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Senior Member
Join Date: Mar 2006
Posts: 4,778
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prophylactic whole brain irradiation may prevent her2 brain metastasis and supposedly
without cognitive decline--SABCS
SABCS: No Cognitive Decline from Radiation to Prevent Brain Mets
A combination of trastuzumab (Herceptin) and prophylactic cranial radiation to prevent brain metastases did not appear to cause cognitive dysfunction among metastatic breast cancer patients, compared with those given the drug without radiation, according to a small clinical trial reported here.
Using the Addenbrooke's Cognitive Examination, the median score for the 13 women randomly assigned to undergo prophylactic cranial irradiation was about 2, virtually the same as the 17 women who did not opt for irradiation in the prospective study (P=0.805), said Peter Canney, MD, a consultant oncologist at the Beatson West of Scotland Cancer Centre in Glasgow.
Although there was no overall survival difference at two years in his prospective randomized study (P=0.867), the risk of experiencing brain metastases was numerically higher among those women who did not receive prophylactic radiation, Canney reported at the annual San Antonio Breast Cancer Symposium.
Seven of the women who did not get radiation suffered brain metastases, compared with brain metastases seen in three women who underwent cranial radiation (P=0.18), Canney told MedPage Today at his poster presentation. However, due to small numbers of patients and events, the difference was not statistically significant.
"About 30-35% of women with HER2-positive metastatic breast cancer develop brain metastases," Canney said. "Among the problems this devastating complication causes is that, in the United Kingdom and many other countries, the development of brain metastases means that the woman is no longer allowed to drive.
"So instead of being able to live a relatively normal life and go about with activities of daily living, she becomes virtually home bound, dependent on others and her quality of life plummets," he explained.
"Various authors have reported a relatively high incidence of central nervous system metastases in patients with HER2 positive tumors who are receiving trastuzumab-based therapy for metastatic breast cancer," Canney said. "There has been concern with regard to the possible neuropsychological sequelae of radiation, although data from two prospective randomized trials assessing toxicity and quality of life after radiation for small cell lung cancer have failed to confirm this."
So Canney and colleagues began recruiting women for their clinical trial to determine what impact, if any, prophylactic cranial irradiation, had on a woman's cognitive functioning. The participants' mean age was 54.
Despite lack of evidence that radiation adversely affects cognition, Canney said he had difficulty recruiting women for the study because their doctors recommended against radiation therapy due to their own anecdotally-derived concerns of its negative impact on cognition. "We have had to close our study because of lack of enrollment," he commented.
His experience is not unique. "Doctors are afraid to irradiate their patients to prevent brain metastases," said Youlia Kirova, MD, a senior radiation oncologist at the Institut Curie in Paris, who commented that she had colleagues who have attempted similar clinical trials but have also been frustrated by their patients' physicians.
"The patients, when the options are explained to them, are not concerned about the radiation," she told MedPage Today, "but their doctors will not co-operate in sending the women to enroll in the trials."
"Studies such as this one may provide the information needed to convince clinicians to submit patients to these clinical trials," suggested Steven Isakoff, MD, a medical oncologist at the Gillette Center for Breast Cancer at Massachusetts General Hospital in Boston. "It is important that it gives reassurance that in these patients quality of life, cognition and other factors are not worsened with radiation therapy," he said.
Isakoff commented that he and most other clinicians have had patients that showed mental cognition deficits after cranial radiotherapy.
But, "this provocative study should spark interest in pursuing a large multicenter trial to look at this treatment to prevent brain metastases." He noted that in the U.S., where most driving laws differ from state-to-state, motorists have their licenses suspended after experiencing seizures -- often a consequence of brain metastases.
Canney said he was hoping to find other researchers with truncated series of patients to include in such trials in hopes that more patients would add power to their findings and perhaps attain statistical significance.
In his trial, women were randomized to either radiation or no radiation if they had been diagnosed with HER2-positive breast cancer and progressive systemic disease, with trastuzumab therapy plus chemotherapy as planned treatment.
Patients underwent a screening MRI or CT brain scan after randomization to exclude patients with subclinical central nervous system disease.
Canney said patients underwent neurocognitive function at baseline and again at three, six, and nine months following randomization -- using various psychological studies to assess quality of life, anxiety, depression and cognition.
Patients randomized to prophylactic radiation received a dose of 30 Gy in 10 fractions.
None of the scores on the tests of quality of life, depression or anxiety achieved statistical significance at any time point, Canney reported.
Primary source: San Antonio Breast Cancer Symposium
Source reference:
Canney P et al, "Neurocognitive function and quality of life of patients treated within a prospective randomised clinical trial testing the role of prophylactic cranial radiotherapy in patients treated with trastuzumab (Herceptin) for metastatic breast cancer: The Anglo Celtic VII Trial" SABCS 2010; Abstract P4-11-12.
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