Effect of age on recurrence in hormone receptor-positive breast cancer, and factors significantly associated with cancer recurrence

Objective: Age is an important factor for predicting survival, with worse prognosis among young women compared to middle-aged women. Hormone receptor-positive breast cancer is the most commonly reported diagnoses among younger women. This study aimed to investigate the effect of age on recurrence in hormone receptor-positive breast cancer patients, and to identify its significant related factors. Methods: Operable hormone receptor-positive breast cancer patients who underwent surgery at the Division of Head, Neck, and Breast Surgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand during 2008-2013 were retrospectively recruited. Age at diagnosis, follow-up time, staging, tumor characteristics, treatment, and date of recurrence were collected, recorded, and analyzed. Results: Of the 431 patients that were included, 145 patients were aged 40 years or younger, and 286 patients were aged older than 40 years. The median follow-up time was 4.1 years. In multivariate analysis, the unadjusted recurrence rate was higher in T3-4, node positive, high pathological grade, and lymphovascular invasion. After adjusting for age, only N stage N1 remained statistically significant (hazard ratio [HR]: 2.75, 95% confidence interval [CI]: 1.18-6.40; p=0.19). The recurrence rate was found to be non-significantly higher in younger patients than in older patients (11% vs. 5.6%, p=0.21). Conclusion: The results of this study revealed no significant difference between age groups for recurrence-free survival in women with hormone receptor-positive breast cancer; however, younger women did demonstrate a higher rate of recurrence. N stage N1 is an independent predictor of cancer recurrence.