Survival Analysis Investigating the Time Process of Breast Cancer: Ten Years of Cancer Registration Data in East Azerbaijan Province

Abstract

Background and Aim: Breast cancer is the most frequent cancer in women, and the second most common cancer across the globe. The aim of this study was to report the survival data and trend analysis of breast cancer between 2007 and 2016 in a northwest region in Iran. Methods: Data were obtained from East Azerbaijan cancer registry database for the 10-years period between 2007 and 2016. Survival analysis was performed to calculate the breast cancer specific survival proportions and mortality rates. Joinpoint trend analysis was performed to estimate the incidence trend of the cancer. Results: A total number of 4989 patients were recorded with primary diagnosis of breast cancer. Of them, we collected follow-up data for 1335 (1309 female and 26 male). The 10-year crude mortality rate was 3.34 (per 100,000). The one-, two-, three-, five-, and ten- year breast cancer specific survival proportions were 0.92 (95% CI 0.91-0.93), 0.88 (95% CI 0.86-0.90), 0.84 (95% CI 0.83-0.86), 0.77 (95% CI 0.74-0.80), and 0.65 (95% CI 0.60-0.70), respectively. Over the study period, the age-standardized incidence rates increased from 21.68 to 36.99 (per 100,000) with an annual percentage change of 5.5 percent. Older individuals and males patients had significantly worse survival, and patients with high-grade tumors had significantly higher risk of mortality.