Abstract
BACKGROUND AND OBJECTIVE: We evaluated clinicopathological changes of breast cancer (BC) during a 22-year time period among the Iranian population. METHODS: This study is part of the largest BC registry in Iran. Patients were categorized as those diagnosed with BC during 1993-2005, 2006-2011, and 2012-2017 and compared regarding baseline characteristics and socioeconomical determinants, and obstetrical/gynecological and BC characteristics. RESULTS: Overall, 688, 1871, and 3020 patients entered the 1993-2005, 2006-2012, and 2012-2017 year groups, respectively. Mean (SD) age at first presentation of BC increased throughout the year groups (47.40 ± 10.34, 49.12 ± 11.70, and 49.43 ± 12.07 years, respectively; p < 0.001). Mean (SD) tumor size increased from 1993-2005 to 2006-2011 and decreased onto 2012-2017 (2.82 ± 1.69, 2.91 ± 1.49, and 2.66 ± 1.52 cm, respectively; p < 0.001). Number of individuals with stage 4 and grade 3 BC also showed an increasing pattern (p < 0.001). Tumor necrosis rates showed an increase onto 2011-2017 (43%, 47.3%, and 56%, respectively; p < 0.001). ER positive (62.4%, 73.4%, and 77.1%, respectively; p < 0.001) and PR positive individuals (59.5%, 64.3%, 72.6%, respectively; p < 0.001) showed an increasing trend. HER2 positive expression rates increased from 1993-2005 to 2005-2011 (24.5% and 31.5%, respectively) and decreased onto 2012-2017 (31.5% and 26.8%, respectively, p < 0.001). Number of involved lymph nodes increased (5.70 ± 6.56, 5.65 ± 6.00, and 5.95 ± 6.99, respectively; p < 0.001). Pattern of BC invasion and recurrence showed significant change (p < 0.001). CONCLUSION: Clinical and pathological characteristics may be showing a changing pattern among the Iranian population.