Dr Chandrika Valal
Nitte University K S Hegde Medical Academy Department of Pathology Deralakatte, Mangalore
Biography
Introduction: Breast cancer is the second most leading cause of death in women. It is an important health issue not only in the developed world but also in resource limited nation. Incidence of breast cancers low in India compared to Western countries, but it is associated with poor prognosis and high mortality, may be due to late presentation at advanced stages. Hormone receptors (estrogen and progesterone) and Human epidermal growth factor receptor-2 (HER-2) study are not routinely carried out as it is expensive, especially in developing countries. This could impact treatment decisions and patients are sometimes treated empirically with tamoxifen. Triple-negative breast cancers are group of primary breast cancers which lack expression for hormone receptors and Human epidermal growth factor receptor-2.
Objectives: This study is aimed to pathologically illustrate morphological prognostic parameters in primary invasive breast carcinoma and triple negative breast cancer. Further, to analyze the association between clinicopathological prognostic parameters and receptor status.
Design: The sample consists of immunohistochemical profile of one hundred and fifty specimens of primary invasive breast cancer. Among these, fifty triple-negative phenotype breast cancer specimens are further assessed for, cytokeratin (CK) 5/6, epidermal growth factor (EGFR) and Ki-67.
Result: Out of 150 tumors studied, 68 (45.3%) are positive for estrogen receptor, 51(34.6%) for progesterone receptor and 5 cases are positive for Human epidermal growth factor receptor - 2. Large number of patients (65/150, 43.3%) are between the age group of 41 to 50years and had tumor size more than 2cm (119/150, 79.3%). Necrosis is observed in 72 of 150 (48.0%), ductal carcinoma in situ (DCIS) in 55 of 150 (36.7%) and majority of the tumors are of histological grade 2 (73/150, 48.6%). Most common histological subtype is Infiltrating ductal carcinoma, no special type (IDC NST) (91/150, 60.6%). Significant inverse association observed between tumor grade and hormone expression (p<0.05, OR 0.53, 95%CI 0.021 – 0.132), necrosis and hormone expression (p<0.05, OR 0.471, 95%CI 0.245 – 0.907).
A total of fifty cases of triple negative phenotype are further analyzed. Out of 50 triple negative phenotype breast cancers, 37 of 50 (74.0%) are positive for basal markers, cytokeratin (CK) 5/6 and or / epidermal growth factor receptor (EGFR) and 26.0% (13/50) cases are neither positive for EGFR nor for CK 5/6. Significant positive association is observed (p<0.05) between tumor necrosis and basal marker expression.
Summary and Conclusions: Breast cancer in our population presents at younger age and is histologically and by receptor profile more aggressive than western population, there by emphasizing role of morphological prognostic factors in molecular era.Triple-negative breast cancers harbor adverse pathobiological features and five marker immunohistochemical panels can be reliably used to define basal-like cancers.