Her-2/neu gene overexpression in breast carcinoma and its association with clinicopathological characteristics of the disease

ABSTRACT

To assess the frequency of Her-2/neu gene amplification in breast cancer and its association with clinicopathologic characteristics of the disease. Cross-sectional comparative study. Study was carried out at Surgical Unit I, Holy Family Hospital, Rawalpindi, from January 2005 to December 2006. A total of 50 patients diagnosed of having breast cancer on biopsy of breast lump were included in the study. All patients underwent mastectomy and samples were submitted to AFIP [Armed Forces Institute of Pathology, Rawalpindi] for histopathology and determination of estrogen and progesterone receptors and Her-2/neu gene amplification. Moreover, association of Her-2/neu amplification to other characteristics like tumor size, node involvement, histological grade and presence of estrogen and progesterone receptors were also studied. Out of 50 patients, 18 [36%] were positive for Her-2/neu over expression. Among the various prognostic factors, age showed a statistically significant relation to Her-2/neu positivity [p=0.001]. The Her-2/neu positive cancers were larger in size [mean size of 7.9 +/- 3.615 and 5.4 +/- 1.906 cm in Her-2/neu positive and negative cases respectively; p=0.002]. Her-2/neu positive cases had statistically significant relation to number of involved lymph nodes [mean number of 9.9 and 4.4 lymph nodes in Her-2/neu positive and negative cases respectively; p=0.001]. Tumor grade and nuclear grade had no statistically significant relation to Her-2/neu status [p=0.19 and 0.434 respectively]. Both estrogen and progesterone receptors are inversely related to Her-2/neu positivity [p=0.028 and 0.006 respectively]. The pathological and clinical characteristics of Her-2/neu positive and negative subsets differ, and Her-2/neu over. expression was associated with other poor prognostic factors of age, tumor size and number of nodes involved. There was an inverse relation of Her-2/neu status and hormone receptor