P4-10-07: Clinico-Pathologic Features of Breast Cancer Patients with Primary Metastatic Disease Versus Localized Disease: A Multicenter Study.

Abstract

Abstract Objective: Approximately 6% of breast cancer patients present with primary metastatic disease (pmBC) at first diagnosis. Clinicopathological differences to non-metastatic patients are undetermined. Methods: Exploratory analysis of patients with pmBC treated in 8 breast cancer units between 1998 and 2010. Tumor characteristics of these patients were compared with non-metastatic breast cancer patients (BC) of one breast cancer center who had neither local-recurrence nor distant metastases during 30 months of follow-up after first diagnosis. Standard staging in patients with first diagnosis of BC included chest X-ray, abdominal ultrasonography and bone scan. Molecular subtypes were analyzed and defined by immunohistochemical markers (ER, PR, Her2-receptor). Results: 2.214 patients were included, 1.642 with BC and 572 with pmBC, respectively. Patients with pmBC were 7 years older (BC 58 years of age vs. pmBC 65 years; p=0.000) and were more likely to be postmenopausal (74% vs. 83%; p=0.000). Most common localizations of distant first metastases were bone (61,5%), liver (24%), lung (21%) and non-axillary lymph nodes (12%). 85 (15%) patients with pmBC were diagnosed in stage T1. Factors associated with pmBC in multivariate analysis for this group were positive lymph node status (OR 3.4; 95%CI 2.3−6.0; p=0.000), grading 3 (OR 2.3; 95%CI 1.3−4.0; p=0.003), lobular histology (OR 2.3; 95%CI 1.2−4.5; p=0,010) and phenotype Luminal B (OR 2.4; 95%CI 1.25−5.0; p=0.014). 197 (34%) patients with pmBC were diagnosed in stage T2; positive lymph node status (OR 4.8; 95%CI 1.1−3.0; p=0.017) and grading 3 (OR 1.6; 95% CI 1.6−2.3; p=0.019) were reported as risk factors for this group. 90 (16%) and 200 (35%) patients were diagnosed with stages T3 and T4, respectively. In T3/4 tumors a positive lymph node status (OR 5.2; 95% CI 2.9−9.3; p=0.000) and grading 3 (OR 2.2; 95%CI 1.2−3.9; p=0.009) could be defined as significant risk factors for distant metastases. Postmenopausal status was associated with primary metastases in stage T2 (OR 1.8; 95%CI 1.2−2.9; p=0.008) and T3/4 (OR 2.4; 95%CI 1.2−4.7; p=0.011) but not in T1 tumors (OR 1.3; 95%CI 0.7−2.1; p=0.420). There was no association with hormone or Her2 receptor status nor with a specific phenotype for T2-4 tumors. Conclusion: The clinico-pathological features of breast cancer patients with or without primary metastases differ. In all stages positive lymph node status and higher grading were associated with pmBC significantly. Lobular histology was reported as a risk factor for T1-2 compared to patients without metastases. This feature was not found for T3/4 pmBC. T1 pmBC were likely to be associated with luminal B phenotype. T3-4 pmBC have not been associated with any phenotype or hormone receptor constellation as risk factor for metastases. Tumor biology seems to play a minor role for risk of metastases in T3-4 stages compared to patients with T1-tumors. Findings from this analysis should be considered in the choice of staging methods, especially in stage T1. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-10-07.