5-Year Survival Rates and Prognostic Factors in Patients with Synchronus and Metachronus Breast Cancer from 2010 to 2015

INTRODUCTION: Currently breast (BC) cancer is a serious medical problem in all countries of the world. Survival depends on many factors. The present study focused on 5-year survival and its related factors in patients with BC in Iran. Material and methods. The present analytical retrospective study was performed (from March 2010 until March 2015) on patients with BC followed for at least 6 months. The main variables assessed were tumor size, grade of lymph node involvement, metastasis, stage, history, human epidermal growth factor receptor expression, and tumor origin. Analysis of survival was accomplished using the Kaplan- Meier method. RESULTS: Some 351 (80.2%) of the total of 438 individuals had unilateral and 87(19.8%) had bilateral cancer, 28 (35.6%) of the latter being synchronous and 56(64.4%) metachronous. Mean duration of follow-up was 47.44±28.19 months, during which 61 (17.3%) patients with unilateral and 18 with bilateral cancer eventually died. The 5-year survival rate in patients with unilateral BC was significantly higher than those with bilateral BC (Log-rank Test chi2= 3.11, p=0.032). In addition, with metachronous cases, the survival rate was 64.2% in comparison with 51.6% for synchronous BCs. Survival rate was significantly (p value =0.038) higher with metachronous than with synchronous cancers (Log-rank Test chi2=3.54, p=0.038). The highest survival rate was reported for BCs originating from lobule tissue and the lowest rate examples of interstitial tissue origin (Log-rank Test chi2=11.54, p=0.0001). Patients with earl stage lesions (M1) survived longer than with other stages (Log-rank Test chi2= 9.55, p=0.001). CONCLUSION: In this study, most women with BC had a positive family history and were married. The 5-year survival rate was lower with advanced stages of cancer. According to our findings, survival rates might improve if patients undergo screening and diagnosis is made at an early stage of the disease.