HER2 and central nervous system metastasis in patients with breast cancer.
We report a case of a patient who developed a central nervous system (CNS) metastasis 17 months after surgery and adjuvant therapy for stage II breast cancer. The HER2 status of the primary tumor as determined by immunohistochemistry (IHC) was 1+, and fluorescence in situ hybridization (FISH) performed retrospectively showed a borderline-negative result (ratio, 1:9), although HER2 amplification was present in a minority of breast cancer cells. By contrast, the HER2 status of the CNS metastasis was positive by IHC (3+) and FISH (ratio, 3:7). This report discusses the possibility that, for metastatic invasion into the CNS, clonal selection may occur, favoring HER2-positive cell clones.
Montemurro
Filippo
F
Medical Oncology, Institute for Cancer Research and Treatment, Candiolo, Torino, Italy. fmontemurro@ircc.mauriziano.it
Sarotto
Ivana
I
Casorzo
Laura
L
Pisacane
Alberto
A
Aglietta
Massimo
M
De Rosa
Giovanni
G
D001943:Breast Neoplasms / Q000235:genetics* / Q000556:secondary; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000235:genetics* / Q000556:secondary; D005260:Female; D018734:Genes, erbB-2; D006801:Humans; D008875:Middle Aged