|
Background.
Multifocal tumor recurrences in glioblastoma patients are described in
4% - 14% of cases.
Two recent studies, treating newly diagnosed glioblastoma patients
with continuous high-dose tamoxifen (TAM), reported an increased
incidence of multifocal tumor recurrences in 45.5% and 33% of study
patients.
Patients and
Methods. Fifty newly diagnosed patients with glioblastoma were
treated with 3 cycles of carboplatin, continuous high-dose TAM and
radiotherapy.
Tumor progression was determined on follow-up MRI studies at 3-month
intervals and categorized as either local or multifocal.
Results.
Multifocal tumor recurrence was found in 16 (33%) out of 49 study
patients.
Compared to tumors which remained local, multifocal tumor recurrences
were characterized by a significantly longer median time to tumor
progression (41 vs. 23 weeks, Breslow test: p = 0.0123).
Multifocal tumor recurrences were mainly observed after an initial
response to the study treatment (81%), whereas local regrowth was more
often associated with initial treatment failure, i.e. progressive
disease (64%).
Conclusion.
The association of the pattern of tumor recurrence with the type of
response to TAM treatment suggests that acquired resistance to TAM
might be an important contributing mechanism in the development of
multifocal glioblastoma disease.
|
