Clinical and Pathological Characteristics of Triple Positive Breast Cancer among Iraqi Patients.

BACKGROUND

Breast cancer is the most common malignancy affecting the Iraqi population and the leading cause of cancer related mortality among Iraqi women. It has been well documented that prognosis of patients depends largely upon the hormone receptor contents and HER-2 over expression of their neoplasm. Recent studies suggest that Triple Positive (TP) tumors, bearing the three markers, tend to exhibit a relatively favorable clinical behavior in which overtreatment is not recommended.

AIM

To document the different frequencies of ER/PR/HER2 breast cancer molecular subtypes focusing on the Triple Positive pattern; correlating those with the corresponding clinico-pathological characteristics among a sample of Iraqi patients diagnosed with the disease.

PATIENTS AND METHODS

This retrospective study involved 570 female patients diagnosed with breast cancer who visited the Main Referral Center for Early Detection of Breast Cancer and the National Cancer Research Center. The requested data was mainly extracted from an established information system database, developed by the principal author over a 4-years period from 2012 to 2016. The registered information comprised data related to clinical presentation, diagnostic and pathologic findings. ER, PR and HER2 status were analyzed immunohistochemically and the detected profiles were correlated with the corresponding clinico-pathological characteristics.

RESULTS

The rates of ER (+), PR (+) and HER-2 (+) tumors were 66.8%, 64% and 29.3% respectively. The tumor marker expression status was documented in eight subtypes; 83 cases (14.6%) of the examined breast carcinomas were categorized as ER+/PR+/HER2+ (Triple Positive/Luminal B), 89 cases (15.6%) were ER-/PR-/HER2- (Triple Negative), 241 (42.2%) were ER+/PR-/HER2- (Luminal A) while 67 (11.8%) showed ER-/PR-/HER2+ expression (HER-2 variant). No significant variations were noted when comparing age, menopausal status and tumor grade of Luminal B pattern to Luminal A and the rest of the studied subtypes. Although our data revealed a statistical difference with respect to the distribution of tumor types; where infiltrative ductal carcinoma constituted the major histology among patients with Triple Positive/Luminal B subtype (86.7% as compared to 67.6% in Luminal A), nevertheless, more than two third of those patients (67.4%) were diagnosed at earlier stages (I and II) compared to 55.2% of those in the remaining groups.

CONCLUSIONS AND RECOMMENDATIONS

Our findings support the hypothesis that the Triple Positive subtype might be driven primarily by the hormone receptor status. Further comprehensive surveys are recommended to focus on the intrinsic interactions and tumor cell heterogeneity of that pattern to avoid overtreatment and predict accurate response to therapy.