Expression of DDR1 and DVL1 in Invasive Ductal and Lobular Breast Carcinoma does not Correlate with Histological Type, Grade and Hormone Receptor Status

Background: Invasive ductal (IDC) and lobular (ILC) carcinomas are the common histological types of breastcarcinoma which are difficult to distinguish when poorly differentiated. Discoidin domain receptor (DDR1) andDrosophila dishevelled protein (DVL1) were recently suggested to differentiate IDC from ILC.
Objectives: Toassess the expression of DDR1 and DVL1 and their association with histological type, grading and hormonalstatus of IDC and ILC. Materials and
Methods: This cross sectional study was conducted on IDC and ILC breasttumours. Tumours were immunohistochemically stained for (DDR1) and (DVL1) as well as estrogen receptor(ER), progesterone receptor (PR) and C-erbB2 receptor. Demographic data including age and ethnicity wereobtained from patient records.
Results: A total of 51 cases (30 IDCs and 21 ILCs) were assessed. DDR1 andDVL1 expression was not significantly associated with histological type (p=0.57 and p=0.66 respectively). Therewas no association between DDR1 and DVL1 expression and tumour grade (p=0.32 and p=1.00 respectively),ER (p=0.62 and 0.50 respectively), PR (p=0.38 and p=0.63 respectively) and C-erbB2 expression (p=0.19 andp=0.33 respectively) in IDC. There was no association between DDR1 and DVL1 expression and tumour grade(p=0.52 and p=0.33 respectively), ER (p=0.06 and p=0.76 respectively), PR (p=0.61 and p=0.43 respectively) andC-erbB2 expression (p=0.58 and p=0.76 respectively) in ILC.
Conclusions: This study revealed that DDR1 andDVL1 are present in both IDC and ILC regardless of the tumour differentiation. More studies are needed toassess the potential of these two proteins in distinguishing IDC from ILC in breast tumours.