Coping with uncertainty: T1a,bN0M0 HER2-positive breast cancer, do we have a treatment threshold?

BACKGROUND

Recent retrospective studies have suggested that patients with T1a,bN0M0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer are at a higher risk for recurrence and might benefit from adjuvant trastuzumab. The absolute benefits associated with treating this subgroup are uncertain.

DESIGN

We reviewed recent studies examining the prognostic value of HER2 in patients with node-negative T1a,b HER2-positive breast cancer. We calculated the number needed to treat (NNT) using baseline risk estimates for untreated T1a,bN0M0 breast cancer and the number needed to harm (NNH) using the incidence of cardiac events in each of the adjuvant trastuzumab clinical trials.

RESULTS

Several studies were identified, each with limitations inherent to retrospective database analyses: small cohort sizes, lack of systematic HER2 testing in older specimens, variations in the use of adjuvant therapy and definitions of study end points, and lack of information relating to comorbidities. The 5-year disease-free survival in the pre-trastuzumab era ranged from 77% to 95%. Comparisons between small HER2 -positive and small HER2 -negative cancers showed numerically worse outcome for the HER2-positive cohort in some but not all studies. In many instances, the NNH was larger (26-250) than the NNT (13-35); however, in a subset of patients, the NNH was lower (6) than the NNT (13-35).

CONCLUSIONS

Better prediction tools to estimate more precisely the risk for death due to comorbid illness versus breast cancer are needed. In some patients, the risks of therapy could outweigh the benefits. Treatment selection for T1a,bN0 HER2-positive cancers remains in the transition area between evidence- and subjective judgment-based medicine.

Evaluation of the Predictive Performance and Regimen Specificity of a 30-Gene Predictor of Pathologic Complete Response in a Prospective Randomized Neoadjuvant Clinical Trial for Stage I-III Breast Cancer

Purpose: To prospectively evaluate in a randomized trial if a previously reported multigene predictor of pathologic complete response (pCR) to preoperative weekly paclitaxel and fluorouracil-doxorubicin-cyclophosphamide (T/FAC) chemotherapy can accurately predict pCR to neoadjuvant T/FAC chemotherapy, and if it also predicts pCR to FAC only chemotherapy. Furthermore, it is unknown if the T/FAC regimen is superior to 6 courses of FAC; therefore we compare the pCR rates for patients who receive T/FAC versus FACx6 preoperative chemotherapy.Materials and Methods: Patients with stage I-III breast cancer (n=273) were randomly assigned to receive either 12 courses of weekly paclitaxel followed by 4 courses of FAC (T/FAC, n=138), or 6 courses of FAC (FACx6, n=135) neoadjuvant chemotherapy. All patients underwent a pretreatment FNA biopsy of the tumor for gene expression profiling on oligonucleotide microarrays, and treatment response prediction (pCR versus residual disease, RD) was performed using the multigene predictor. Predicted and observed pathologic responses were compared independently in the two treatment arms.Results: The pCR rate was 19% with T/FAC and 9% with FACx6 (p<0.05). In the T/FAC arm, the positive predictive value (PPV) of the genomic predictor was 38% (95%CI:21-56%), the negative predictive value (NPV) 88% (CI:77-95%), sensitivity 63% (CI:38-84%), specificity 72% (CI:60-82%), and the AUC 0.711. In the FAC only treatment arm, the PPV was 9% (CI:1-29%), the NPV 92% (CI:83-97%), sensitivity 29% (CI:4-71%), specificity 75% (CI:64-84%), and the AUC 0.584. This suggests that the genomic predictor is regimen-specific. In a multivariate analysis including age, tumor size, nodal status, histologic grade, HER2 and estrogen receptor (ER) status and the genomic predictor, only ER status was a significant predictor of pCR.Discussion: Pathologic complete response rate was significantly higher in the T/FAC arm compared to the FACx6 arm indicating a higher efficacy of the paclitaxel containing arm. Patients who were predicted to achieve pCR to T/FAC had a significantly higher pCR rate (38%) than unselected patients (19%) or patients predicted to have RD (12%) when treated with this regimen. These results confirm that the multigene predictor can identify patients with greater than average sensitivity to T/FAC chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 101.

Decreased TGFβ signaling and increased COX2 expression in high risk women with increased mammographic breast density

Abstract #1107

Background
 High mammographic density is associated with up to a 6-fold increased risk of breast cancer. Pathways responsible for this increased density are unknown. We hypothesize that specific molecular pathways exist that are associated with increased mammographic density and breast cancer risk, and may therefore be used to identify potential targets for chemoprevention.
 Methods
 Histologically confirmed normal breast tissue was collected from women undergoing breast surgery who had available demographic data and mammograms for review. Breast parenchymal density was classified according to the American College of Radiology's Breast Imaging – Reporting and Data System reporting system. Quantitative classification of mammographic parenchyma was performed using thresholding method and percent density. Women with low (less than 50%) versus high (greater than 50%) breast density were compared. Double-stranded cDNA was synthesized from the normal breast tissue using an oligo-dT primer containing a T7 RNA polymerase promoter, followed by in vitro transcription with biotinylated ribonucleotides. The labeled cRNA was hybridized to Affymetrix HG U133Plus2 chips which comprise ∼28,600 genes to determine gene expression patterns. Immunohistochemical analysis (IHC) of estrogen receptor, progesterone receptor, proliferation (Ki67) and COX2 expression was performed.
 Results
 Sixty-two women were identified, 26 (42%) had high, and 36 (58%) had low mammographic density. Neither age, menopausal nor hormone receptor status influenced the gene expression pattern. Seventy-three genes had differential expression between normal breast tissue with high and low mammographic density (p<0.001, fold change>1.5) and had a low false discovery rate (<10%). Of these 73 differentially expressed genes, network and canonical pathway analysis demonstrate decreased TGFβ signaling (TGFBR2, SOS, SMAD3 and CD44 expression) in dense breast relative to non-dense breast. By IHC, Ki67 (stroma) and COX2 expression were significantly higher in dense breasts (p<0.05) on univariate analysis, and only COX2 expression in the stroma was statistically significant at (p<0.01) on multivariate analysis.
 Conclusion
 TGFβ ligands are currently the only growth factors known to prevent mammary epithelial cell proliferation. TGFβ has been reported to influence COX-2 expression, and these molecules are highly differentially expressed in individuals at high risk of developing breast cancer. These results suggest that COX2 inhibition should be further investigated for breast cancer prevention despite possible increase in cardiovascular risk.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1107.

Analysis of hospitalizations comparing rifaximin versus lactulose in the management of hepatic encephalopathy

INTRODUCTION

Patients with end-stage liver disease often develop hepatic encephalopathy. The loss in cognitive abilities results in marked economic loss to the patient and health care community. We report hospital admission rates and economic impact of patients with end-stage liver disease suffering from hepatic encephalopathy.

METHODS

The medical records were reviewed involving liver transplant patients started on lactulose or rifaximin therapy after presenting with stage 2 hepatic encephalopathy from January 2004 to November 2005. Information collected included demographics, hospitalizations required for hepatic encephalopathy, economic data, and Model for End-stage Liver Disease (MELD) score.

RESULTS

Thirty-nine patients met study criteria: 24 patients treated with lactulose (group one) and 15 with rifaximin (group two). Group one included 18 men and six women of mean age 48 (range 39 to 58), average MELD 14 (range 10 to 19). Group two included 10 men and five women of mean age 47 (range 42 to 58), average MELD 15 (range 10 to 19). Group one patients required 19 hospitalizations overall: three patients with three hospitalizations, four patients with two hospitalizations, and two patients required one hospitalization. Total drug cost per month was 50 dollars(group one) and 620 dollars(group two). The average annual cost of hospitalization, emergency room visit, and drug per patient treated was 13,284.96 dollars for a total of 318,839 dollars (range 5005 dollars to 26,255 dollars, including drug cost and hospital care). Group two required three hospitalizations, all three with one visit. The average annual cost of hospitalization, emergency room visit, and drug per patient treated was 7958.13 dollars for a total of 119,372 dollars (range 6005 dollars to 19,255 dollars, including drug cost and hospital care). The total cost of therapy per patient per year was 13,285 dollars (group one) versus 7958 dollars (group two). The average length of stay was shorter in group two [3.5 days (range 3 to 4)] versus group 1 [5.0 days (range 3 to 10); P < .0001].

CONCLUSION

These pilot data demonstrate the marked difference in economic costs for the treatment of hepatic encephalopathy. The results also show that in comparative groups, the economic gains are quickly lost when using lactulose.

Influence of timing on CSF tests value for Creutzfeldt-Jakob disease diagnosis

Background

The analysis of markers in the cerebrospinal fluid (CSF) is useful in the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). However, the time at which the study of these markers is most sensitive remains controversal.

Objective

To assess the influence of time of sampling on the value of CSF tests in the diagnosis of sCJD.

Method

In the framework of a multinational European study, we studied the results of 14-3-3, S100b, neurone specific enolase (NSE) and tau protein in 833 CSF samples from sCJD patients at different stages of disease and in 66 sequentially repeated lumbar punctures (LP).

Results

14-3-3 and tau protein tended to increase in sensitivity from onset (88%, 81%) to the advanced stage (91%, 90%). This was significant only in the methionine-valine (MV) heterozygous group of patients at codon 129. The absolute levels of S100b (p < 0.05), NSE and tau protein increased in the last stage of disease. High levels of tau protein, NSE and S100b were associated with shorter survival times (p < 0.01). Sixty-six sCJD patients underwent repeated LP. These sCJD patients were younger, had longer disease durations and were more frequently MV at codon 129 (p < 0.001) than the whole group. 14-3-3 sensitivity increased from 64% to 82% in the second LP (p = 0.025) and 88% sCJD patients had at least one positive result.

Conclusions

Sensitivity and absolute levels of CJD markers increased with disease progression and were modulated by the codon 129 genotype. Early negative results should be inter-preted with caution, especially in young patients or those who are MV at codon 129.

CSF analysis in patients with sporadic CJD and other transmissible spongiform encephalopathies

Patients with suspected Creutzfeldt-Jakob disease (CJD) often have routine cerebrospinal fluid (CSF) analysis performed to exclude treatable inflammatory conditions; however, little information is available about the range of results obtained for CSF tests in patients with sporadic CJD and other transmissible spongiform encephalopathies (TSE). Data from 450 patients with sporadic CJD and 47 patients with other TSEs were collected as part of an EC-supported multinational study. Raised white cell counts of >5 cells/microl were found in three of 298 patients with sporadic CJD, with two cell counts of 7 cells/microl and one of 20 cells/microl. Total protein concentrations of >0.9 g/l were found in five of 438 patients with sporadic CJD, although none had a concentration of >1 g/l. CSF oligoclonal IgG was detected in eight of 182 sporadic CJD patients. Of the patients with other TSEs, six had elevated cell counts ranging from 6 to 14 cells/microl but none had total protein concentrations of >0.9 g/l and one patient had detectable oligoclonal IgG. None of the patients with sporadic CJD or other TSEs had abnormalities in all three tests.

A novel inhibitor of the STAT3 pathway induces apoptosis in malignant glioma cells both in vitro and in vivo

Signal transducer and activator of transcription-3 (STAT3) is constitutively activated in a variety of cancer types, including malignant gliomas. STAT3 is activated by phosphorylation of a tyrosine residue, after which it dimerizes and translocates into the nucleus. There it regulates the expression of several genes responsible for proliferation and survival at the transcriptional level. A selective inhibitor of STAT3 phosphorylation, AG490, has been shown to inhibit growth and induce apoptosis in some cancer cell types. However, although AG490 routinely shows in vitro anticancer activity, it has not consistently demonstrated an in vivo anticancer effect in animal models. Here, we have tested WP1066, a novel inhibitor structurally related to AG490 but significantly more potent and active, against human malignant glioma U87-MG and U373-MG cells in vitro and in vivo. IC(50) values for WP1066 were 5.6 muM in U87-MG cells and 3.7 muM in U373-MG cells, which represents 18-fold and eightfold increases in potency, respectively, over that of AG490. WP1066 activated Bax, suppressed the expression of c-myc, Bcl-X(L) and Mcl-1, and induced apoptosis. Systemic intraperitoneal administration of WP1066 in mice significantly (P<0.001) inhibited the growth of subcutaneous malignant glioma xenografts during the 30-day follow-up period. Immunohistochemical analysis of the excised tumors revealed that phosphorylated STAT3 levels in the WP1066 treatment group remained inhibited at 3 weeks after the final WP1066 injection, whereas tumors from the control group expressed high levels of phosphorylated STAT3. We conclude that WP1066 holds promise as a therapeutic agent against malignant gliomas.

CSF tests in the differential diagnosis of Creutzfeldt-Jakob disease

OBJECTIVES

To analyze the diagnostic sensitivity and specificity of various brain-derived proteins (14-3-3, Tau, neuron specific enolase [NSE], and S100b) in the CSF of patients with Creutzfeldt-Jakob disease (CJD) and to analyze biologic factors that modify these parameters.

METHODS

CSF was tested for 14-3-3, Tau, NSE, and S100b in 1,859 patients with sporadic, genetic, iatrogenic, and variant CJD, and in 1,117 controls.

RESULTS

The highest sensitivity was achieved for 14-3-3 and Tau in sporadic CJD (85% and 86%), and a combined determination of 14-3-3 and Tau, S100b, or NSE increased the sensitivity to over 93%. A multivariate analysis showed that the sensitivity of all tests was highest in patients with the shortest disease duration, age at onset >40 years, and homozygosity at codon 129 of the prion protein gene. In a group of patients with repeated lumbar punctures, a second test also increased the diagnostic sensitivity.

CONCLUSIONS

The detection of elevated levels of brain-derived proteins in the CSF in patients with suspected Creutzfeldt-Jakob disease is a valuable diagnostic test. A second lumbar puncture may be of value in patients with atypical clinical course in whom the first test was negative.