrounding tumors to secrete proteins that promote the tumors’ recurrence in more aggressive forms, researchers at Taipei Medical University and the National Institute of Cancer Research in Taiwan and University of California, San Francisco, have discovered. Frequent, low-dose chemotherapy regimens avoid this effect and may therefore be more effective at treating certain types of breast and pancreatic cancer, according to the murine study “Metronomic chemotherapy prevents therapy-induced stromal activation and induction of tumor-initiating cells,” which will be published online November 23 in The Journal of Experimental Medicine.