Risk factors of local relapse in breast cancer:: the importance of age

Purpose: The objective of the present analysis is to know what risk factors affect local relapse in breast cancer. Methods and materials: A total of 1165 patients diagnosed with early breast cancer were included. Boost dose was modulated in the presence of risk factors. Patients with one risk factor received a boost of 10 Gy, while 20 Gy was administered in those with two risk factors. Results: Median follow-up was of 60 months. Mean age of patients was 56.7 +/- 10.8 years. Local risk factors were present in 82.8% of patients. The probability of remaining free of local recurrence at 5 and 10 years is 97.7% (CI 95%: 96.7 - 98.7) and 94.5% (CI 95%: 92.1 - 96.9). Only age showed an impact in local relapse on multivariate analysis. Patients 40 years or younger had a relative risk of local relapse of 5.27 and patients 41 - 50 of 3.7 with respect to patients older than 50 years. Conclusion: Patients 40 years or younger have a higher risk of local failure than older patients. Other risk factors such as tumour size, intraductal carcinoma or margin status could be masked by an increase of radiation dose.