الفهرس 
TitleOnly 14 pages are availabe for public view
 |  | from | 145 |  |  |
| | | from | 145 | | |
Abstract
Breast cancer is one of the most common human malignancies accounting for 22% of all cancers of women worldwide.
Breast cancer represents a complex and a heterogeneous disease that comprises distinct pathologies, histological features, and clinical outcomes.
Basal-like breast cancer (BLBC) is highly aggressive tumor constituting 10-15% of invasive breast carcinomas.
Triple negative breast cancer has become a commonly used descriptor for malignancies that are estrogen receptor (ER), progesterone receptor (PR), and HER2/neu negative.
Although TNBC is accepted as a clinical surrogate for basal-like breast cancer, it was found that 50-85% of TNBC tumors were estimated to be true basal-like breast cancer.
EGFR and CK5/6 are readily available positive markers for basal-like breast cancer that are applied to standard pathology specimens in clinics.
Caveolin-1 is a 22-KD transmembrane protein present in plasma membrane invaginations known as caveolae. Recent data have shown that down regulation of caveolin-1` expression in stromal breast tumors is associated with poor outcome.
The present work aimed at evaluating the use of tissue microarray technique for detection of basal-like breast cancer using EGFR, and CK5/6 with correlation of different clinicopathological parameters. Also, to investigate the correlation between stromal loss of caveolin-1 expression with different clinicopathological parameters in TNBC cases.
To achieve these aims, one hundred triple negative breast cancer cases retrieved after surgery were collected from the archives of Pathology Department, MRI, Alexandria University, and Pathology Department, Damanhur Oncology Center. The mean age of the collected cases was 47.51.
In the present work TMA was used. Two spots of 0.6 mm were chosen from every tumor specimen giving 200 cores. Out of a total number of 200 cores, 192 cores were representative and 8 were not. However, for each of the lost cores, a sister core of the same case was found to be representative.
Immunohistochemical staining of sections of the resulting tumor tissue microarray block with EGFR, CK5/6, and Caveolin-1 were done.
The histologic subtypes were stratified using WHO classification (2012). The most commonly encountered type was IDC (NST); representing 82 (82%) cases. The histologic grade of the tumors was assessed using the modified Bloom-Richradson grading system. The grades of the tumors were as follows: 44 (44%) cases were grade II, and 56 (56%) cases were grade III.
EGFR immunohistochemical reaction was found in 64 of 100 cases (64%). Correlation was done between EGFR positivity and different clinicopathological variables. As regards the age, there was a statistically significant difference among the EGFR positive and EGFR negative cases.
There were also a statistically significant differences between EGFR positive and EGFR negative groups regarding the histologic grade (P= 0.001), tumor size (P= 0.003), nodal stage (P= 0.036), lymphovascular invasion (0.001), necrosis (P= 0.006), DCIS (0.001), and lymphocytic infiltration (p=0.004).
CK5/6 immunohistochemical reaction was found in 56 of 100 cases (56%). A significant statistical difference was present among CK5/6 positive and negative cases as regards age (P= 0.038), histologic grade (P= 0.010), tumor stage (P=0.018), vascular invasion (P= 0.001), necrosis (P= 0.008), DCIS (P= 0.001), and lymphocytic infiltration (P= 0.005). No significant difference was found between CK5/6 positive and negative groups as regards the histologic subtype and nodal status.
Stromal caveolin-1 expression was assessed among the triple negative breast cancer cases. Loss of stromal caveolin-1 expression was found in 66 of 100 cases (66%) . The loss of caveolin-1 expression was assessed in relation to different clinicopathological variables. Significant statistical differences were detected among stromal caveolin-1 negative and positive cases as regards the histologic grade (P=0.001), tumor stage (P= 0.004), nodal stage (0.015), lymphovascular invasion (0.008), necrosis (P= 0.017), DCIS (P=0.003), and lymphocytic infiltration (P= 0.001).