Chronological changes and trend of breast cancer clinics and pathology among Iranian women during 22 years from the largest breast cancer registry in Iran

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.