Objectives: To measure the frequency of estrogen receptor (ER), progesterone receptor (PR), and Her 2 Neu positivity and to study their association with tumour characteristics and menopausal status in a breast cancer cohort from Northern Pakistan.
Methodology: Patients attending NORI with histopathologically proven diagnosis of invasive ductal carcinoma of the breast were included after providing informed consent. Age, menopausal status, and tumour size were recorded. The presence or absence of nodal involvement (including site and number), distant metastases, sites of metastases, skin involvement, chest wall involvement, recurrent disease, and bilateral breast cancer were noted along with ER, PR, and Her 2 Neu status. Mean ± standard deviations were calculated for continuous variables like age. Frequency and percentage were calculated for categorical variables like ER, PR, and Her 2 Neu status. Association of ER, PR, and Her 2 Neu status with menopausal status and tumour-related characteristics were sought employing t test, c2 square test, and ANOVA wherever appropriate. P value <0.05 was considered significant.
Results: There were 1226 patients included in the study. Mean patient age was 48.04 ± 11.97 years, and 743 (60.6%) patients were premenopausal. ER, PR, and Her 2 Neu were found positive in 763 (62.2%), 738 (60.1%), and 478 (38.9%) patients, respectively. Significant association (P < 0.05) was found between ER, PR positivity, and Her 2 Neu over expression with menopausal status, tumour size, involvement of skin, chest wall and lymph nodes and the presence of distant metastases. However, no significant association was detected between ER, PR, Her 2 Neu and recurrent disease.
Conclusions: The frequency of expression of hormonal receptors in breast cancer patients from Northern Pakistan is the same as reported in the literature although overexpression of Her 2 Neu is a little higher in our population. There is an inverse relationship between hormonal receptors expression and Her 2 Neu expression. Postmenopausal women have a higher incidence of ER and PR positivity and Her 2 Neu negativity. ER and PR negativity and Her 2 Neu positivity are associated with more advanced disease and poor outcome.
Keywords: estrogen receptor, progesterone receptor, Her 2 Neu oncogene, postmenopausal, overall survival