Purpose: The aim of this study was to evaluate contemporary rates of local recurrence (LR) and regional recurrence (RR) in young patients with breast cancer in relation to tumor biology as expressed by biomarker subtypes.
Patients and Methods: Women < 35 years of age who underwent surgery for primary unilateral invasive breast cancer between 2003 and 2008 were selected from the Netherlands Cancer Registry. Patients were categorized according to biomarker subtypes on the basis of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. The 5-year risks of developing LR and regional lymph node recurrence were estimated by using Kaplan-Meier statistics.
Results: A total of 1,000 patients were identified, of whom 59% had a known subtype: 39% HR-positive/HER2-negative; 17% HR-positive/HER2-positive; 10% HR-negative/HER2-positive; and 34% HR-negative/HER2-negative (triple negative). Overall 5-year LR and RR rates were 3.5% and 3.7%, respectively. A decreasing trend for both rates was observed over time and was accompanied by a significant decrease in the risk of distant metastases (DM). LR occurred in 4.2%, RR in 6.1%, and DM in 17.8% of patients in 2003, and in 3.2%, 4.4%, and 10.0%, respectively, in 2008. LR and RR rates varied with biomarker subtype. These differences were borderline significant when analyzed for the entire study period (P = .056 and P = .014, respectively) and leveled off after the introduction of trastuzumab after 2005 (P = .24 and P = .42, respectively). Patients with lymph node metastases at the time of diagnosis had an increased risk of RR. The type of surgery performed—breast-conserving or mastectomy—did not influence rates of LR and RR.
Conclusion: Overall, the rates of LR and RR in young patients with early-stage breast cancer were relatively low and varied by biomarker subtype.