The influence of Breast Cancer Molecular Subtypes on Metastatic pattern in Iraqi patients

Background: Breast cancer is first of the top ten malignancies in Iraq. Aim: To discuss, explore, and describe clinico-pathologic features, and metastasis patterns of breast cancer according to molecular subtypes. Methods: A retrospective study of 315 metastatic breast cancer women was performed. The study conducted at Baghdad Medical City, in a period for 6 months between January 2019 and June 2019. The HR expression status, and HER2 gene amplification were evaluated by IHC. The associations of molecular subtypes, and distant metastases modeled by regression analysis and correlation tests. Furthermore, the Box-Ljung test, the Bartlett's scale, and Kaplan-Meier survival curveused. Results: Age was most frequent in group 46-55 years, as 107(34%) patients. The BMI characterized by moderate obesity as 89(28.3%). The IDC was the most common histopathology 273(87%) patients. The T2 stage rank first with 168(58.5%), with high frequency of N1 staging in 93(32.5%). Bone was the common metastatic site. The HR positive, and Her 2neu negative recorded doubling than opposite. The HR+/HER- was the prominent subtypes as 141(57.1%). All subtypes were significantly associated with all sites of metastasis that analyzed by univariate, and multivariate. Conclusions: The BMI has high impaction as a risk factor for breast cancer. The HR+/HER- have better prognosis & best survival. The metastasis presentations are strongly associated with molecular subtype patterns.