Published online Aug 26, 2016. doi: 10.4252/wjsc.v8.i8.243
Peer-review started: April 28, 2016
First decision: June 16, 2016
Revised: June 18, 2016
Accepted: July 11, 2016
Article in press: July 13, 2016
Published online: August 26, 2016
Processing time: 113 Days and 22.9 Hours
Radiotherapy is a cornerstone of anticancer treatment. However in spite of technical evolutions, important rates of failure and of toxicity are still reported. Although numerous pre-clinical data have been published, we address the subject of radiotherapy-stem cells interaction from the clinical efficacy and toxicity perspective. On one side, cancer stem cells (CSCs) have been recently evidenced in most of solid tumor primary locations and are thought to drive radio-resistance phenomena. It is particularly suggested in glioblastoma, where CSCs were showed to be housed in the subventricular zone (SVZ). In recent retrospective studies, the radiation dose to SVZ was identified as an independent factor significantly influencing overall survival. On the other side, healthy tissue stem cells radio-destruction has been recently suggested to cause two of the most quality of life-impacting side effects of radiotherapy, namely memory disorders after brain radiotherapy, and xerostomia after head and neck radiotherapy. Recent publications studying the impact of a radiation dose decrease on healthy brain and salivary stem cells niches suggested significantly reduced long term toxicities. Stem cells comprehension should be a high priority for radiation oncologists, as this particular cell population seems able to widely modulate the efficacy/toxicity ratio of radiotherapy in real life patients.
Core tip: Radiotherapy is a cornerstone of anticancer treatments. However, significant levels of toxicity and recurrences are still reported. On the one hand, cancer stem cells have been recently suggested to be the root of radio-resistance, with strong pre-clinical rational. One the other hand, convincing pre-clinical data suggesting the importance of healthy tissue stem cells radiation-induced destruction in long term side effects of radiotherapy surfaced. This article provides an overview of the available literature analyzing from the clinical efficacy and toxicity perspective the interactions between stem cells and radiation. Significant improvement of radiotherapy toxicity/efficacy ratio is suggested.