Proteomic Profiling of Primary Breast Cancer Predicts Axillary Lymph Node Metastasis

Abstract

To determine if protein expression in primary breast cancers can predict axillary lymph node (ALN) metastasis, we assessed differences in protein expression between primary breast cancers with and without ALN metastasis using surfaceenhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Laser capture microdissection was performed on invasive breast cancer frozen sections from 65 patients undergoing resection with sentinel lymph node (SLN) or level I and II ALN dissection. Isolated proteins from these tumors were applied to immobilized metal affinity capture (IMAC-3) ProteinChip arrays and analyzed by SELDI-TOF-MS to generate unique protein profiles. Correlations between unique protein peaks and histologically confirmed ALN status and other known clinicopathologic factors were examined using ANOVA and multivariate logistic regression. Two metalbinding polypeptides at 4,871 and 8,596 Da were identified as significant risk factors for nodal metastasis (P = 0.034 and 0.015, respectively) in a multivariate analysis. Lymphovascular invasion (LVI) was the only clinicopathologic factor predictive of ALN metastasis (P = 0.0038). In a logistic regression model combining the 4,871 and 8,596 Da peaks with LVI, the area under the receiver operating characteristic curve was 0.87. Compared with patients with negative ALN, those with z2 positive ALN or non-SLN metastases were significantly more likely to have an increased peak at 4,871 Da (P = 0.016 and 0.0083, respectively). ProteinChip array analysis identified differential protein peaks in primary breast cancers that predict the presence and number of ALN metastases and non-SLN status. (Cancer Res 2006; 66(24): 11825-30)

Clinical Application of Proteomics in Breast Cancer: State of the Art and Perspectives

“…Another study examined laser-microdissected invasive breast cancer cells and identified 2 proteins whose expression correlated with lymph node involvement. Interestingly, one of them (with low expression in node-positive disease) had an m/z ratio of 8.5 kDa, consistent with ubiquitin [94] . We have recently profiled the cytosol of 27 human breast cancer cell lines [95] .…”

Primary Study of Lymph Node Metastasis‐Related Serum Biomarkers in Breast Cancer

“…Currently, the use of proteomics research on tumor metastasis in prostate cancer (Pang et al, 2010), colon cancer (Xue et al, 2010), multiple myeloma (Wang et al, 2009) and larynx cancer (Cheng et al, 2008) have been successfully reported, but few studies have been reported in axillary lymph node metastasis of breast cancer. Nakagawa et al (2006) reported the use of Surface-enhanced laser desorption and ionization time-offlight mass spectrometry (SELDI)-TOF-MS combined with microdissection to detect 65 cases of primary breast cancer and found that protein m/z peaks at 4871 and 8596 Da were associated with axillary lymph node metastasis. Hu and colleagues used two-dimensional liquid chromatography tandem MS (2D-LC-MS/MS) to detect seven lymph node-positive cases and seven lymph nodenegative cases in breast cancer patients.…”

Proteomic studies in breast cancer (Review)

“…Another SELDI-TOF MS study using LCM, analyzed the tumor tissues of 65 patients with or without axillary compromise and identified two peaks (4,871 and 8,596 Da) differentially expressed for the conditions; the 8,596 Da peak corresponded to ubiquitin. This peak was under-expressed in breast cancers with axillary lymph node metastasis, indicating that ubiquitin is a good prognostic biomarker (55). Ubiquitin was differentially expressed in two further cell lineage studies (56).…”