Metastatic breast cancer: are we treating the same patients as in the past?

BACKGROUND: Early detection and improved (neo)-adjuvant treatment has extended survival of breast cancer over the last decades. It remains controversial whether a survival benefit is achieved once metastases have occurred. This study investigates survival trends in metastatic breast cancer (MBC) looking at the distribution of prognostic factors and the time period of the diagnosis of the primary and metastatic disease. PATIENTS AND METHODS: In this retrospective study, 1635 patients, diagnosed with MBC and treated at three German cancer centers, were included. For the survival analysis, patients were grouped into three time periods [1980-1994 (a), 1995-1999 (b) and 2000-2009 (c)], which were chosen according to the availability of new antineoplastic drugs for the treatment of MBC. Additionally, patients were divided into three risk groups using the simultaneously published prognostic score. RESULTS: The analysis of overall survival according to the date of primary diagnosis demonstrated a significant decline compared with the reference (a): (a versus b) hazard ratio (HR) = 1.37; P < 0.001; (a versus c) HR = 2.45; P < 0.001. Considering the time of first occurrence of metastasis, survival remains unchanged over the three periods (a versus b): HR = 0.94 P = 0.436; (a versus c): HR = 0.95; P = 0.435. However, a significant shift towards more unfavorable risk factors was seen. CONCLUSIONS: Although survival in MBC remains unchanged over time, patients developing metastatic disease have a more aggressive disease that is presumably compensated by more effective treatment. This alteration of tumor biology in MBC may be explained by a negative selection of patients with adverse risk profiles due to the advantages of the adjuvant therapy.

An internally and externally validated prognostic score for metastatic breast cancer: analysis of 2269 patients.

BACKGROUND: The prognosis of metastatic breast cancer (MBC) is extremely heterogeneous. Although patients with MBC will uniformly die to their disease, survival may range from a few months to several years. This underscores the importance of defining prognostic factors to develop risk-adopted treatment strategies. Our aim has been to use simple measures to judge a patient's prognosis when metastatic disease is diagnosed. PATIENTS AND METHODS: We retrospectively analyzed 2269 patients from four clinical cancer registries. The prognostic score was calculated from the regression coefficients found in the Cox regression analysis. Based on the score, patients were classified into high-, intermediate-, and low-risk groups. Bootstrapping and time-dependent receiver operating characteristic curves were used for internal validation. Two independent datasets were used for external validation. RESULTS: Metastatic-free interval, localization of metastases, and hormone receptor status were identified as significant prognostic factors in the multivariate analysis. The three prognostic groups showed highly significant differences regarding overall survival from the time of metastasis [intermediate compared with low risk: hazard ratio (HR) 1.76, 95% confidence interval (CI) 1.36-2.27, P < 0.001; high compared with low risk: HR 3.54, 95% CI 2.81-4.45, P < 0.001). The median overall survival in these three groups were 61, 38, and 22 months, respectively. The external validation showed congruent results. CONCLUSIONS: We developed a prognostic score, based on routine parameters easily accessible in daily clinical care. Although major progress has been made, the optimal therapeutic management of the individual patient is still unknown. Besides elaborative molecular classification of tumors, simple clinical measures such as our model may be helpful to further individualize optimal breast cancer care.