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

Abstract

Objective: To assess the frequency of Her-2/neu gene amplification in breast cancer and its association with clinicopathologic characteristics of the disease.

Study design: Cross-sectional comparative study.

Place and duration of study: Study was carried out at Surgical Unit I, Holy Family Hospital, Rawalpindi, from January 2005 to December 2006.

Methodology: 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 tumour size, node involvement, histological grade and presence of estrogen and progesterone receptors were also studied.

Results: Out of 50 patients, 18 (36%) were positive for Her-2/neu overexpression. 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). Tumour 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).

Conclusion: The pathological and clinical characteristics of Her-2/neu positive and negative subsets differ, and Her-2/neu overexpression was associated with other poor prognostic factors of age, tumour size and number of nodes involved. There was an inverse relation of Her-2/neu status and hormone receptor.