370P - Cns metastases, subtypes and survival in breast cancer: a population based study in eastern Switzerland

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Breast Cancer, Metastatic
Presenter David König
Authors D. König1, B. Thürlimann2, F. Otto3, L. Plasswilm4, M. Hoefliger5, I.K. Senn-Schönenberger6, U. Müller7, C. Öhlschlegel8, H. Senn3, S.M. Ess9
  • 1Krebsliga Ostschweiz, Cancer Registry St. Gallen-Appenzell, 9000 - St. Gallen/CH
  • 2Breast Center St. Gallen, Kantonsspital St. Gallen, 9000 - St. Gallen/CH
  • 3Tumor-und Brustzentrum ZeTuP AG, CH-9006 - St. Gallen/CH
  • 4Department Of Radiation Therapy, Kantonsspital St. Gallen, 9007 - St. Gallen/CH
  • 5Oncology Practice, Oncology Practice, 9450 - Altstätten/CH
  • 6Oncology Practice, Oncology Practice, 9000 - St. Gallen/CH
  • 7Oncology Practice, 7320 - Sargans/CH
  • 8Institute Of Pathology, Kantonsspital St. Gallen, 9007 - St. Gallen/CH
  • 9Cancer League Eastern Switzerland, Cancer Registry St. Gallen-Appenzell, 9000 - St. Gallen/CH

Abstract

Purpose

To examine tumor characteristics and outcomes associated with central nervous system (CNS) metastases in patients with metastatic breast cancer (MBC).

Methods

Patients listed in the regional cancer registry of St. Gallen-Appenzell with MBC between 2003-2009 were included. Estrogen- (ER), progesterone receptor (PR) and HER2 status were collected from pathology reports. Biologic subtypes were approximated using standard immunohistochemical markers. Survival status was assessed in January 2012. Multivariate logistic regression models were used to identify factors associated with the risk of developing CNS metastases and with survival >12 months (mt) after the diagnosis of CNS involvement.

Results

Overall, CNS metastases were observed in 170 (22%) of 773 patients with MBC included in the study. In the multivariate model, factors associated with CNS metastases were age <65 (odds ratio (OR) 3.40; 95% confidence interval (CI) 2.32-4.98) and biologic subtype. Compared to patients with ER- and/or PR-positive and HER2-negative tumors, the risk to develop CNS metastases was two-fold higher for patients with triple negative (TN) tumors (OR 2.10; 95% CI 1.17-3.76) and 72% higher for patients with HER2-positive tumors (OR 1.72; 95% CI 1.14-2.61). CNS involvement occurred rarely as first metastatic manifestation. In most patients (n = 137, 81%), CNS metastases were observed metachronically: in TN disease after a median time of 12 mt, and in the other subtypes after a median time of 19 mt (p < 0.01). Median survival of all patients after diagnosis of CNS metastases was 6 mt (interquartile range 2-14 mt) with no significant differences among subtypes (log-rank test p = 0.28). After diagnosis of CNS metastases, 48 patients (28%) lived longer than 12 mt and 14 (8%) longer than 24 mt. Age <65 (OR 3.50), surgical excision (OR 3.30) and radiotherapy of CNS (OR 4.10) were independently associated with survival >12 mt.

Conclusion

Patients with TN or HER2-positive tumors showed increased risk for CNS metastases. However, after diagnosis of CNS metastases only surgery and radiotherapy favorably influenced survival. New approaches to control CNS disease in young patients with these subtypes need to be developed.

Disclosure

All authors have declared no conflicts of interest.