A study that was carried out by the UCLA’s Jonsson Comprehensive Cancer Center’s Radiation Oncology Department discovered that patients with lethal glioblastomas who experienced important doses of radiation that reached a section of the brain that conceals neural stem cells had increase the progression-free survival time to twice as much compared to those patients who received lower doses or no radiation in that particular portion area.
In accordance to Doctor Frank Pajonk, who is a cancer center researcher, an associate professor of radiation oncology as well as the lead author of this study, the patients who had high doses of radiation that targeted that particular neural stem cell site, called the stem cell niche, underwent fifteen months of progression-free survival. On the other hand, the patients that underwent lower or no doses of radiation experienced merely a progression-free survival period of 7.2 months.
Doctor Pajonk is of view that the study that has been done could result in alterations in the technique of radiation therapy that is given to the patients who suffer from these fatal brain cancers. The study was published in an online edition of the BMC Cancer journal.
Pajonk stated that their study has discovered that if one irradiates a section of the brain that is not essentially part of the tumor, the patients tend to do better. He declared that they have been struggling for several years in order to come up with novel amalgamation of drugs and targeted therapies that would be able to boost survival for the patients with glioblastoma. Pajonk believes that by redesigning the radiation methods the survival of these patients can be extended.
The retrospective study that was carried out concentrated on 55 cases of adult patients who suffered from grade 3 or grade 4 glioblastomas and who were treated with radiation at UCLA during the period of February 2003 and May 2009. According to Pajonk, in order to confirm the results a prospective study is required.
There exist some proofs that many, if not all, cancers possibly spring from progenitor cells or stem cells, that in normal cases repair damage to the body, but that in a way or another become mutated and turn into cancer. In such cases, Pajonk declares that the neural stem cell niche, also known as the periventricular area of the brain, may moreover harbour stem cells that have changed into brain cancer stem cells. On the other hand, the niche serves as a kind of secure harbour for the cancer stem cells. The niche keeps them away from the region of the tumour but it is able to re-grow it even though it has been formerly removed and the malignant areas of the brain have been healed.
Pajonk hypothesizes that the brain cancer stem cells in the people whose niches have been irradiated with greater doses, have probably been eliminated or damaged, thus granting these patients with more time before their cancer reappeared.
The study stated that this implies that there is the possibility that the neural stem cell niche in the brain harbours cancer stem cells, consequently offering new therapy targets. The researchers have theorized that greater doses of radiation to these niches enhance the survival of the patients as there is better eradication of the cancer stem cells.
Glioblastomas are known to be the most lethal kind of brain cancer. Chemotherapy, radiation as well as surgery are not often effective and the life expectancy is around twelve to eighteen months. Novel and more efficient treatments are required so as to help this patient population, said Pajonk.
Furthermore, Pajonk stated that the radiation therapy could in fact cause damage to the neural stem cells in addition to the cancer stem cells, nevertheless, those may be replaceable in the future by making use of pluripotent stem cells that have been made from the very own cells of the patients. The pluripotent stem cells which have been induced, that similar to embryonic stem cells are able to make each cell in the body, could be stimulated to become neural stem cells so as to replace those that have been damaged or eliminated through radiation to the niche.
Source: E-science News
Mon, Aug 2, 2010
Anti Aging, Stem cells