Comparative study between paired primary and relapsed breast cancer patients based on clinicopathological features and molecular subtypes of breast cancer in Babylon Province

Abstract

Immunohistochemistry is routinely used to direct therapy of primary breast cancer. Biopsy from the relapsed tumor is controversy. No study in Iraqfocused on the molecular subtypes of breast cancer in loco-regional recurrence or distant metastases and correlate between these subtypes with the clinicopathological features. Paired Primary and Relapsed Breast Cancer patientswere included in this study in which 54 women with recurrent breast cancer which presented with loco-regional recurrence or distant metastases. Tissue sampling were taken from the site of recurrence either through excisional biopsy or true cut biopsy. Immunohistochemical staining were carried out for the assessment of ER, PR and (HER2) status. Retrospective dataof the primary breast cancer were collected from medical records in the oncology unit in Almerjanhospital. The primary outcomewere detection of molecular subtypes expression in both primary and relapsed breast cancer. Secondary outcome were studying the association between of these molecular subtypes of patients with recurrent breast cancer with age, duration of recurrence, stage of disease, grade of disease, type of surgery and site of metastasis and histopathological diagnosis, type of treatment including (chemotherapy, radiotherapy, hormonal therapy and monoclonal antibodies). Results show that 54 patients were diagnosed with breast cancer and treated in the tertiary breast cancer center in Alhilla general teaching hospital and followed in the oncology center in Almerjan medical teaching hospital in Alhilla, Babylon, Iraq between 2014 and 2017. The overall mean age of all patients with Recurrent Breast Cancer was(49.94±9.96). The mean Interval time for recurrence was (20.68±8.29) months. Majority (77.8%) ofpatients diagnosed as Invasive ductal carcinoma. Mastectomy plus Axillary clearance were done for 77.8% of the total patients and Breast Conserving Surgery plus Axillary clearance were done for the remainder. Site of metastasis were Local recurrence in 46.2%, Lymph node metastasis in 29.6%, Liver metastasis 13.0%, Lung metastasis 5.6% and Bone metastasis 5.6%. ImmunoHistochemical results of the studied group were either Luminal A (37%) or Luminal B (48.1%) at time of primary diagnosis while majority (75.9%) of patients with recurrent tumor presented with triple negative results. There were significant association between breast cancer subtypes at time of recurrence and grade of disease, type of surgery, histopathological diagnosis, type of treatment including chemotherapy, hormonal therapy and monoclonal antibodies inwhich the p value were 0.002, 0.044, 0.011, 0.015, 0.001 and 0.002 respectively.