Aberrant expression of cyclin E in low-risk node negative breast cancer.
BACKGROUND
Cyclin E is a cell cycle regulatory protein which occurs in G1, peaks in late G1 and is degraded in early S-phase. Cyclin E overexpression appears to be an independent prognostic factor for overall survival in breast cancer. Nuclear cyclin A is a reliable marker for S-and G2-phases. Consequently, aberrant expression of cyclin E can be detected by simultaneous immunostainings for cyclin A and cyclin E. Studies have shown that aberrant cyclin E might provide additional prognostic information compared to that of cyclin E alone. This study aimed to investigate cyclin E and aberrant cyclin E expression in low-risk node negative breast cancer.


METHODS
We compared women that died from their breast cancer (n=17) with women free from relapse > 8 years after initial diagnosis (n=24). All women had stage I, low risk breast cancer. The groups were matched regarding tumour size, receptor status, adjuvant chemotherapy and tumour differentiation. Tumour samples were analysed regarding expression of cyclin A, cyclin E and double-stained tumour cells using immunoflourescence staining and digital microscopy.


RESULTS
No differences were seen regarding expression of cyclin E or aberrant cyclin E in cases compared to controls.


CONCLUSIONS
We conclude that neither cyclin E nor aberrant cyclin E is a prognostic factor in low-risk node negative breast cancer patients.
Ahlin
Cecilia
C
Department of Oncology, Radiology and Clinical Immunology, Uppsala University Hospital, Uppsala, Sweden.
Gruhne
Bettina
B
Holmqvist
Marit
M
Zetterberg
Anders
A
Fjällskog
Marie-Louise
ML
D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000556:secondary; D018275:Carcinoma, Lobular / Q000378:metabolism / Q000556:secondary; D016022:Case-Control Studies; D019925:Cyclin A / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D005500:Follow-Up Studies; D006801:Humans; D009367:Neoplasm Staging; D015513:Oncogene Proteins / Q000378:metabolism*; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012307:Risk Factors; D015996:Survival Rate
D014408:Biomarkers, Tumor; C475820:CCNE1 protein, human; D019925:Cyclin A; D019927:Cyclin E; D015513:Oncogene Proteins; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone