Efficacy of High-Sensitivity Troponin T in Identifying Very-Low-Risk Patients With Possible Acute Coronary Syndrome

Importance

Physicians need information on how to use the first available high-sensitivity troponin (hsTnT) assay in the United States to identify patients at very low risk for 30-day adverse cardiac events (ACE).

Objective

To determine whether a negative hsTnT assay at 0 and 3 hours following emergency department presentation could identify patients at less than 1% risk of a 30-day ACE.

Design, Setting, and Participants

A prospective, observational study at 15 emergency departments in the United States between 2011 and 2015 that included individuals 21 years and older, presenting to the emergency department with suspected acute coronary syndrome. Of 1690 eligible individuals, 15 (no cardiac troponin T measurement) and 320 (missing a 0-hour or 3-hour sample) were excluded from the analyses.

Exposures

Serial hsTnT measurements (fifth-generation Roche Elecsys hsTnT assay).

Main Outcomes and Measures

Serial blood samples from each patient were collected after emergency department presentation (once identified as a potential patient with acute coronary syndrome) and 3 hours, 6 to 9 hours, and 12 to 24 hours later. Adverse cardiac events were defined as myocardial infarction, urgent revascularization, or death. The upper reference level for the hsTnT assay, defined as the 99th percentile, was established as 19 ng/L in a separate healthy US cohort. Patients were considered ruled out for acute myocardial infarction if their hsTnT level at 0 hours and 3 hours was less than the upper reference level. Gold standard diagnoses were determined by a clinical end point committee. Evaluation of assay clinical performance for acute myocardial infarction rule-out was prespecified; the hypothesis regarding 30-day ACE was formulated after data collection.

Results

In 1301 healthy volunteers (50.4% women; median age, 48 years), the upper reference level was 19 ng/L. In 1600 patients with suspected acute coronary syndrome (48.4% women; median age, 55 years), a single hsTnTlevel less than 6 ng/L at baseline had a negative predictive value for AMI of 99.4%. In 974 patients (77.1%) with both 0-hour and 3-hour hsTnT levels of 19 ng/L or less, the negative predictive value for 30-day ACE was 99.3% (95% CI, 99.1-99.6). Using sex-specific cutpoints, C statistics for women (0.952) and men (0.962) were similar for acute myocardial infarction.

Conclusions and Relevance

A single hsTnT level less than 6 ng/L was associated with a markedly decreased risk of AMI, while serial levels at 19 ng/L or less identified patients at less than 1% risk of 30-day ACE.

Detection and Prognostic Significance of Circulating Tumor Cells in Patients With Metastatic Thyroid Cancer

CONTEXT

Individual patient prognostication for advanced thyroid cancer (TC) is challenging. Circulating tumor cells (CTCs) have been shown to be a valuable prognostic marker for other solid cancers.

OBJECTIVE

We hypothesized that CTCs are present in the blood of patients with advanced TC and their number can predict overall survival (OS).

SETTING

This is a prospective study at a tertiary cancer hospital. Patients, Interventions, and Main Outcome Measures: Initial studies were performed with TC cell lines to determine the feasibility of detection using the Veridex CellSearch. CTC enumeration was performed in blood samples from 18 patients with distantly metastatic medullary TC (metMTC), 14 with distantly metastatic differentiated TC (metDTC), and 10 controls with a history of TC but no evidence of disease. The prognostic value of CTC levels to predict OS in metMTC patients was assessed.

RESULTS

CellSearch detected cells from MTC and DTC but not anaplastic TC cell lines. Six metMTC patients but no metDTC or control patients had more than or equal to 5 CTCs detected by the CellSearch assay. Median survival in metMTC patients with more than or equal to 5 CTCs was 13 months vs 51.5 months for those with less than 5 CTCs (P = .0116). The hazard ratio for mortality of patients with more than or equal to 5 CTCs compared with those with less than 5 CTCs was 3.95 (1.20-13.0, P = .0245).

CONCLUSIONS

The presence of more than or equal to 5 CTCs in patients with metMTC is associated with worse OS. Larger cohorts are required to validate the prognostic value of CTC enumeration.

Value of novel agents and intensive therapy for patients with multiple myeloma

We conducted a retrospective evaluation of response and survival for 293 patients with multiple myeloma treated since June 2000 with primary thalidomide- or bortezomib-based combinations, of whom 207 patients received intensive therapy supported by autologous blood stem cells within the first year. Survival times were calculated after a landmark of 1 year from start of therapy, so that subsequent median survival was 8.9 years for patients with CR, 4.9 years for those with PR and 0.6 year for patients with NR (P<0.001). Multivariate analyses confirmed CR or PR as the major favorable factors with less impact on prognosis for age or disease stage. Both novel agents and high-dose therapy (HDT) resulted in high frequencies of PR or CR, with early HDT useful for many patients with NR or PR in improving response status and subsequent survival.

Bortezomib in combination with thalidomide-dexamethasone for previously untreated multiple myeloma

In a previous trial among 137 previously untreated patients with multiple myeloma, the combination of thalidomide-dexamethasone induced remission in 66% of patients, including complete remission in 13%. In an attempt to induce more frequent remissions, we added bortezomib to this program. Between 7/03 and 3/06, 38 newly diagnosed patients with multiple myeloma received at least one, but no more than 3, courses of bortezomib in a dose of 1.3 mg/m(2) IV x 4; dexamethasone 20 mg/m(2) PO for 4 days beginning on days 1, 9, 17; thalidomide 100 mg PO daily increasing to a maximum of 200 mg. There was rapid onset of remission in 33 patients (87%) including 6 patients with complete remission (16%). Most side effects were preventable, but otherwise were usually mild and reversible. After a median of 4 months, 25 eligible patients received intensive therapy with high-dose melphalan supported by autologous blood stem cells, so that the myeloma was in complete remission in 14 patients (37% of all patients). The combination of bortezomib-thalidomide-dexamethasone was a highly effective primary treatment for newly diagnosed patients with multiple myeloma.

A randomized parallel-group dietary study for stages II-IV ovarian cancer survivors

OBJECTIVE

Few studies have examined the dietary habits of ovarian cancer survivors. Therefore, we conducted a study to assess the feasibility and impact of two dietary interventions for ovarian cancer survivors.

METHODS

In this randomized, parallel-group study, 51 women (mean age, 53 years) diagnosed with stages II-IV ovarian cancer were recruited and randomly assigned to a low fat, high fiber (LFHF) diet or a modified National Cancer Institute diet supplemented with a soy-based beverage and encapsulated fruit and vegetable juice concentrates (FVJCs). Changes in clinical measures, serum carotenoid and tocopherol levels, dietary intake, anthropometry, and health-related quality of life (HRQOL) were assessed with paired t-tests.

RESULTS

The recruitment rate was 25%, and the retention rate was 75% at 6 months. At baseline, 28% and 45% of women met guidelines for intake of fiber and of fruits and vegetables, respectively. After 6 months, total serum carotenoid levels and α- and β-carotene concentrations were significantly increased in both groups (P<0.01); however, β-carotene concentrations were increased more in the FVJC group. Serum β-cryptoxanthin levels, fiber intake (+5.2g/day), and daily servings of juice (+0.9 servings/day) and vegetables (+1.3 servings/day) were all significantly increased in the LFHF group (all P<0.05). Serum levels of albumin, lutein and zeaxanthin, retinol, and retinyl palmitate were significantly increased in the FVJC group (all P<0.05). No changes in cancer antigen-125, anthropometry, or HRQOL were observed.

CONCLUSION

Overall, this study supports the feasibility of designing dietary interventions for stages II-IV ovarian cancer survivors and provides preliminary evidence that a low fat high fiber diet and a diet supplemented with encapsulated FVJC may increase phytonutrients in ovarian cancer survivors.

Multicenter analytical evaluation of a high-sensitivity troponin T assay

BACKGROUND

High-sensitivity cardiac troponin assays are being introduced clinically for earlier diagnosis of acute myocardial infarction (AMI). We evaluated the analytical performance of a high-sensitivity cardiac troponin T assay (hscTnT, Roche Diagnostics) in a multicenter, international trial.

METHODS

Three US and 5 European sites evaluated hscTnT on the Modular® Analytics E170, cobas® 6000, Elecsys 2010, and cobas® e 411. Precision, accuracy, reportable range, an inter-laboratory comparison trial, and the 99th percentile of a reference population were assessed.

RESULTS

Total imprecision (CVs) were 4.6-36.8% between 3.4 and 10.3 ng/L hscTnT. Assay linearity was up to 10,000 ng/L and the limit of blank and detection were 3 and 5 ng/L, respectively. The 99th percentile reference limit was 14.2 ng/L (n=533). No significant differences between specimen types, assay incubation time, or reagent lots existed. A substantial positive bias (76%) exists between the 4th generation and hscTnT assays at the low end of the measuring range (<50 ng/L). hscTnT serum pool concentrations were within 2SD limits of the mean of means in the comparison trial, indicating comparable results across multiple platforms and laboratories.

CONCLUSION

The Roche hscTnT assay conforms to guideline precision requirements and will likely identify additional patients with myocardial injury suspicious for AMI.

Characterization of metastatic breast cancer patients with nondetectable circulating tumor cells

Circulating tumor cells (CTC) are an independent prognostic factor in metastatic breast cancer patients (MBC). However, CTC are undetectable in one third of patients. The aim of this study was to assess the prognostic factors in MBC patients without detectable CTC. This retrospective study included 292 MBC patients evaluated between January 2004 and December 2007. CTC were enumerated before patients started a new line of treatment using the CellSearch™. Overall survival (OS) was calculated from the date of CTC measurement and estimated by the Kaplan-Meier product limit method. CTC were not detected in 35.96% patients, whereas 40.75% patients had CTC ≥ 5. Undetectable CTC status was positively correlated with presence of brain metastasis (OR: 6.17, 95%CI = 2.14-17.79; p = 0.001), and inversely correlated with bone metastasis (OR: 0.47; 95%CI = 0.27-0.80; p = 0.01). In multivariate analysis, hormone receptors, number of metastatic sites and lines of therapy were independent prognostic factors for OS in patients without detectable CTC. Patients without detectable CTC before starting of a new line of therapy comprise a heterogeneous group with substantially different prognosis. We showed that some important metastatic disease characteristics are predictive of undetectable CTC status in MBC.

Circulating Tumor Cells and FDG-PET/CT for the Therapeutic Monitoring of Bone Metastases from Breast Cancer

Background: Circulating tumor cells (CTCs) and [18F]fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) are two promising new tools for monitoring therapy in patients with metastatic breast cancer. The two modalities showed high sensitivity in detection of bone relapse/progression from breast cancer (De Giorgi U et al. Ann Oncol 2009). In this study, we sought to evaluate the prognostic significance of two different modalities represented by the detection of CTC and FDG-PET/CT in patients with bone metastases from breast cancer treated with standard therapies. Our objective was to compare the two modalities to identify which technology could be more sensitive in prospectively monitoring such patients.Patients and Methods: This is a retrospective study of 54 patients with bone metastases from breast cancer without visceral metastases treated at The University of Texas M. D. Anderson Cancer Center from September 2004 to May 2008. CTC were detected and enumerated using the CellSearch system (Veridex LLC, Rariten NJ, USA). Patients were categorized according to first follow-up CTC counts as having a favorable (&lt; 5 CTC/7.5 mL of blood) or unfavorable (≥ 5 CTC) outcome. Reassessment of disease status by CTC count and FDG-PET/CT was performed approximately 2-3 months after initiation of the new treatment, depending on treatment type and schedule. Progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier product limit method, and compared between groups with the log-rank test.Results: In 54 evaluable patients, the median overall survival time was 17 months (range, 3 to &gt;36). Follow-up CTC levels and FDG-PET/CT response predicted both PFS (p = 0.02 and p = 0.0001, respectively) and OS (p = 0.01 and p = 0.02, respectively), while baseline CTC predicted neither PFS (p = 0.8) nor OS (p = 0.76). In patients with either CTC or FDG-PET/CT response PFS has been 13 months, while in patients with discordant CTC and FDG-PET/CT response PFS has been 6 months and in patients with neither CTC nor FDG-PET/CT response PFS has been 5 months (p = &lt;0.00002). In patients with either CTC or FDG-PET/CT response, OS has not been reached (&gt;31 months); in patients with discordant CTC and FDG-PET/CT response, OS has been 24 months; and in patients with neither CTC nor FDG-PET/CT response, OS has been 18 months (p = 0.02).Conclusions: CTC and FDG-PET/CT are useful tools for therapeutic monitoring of bone metastases from breast cancer. Prospective studies in this specific clinical context are needed to assess the critical roles that CTC and FDG-PET/CT individually as well as collectively play in the prognostic and therapeutic monitoring of bone metastases from breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1109.

Effect of Trastuzumab and Chemotherapy on Circulating Tumor Cells in Patients with Poor Prognosis Metastatic Breast Cancer

Background. Trastuzumab has significant activity in HER2 neu amplified metastatic breast cancer (MBC). We hypothesized that it may selectively act against circulating tumor cells (CTC) in HER2-positiveMBC. We assessed the effect of trastuzumab-based regimens on CTC in HER2-positive MBC with poor prognosis (≥ 5 CTC).Patients and Methods. We retrospectively evaluated patients with poor prognosis MBC (baseline ≥ 5 CTC) treated with a first-line regimen consisting of trastuzumab+antimitotic agents in 11 HER2-positive patients not previously pretreated with trastuzumab, chemotherapy with antimitotic agents in 24 HER2-normal patients, and other chemotherapeutic drugs (mainly capecitabine) in other 16 HER2-normal patients. CTC were detected and enumerated using the CellSearch system (Veridex LLC, Warren NJ, USA). We evaluated the effect on CTC counts and on progression-free survival (PFS) and overall survival (OS).Results. At a median follow-up of 16 months (range, 4 to 48), 24 patients (47%) died. All 11 HER2-positive patients treated with trastuzumab+antimitotic agents had &lt;5 CTC during the treatment. Only 16 (67%) with HER2-normal MBC had &lt;5 CTC with antimitotic agents (p = 0.037), and 28 (70%) with other chemotherapeutic regimens (p = 0.048). No statistically significant difference was observed between patients treated with antimitotic agents and those treated with other chemotherapeutic agents (p = 0.73). There was no difference between patients receiving polychemotherapy and monochemotherapy (p = 0.73). The median PFS was 12 months in HER2-positive patients treated with trastuzumab+antimitotic agents compared with 7 months for those with HER2-normal (p = 0.09). The median OS was not reached (&gt;20 months) and 19 months (p = 0.034), respectively. The median PFS was 8 months in HER2-normal patients with ≥5 CTC and 4 months in those with &lt;5 CTC (p = 0.01). The median OS was not reached (&gt;17 months) and 9 months (p = 0.01), respectively.Conclusions. Trastuzumab is highly effective in patients with HER2-positive MBC with poor prognosis (≥ 5 CTC). Antimitotic agents and other chemotherapy agents did not show a similar effect in HER2-normal MBC. CTC might be useful in the monitoring of poor prognosis MBC patients undergoing therapy with trastuzumab.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3014.

Predictive Value of Circulating Tumor Cells (CTCs) in Metastatic Breast Cancer Patients Treated by Bevacizumab-Based Therapy

Background:Circulating tumor cells (CTC) are involved in cancer dissemination and are an independent prognostic factor in metastatic breast cancer (MBC). Antiangiogenic, bevacizumab-based chemotherapy improves response rate and progression free survival in patients with metastatic breast cancer (MBC), without impact on overall survival. Preclinical data suggest the possibility of increased metastatic potential of tumor cells pretreated by anti-angiogenic therapy (Ebos et al. Cancer Cell 2009,15: 232–9). The aim of this study was to determine the prognostic value of CTC in MBC patients treated by bevacizumab-based therapy.Patients and Methods: This retrospective study included 48 MBC treated with bevacizumab combined chemotherapy regimens and 46 patients treated with chemotherapy alone between January 2004 and December 2008 at M.D.Anderson Cancer Center. CTCs were detected and enumerated before patients started therapy using the CellSearch™ system (Veridex, LLC, NJ, USA). Progression free survival (PFS) and overall survival (OS) were calculated from the date of CTC measurement, estimated by the Kaplan-Meier product limit method, and compared between groups with the log-rank test.Results: At a median follow up of 10.1 months (range: 1-26 months), 22 patients (45.8%) had died. The estimated medians of PFS in bevacizumab-treated patients were 8.1 vs. 5.2 months (p = 0.42) in patients with baseline &lt; 5 CTCs vs. ≥ 5 CTCs. Moreover, the OS for the two subgroups were 18.3 vs. 12.4 months (p = 0.41), respectively. Twenty-three patients had CTC measurements at the time of progression. Median CTC counts at baseline and at time of disease progression were 6 (range: 0-230) and 7 (range: 0-359) respectively in the bevacizumab-treated group. The median CTC counts in the control group at same time points were 7 (range: 0-724) and 2 (range:0-999), respectively. Thirteen (56.5%) and 12 (52.2%) patients had CTC ≥ 5 at baseline and at time of disease progression in bevacizumab-treated group compared to CTC counts of 24 (52.2%) and 17 (37%) in control group treated with chemotherapy without bevacizumab. Post progression overall survival in patients with CTC &lt; 5 and CTC ≥ 5 measured at time of disease progression were 11.0 and 10.4 months (p = 0.36), in the bevacizumab treated group vs. 27 and 12.4 months (p = 0.04), in the control group respectively.Conclusion: Our data support the prognostic value of CTC measured before therapy in MBC. The detection of higher CTC counts at time of disease progression and the limited prognostic value of CTC after failure of bevacizumab-based chemotherapy although intriguing, warrants further prospective investigations. Moreover, a comparison between the differential effects of monoclonal antibodies and tyrosine kinases inhibitors on CTCs detection and monitoring will better clarify the role of specific targeted therapies on micrometastatic disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3013.

Characterization of Metastatic Breast Cancer Patients with Non-Detectable Circulating Tumor Cells

Background: Circulating tumor cells (CTC) are independent predictor of progression free and overall survival in metastatic breast cancer patients, with superior prognosis for patients with CTC &lt;5 per 7.5mL of peripheral blood. However, 30-50% of patients have non-detectable CTC. The aim of this study was to assess the prognostic factors in MBC patients with non-detectable CTC.Methods: This retrospective study included 271 MBC patients evaluated between January 2004 and December 2007. Median age of patients was 56 years (range: 23-82 years). CTCs were enumerated before patients started a new line of treatment using the CellSearchTM. Overall survival (OS) was calculated from the date of CTC measurement, estimated by the Kaplan-Meier product limit method, and compared between groups with the log-rank test.Results: Median CTC count was 2 (range: 0-1780) per 7.5 mL. CTCs were not detected in 99 (36.5%) patients, while 112 (41.3%) patients had CTC ≥ 5. Median OS for patients with 0 CTC; 1-4 CTC and ≥ 5 CTC was 29.3; 26.4; and 19.4 months (p = 0.04), respectively. Patients with brain metastasis have the highest probability of non-detectable CTC (71.4% vs. 33.6%; p = 0.001), while patients with bone metastasis are more likely to have CTC ≥ 1 (48.2% vs. 31.8%; p = 0.01). There was no association between other tumor characteristics (ER, PR, HER2, number and localization of tumor metastasis) and non-detectable CTC status. Patients with CTC = 0 have non-significantly better OS compared to patients with CTC ≥ 1 (29.3 vs. 23.3 months; p = 0.09) and have superior survival in all but one analyzed subgroups; only inflammatory breast cancer (IBC) patients with CTC = 0 have inferior OS compared with patients with CTC ≥ 1 (26 vs. 37 months; p = 0.67). In a subgroup of patients with non-detectable CTC, triple negative MBC has the poorest survival (median OS = 18.8 months), while hormone receptor positive MBC, without visceral metastases and non-inflammatory breast cancer has the best survival (median OS = 36.9 months). In multivariate analysis, hormone receptor status and line of therapy were only independent prognostic factors for OS in patients with non-detectable CTC (Table 1).Conclusion: Patients with non-detectable CTC before start of new line of therapy comprise a heterogeneous group of patients with substantially different prognosis. Triple negative and IBC patients represent poor prognosis subgroups. These data suggest heterogeneity of microscopic disease in advanced cancer and indicate the need to investigate combining additional detection technologies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3006.

Circulating tumour cells are associated with increased risk of venous thromboembolism in metastatic breast cancer patients

BACKGROUND

Cancer is a risk factor for venous thromboembolism (VTE). Circulating tumour cells (CTCs) are an independent predictor of survival in metastatic breast cancer (MBC) patients. The aim of this study was to test the hypothesis that CTCs are associated with the risk of VTE in MBC patients.

METHODS

This retrospective study included 290 MBC patients treated in the MD Anderson Cancer Center from January 2004 to December 2007. Circulating tumour cells were detected and enumerated using the CellSearch system before starting new lines of therapy.

RESULTS

At a median follow-up of 12.5 months, 25 patients experienced VTE and 53 patients died without experiencing thrombosis. Cumulative incidence of thrombosis at 12 months was 8.5% (95% confidence interval (CI)=5.5%, 12.4%). Patients with CTCs > or = 1 and > or = 5 had a higher incidence of VTE compared with patients with 0 and <5 CTCs (12-month estimate, 11.7 and 11.6% vs 3 and 6.6%; P=0.006 and P=0.076, respectively). In the multivariate model, patients with CTCs > or = 1 had a hazard ratio of VTE of 5.29 (95% CI=1.58, 17.7, P=0.007) compared with patients with no CTCs.

CONCLUSION

These results suggest that CTCs in MBC patients are associated with increased risk of VTE. These patients should be followed up more closely for the risk of VTE.

Circulating tumor cells and risk of venous thromboembolism in metastatic breast cancer patients

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Background: Cancer is well-recognized risk factor for venous thromboembolism (VTE), and VTE is associated with a higher risk of death in cancer patients. Coagulation activation by tissue factor (TF) is associated with cancer growth and disease progression. Circulating tumor cells (CTCs) are an independent predictor of survival in metastatic breast cancer (MBC) patients. The aim of this study was to test the hypothesis that CTCs are associated with the risk of VTE in MBC patients. Methods: This retrospective study included 362 MBC patients treated in M. D. Anderson Cancer Center between January 2004 and December 2007. CTCs were detected and enumerated using the CellSearch system. Patients were assigned to cohorts based on the highest CTC counts during the course of the disease. All venous thrombosis and/or pulmonary embolism in the presence of unequivocal medical documentation were classified as events. Results: At a median follow up of 11.1 months (range 0–38 months) 30 patients (8.3%) experienced VTE. Median survival was 16.3 months vs. 37.2 months (p = 0.003) in patients with and without VTE, respectively. Patients with ≥ 3 CTCs had an elevated risk of VTE in comparison to patients with < 3 CTCs (12.1% vs 3.7%; p = 0.003). In multivariate analysis, the presence of visceral metastasis, increased number of metastatic sites and ≥ 3 CTCs were associated with the risk of VTE. Conclusions: This retrospective study showed that CTCs are associated with increased risk of VTE in MBC. Prospective assessment of coagulation status and its correlation to CTC counts and clinical outcome are warranted.

No significant financial relationships to disclose.

Circulating tumor cells in metastatic breast cancer: from prognostic stratification to modification of the staging system?

BACKGROUND

The aim of the current study was to assess the prognostic value of baseline circulating tumor cells (CTCs) in a large cohort of patients with newly diagnosed metastatic breast cancer (MBC).

METHODS

This retrospective study included 185 patients with newly diagnosed MBC evaluated between 2001 and 2007. CTCs were isolated and enumerated before patients started first-line treatment using the CellSearch system. Overall survival (OS) was calculated from the date of CTC measurement, estimated by the Kaplan-Meier product limit method, and compared between groups with the log-rank test. Cox proportional hazards models were fitted to determine the association between CTC levels and OS after controlling for other prognostic factors.

RESULTS

The median age of the patients at the time of MBC diagnosis was 49 years. Fifty-six (30.3%) patients presented with de novo metastatic disease, and 129 (69.7%) presented with newly recurrent breast cancer. A total of 114 patients (61.6%) had CTC<5, and 71 (38.4%) had CTC >or= 5. The median OS was 28.3 months and 15 months (P< .0001) for patients with CTC<5 and CTC >or= 5, respectively. Superior survival among patients with CTC<5 was observed regardless of hormone receptor and HER-2/neu status, site of first metastases, or whether the patient had recurrent or de novo metastatic disease. In the multivariate model, patients with CTC >or= 5 had a hazards ratio of death of 3.64 (95% confidence interval, 2.11-6.30) compared with patients with CTC <5.

CONCLUSIONS

The results of this large retrospective study confirms that CTCs are a strong independent predictor of survival among women with either de novo or newly recurrent MBC. CTCs should be considered as a new stratification method for women with newly diagnosed MBC.

Circulating tumor cells in peripheral blood samples from patients with increased serum prostate specific antigen: initial results in early prostate cancer

PURPOSE

We evaluated the hypothesis that circulating tumor cells as determined using the CellSearch System would correlate with tumor volume, pathological stage and Gleason score in men with localized prostate cancer.

MATERIALS AND METHODS

Samples of blood (30 ml) were drawn from 97 men with localized prostate cancer before radical prostatectomy, on postoperative days 2 to 3 and at 6 weeks. A control group consisted of 25 men with an increased prostate specific antigen and no tumor detected on extended prostate biopsy. Samples were analyzed for circulating tumor cells using the CellSearch System.

RESULTS

Circulating tumor cells were detected in 21% of patients with cancer and 20% of controls (p = 0.946). At 6 weeks after prostatectomy circulating tumor cells were detected in 16% and 11% (p = 0.51) of the men positive and negative for circulating tumor cells at baseline, respectively. Of the 20 patients with cancer who had circulating tumor cells at baseline 18 showed no circulating tumor cells after surgery. Circulating tumor cell values did not correlate with tumor volume, pathological stage or Gleason score. Only 3.1% of the men with cancer and 8% of the control group had 3 or more circulating tumor cells per 22.5 ml blood at baseline.

CONCLUSIONS

In metastatic breast, prostate and other cancers more than 5 circulating tumor cells are often detected using the CellSearch System, and may correlate with prognosis. However, in the setting of localized prostate cancer the number of detectable circulating tumor cells was low, with findings comparable to those in men who were biopsy negative for cancer. We found no correlation between the number of circulating tumor cells and known prognostic factors in this population.

Naturally occurring proteolytic antibodies: selective immunoglobulin M-catalyzed hydrolysis of HIV gp120

We report the selective catalytic cleavage of the HIV coat protein gp120, a B cell superantigen, by IgM antibodies (Abs) from uninfected humans and mice that had not been previously exposed to gp120. The rate of IgM-catalyzed gp120 cleavage was greater than of other polypeptide substrates, including the bacterial superantigen protein A. The kinetic parameters of gp120 cleavage varied over a broad range depending on the source of the IgMs, and turnover numbers as great as 2.1/min were observed, suggesting that different Abs possess distinct gp120 recognition properties. IgG Abs failed to cleave gp120 detectably. The Fab fragment of a monoclonal IgM cleaved gp120, suggesting that the catalytic activity belongs to the antibody combining site. The electrophoretic profile of gp120 incubated with a monoclonal human IgM suggested hydrolysis at several sites. One of the cleavage sites was identified as the Lys(432)-Ala(433) peptide bond, located within the region thought to be the Ab-recognizable superantigenic determinant. A covalently reactive peptide analog (CRA) corresponding to gp120 residues 421-431 with a C-terminal amidino phosphonate diester mimetic of the Lys(432)-Ala(433) bond was employed to probe IgM nucleophilic reactivity. The peptidyl CRA inhibited the IgM-catalyzed cleavage of gp120 and formed covalent IgM adducts at levels exceeding a control hapten CRA devoid of the peptide sequence. These observations suggest that IgMs can selectively cleave gp120 by a nucleophilic mechanism and raise the possibility of their role as defense enzymes.

Clinical outcomes with intensive therapy for patients with primary resistant multiple myeloma

Clinical outcomes were evaluated in 89 consecutive patients with multiple myeloma that had not responded to dexamethasone-based primary therapy, who received early intensive therapy supported by autologous stem cell transplantation. Results were compared with those of 45 comparable patients who refused or were unable to receive intensive treatment for socioeconomic reasons. Following high-dose therapy, the response rate was 69% including 16% with CR. Survival of 14 patients with CR (median >7.0 years) was significantly longer than those of 47 patients with PR (median 4.5 years) or of 28 patients who remained NR (median 2.2 years). CR occurred in 43% of patients with serum myeloma protein <1.5 gm/dl, in contrast to 7% of those with higher values, a finding similar to that observed previously for patients consolidated in PR. No prognostic factor was associated with PR and, in view of the high frequencies of PR or CR, all patients with primary resistant myeloma should be considered for early intensive therapy. The limited improvement of lifespan and disease-free survival for those in PR indicated the need for further treatment to achieve CR, the major surrogate marker for long survival.

Efficacy of gadolinium in MR brain imaging of HIV-infected patients

PURPOSE

To determine the value of gadolinium in routine head MR imaging of HIV-infected patients.

METHODS

One hundred and three consecutive human immunodeficiency virus-infected patients referred for head MR imaging were scanned without and with intravenous gadopentetate dimeglumine (Gd-DTPA) contrast.

RESULTS

The precontrast scans of 82 patients were either normal, or had atrophy or diffuse white matter changes only. Sixteen of these 82 demonstrated enhancing abnormalities: eight meningeal/ependymal enhancement and eight focal enhancing lesions. Twenty-one of the 103 scans had focal or mass lesions on the precontrast images; in eight of these scans, new information was obtained with Gd-DTPA. Of the 24 patients in both groups where new information was obtained with Gd-DTPA, the information contributed to a change in the clinical care of nine patients.

CONCLUSION

Gadolinium-enhanced MR is useful in the management of selected patients with human immunodeficiency virus infection, for example those with symptoms suggesting meningeal involvement, focal brain lesions, or if the unenhanced MR does not explain all the patient's symptoms.