Investigation of Prognostic Factors and Survival without Recurrence in Patients with Breast Cancer

BACKGROUND One of the major consequences of breast cancer is the recurrence of the disease. The objective of present study was to estimate the 7-year survival without recurrence as well as the effective prognostic factors in recurrence. MATERIALS AND METHODS This historical cohort survival analysis was conducted on 1329 patients diagnosed with breast cancer in Motahari Breast Clinic, Shiraz, Iran between 2004 and 2011. We estimated the rate of survival without recurrence through the Kaplan-Meier method and the difference between the survival curves was investigated using the log-rank test. Furthermore, Cox regression model was used to model the effective factors in local recurrence as well as metastasis. RESULTS The mean age of the patients was 54.8 ± 11.4 years. Estrogen receptor positive, progesterone receptor positive, and human epidermal growth factor receptor-2 positive were observed in 70.6%, 66.6%, and 34.4% of the cases, respectively. The mean of the follow-up period was 3.7 ± 1.8 years in all patients. The results of the Kaplan-Meier method revealed 1-, 3-, 5-, and 7-year rate of survival without recurrence as 96.4%, 78.4%, 66.3%, and 54.8%, respectively. There was a significant relationship between survival without recurrence and histology grade (hazard ratio [HR] = 1.66, P = 0.009), neural invasion (HR = 1.74, P = 0.006), and progesterone receptors (HR = 0.69, P = 0.031). CONCLUSION In this study, the rate of survival without recurrence in breast cancer was 54.8%. Among factors, histology grade and neural involvement at the time of diagnosis increased the chance of recurrence and progesterone receptors caused a longer interval between diagnosis and recurrence.