Prognostic factors for patients with brain metastases vary by diagnosis, and for each diagnosis, a robust separation into different GPA scores was discerned, implying considerable heterogeneity in outcome, even within a single tumor type. In summary, these indices and related worksheet provide an accurate and facile diagnosis-specific tool to estimate survival, potentially select appropriate treatment, and stratify clinical trials for patients with brain metastases.

No abstract

BACKGROUND The diagnosis-specific Graded Prognostic Assessment (GPA) was published to clarify prognosis for patients with brain metastases. This study refines the existing Breast-GPA by analyzing a larger cohort and tumor subtype. METHODS A multi-institutional retrospective database of 400 breast cancer patients treated for newly-diagnosed brain metastases was generated. Prognostic factors significant for survival were analyzed by multivariate Cox regression (MCR) and recursive partitioning analysis (RPA). Factors were weighted by the magnitude of their regression coefficients to define the GPA index. RESULTS Significant prognostic factors by MCR and RPA were Karnofsky Performance Status (KPS), HER2, ER/PR status, and the interaction between ER/PR and HER2. RPA showed age was significant for patients with KPS 60–80. The median survival time (MST) overall was 13.8 months, and for GPA scores of 0–1.0, 1.5–2.0, 2.5–3.0 and 3.5–4.0 was 3.4 (n=23), 7.7 (n=104), 15.1 (n=140) and 25.3 (n=133) months, respectively (p < 0.0001). Among HER2-negative patients, being ER/PR-positive improved MST from 6.4 to 9.7 months whereas in HER2-positive patients, being ER/PR-positive improved MST from 17.9 to 20.7 months. The log-rank statistic (predictive power) was 110 for the Breast-GPA versus 55 for tumor subtype. CONCLUSIONS The Breast-GPA documents wide variation in prognosis and shows clear separation between subgroups of patients with breast cancer and brain metastases. This tool will aid clinical decision-making and stratification of clinical trials. These data confirm the effect of tumor subtype on survival and show the Breast-GPA offers significantly more predictive power than the tumor subtype alone.

The physiological functions and substrates of the calcium-dependent protease calpain remain only partly understood. The -and m-calpains consist of a -or m-80-kDa large subunit (genes Capn1 and Capn2), and a common 28-kDa small subunit (Capn4). To assess the role of calpain in migration, we used fibroblasts obtained from Capn4 ؊/؊ mouse embryos. The cells lacked calpain activity on casein zymography and did not generate the characteristic calpain-generated spectrin breakdown product that is observed in wild-type cells. Capn4؊/؊ cells had decreased migration rates and abnormal organization of the actin cytoskeleton with a loss of central stress fibers. Interestingly, these cells extended numerous thin projections and displayed delayed retraction of membrane protrusions and filopodia. The number of focal adhesions was decreased in Capn4 ؊/؊ cells, but the cells had prominent vinculincontaining focal complexes at the cell periphery. The levels of the focal adhesion proteins, ␣-actinin, focal adhesion kinase (FAK), spectrin, talin, and vinculin, were the same in Capn4 ؉/؉ and Capn4 ؊/؊ cells. FAK, ␣-actinin, and vinculin were not cleaved in either cell type plated on fibronectin. However, proteolysis of the focal complex component, talin, was detected in the wild-type cells but not in the Capn4 ؊/؊ cells, suggesting that calpain cleavage of talin is important during cell migration. Moreover, talin cleavage was again observed when calpain activity was partially restored in Capn4 ؊/؊ embryonic fibroblasts by stable transfection with a vector expressing the rat 28-kDa calpain small subunit. The results demonstrate unequivocally that calpain is a critical regulator of cell migration and of the organization of the actin cytoskeleton and focal adhesions.

BACKGROUND-The diagnosis-specific Graded Prognostic Assessment (GPA) was published to clarify prognosis for patients with brain metastases. This study refines the existing Breast-GPA by analyzing a larger cohort and tumor subtype.