METHODS
Total of 85 estrogen receptor (ER)-positive breast cancer patients were included. Expression of cyclin D1, ER, progesterone receptor (PR), and Ki-67 were determined using immunohistochemistry evaluation.
RESULTS
Patients" median age was 49 years (range: 27-83 years) and cyclin D1 was positive in 90.5% of the patients. Cyclin D1 expression was positively correlated with rate of ER positivity and Ki-67 expression (r=0.4; p<0.0001 and r=0.3; p=0.001, respectively). Five-year disease-free and overall survival (OS) rates were not different between patients with or without cyclin D1 expression (81% vs 79% and 93% vs 87%; p=0.8 and 0.4, respectively). High modified Bloom-Richardson grade (p=0.04), high nuclear grade (p=0.021), and PR negativity (p=0.011) were found to be poor prognostic factors for OS rate in univariate analysis.
CONCLUSION
In this study, cyclin D1 was not found to be prognostic factor; however, it is correlated with ER positivity and Ki-67 expression in breast cancer patients.
Keywords: Breast cancer; cyclin D1; prognostic factors
There are well known and widely used prognostic
and predictive factors of breast cancer include patient
age, stage, presence of lymph node metastasis and tumor
biology.[
However, intensive investigations have been carried
out on signal transduction mechanisms involved in cell
cycle.[
We aimed to evaluate Cyclin D1 expression and
to investigate its prognostic significance in our breast
cancer patient population.
External RT was applied to the breast / chest wall and peripheral lymphatics with a total of 50-60 Gy at 5-6 weeks with 2 Gy fractions per day; chemotherapy (CT) were administered before or after RT or by sandwich method. Hormonal therapy (antiestrogen / aromatase inhibitor) was administered to patients for 5 years after RT. Patients were followed up once every 3 months for the first 2 years, every 6 months for 2-5 years after treatment and annually thereafter.
Immunohistochemical analysis
Macroscopic data of the operation materials were
obtained from archival records of Pathology Department.
The operation material for each patient was
stained with hemotoxylin-eosin for 6-8 hours after
10% neutral formalin fixation. In our study, sections
of 4-5 micrometer thickness were taken and immunohistochemical
examination was performed on sections
made from paraffin embedded tissue samples
with formalin fixation. Estrogen (clone SP1, Neomarkers,
1: 250 dilution), progesterone (clone SP2,
Neomarkers, 1: 250 dilution) p 53 (Clone DO-7, Dako,
1:50 dilution), cyclin-D1 (clone SP4, Neomarkers, 1:
100 dilution) primer antibodies were investigated. As
the immunohistochemical staining system, we used a
biotin-free, HRP multimer-based, hydrogen peroxide
substrate and 3,3"-diaminobenzidine tetrahydrochloride
(DAB) chromogen (UltraViewTM Universal DAB
Detection Kit, Catalog number 760-500, Ventana
Medical Systems, Tucson, AZ). Tissue sections were
taken from electrostatically charged slides (X-traTM,
Surgipath Medical Industries, Richmond, Ill., USA)
and dried at 60 ° C for at least two hours. All immunohistochemical
staining procedures, including deparafinization
and antigen removal, were performed
in the BenchMark XT fully automatic immunohistochemical
staining device. Only the primary antibodies
estrogen (SP1), progesterone (SP2), cyclin D1
(SP4) were manually instilled and incubated at 37°C
for 32 minutes. In the device, the process was terminated
by dehydration of hematoxylin and bluerization
solution, cross-sectioning of xylenes, transparency of
xylene and closure of coverglass.
Histological evaluation was performed using a standard light microscope (Olympus Bx50; x40 magnification, 0.54 mm diameter, Ocular magnification: x10) without using a special ocular grating. As positive controls, serial sections for breast carcinomas detected by immunohistochemistry for 100% (+3) for estrogen and progesterone and mantle cell lymphoma for cyclin D1 were used.
In immunohistochemical examination, nuclear
staining of estrogen, progesterone and cyclin-D1 was
accepted as positive. The ratio of tumor cells showing
nuclear positivity and the intensity of staining were
evaluated as 1, 2 and 3 positive for ER and PR. The ratio
of tumor cells showing nuclear positivity for Cyclin
D1 and the intensity of staining were evaluated as 1, 2
and 3 positive. Nuclear positivity for Ki-67 and p53 was
considered significant. Positive tumor cell ratios were
given by choosing the areas that were most intense.
The threshold value for positive staining was accepted
as 10%. Negative and positive expressions of Cyclin D1
are shown in Figures
For statistical analysis, data were entered in SPSS 13.0 (Statistical Package for the Social Sciences) software, general characteristics of cases were defined with basic statistical methods and Kaplan Meier, log-rank and chi-square methods were used for correlation and survival analysis.
All cases were ER positive and immunohistochemical
results are presented in Table
Cyclins, cyclin-dependent kinases (CDKs) and inhibitors
(CDKI) are proteins that directly control cell
cycle. Cyclin D1 is located on the chromosome 11q13
and encodes the 36kD Cyclin D1 protein. Cyclin D1
plays a role in regulating the G1 phase in normal cell
cycle. With the induction of cyclin D1, the duration
of the G1 phase is shortened and the number of cells
passing through the G1 phase increases. Therefore the
overexpression of Cyclin D1 is resulted with uncontrolled
growth in tumor cell. In normal cells, Cyclin D1
behaviour varies according to external stimuli such as
growth factors, and estrogen.[
Cyclin D1 levels were found to increase by 20% in
benign and premalign (atypical ductal hyperplasia)
breast lesions, by 70-80% in ductal carcinoma in situ
lesions and by 30-70% in invasive breast cancer.[
Cyclin D1 is one of the 21 genes evaluated in the
Oncotype DX gene test using for the patient-specific
treatment selection for breast cancer. While some studies
reported increased expression as a good prognostic
factor in estrogen receptor positive patients, other
studies found that it was associated with early recurrence
and poor prognosis. Pelosio et al. investigated the
association of Cyclin D1 expression with ER and PR
receptor status and its prognostic significance in 180
breast cancer patients with axillary lymph node metastasis.
They found that ER and PR positivity was higher
in tumors with Cyclin D1 expression and the increased
Cyclin D1 nuclear staining is related with high recurrence
free survival rates.[
Seshadri et al. investigated the relationship between
CCND1 gene amplification and its relation with the clinicopathologic features and prognosis of 1014 breast
cancer cases. The researchers found that CCND1 gene
amplification was observed in hormone receptor positive
tumors and this amplification was significantly
correlated with ER and PR positivity. With a median
follow-up of 66 months, they found that CCND1 amplification
was not associated with breast cancer recurrence
and breast cancer-related mortality in the whole
group. However this amplification was associated with
increased recurrence rates in node-negative and ER (+)
groups.[
Xu et al. performed a meta-analysis including approximately
9000 cases in 33 trials and found that for
patients with overexpression of Cyclin D1, HR was 1.13
(p=0.35), 1.25 (p=0.12) and 1.04 (p=0.76) for overall
survival, progression free survival and distant metastases
free survival respectively. However, specifically for
ER (+) breast cancers, overexpression of Cyclin D1, HR
was 1.67 (p=0.00) for overall survival, and researchers
found that Cyclin D1 expression is related with poor
prognosis of ER (+) patients.[
Warwick et al. analysed the prognostic factors in
their 20 year follow-up study, and concluded that the
importance of tumor grade at the time of diagnosis
have a lasting influence on survival.[
Since we don"t have the HER-2 information of the
patient, we cannot perform prognostic analysis according
to molecular subtypes. However as already shown
in other studies, we also found that ER (+) PR (+) tumors tend to have better survival rates than ER (+) and
PR(-) tumors.[
Jirström et al. suggest that Cyclin D1 is associated
with ER and PR receptors and may interact with antiestrogen
therapy. They immunohistochemically assessed
CCND1 gene amplification in 500 breast cancer
patients. It has been reported that there is an agonistic
effect between tamoxifen treatment and CCND1 amplification
in ER-positive tumors.[
Ahnström et al. investigated the prognostic significance
of overexpression of Cyclin D1 and C-erbB2
in 230 breast cancer patients randomized to tamoxifen,
chemotherapy and radiotherapy arms and found
that the prognostic value of C-erbB2 expression was
greater in patients with overexpressed Cyclin D1. In
ER positive cases, it was found that cases with no
expression or poor expression of Cyclin D1 did not
benefit from tamoxifen treatment. Investigators have
indicated that Cyclin D1 may be a marker for tamoxifen
resistance.[
Understanding the potential role of Cyclins, cyclin
dependent kinases (CDKs) and inhibitors (CDKI) in
breast cancer has made them an important target. In
the recently published PALOMA-1/TRIO-18 trial, palbociclib,
an inhibitor of Cyclin-dependent kinases 4
and 6, was used. In the cell cycle, G1 to S phase transition
is controlled by cyclin dependent kinases (CDK4
and 6) and palbociclib is an oral CDK 4/6 inhibitor. In
this Phase II trial, ER-positive metastatic breast cancer
patients were randomised to letrazol versus letrazol
and palbociclib arms. At 2.5 years follow-up, median
progression-free survival was 20.2 months in the palbociclib
arm, whereas only 10.2 months in the letrazol
arm, and this difference was statistically significant.
[
Our study is valuable in determining the expression
and prognostic role of Cyclin D1 in the ER
positive breast cancer population in Turkey and but
limited with the number of cases. In our daily clinical
practice, we believe that the identification of cases
with Cyclin D1 expression and administration of targeted
therapies will increase response and cure rates
of the patients.
Acknowledgments
Disclosure Statement
We would like to thank Professor Serra Kamer for her
valuable comments for editing the manuscript.
The authors declare no conflicts of interest.