C-erbB-2 in Serum of Patients with Breast Cancer

c-erbB-2 is an oncoprotein which is overexpressed in some breast cancers. Recently it has been established that the extracellular domain of c-erbB-2 is shed into the serum of patients with breast cancer. There appears to be no association between tumor stage and extracellular domain of c-erbB-2 (c-erbB-2/ECD): c-erbB-2/ECD seems to correlate with patient prognosis whatever the stage of disease. The data also suggest that c-erbB-2/ECD may be useful in monitoring for tumor recurrence and in predicting resistance to hormonal therapy, but not as useful in predicting response to chemotherapy. This may relate to the power of this marker to reflect disease burden, which has an overwhelmingly negative impact on outcome.

Discordant Results Obtained for Different Methods of HER-2/Neu Testing in Breast Cancer – A Question of Standardization, Automation and Timing

Background

HER-2/neu positivity is required for the selection of stage IV breast cancer patients for trastuzumab therapy. We compared the results of the recommended immunohistochemistry (IHC) evaluation with the automated ACIS™ IHC system and with fluorescence in situ hybridization (FISH). These HER-2/neu tissue results were correlated with the serum HER-2/neu (sHER-2/neu) levels at the time of metastatic spread.

Patients and Methods

A total of 61 IHC slides from 30 patients were stained using the HercepTest™. HER-2/neu gene amplification was determined using the Ventana™ FISH assay. sHER-2/neu levels were measured with the Oncogene Science” ELISA kit. The concordance of HER-2/neu results was determined using the concordance index Kappa (κ).

Results

The best concordance between any IHC and FISH was found for the automated ACIS system (88.5%, κ=0.68, category “good”). The comparison between the manual interpretations and the automated IHC was categorized as “very good” (95.1%, κ=0.85). The median sHER-2/neu level of FISH positive patients was significantly higher (67 ng/mL) than that of FISH negative patients (17 ng/mL, p=0.018). The increase in HER-2/neu positivity comparing tissue to stage IV serum was statistically significant (p=0.001).

Conclusions

The concordance between conventional IHC and computerized analysis was very good. The number of patients with stage IV breast cancer with an elevated sHER-2/neu level was much higher than HER-2/neu positivity in tissue. This discrepancy is only partially explained by the influence of tumor load. Patients with an elevated sHER-2/neu level and no tissue overexpression should be considered for retesting of tissue or a new biopsy.

Analysis of the prognostic value of the shed antigen of HER2/neu in premenopausal breast cancer patiens in the TABLE study

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Background: The HER-2/neu oncoprotein is a transmembrane tyrosine kinase that belongs to the family of epidermal growth factor receptors. It is known to be overexpressed in 20–40% of breast cancers. Increased serum HER-2/neu (sHER-2/neu) concentrations at the beginning of adjuvant breast cancer therapy have been shown to be of prognostic importance (Mehta et al, 1998). Using the sera from the Takeda® Adjuvant Breast Cancer Study with Leuprorelin (TABLE study), we tested for the prognostic value of sHER-2/neu. Methods: A total of 133 premenopausal, node-positive, hormone-receptor positive patients received either 11.25 mg of leuprorelin s.c. every 3 months over 2 years or CMF chemotherapy for 6 cycles. Blood samples were collected at baseline and at 3, 6, 12, 18, 24 and 30 mo. The primary endpoint of the study was to determine the relapse-free survival (RFS) after 2 years. sHER-2/neu was measured using a standardized ELISA (upper limit of normal 15 ng/ml). As the baseline sHER-2/neu concentrations ranged from 3.8–14.0 ng/ml, results were grouped in terciles. Data were analyzed using Kaplan-Meier and Cox Proportional Hazards survival analysis. Results: Material was available from 80 patients in leuprorelin arm and 53 patients in CMF arm. 65 of 133 patients had relapsed during the follow-up time of up 7 years after treatment. The median RFS was 62.9 mo. The RFS time depended on the concentrations of sHER-2/neu at baseline: RFS was significantly shorter in patients of the third tercile with sHER-2/neu levels >8.8 ng/ml than in patients of the first tercile with levels <7.2 ng/ml (p=0.0232). Five years after initial therapy, we found that 73% of patients in the first tercile group of baseline sHER-2/neu had no relapse. In the second tercile, 63.3% of patients were relapse-free, while in the third tercile only 47.2% of patients had not suffered from a relapse. Conclusions: Higher sHER-2/neu concentrations at the beginning of adjuvant therapy in the TABLE-Study have a prognostic importance for RFS. This observation was evaluated irrespective of the HER-2/neu tissue status and could be of clinically importance for adjuvant therapy with the monoclonal anti-HER-2/neu antibody trastuzumab or other anti-HER-2/neu targeted therapies.

No significant financial relationships to disclose.

Serum HER-2/neu change predicts clinical outcome to trastuzumab-based therapy

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Background: Trastuzumab monotherapy has a 34% objective response rate (ORR) in patients with HER-2/neu IHC 3+ or FISH-positive first-line metastatic breast cancer (C. Vogel et al, JCO 20:719–726, 2002). Predicting response and survival to trastuzumab-based therapy is an unsolved problem. The HER-2/neu extracellular domain (ECD) is released after cleavage by the ADAM metalloproteinases, and the remaining membrane-bound internal domain is constitutively activated. Trastuzumab inhibits cleavage of the HER-2/neu ECD. Methods: A pooled analysis of 7 trials of first-line trastuzumab therapy (with or without chemotherapy) with serial serum HER-2/neu levels were included. The FDA-approved HER-2/neu ELISA (Oncogene Science/Bayer HealthCare) was used to determine serum HER-2/neu levels. A pretreatment and post-treatment serum (16–120 days) from 307 patients was available. 236 patients had data on overall survival. Kaplan Meier Life table analysis was performed to compare duration of response (DRP), time to progression (TTP), and overall survival (OS). Results: The median decrease in serum HER-2/neu levels for all patients was 31.0% (Range: 98% decrease to 239% increase). Patients with > 20% decrease in HER-2/neu levels had a significantly higher objective response rate (ORR, complete + partial response) and longer DRP, TTP and OS. The results were similar regardless of the timing of the second serum draw (≤ 30 days vs. > 30 days) after the start of trastazumab. Conclusion: Patients with < 20% decrease in serum HER-2/neu levels have decreased benefit from trastuzumab therapy. Patients who do not have a significant decrease in serum HER-2/neu levels should be considered for additional HER-2/neu-targeted therapies.

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Randomized, phase III trial comparing liposomal platin with cisplatin in patients (pts) with advanced squamous cell carcinoma of the head & neck (SCCHN) regarding safety and efficacy profiles

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Background: Based on a metanalysis of > 16,000 patients (Bourhis, ASCO 2004), cisplatin emerges as the essential agent for the treatment of advanced SCCHN. However, its clinical use is impeded by its severe adverse reactions, as renal toxicity. In a randomized, phase III trial we replaced conventional cisplatin by a liposomal formulation of cisplatin (lipoplatin) and compared the safety and efficacy profiles. Methods: The study was designed for two treatment arms: A: 100 mg/m2/d lipoplatin (d 1,8,15) plus 1,000 mg/m2/d 5-FU (d 1–5) q3w for 6 cycles; B: 100 mg/m2/d cisplatin (d 1) plus 1000 mg/m2/d 5-FU (d 1–5) q3w for 6 cycles. Main inclusion criteria selected pts with primary metastatic, relapsed or progressive SCCHN between 18–75 years and creatinin clearance >50ml/min. Main endpoints for this interims analysis were hemato- and nephrotoxicity. First response data were collected. The study was designed for non-inferiority. Results: Out of 41 randomized pts, 30 pts are evaluable for toxicity (15 pts for every arm) and 27 pts (15 pts for lipoplatin, 12 pts for cisplatin) for outcome. In the cisplatin arm hematotoxicity was more frequent (leucopenia grade I/II: 5 pts, grade III/IV: 3 and 1 pts vs 5 pts with grade I/II in the lipoplatin arm). The rate of anemia was similar between the treatment arms. A total of 11 pts in the lipoplatin arm experienced renal toxicity grade I/II as measured by a reduction of the creatinine clearance and 12 pts in the cisplatin arm (grade I/II: 7 pts; grade III: 5 pts). No renal toxicity grade III was developed in the lipoplatin arm until now. Outcome was as follows: lipoplatin arm: PR: 1 pt; SD: 6 pts; PD: 8 pts; cisplatin arm: PR: 7 pts; SD: 3 pts; PD: 2 pts. Thus, the non-PD pts (PR or SD) is 7/15 (47%) in the lipoplatin arm vs 10/12 (83%) cases in the cisplatin arm. Conclusions: Liposomal platin seems to reduce both the hematological and non-hematological toxicity profiles as compared to conventional cisplatin to a clinically relevant extent. As patients with advanced SCCHN have an increased risk of renal toxicity due to poor hydration, the observed reduction of side effects will influence the chance to preserve the dose density of chemotherapy, and thereby, the efficacy of treatment.

No significant financial relationships to disclose.