The shifting landscape of metastatic breast cancer to the CNS

Abstract

The improved survival following the diagnosis of breast cancer has potentially altered the characteristics and course of patients presenting with CNS involvement. We therefore sought to define our current cohort of breast cancer patients with metastatic disease to the CNS in regard to modern biomarkers and clinical outcome. Review of clinical and radiographic records of women presenting to a tertiary medical center with the new diagnosis of CNS metastatic disease from breast cancer. This was a retrospective review from patients identities obtained from two prospective databases. There were 88 women analyzed who were treated over the period of January 2003 to February 2010, average age 56.9years. At the time of initial presentation of CNS disease, 68% of patients had multiple brain metastases, 17% had a solitary metastasis, and 15% had only leptomeningeal disease (LMD). The median survival for all patients from the time of diagnosis of breast disease was 50.0months, and 9.7months from diagnosis of CNS involvement. The only factor related to overall survival was estrogen receptor-positive pathology (57.6 v. 38.2months, p = .02 log-rank); those related to survival post CNS diagnosis were presentation with LMD (p = .004, HR = 3.1, Cox regression) and triple-negative hormonal/HER2 status (p = .02, HR = 2.3, Cox regression). Patients with either had a median survival of 3.1months (no patients in common). Of the 75 patients who initially presented with metastatic brain lesions, 20 (26%) subsequently developed LMD in the course of their disease (median 10.4months), following which survival was grim (1.8months median). Symptoms of LMD were most commonly lower extremity weakness (14/33), followed by cranial nerve deficits (11/33). The recently described Graded Prognostic Assessment (GPA) tumor index stratified median survival at 2.5, 5.9, 13.1, and 21.7months, respectively, for indices of 1-4 (p = .004, log-rank), which contrasted with the nonsignificant survival difference between Radiation Therapy Oncology Group Recursive Partitioning Analysis classes one and two. (13.1 v. 13.2, p = .8, log-rank). Treatment of patients with metastatic brain disease from breast cancer should be tailored to the patient's hormonal status and GPA index. Practitioners must be vigilant for the development of LMD, especially as it often presents with nondescript complaints such as back pain.