M.R Ghavam-Nasiri - Associate professor of Radiation Oncology, ۲ Cancer Research Center, Omid Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
S. Shahidsales - Assistant Professor of Radiation Oncology, ۲ Cancer Research Center, Omid Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
S. Ahmadi-Simab - Master degrees in Statistics, Mashhad University of Medical Sciences, Mashhad, Iran

Breast cancer is the most common malignancy and second cause of death in Iranian women. Patient’s prognosis and treatment planning are determined by different factors such as histologic grade, clinical stage (TNM), hormone receptor (estrogen and progesterone) and Her-2 status. Based on the status of estrogen, progesterone receptors and Her-2, breast cancer is classified into 4 subgroups (Luminal A ,B , Her2 positive ,Triple Negative),therefore, treatment plan is adjusted according to pathological subtype. Recent studies have focused on the clinical and molecular aspects of breast cancer that determined the immunophenotype and genotype for proper treatment protocol. In this study, we decided to evaluate the clinicopathological aspects In various pathological subtypes of Breast cancer Material and Method: In a retrospective cohort study, over a 11-year period (1380- 1390), 2825 cases of breast cancer referred to radiation oncology centers in Mashhad were evaluated. All female patients with breast cancer who completed their profile information, having had IHC report for hormone receptors with a minimum of 6 months follow up entered the study. Results: Of 2825 eligible patients, 2787 (98.7%) were female .Among this patients 1295 who had complete information enrolled to study. Based on ER, PR, Her-2 status patients classified as luminal A subtype 49.7%, luminal B 11%, Triple Negative (TN) 25.3% and Her-2 14.1%. As far as the age is concerned, mean age of patients was 48.91 + / - 0.32 years ( 22 to 85 years).There were significant differences among breast cancer subtypes according to the mean age at diagnosis (P<0.001). The mean age was lowest in the Triple Negative group (46.6+/- 0.67 years) and highest in the luminal A group (50.11+/-0.45 years). No significant relationship was observed between the subgroups and tumor size (P=0.204).We observed significant relationship between the subgroups and nodal involvement (P<0.001) so the highest percentage of lymph node involvement in Her- 2 positive status and luminal B.Although the incidence of metastases in Her-2 + group (7.4%) was higher than other subtypes, no significant correlation was found between the subtypes and metastasis(P = 0.19). There is a significant relationship among subgroups and stage of disease. Most of Stage IV patients had Her-2 + while the Most luminal A patients had stage I. The median time of follow-up was 119.83 months. luminal A groups had the highest mean DFS rates (108 months) and the lowest mean DFS in Her-2+(81 months) that was significant (P < 0.001). Five -years OS was 79%+/- 3in luminal A,67%+/- Luminal B,64%+/- triple negative and 54%+/- 5 In Her-2 + group. The significant correlation was found between the subtypes and five - year OS(P < 0.001). Conclusion: The results of this study indicate that classification of different breast cancer subtypes based on IHC, show significant differences in the clinicopathological aspects. It seems that the evaluation of Subgroups according to molecular-path classification in the early management time, treatment decision making and follow up is essential.

Breast cancer - Luminal A- Luminal B - Triple negative - HER2 +