Trends in Epidemiology, Clinical and Histopathological Characteristics of Breast Cancer in Iran: Results of a 17 Year Study

Background: Breast cancer (BC) is the top cancer among women worldwide and the most frequent malignancyamong Iranian women over the past few decades. The increasing trend and high mortality rate of BC in thedeveloping world necessitates studies concentrating on its characteristics in countries in Asia. The current studyfocused on clinical and histopathological features of BC among Iranian females. Materials and
Methods: Thisretrospective study involved 714 Iranian patients with histopathologically proven BC undergoing resection ofprimary tumours and axillary clearance. Demographic, clinical and histopathological data were obtained andstudied between ten year age groups (≤40 years, 41-50 years, 51-60 years, 61-70 years, and ≤71 years) in fourchronologic phases from 1994-2009.
Results: Mean age of patients was 49.4±13.1 years. Most of cases (33.2%)were in 41-50 group. Mean size of primary tumors was 3.94±2.47 cm and 87.1% of cases had infiltrative ductalcarcinoma. Modified radical mastectomy was the most common method of surgery carried out (48.8%). Some57.1% of tumors were in pT2 and tumor size decreased significantly during the period (p<0.05). The mostcommon BC stage was llla (27%). Lower BC stages (0 and 1) constituted 13.9% of the diagnosed tumors. Ourseries of patients aged ≤40 had larger tumors (mean 4.73±3.02 cm) compared to older age groups (p=0.003).Lower stages (0 and I) were more frequent among the oldest patients while nearly 50% of patients aged ≤40had tumor stage III. We also observed a significant decreasing trend in the mean LN count (p<0.05) and bloodvessel invasion (p=0.023) from younger to older age groups.
Conclusions: More aggressive disease for youngerage groups, earlier peak incidence age and high rate of advanced BC at the time of diagnosis among Iranianwomen, were the main findings of this study.