Utility of monocyte HLA-DR and rationale for therapeutic GM-CSF in sepsis immunoparalysis.

Sepsis, a heterogeneous clinical syndrome, features a systemic inflammatory response to tissue injury or infection, followed by a state of reduced immune responsiveness. Measurable alterations occur in both the innate and adaptive immune systems. Immunoparalysis, an immunosuppressed state, associates with worsened outcomes, including multiple organ dysfunction syndrome, secondary infections, and increased mortality. Multiple immune markers to identify sepsis immunoparalysis have been proposed, and some might offer clinical utility. Sepsis immunoparalysis is characterized by reduced lymphocyte numbers and downregulation of class II human leukocyte antigens (HLA) on innate immune monocytes. Class II HLA proteins present peptide antigens for recognition by and activation of antigen-specific T lymphocytes. One monocyte class II protein, mHLA-DR, can be measured by flow cytometry. Downregulated mHLA-DR indicates reduced monocyte responsiveness, as measured by ex-vivo cytokine production in response to endotoxin stimulation. Our literature survey reveals low mHLA-DR expression on peripheral blood monocytes correlates with increased risks for infection and death. For mHLA-DR, 15,000 antibodies/cell appears clinically acceptable as the lower limit of immunocompetence. Values less than 15,000 antibodies/cell are correlated with sepsis severity; and values at or less than 8000 antibodies/cell are identified as severe immunoparalysis. Several experimental immunotherapies have been evaluated for reversal of sepsis immunoparalysis. In particular, sargramostim, a recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF), has demonstrated clinical benefit by reducing hospitalization duration and lowering secondary infection risk. Lowered infection risk correlates with increased mHLA-DR expression on peripheral blood monocytes in these patients. Although mHLA-DR has shown promising utility for identifying sepsis immunoparalysis, absence of a standardized, analytically validated method has thus far prevented widespread adoption. A clinically useful approach for patient inclusion and identification of clinically correlated output parameters could address the persistent high unmet medical need for effective targeted therapies in sepsis.

Impact of serum HER2, TIMP-1, and CAIX on outcome for HER2+ metastatic breast cancer patients: CCTG MA.31 (lapatinib vs. trastuzumab).

BACKGROUND: The lapatinib-taxane combination led to shorter PFS than trastuzumab-taxane in HER2+ metastatic breast cancer. We investigated the prognostic and predictive effects of pretreatment serum HER2, CAIX, and TIMP-1. METHODS: MA.31 accrued 652 patients; 537 (82%) were centrally confirmed HER2+. Biomarkers were categorized for univariate and multivariable predictive investigations with a median cut-point, ULN cut-points (15 ng/ml for HER2; 506 pg/ml for CAIX; 454 pg/ml for TIMP-1), and custom cut-points (30 and 100 ng/ml for HER2). Stratified step-wise forward Cox multivariable analysis examined continuous and categorical effects of biomarkers on PFS in the ITT and central HER2+ populations; central HER2+ biomarker results are shown. RESULTS: Serum was banked for 472 (72%) of 652 patients. Higher serum HER2 (>median; >15; >30; or >100 ng/ml; p = 0.05-0.002); higher CAIX (>median; >506 pg/ml; p = 0.02; p = 0.001); and higher TIMP-1 (> median; > 454 pg/ml; p = 0.001; p = 0.02) had shorter univariate PFS. In multivariable analysis, higher continuous TIMP-1 was associated with significantly shorter PFS: HR = 1.001 (95% CI = 1.00-01.002; p = 0.004). Continuous serum HER2 and CAIX were not significantly associated with PFS. HER2 of 15 ng/ml or higher had shorter PFS (p = 0.02); higher categorical CAIX had shorter PFS (p = 0.01-0.08). Interaction terms of HER2, CAIX, and TIMP-1 with treatment were not significant; the predictive test power was low. CONCLUSIONS: Higher levels of serum TIMP-1, CAIX, and HER2 were significant prognostic biomarkers of shorter PFS. We found no significant interaction between serum biomarkers and response to lapatinib versus trastuzumab. Evaluation of TIMP-1 and CAIX-targeted therapy in addition to HER2-targeted therapy appears warranted in patients with elevated serum levels of these biomarkers.

Circulating HER2 Extracellular Domain: A Specific and Quantitative Biomarker of Prognostic Value in all Breast Cancer Patients?

The HER2 oncoprotein has emerged as an essential biomarker in the treatment of breast cancer patients. Once the primary breast cancer is removed, there is an increasing need to detect breast cancer recurrence as early as possible with the hope that earlier intervention with new anti-HER2 therapies will improve quality of life and increase overall survival. Numerous publications have shown that increasing blood levels of circulating HER2 is an early indicator of progression, particularly in HER2-positive patients and that the rise and fall parallels the clinical course of disease and independent of therapy. Many studies show that the HER2 status of the primary tumor may not fully and accurately reflect the HER2 status of recurrent cancer. Thus, elevated serum HER2 levels may be an early signal of the emergence of a HER2-positive metastatic tumor and therefore alert the physician to re-assess HER2 status using a tissue test.

Soluble human epidermal growth factor receptor 2 (HER2) levels in patients with HER2-positive breast cancer receiving chemotherapy with or without trastuzumab: results from North Central Cancer Treatment Group adjuvant trial N9831.

BACKGROUND: Increased soluble human epidermal growth factor receptor 2 (sHER2) is an indicator of a poor prognosis in HER2-positive metastatic breast cancer. In this study, the authors evaluated levels of sHER2 during treatment and at the time of disease recurrence in the adjuvant North Central Cancer Treatment Group N9831 clinical trial. METHODS: The objectives were to describe sHER2 levels during treatment and at the time of recurrence in patients who were randomized to treatment arms A (standard chemotherapy), B (standard chemotherapy with sequential trastuzumab), and C (standard chemotherapy with concurrent trastuzumab). Baseline samples were available from 2318 patients, serial samples were available from 105 patients, and recurrence samples were available from 124 patients. The cutoff sHER2 value for the assay was 15 ng/mL. Statistical methods included repeated measures linear models, Wilcoxon rank-sum tests, and Cox regression models. RESULTS: There were differences between groups in terms of age, menopausal status, and hormone receptor status. Within treatment arms A, B, and C, patients who had baseline sHER2 levels ≥15 ng/mL had worse disease-free survival than patients who had baseline sHER2 levels <15 ng/mL (arm A: hazard ratio, 1.81; P = .0014; arm B: hazard ratio, 2.08; P = .0015; arm C: hazard ratio, 1.96; P = .01). Among the 124 patients who experienced disease recurrence, sHER2 levels increased from baseline to the time of recurrence in arms A and B but remained unchanged in arm C. Patients who had recurrence sHER2 levels ≥15 ng/mL had a shorter survival after recurrence with a 3-year overall survival rate of 51% compared with 77% for those who had recurrence sHER2 levels <15 ng/mL (hazard ratio, 2.36; 95% confidence interval, 1.19-4.70; P = .01). CONCLUSIONS: In patients with early stage, HER2-positive breast cancer, a high baseline sHER2 level was identified as a prognostic marker associated with shorter disease-free survival, and a high sHER2 level at recurrence was predictive of shorter survival.

Microfluidics and circulating tumor cells.

Circulating tumor cells (CTCs) are shed from cancerous tumors, enter the circulatory system, and migrate to distant organs to form metastases that ultimately lead to the death of most patients with cancer. Identification and characterization of CTCs provides a means to study, monitor, and potentially interfere with the metastatic process. Isolation of CTCs from blood is challenging because CTCs are rare and possess characteristics that reflect the heterogeneity of cancers. Various methods have been developed to enrich CTCs from many millions of normal blood cells. Microfluidics offers an opportunity to create a next generation of superior CTC enrichment devices. This review focuses on various microfluidic approaches that have been applied to date to capture CTCs from the blood of patients with cancer.

Hidden HER-2/neu-positive breast cancer: how to maximize detection.

The HER-2/neu oncoprotein is an important cellular target for the development of a variety of targeted therapies for HER-2/neu-positive breast cancer. Methods for tumor analysis such as immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) are routinely used to determine the HER-2/neu status of patients with breast cancer and their eligibility for HER-2/neu-targeted therapies, such as trastuzumab (Herceptin) and lapatnib (Tykerb). In a January 2008 article in the Wall Street Journal, it was reported that breast cancer patients may be receiving the wrong treatments or no treatment because of errors in the laboratory tests (IHC/FISH) that are widely used to determine the HER-2/neu status of breast cancers. Numerous reports have demonstrated that 20 to 30% of patients with primary breast cancer have HER-2/neu positive tumors. However, several studies have also shown that up to 40% of patients who are designated HER-2/neu negative with primary tumor analysis by IHC/FISH are actually HER-2/neu positive when the corresponding metastatic tumor is also evaluated by IHC/FISH. Studies have also demonstrated that up to 40% of patients with breast cancer who have a HER-2/neu-negative primary tumor as determined by IHC/FISH can develop elevated levels (> 15 ng/ml) of the circulating HER-2/neu oncoprotein during metastasis. Therefore, elevated serum HER-2/neu levels can be used to alert physicians of the possible presence of HER-2/neu-positive breast cancer in patients who have been previously classified as HER-2/neu negative. Collectively, these studies identify a population of women designated HER-2/neu negative that could have HER-2/neu-positive breast cancer, but have not been eligible for targeted therapies such as trastuzumab and lapatinib. Women who are incorrectly classified as HER-2/neu negative, but are also ineligible for approved HER-2/neu-targeted therapies, may also not be considered for clinical trials of additional HER-2/neu therapies in development. Several studies have also demonstrated that serum HER-2/neu can be elevated in patients with early breast cancer, and up to 90% of patients with HER-2/neu-positive metastatic breast cancer can have elevated serum HER-2/neu levels. These studies have also revealed that the frequency of patients who have HER-2/neu-positive breast cancer is greater than indicated previously by IHC/FISH. Thus, the number of patients classified incorrectly as HER-2/neu negative could be substantially greater than recognized previously. This feature review presents a HER-2/neu testing algorithm that combines the serum HER-2/neu test result with IHC/FISH test results to maximize the identification of patients who are HER-2/neu positive and could be potential candidates for HER-2/neu-targeted therapies. The HER-2/neu situation also exemplifies that multiple diagnostic tools are required to correctly and accurately identify patients for targeted therapies--an important lesson as many new biomarkers are identified for the multitude of new targeted therapies in development for various forms of cancers.

Serum HER-2/neu and relative resistance to trastuzumab-based therapy in patients with metastatic breast cancer.

BACKGROUND: Previous reports based on small patient numbers suggested that changes in serum HER-2/neu levels may predict response or lack of response to trastuzumab-based therapies in metastatic breast cancer (MBC). The objectives of this study were to pool data from 307 patients with MBC from 7 medical institutions to validate that the serum HER-2/neu profile predicts patient resistance to trastuzumab and to establish a clinically relevant cutoff. METHODS: This was an international, multicenter, retrospective analysis of individual pooled data from 307 patients with MBC who were treated with first-line trastuzumab-based therapy. Serum was collected at baseline and 30 to 120 days after the initiation of trastuzumab therapy. A serum HER-2/neu decrease >or=20% (receiver operating curve analysis) was defined as a significant HER-2/neu change. RESULTS: Of the 307 patients with MBC, 191 patients (62%) had a significant decline (>20%) in serum HER-2/neu and 116 patients (38%) did not. The objective response rate was 57% for patients who achieved this decline in serum HER-2/neu (>20%) compared with 28% for patients who did not. Patients who achieved this decline in serum HER-2/neu also had a significantly longer time to disease progression (320 days vs 180 days; P < .0001), longer duration of response (369 days vs 230 days; P = .008), and longer overall survival (898 days vs 593 days; P < .018). CONCLUSIONS: In this pooled analysis of 307 patients with MBC, individuals who did not achieve a significant decline (>or=20%) in serum HER-2/neu levels had decreased benefit from trastuzumab-based therapy, and these patients should be considered for clinical trials evaluating additional HER-2/neu-targeted interventions.

HER-2/neu diagnostics in breast cancer.

HER-2/neu status of the primary breast cancer (PBC) is determined by immunohistochemistry and fluorescent in situ hybridization. Because of a variety of technical factors, however, the PBC may not accurately reflect the metastatic tumor in terms of HER-2/neu status. Recently published guidelines recommend that tumors be defined as HER-2/neu positive if 30% or more of the cells are 3+. Circulating levels of the HER-2 extracellular domain can be measured in serum using a test cleared by the US Food and Drug Administration, and increased serum HER-2/neu levels to above 15 ng/ml can reflect tumor progression. Studies comparing tissue HER-2/neu status of the PBC and HER-2/neu levels above 15 ng/ml in metastatic breast cancer patients are also reviewed.

Circulating oncoproteins HER2/neu, EGFR and CAIX (MN) as novel cancer biomarkers.

Pharmaceutical companies have developed targeted therapies such as trastuzumab and lapatinib for human epidermal growth factor receptor (HER)2/neu-positive tumors, while others have developed antiepidermal growth factor receptor (EGFR) therapies, such as tarceva and erbitux for EGFR-positive tumors. A drug called rencarex is targeted to an oncoprotein designated carbonic anhydrase IX (CAIX), which is being evaluated in renal cell carcinoma patients. Based on these targeted therapeutic approaches, this review describes clinical research studies performed with enzyme-linked immunosorbent assays specific for the circulating oncoproteins, HER2/neu, EGFR and CAIX. These circulating biomarkers have the potential to be used in conjunction with the specific targeted therapies for patient selection, monitoring and management. With the variety of new therapeutic options, the major challenge ahead will be to select the appropriate therapy or combinations of therapies for each patient. Specific biomarker tests, either alone or in panels, will be needed at the appropriate time in the course of disease to ensure that patients receive the right drug at the right time. These tests will also be valuable in monitoring the efficacy of the targeted therapies. A circulating biomarker such as serum HER2/neu may be able to specifically identify patients with progressing HER2/neu-positive disease and provide the information needed by physicians to choose from the variety of HER2/neu-targeted therapies that will soon be available to cancer patients.

HER2 status is an important biomarker in guiding personalized HER2 therapy.

The human epidermal growth factor receptor (HER)2 oncoprotein has emerged as an important cellular target for the development of a variety of new cancer therapies. The method used to define the HER2 status is a major factor in determining who will receive these targeted therapies. The HER2 status can be determined by using either tissue tests to look at the primary tumor cells, or an enzyme-linked immunosorbent assay (ELISA) that measures the circulating levels of the extracellular portion of HER2 protein. Tissue test (immunohistochemistry and fluorescence in situ hybridization) results indicate that approximately 20-30% of patients with primary breast cancer have a HER2-positive tumor, whereas ELISA results demonstrate that an average of 45% (range: 23-80%) of metastatic breast cancer (MBC) patients can have an abnormally high (> 15 ng/ml) serum HER2 level, which is evidence that a HER2-positive tumor is present. Published studies show that the HER2 status of a breast cancer patient can differ both by the test method used and the time at which HER2 status is assessed. In this review, data will be shown that demonstrates that not all HER2 test results obtained from the primary breast cancer are correct, and that there is a population of patients categorized as HER2 negative by tissue tests that, in fact, have HER2-positive tumors. This observation has important therapeutic implications for breast cancer patients with HER2-positive tumors that are classified as HER2 negative, since they are not eligible for anti-HER2 therapy, such as trastuzumab. If a patient is found to have an elevated (> 15 ng/ml) serum HER2 level in MBC, then either the original tumor should be re-evaluated for HER2 status, or a metastatic lesion should be tested for HER2 positivity, to determine if the patient is eligible for anti-HER2 therapy. Studies have also shown that lack of adequate validation of a testing method can result in false conclusions concerning the HER2 status. If the goal of personalized medicine is to deliver the right treatment to the right patient at the right time then we need to ensure the validity of all test methods, regardless of whether they are for research purposes or are registered as in vitro diagnostics. In the case of establishing HER2 status, it takes more than one type of test to identify patients with HER2-positive tumors. It is highly likely that the introduction of additional targeted drugs to growth factor receptors or to angiogenesis targets will take a variety and combinations of tests to tailor the most appropriate therapy to the patient.

Monitoring the circulating levels of the HER2/neu oncoprotein in breast cancer.

The HER2/neu oncoprotein is a major target for the development of new cancer therapies and is similar to the estrogen receptor, which guides hormone therapy. The HER2/neu status is used to guide therapy decisions in patients with HER2/neu-overexpressing breast cancer tumors. The HER2/neu oncogene, or c-erbB-2, encodes a transmembrane receptor protein that is expressed on normal epithelial cells and can be overexpressed in breast cancer cells. Studies have shown that the extracellular domain (ECD) of the HER2/neu oncoprotein is released from the cell and can be measured in the circulation of women with breast cancer. Enzyme-linked immunosorbent assay methods used to measure the circulating HER2/neu ECD have shown that the prevalence of elevated ECD levels is approximately 18.1% in women with primary breast cancer and approximately 45.6% in women with metastatic breast cancer (MBC). Many studies have monitored the circulating ECD levels after surgery and indicate that increasing ECD levels can indicate recurrence of breast cancer earlier than clinical diagnosis. Studies in women with MBC showed that serial changes in circulating HER2/neu ECD levels paralleled the clinical course of disease, regardless of the treatment regimen. Several studies identified a subgroup of patients with MBC who had HER2/neu-negative disease by tissue testing but developed elevated ECD levels with MBC. In contrast to tissue testing, which is a one-time event, monitoring the circulating levels of the HER2/neu ECD in patients with breast cancer provides a real-time assessment of the HER2/neu status and provides important information for managing the therapy of patients with MBC.

Potential clinical utility of serum HER-2/neu oncoprotein concentrations in patients with breast cancer.

BACKGROUND: The HER-2/neu oncogene and its p185 receptor protein are indicators of a more aggressive form of breast cancer. HER-2/neu status guides Herceptin therapy, specifically directed to the extracellular domain (ECD) of the HER-2/neu oncoprotein. The HER-2/neu ECD is shed from cancer cells into the circulation and is measurable by immunoassay. METHODS: We performed a systematic review of the peer-reviewed literature on circulating ECD with respect to prevalence, prognosis, prediction of response to therapy, and monitoring of breast cancer. RESULTS: The prevalence of increased ECD in patients with primary breast cancer varied between 0% and 38% (mean, 18.5%), whereas in metastatic disease the range was from 23% to 80% (mean, 43%). Some women with HER-2/neu-negative tumors by tissue testing develop increased ECD concentrations in metastatic disease. Increased ECD has been correlated with indicators of poor prognosis, e.g., overall survival and disease-free survival. Increased ECD predicts a poor response to hormone therapy and some chemotherapy regimens but can predict improved response to combinations of Herceptin and chemotherapy. Many studies support the value of monitoring ECD during breast cancer progression because serial increases precede the appearance of metastases and longitudinal ECD changes parallel the clinical course of disease. CONCLUSIONS: The monitoring of circulating HER-2/neu ECD provides a tool for assessing prognosis, for predicting response to therapy, and for earlier detection of disease progression and timely intervention with appropriate therapy.