Incidence of Brain Metastasis and Related Subtypes in Patients with Breast Cancer Receiving Adjuvant Radiation Therapy after Surgery / 한국유방암학회지

ABSTRACT

PURPOSE: To assess the incidence of brain metastasis in patients with breast cancer receiving surgery and adjuvant radiotherapy (RT) and to evaluate subtypes associated with brain metastasis. METHODS: We retrospectively reviewed the medical records of 1,000 patients with breast cancer who were treated with surgery and adjuvant RT for a cure between January 2001 and July 2005 at Samsung Medical Center. Seventy-one patients received neoadjuvant chemotherapy before surgery. The pathological stage was I in 430 patients, II in 327, and III in 243. We divided the patients into three subtypes according to immunohistochemistry triple negative (TN, 245 patients), human epidermal growth factor 2 (HER2) enriched (HE, 166 patients) and positive estrogen receptor or progesterone receptor without HER2 overexpression (EP, 589 patients). The median follow up time was 72 months after surgery. RESULTS: Locoregional failure-free survival rate and distant metastasis-free survival rate at 5 years were 92.8% and 86.1%, respectively. The disease free survival rate and overall survival rate at 5 years were 84.6% and 94.7%, respectively. Thirty-nine patients had brain metastasis, and the brain metastasis-free survival rate at 5 years was 97.2%. A univariate analysis showed that younger age, neoadjuvant chemotherapy, modified radical mastectomy, advanced pathological stage and the TN and HE subtypes were significant risk factors for brain metastasis. A multivariate analysis revealed that age, neoadjuvant chemotherapy, pathological stage and the TN and HE subtypes were statistically significant factors for brain metastasis. CONCLUSION: The cumulative incidence of brain metastasis was 3.9% after curative treatment. If patients have a clinically suspicious symptoms suggesting brain metastasis, clinicians should be aware that an early brain imaging work up and management are necessary. Because patients with the TN or HE subtypes accompanied by younger age and advanced pathological stage have increased brain metastasis (>10%), annual regular imaging follow-up may be recommended for these high risk patients.