ASCORecent data suggest that HER2 positivity predicts for the development of CNS metastases in breast cancer patients. Studies presented at the ASCO 2007 annual meeting found that risk of brain metastases is indeed increased in HER2-positive patients but does not appear to compromise survival.
Trastuzumab and survival
In a retrospective study, M.D. Anderson Cancer Center investigators (abstract 1018) evaluated time to CNS metastasis, death, and death subsequent to brain metastases in relation to trastuzumab (Herceptin) treatment in a population of HER2-positive patients.
The analysis included 231 patients who received trastuzumab as first-line therapy and 61 who were treated before trastuzumab was available and therefore did not receive the drug.
At 2 years, 41% of trastuzumab-treated patients had developed brain metastases and 34% had died, compared with 20% and 44%, respectively, of the non-trastuzumab-treated patients. Median survival was 33.5 months for the trastuzumab patients, compared with 29.4 months for the controls.
After adjusting for other prognostic variables, patients who received trastuzumab had nearly a threefold higher risk of developing CNS metastases (HR 2.81, P < .03), compared with patients not receiving trastuzumab.
"Improved survival among patients treated with first-line trastuzumab may explain, in part, the increased incidence of brain metastases in this group, as more patients survived long enough to develop brain metastases," Mary C. Pinder, MD, reported.
Among those patients who did develop brain metastases, survival after the brain metastases diagnosis was better for the trastuzumab-treated patients than the patients who did not receive trastuzumab (HR 0.25, P = .01).
Brain mets and survival