Tissue biomarkers of breast cancer and their association with conventional pathologic features.

BACKGROUND: Tissue protein expression profiling has the potential to detect new biomarkers to improve breast cancer (BC) diagnosis, staging, and prognostication. This study aimed to identify tissue proteins that differentiate breast cancer tissue from healthy breast tissue using protein chip mass spectrometry and to examine associations with conventional pathological features. METHODS: To develop a training model, 82 BC and 82 adjacent unaffected tissue (AT) samples were analysed on cation-exchange protein chips by time-of-flight mass spectrometry. For validation, 89 independent BC and AT sample pairs were analysed. RESULTS: From the protein peaks that were differentially expressed between BC and AT by univariate analysis, binary logistic regression yielded two peaks that together classified BC and AT with a ROC area under the curve of 0.92. Two proteins, ubiquitin and S100P (in a novel truncated form), were identified by liquid chromatography/tandem mass spectrometry and validated by immunoblotting and reactive-surface protein chip immunocapture. The combined marker panel was positively associated with high histologic grade, larger tumour size, lymphovascular invasion, ER and PR positivity, and HER2 overexpression, suggesting that it may be associated with a HER2-enriched molecular subtype of breast cancer. CONCLUSION: This independently validated protein panel may be valuable in the classification and prognostication of breast cancer patients.

Patterns of breast cancer relapse.

AIMS: Although breast cancer is the major cause of cancer-related death in women, there is little comprehensive information on long-term outcomes, particularly pertaining to site of relapse. The Strathfield Breast Centre (TSBC) is a multidisciplinary breast clinic that has collected patient data prospectively over 14 years. METHODS: All women with invasive, non-metastatic breast cancer, referred to TSBC from 1989 until 2002, were studied (n=2509). After initial treatment, patients were reviewed at 3-12-month intervals, including annual mammography and/or breast ultrasound. Information was collected on demographics, pre- and post-operative management and patient outcomes. Survival was analysed by the method of Kaplan and Meier. RESULTS: The mean age was 58 years and median follow-up 4 years (range <1-14) with complete data for 81%. In total, 456 patients (18%) had a local, nodal or distant relapse. The most common site of first relapse was to bone (in 125 patients), followed by local recurrence (124), lung (73) and liver (57). The median interval from primary breast surgery until recurrence was 2.3 years and disease-free intervals correlated to survival (p<0.0001). After local recurrence the 5-year survival was 41%, vs. 20% for nodal and 13% for distant recurrence (p<0.0001). Following breast-conserving surgery, the 5-year disease-free survival after local recurrence was 49.4%, vs. 33.1% after chest wall recurrence (p=0.0361). Of distant relapses, bone metastases had the best prognosis, with median survival 2.4 years. CONCLUSION: These data provide information on treatment outcomes in a multidisciplinary setting and statistical information that will be useful when discussing the fears and expectations of patients after the diagnosis of breast cancer.