MRI Detects Asymptomatic Brain Metastases in Women With Advanced Breast Cancer: Presented at SABCS
By Alex Morrisson
SAN ANTONIO, Tex -- December 13, 2011 -- A substantial percentage of women diagnosed with advanced breast cancer appear to have asymptomatic brain metastases, according to a study presented here at the 34th Annual San Antonio Breast Cancer Symposium (SABCS).
“We have clearly underestimated the incidence of asymptomatic brain metastases in women with advanced breast cancer,” said Xavier Pivot, MD, University Hospital of Besancon, Besancon, France, on December 9.
In screening for inclusion in the study, researchers performed magnetic resonance imaging (MRI) studies on 605 women. The protocol for determining brain lesions required scanning with a 1.5-Tesla device, with 3-mm slices, using gadolinium contrast agents for the T1-weighted images.
Of the 211 patients who were found to have brain abnormalities, 120 were found to have breast cancer metastases.
“That means that about 20% of the women with stage 4 breast cancer had asymptomatic metastases,” said Dr. Pivot.
In the current study, researchers examined patient data to compare outcomes in metastatic disease in which lapatinib was being compared with trastuzumab. An exclusion criterion was the presence of brain metastases assessed by MRI. All the patients in the study had human epidermal growth factor receptor 2 (HER2)-positive tumours.
Although the MRI screening was required for inclusion into the clinical trial, Dr. Pivot said he is not sure whether all patients with stage 4 disease should be screened for brain abnormalities.
“We do not know the natural history of what happens to these patients with asymptomatic brain metastases,” he explained. “We do not know if these asymptomatic lesions become symptomatic. We don’t know if treating these metastases will impact overall survival and other outcomes. We have no idea at all.
Dr. Pivot suggested that the main reason for performing the MRI studies is to select patients for clinical trials with central nervous system endpoints.
“Approximately 20% of all screened patients and 57% of the screening failures in this study thought to be clinically-free of brain lesions actually had brain metastases verified by brain MRI,” Dr. Pivot reported.
He said that he plans to follow this retrospective patient population in a prospective manner. It will take at least 1 year of prospective study to determine what impact these silent lesions have on overall outcomes.
Funding for this study was provided by GlaxoSmithKline.
[Presentation title: Incidence Rate of Asymptomatic Brain Metastases in Patients With HER2+ Metastatic Breast Cancer Screened for EGF111438/CEREBEL Study. Abstract P4-17-03]
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