Prognostic value of HER2 on breast cancer survival

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Background: HER2 overexpression and overamplification have originally been described as a prognostic factor indicating a poor prognosis. However the highly effective anti-HER2 treatment was approved in 2006 after several large randomized trials showing that the prognosis in HER2 positive women could be improved. Few data has been generated comparing HER2 positive patients treated with trastuzumab with comparable HER2 negative patients. Aim of this analysis was to investigate the prognostic relevance of HER2 status in a post trastuzumab approval study. Methods: The SUCCESS trial is an open-label, multicenter, randomized controlled, phase III study comparing FEC-docetaxel (Doc) vs. FEC-Doc-gemcitabine (Doc-G) regime and 2 vs. 5 year treatment with zoledronat in 3754 patients with primary breast cancer (N+ or high risk). All patients were treated per protocol with trastuzumab, if HER2 status was shown to be positive by local pathology. Furthermore HER2 status was a stratification factor. The prognostic value of HER2 status with respect to overall survival (OS) and progression-free survival (PFS), disregarding the above stated treatment arms, was studied with Cox proportional hazards regression models in univariate as well as multivariate analyses adjusted for age, BMI, tumor size, nodal status, grading, estrogen receptor status and progesterone receptor status. Results: 2628 patients were included into this analysis. Median Follow up time was 4.8 years, 221 deaths and 412 recurrences were recorded until data base closure. HER2 was not a prognostic factor in the univariate analysis (OS: HR= 0.86, 95% CI: 0.63 to 1.19; PFS: HR = 0.95, 95% CI: 0.76 to 1.19). In the multivariate analysis all of the above stated prognostic factors were of prognostic relevance. HER2 was of prognostic relevance with a HR of 0.67 (OS, 95% CI: 0.48 to 0.92) and 0.79 (PFS, 95% CI: 0.62 to 0.99) indicating that patients with a positive HER2 status had a better prognosis. Conclusions: Patients treated with trastuzumab showed a more favourable prognosis compared to HER2 negative patients in this prospectively randomized trial, possibly due to the therapeutic effect of HER2-targeted treatment.

The presence and prognostic impact of apoptotic and nonapoptotic disseminated tumor cells in the bone marrow of primary breast cancer patients after neoadjuvant chemotherapy

INTRODUCTION

Neoadjuvant systemic therapy of primary breast cancer (PBC) patients offers the possibility to monitor treatment response. However, patients might have metastatic relapse despite achieving a pathologic complete response (pCR). This indicates that local response to therapy must not be representative for systemic treatment efficacy. Therefore, the aim of this study was to compare local response with systemic tumor cell dissemination by determining the presence of disseminated tumor cells (DTCs), including apoptotic tumor cells, in the bone marrow (BM) of PBC patients after neoadjuvant chemotherapy (NACT).

METHODS

DTCs were detected by immunocytochemistry (pancytokeratin antibody A45-B/B3) and cytomorphology (DTC status). The presence of apoptotic tumor cells was determined by using the M30 antibody (M30 status). This antibody detects a neo-epitope that is expressed only during early apoptosis.

RESULTS

BM aspirates from 400 PBC patients that had completed NACT were eligible for this study. Of these, 167 (42%) patients were DTC positive (DTC status). The M30 status was investigated in 308 patients. Apoptotic (M30-positive) tumor cells were detected in 89 (29%) of these. Whereas the DTC status was not correlated (P = 0.557) to local treatment response (that is, pCR or a clinical complete/partial response), the presence of M30-positive tumor cells was significantly higher in patients that responded to therapy (P = 0.026). Additionally, DTC-positive patients were at an increased risk for disease relapse (hazard ratio, 1.87; 95% CI, 1.11 to 3.15; P = 0.019).

CONCLUSION

The presence of DTC is independent of therapy response of the primary tumor. As patients that are DTC positive after NACT have an unfavorable outcome, they might benefit from additional systemic treatment.

Abstract P2-01-02: Circulating Tumor Cells (CTC) may Express HER2/neu in Patients With Early HER2/neu Negative Breast Cancer – Results of the German SUCCESS C Trial

Background: There is growing evidence that the HER2/neu-status of distant metastases or minimal residual disease in blood and bone marrow may differ from the primary tumor in patients with breast cancer. The HER2/neu-status of CTCs was prospectively evaluated in patients with HER2/neu negative primary breast cancer randomized into the German multicenter SUCCESS C study.

Methods: The SUCCESS C trial is a randomized Phase III study comparing FEC-Docetaxel (FEC-Doc) vs. Docetaxel-Cyclophosphamid (DC) as well as 2 years of a lifestyle-intervention in patients with early, HER2/neu negative, node positive or high-risk node negative primary breast cancer.

As part of the translational research program, 23ml peripheral blood were drawn after adjuvant chemotherapy. In 505 samples, the prevalence of CTCs and their HER2/neu-status were assessed using the CellSearch System (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labelled with anti-CK8/18/19 and anti-CD45 antibodies. A fluorescein conjugate antibody with anti-CK-Fluorescein Isothiocyanate (FITC) was used for HER2/neu phenotyping. The cut-off for CTC-positivity was ≥ 1 CTC and for HER2/neu ≥ 1 CTC with strong HER2/neu-staining (+++).

Results: 26,9% of pts (n = 136) were positive for CTCs (mean 1.78; range 1–7; median = 1). The number of detected CTC was distributed as follows: 1 CTC (n = 76; 55.9%), 2 CTCs (n = 35; 25.7%), 3 CTCs (n = 13; 9.6%), 4 CTCs (n = 7; 5.2%) and ≥ 5 CTCs (n = 5; 3.7%). HER2/neu staning of CTCs was not detectable or weak in 26.5% (n = 36) and 4.4% (n = 6) of CTC positive patients respectively and therefore categorized as HER2/neu negative. In 32.4% of the CTC-positive patients (n = 44), we detected moderate and in 36.8% (n = 50) strong HER2/neu-staining of ≥ 1 CTC per sample. No association was found between CTCs or the HER2/neu-status of CTCs with tumor size, histopathological grading, hormone receptor status or axillary lymph node involvement.

Conclusions: The data of this trial confirm previous findings that patients with HER2/neu negative primary breast cancer can show HER2/neu positive minimal residual disease. These results underline the importance of frequent HER2/neu determination during follow up and disease progression. Survival data within the Success C trial will give further insight into the tumor biology of HER2/neu negative disease.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-01-02.

Abstract P4-13-11: Prognostic factors in young breast cancer patients over time – a 40 year longitudinal analysis

Background: In younger patients (pts) breast cancer (BC) is associated with a worse prognosis compared to older pts. Only few data are available presenting the development of prognostic factors regarding a period of several decades. This 40 year (y) longitudinal comparison of the main prognostic factors was performed to investigate differences in younger women with primary BC in contrast to older women over time.

Patients and Methods: In this retrospective analysis a consecutive pts cohort of 4010 pts was analyzed. Pts were documented and treated for primary invasive breast cancer between 1963 and 2003 at two University Hospitals in Germany. To be eligible, pts were required to have identified tumor characteristics, including TNM-status. Pts with carcinoma in situ or distant metastases were excluded. The cohort was divided in two age groups, ≤40y and >40y. Furthermore to reveal trends and changes over the duration of 41 years the period of analysis was split into 3 time frames: 1963–1976, 1977–1989 and 1990–2003. We analyzed the main prognostic factors for BC including tumor size, grading, nodal status and HR-status in longitudinal comparison regarding the three time frames, respectively. During 1963–77 HR-status was determined in just 12.6% of pts. Thus, this time frame was excluded in the analysis of HR-status.

Results: In 41 yrs, 747 (18.6%) pts were treated between 1963–76, 1722 pts (42.9%) in 1977–89 and 1541 pts (38.4%) in 1990–2003. Overall 358 pts were ≤40y and 3652 pts were over the age of 40.

A significant reduction of tumor size (metric assessment) at primary diagnosis was observed for both age groups (pts≤40y: p = 0.012; pts>40y: p < 0.0001) with no difference between the time frames, respectively (1963–76: p = 0.289; 1977–89: p = 0.647; 1990–2003: p = 0.937).

The number of node-positive pts significantly decreased in pts >40 y (p = 0.001) whereas no difference could be seen in pts aged ≤40 y (p = 0.991).

In both age groups the number of G2/3 tumors increased over the yrs (pts≤40y: p = 0.001; pts>40y: p < 0.0001). Between 1963–76 more G1-tumors were diagnosed in younger pts (p = 0.041) whereas in the two following periods significantly more G2/3 tumors (p = 0.001; p = 0.002) were observed in this group.

In young pts, 54.2% were HR-negative in 1977–89 and 47.6% in 1990–2003 (p = 0.323). In pts >40y 38.4% and 21.7% were HR-negative, respectively (p < 0.0001). Comparing the age groups, significantly more pts were HR-negative in the young patient group (p = 0.001 (1977–89) and p < 0.0001 (1990–2003)).

Conclusions: Concerning the large period of 40yrs, technical improvement and increasing awareness for BC are reasons for decreasing tumor size at the time of primary diagnosis. However, the rate of node-positive pts in the young patient group remained stable. Furthermore, the high percentage of HR-negative pts and the increasing number of pts with unfavorable tumor grade demonstrate more aggressive tumor types in younger pts. These data confirm the need to improve screening tools to early identify young women with the risk to develop breast cancer, and for personalized treatment approaches in these patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-13-11.

DETECT III: A multicenter, randomized, phase III study to compare standard therapy alone versus standard therapy plus lapatinib in patients (pts) with initially HER2-negative metastatic breast cancer but with HER2-positive circulating tumor cells (CTC)

TPS1146

Background: HER2 status may change over the course of disease in breast cancer pts. Approx. 20-30% of pts with initially HER2-negative breast cancer have HER2-positive metastasis (Zidan et al. 2005; Tewes et al. 2009). Determining HER2 status on CTC is one option to re-evaluate HER2 status at the time metastasis is diagnosed. Currently it is unclear if HER2-targeted therapy based on the assessment of HER2 status of CTC reveals a clinical benefit. Methods: This is a randomized, open-label, two arm phase III study to investigate the clinical efficacy of lapatinib, as a HER2-targeted therapy in initially HER2-negative metastatic breast cancer pts with HER2-positive CTC at the time of distant disease. As only half of the pts with HER2-negative metastatic breast cancer show CTC-positivity and of those approx. 32% will exhibit HER2-positive CTC (Fehm et al. 2010), screening of about 1420 pts is required to enroll 228 pts. Main inclusion criteria: metastatic breast cancer with HER2-negative primary tumor tissue and/or biopsies from metastatic sites or locoregional recurrences, evidence of ≥1 HER2-positive CTC and ≥1 measurable metastatic lesion according to RECIST. Eligible pts will be randomized 1:1 to receive standard treatment vs. standard treatment plus lapatinib. Standard chemo- or endocrine therapy must be approved in combination with lapatinib or been investigated in prior clinical trials. Primary endpoint is progression free survival. Secondary endpoints include overall response rate, clinical benefit rate, overall survival and dynamic of CTC. The DETECT III trial is one of the first trials where treatment is based on phenotypic characteristics of CTC. If this trial succeeds in proving efficacy of lapatinib in pts with initially HER2-negative metastatic breast cancer but HER2-positive CTC, this will establish a new strategy in the treatment of metastatic breast cancer.

Correlation of BMI with tumor stage in early breast cancer patients (pts): Pooled analysis of the German SUCCESS A, B, and C trials

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Background: Independent from known prognostic factors, e.g., tumor size and nodal status, obesity is a risk factor for poor disease free, distant disease free, and overall survival in breast cancer. The aim of this analysis was to examine the correlation of the body mass index (BMI) with tumor characteristics in early breast cancer. Methods: We analyzed the data of 7,997 pts with early, node positive or high risk node negative primary breast cancer treated with adjuvant taxan-based chemotherapy within the German multicenter phase III SUCCESS A, B, or C trials. The pts’ tumor stage at primary diagnosis was classified according to the UICC tumor-node-metastasis (TNM) classification. Additionally, the tumor’s hormone-receptor status and HER2/neu status were determined. Before enrollment into the study each patient was grouped according to the WHO global database on BMI. Contingency table methods were used to analyze the correlation of BMI and tumor characteristics. Results: Among the 7,997 pts 100 (1.3%) pts were underweight, 3,556 (44.5%) pts were normal weight, 2,569 (32.1%) pts were overweight and 1,772 (22.2%) were obese. Of all pts 4,508 pts (56.4%) suffered from a pT2-4 tumor, 4830 (60.4%) showed lymph node involvement (pN1-3) and 7509 (93.9%) had G2-3 tumors. 5839 pts (73.0%) showed positivity for ER or PR and 935 (11.7%) for HER2/neu. Overweight and obese pts had significantly larger tumors compared to pts with normal BMI (p<0.0001; p<0.0001). Furthermore, overweight and obesity were associated with a significantly higher rate of lymph node involvement (p=0.0001; p=0.0003) respectively. In contrast neither grading, tumor histology, ER/PR-status nor HER2/neu-overexpression were correlated with BMI. Conclusions: These data are the first to show in a large number of pts that both obese and overweight women suffering from primary breast cancer have significantly larger tumors and more often positive axillary lymph nodes. As there are no differences in tumor biology, the advanced tumor stage might be due to more difficult and delayed detection of breast cancer and lymph node lesions in these women.

Breast Cancer: State of the Art and New Findings

Advances in research have a highly influential role to play in the strategy of early detection, treatment and aftercare of breast cancer and therefore everyday clinical practice. Newly-defined prognosis factors and a new form of molecular subtype classification, for example, are intended to help identify patients who will actually benefit from chemotherapy. In the field of neoadjuvant chemotherapy, the inclusion of the angiogenesis inhibitor Bevacizumab and dual antiHER2 therapy is being discussed. What's more, where defined criteria are met, even with positive sentinel lymph nodes, axillary dissection is not performed; besides bisphosphonates RANKL antibody Denosumab is now an option in the treatment of bone metastases.