A multimarker QPCR-based platform for the detection of circulating tumour cells in patients with early-stage breast cancer

Background:

The detection of circulating tumour cells (CTCs) has been linked with poor prognosis in advanced breast cancer. Relatively few studies have been undertaken to study the clinical relevance of CTCs in early-stage breast cancer.

Methods:

In a prospective study, we evaluated CTCs in the peripheral blood of 82 early-stage breast cancer patients. Control groups consisted of 16 advanced breast cancer patients and 45 healthy volunteers. The CTC detection was performed using ErbB2/EpCAM immunomagnetic tumour cell enrichment followed by multimarker quantitative PCR (QPCR). The CTC status and common clinicopathological factors were correlated to relapse-free, breast cancer-related and overall survival.

Results:

Circulating tumour cells were detected in 16 of 82 (20%) patients with early-stage breast cancer and in 13 out of 16 (81%) with advanced breast cancer. The specificity was 100%. The median follow-up time was 51 months (range: 17–60). The CTC positivity in early-stage breast cancer patients resulted in significantly poorer relapse-free survival (log rank test: P=0.003) and was an independent predictor of relapse-free survival (multivariate hazard ratio=5.13, P=0.006, 95% CI: 1.62–16.31).

Conclusion:

The detection of CTCs in peripheral blood of early-stage breast cancer patients provided prognostic information for relapse-free survival.     

A direct comparison of CellSearch and ISET for circulating tumour-cell detection in patients with metastatic carcinomas

Background:

Circulating tumour cells (CTCs) can provide information on patient prognosis and treatment efficacy. However, there is no universal method to detect CTC currently available. Here, we compared the performance of two CTC detection systems based on the expression of the EpCAM antigen (CellSearch assay) or on cell size (ISET assay).

Methods:

Circulating tumour cells were enumerated in 60 patients with metastatic carcinomas of breast, prostate and lung origins using CellSearch according to the manufacturer''s protocol and ISET by studying cytomorphology and immunolabelling with anti-cytokeratin or lineage-specific antibodies.

Results:

Concordant results were obtained in 55% (11 out of 20) of the patients with breast cancer, in 60% (12 out of 20) of the patients with prostate cancer and in only 20% (4 out of 20) of lung cancer patients.

Conclusion:

Our results highlight important discrepancies between the numbers of CTC enumerated by both techniques. These differences depend mostly on the tumour type. These results suggest that technologies limiting CTC capture to EpCAM-positive cells, may present important limitations, especially in patients with metastatic lung carcinoma.     

A pilot study to explore circulating tumour cells in pancreatic cancer as a novel biomarker

Background:

Obtaining tissue for pancreatic carcinoma diagnosis and biomarker assessment to aid drug development is challenging. Circulating tumour cells (CTCs) may represent a potential biomarker to address these unmet needs. We compared prospectively the utility of two platforms for CTC enumeration and characterisation in pancreatic cancer patients in a pilot exploratory study.

Patients and methods:

Blood samples were obtained prospectively from 54 consenting patients and analysed by CellSearch and isolation by size of epithelial tumour cells (ISET). CellSearch exploits immunomagnetic capture of CTCs-expressing epithelial markers, whereas ISET is a marker independent, blood filtration device. Circulating tumour cell expression of epithelial and mesenchymal markers was assessed to explore any discrepancy in CTC number between the two platforms.

Results:

ISET detected CTCs in more patients than CellSearch (93% vs 40%) and in higher numbers (median CTCs/7.5 ml, 9 (range 0–240) vs 0 (range 0–144)). Heterogeneity observed for epithelial cell adhesion molecule, pan-cytokeratin (CK), E-Cadherin, Vimentin and CK 7 expression in CTCs may account for discrepancy in CTC number between platforms.

Conclusion:

ISET detects more CTCs than CellSearch and offers flexible CTC characterisation with potential to investigate CTC biology and develop biomarkers for pancreatic cancer patient management.     

Prophylactic use of lamivudine for hepatitis B exacerbation in post-operative breast cancer patients receiving anthracycline-based adjuvant chemotherapy

Background:

With the increasing incidence of breast cancer worldwide, in particular in southeast Asia (including Korea), and the common use of anthracyclines in the adjuvant and metastatic settings, the occurrence of Hepatitis B virus (HBV) reactivation may develop in this patient population. The use of prophylactic antiviral agents in cancer patients may result in a reduced HBV exacerbation. The purpose of the current study was to assess the efficacy of prophylactic lamivudine in reducing the incidence and severity of HBV reactivation in post-operative breast cancer patients undergoing adjuvant doxorubicin-containing chemotherapy.

Methods:

The medical records of patients undergoing anthracycline-based adjuvant chemotherapy at Samsung Medical Center between January 2001 and September 2008 were reviewed.

Results:

From the database, 1912 breast cancer patients who had received anthracycline-based adjuvant chemotherapy were identified. Of 131 patients who were HBV surface antigen positive, 55 and 76 did and did not receive prophylactic lamivudine, respectively. In all, 30 patients (23%) developed hepatitis during doxorubicin-containing adjuvant chemotherapy. Of the 30 patients, 5 (9%) were in the prophylactic lamivudine group and 25 (33%) in the control group (P=0.001). In the prophylactic lamivudine group, there was significantly less HBV reactivation (1 patient (2%) vs 20 patients (16%); P=0.002), less disruption of chemotherapy (7 vs 14% P=0.04), and less severe hepatitis (0 vs 17% P=0.002).

Conclusion:

Prophylactic lamivudine significantly reduced the incidence and severity of HBV reactivation in breast cancer patients undergoing anthracycline-based adjuvant chemotherapy.     

Frequency of HER2 expression of circulating tumour cells in patients with metastatic or recurrent gastrointestinal cancer

Background:

The clinical significance of circulating tumour cell (CTC) detection in gastrointestinal (GI) cancer remains controversial and the molecular biological characteristics of CTCs are poorly understood.

Methods:

A total of 87 patients with metastatic or recurrent GI cancer were prospectively enrolled. Circulating tumour cells and their HER2 status were assessed using the CellSearch System.

Results:

Among the 62 CTC-positive cases, we found 22 discordant cases (35.5%). Among the HER2-negative primary tumours, 17 of 54 developed HER2-positive CTCs. Five of eight had HER2-negative CTCs among the HER2-positive primary tumours.

Conclusion:

The findings in the current study suggest that it is critical to evaluate the HER2 status of not only the primary tumour but also the CTCs because the metastasising tumour cells are the primary target of systemic therapy.     

Molecular characteristics of screen-detected vs symptomatic breast cancers and their impact on survival

Background:

Several recent studies have shown that screen detection remains an independent prognostic factor after adjusting for disease stage at presentation. This study compares the molecular characteristics of screen-detected with symptomatic breast cancers to identify if differences in tumour biology may explain some of the survival benefit conferred by screen detection.

Methods:

A total of 1379 women (aged 50–70 years) with invasive breast cancer from a large population-based case–control study were included in the analysis. Individual patient data included tumour size, grade, lymph node status, adjuvant therapy, mammographic screening status and mortality. Immunohistochemistry was performed on tumour samples using 11 primary antibodies to define five molecular subtypes. The effect of screen detection compared with symptomatic diagnosis on survival was estimated after adjustment for grade, nodal status, Nottingham Prognostic Index (NPI) and the molecular markers.

Results:

Fifty-six per cent of the survival benefit associated with screen-detected breast cancer was accounted for by a shift in the NPI, a further 3–10% was explained by the biological variables and more than 30% of the effect remained unexplained.

Conclusion:

Currently known biomarkers remain limited in their ability to explain the heterogeneity of breast cancer fully. A more complete understanding of the biological profile of breast tumours will be necessary to assess the true impact of tumour biology on the improvement in survival seen with screen detection.     

Detection of HER2 amplification in circulating free DNA in patients with breast cancer

Background:

Human epidermal growth factor receptor 2 (HER2) is amplified and overexpressed in 20–25% of breast cancers. This study investigated circulating free DNA (cfDNA) for detection of HER2 gene amplification in patients with breast cancer.

Methods:

Circulating free DNA was extracted from plasma of unselected patients with primary breast cancer (22 before surgery and 68 following treatment), 30 metastatic patients and 98 female controls using the QIAamp Blood DNA Mini Kit (Qiagen). The ratio of HER2 to an unamplified reference gene (contactin-associated protein 1 (CNTNAP1)) was measured in cfDNA samples by quantitative PCR (qPCR) using SK-BR-3 cell line DNA as a positive control.

Results:

We validated the qPCR assay with DNA extracted from 23 HER2 3+ and 40 HER2-negative tumour tissue samples; the results agreed for 60 of 63 (95.2%) tumours. Amplification was detected in cfDNA for 8 of 68 patients following primary breast cancer treatment and 5 of 30 metastatic patients, but was undetected in 22 patients with primary breast cancer and 98 healthy female controls. Of the patients with amplification in cfDNA, 10 had HER2 3+ tumour status by immunohistochemistry.

Conclusions:

The results demonstrate for the first time the existence of amplified HER2 in cfDNA in the follow-up of breast cancer patients who are otherwise disease free. This approach could potentially provide a marker in patients with HER2-positive breast cancer.     

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 ⩾1 and ⩾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⩾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.     

Ki 67 is a major, but not the sole determinant of Oncotype Dx recurrence score

Background:

Immunohistological assessment of Ki 67 expression is less expensive than Oncotype Dx, which is currently used to identify patients with lymph node-negative breast cancer, who will benefit from adjuvant chemotherapy.

Methods:

The relationship of immunohistologically measured Ki 67 to Oncotype DX recurrence score (RS) was examined in 53 cases of T1–2 N0 M0 (oestrogen receptor-positive, HER2/neu negative) breast cancer.

Results:

There was a strong linear correlation between Ki 67 value and the Oncotype Dx RS. All patients in the low Ki 67 group (Ki 67 of ⩽10%) had Oncotype Dx RSs of low or intermediate risk. The vast majority of patients (93.8%) in the high-Ki 67 group (Ki 67⩾25%) had oncotype RSs of high or intermediate risk.

Conclusion:

Ki 67 proliferation value is a major, but not the sole determinant of Oncotype Dx score.     

Identification of a low-risk subgroup of HER-2-positive breast cancer by the 70-gene prognosis signature

Background:

Overexpression of HER-2 is observed in 15–25% of breast cancers, and is associated with increased risk of recurrence. Current guidelines recommend trastuzumab and chemotherapy for most HER-2-positive patients. However, the majority of patients does not recur and might thus be overtreated with adjuvant systemic therapy. We investigated whether the 70-gene MammaPrint signature identifies HER-2-positive patients with favourable outcome.

Methods:

In all, 168 T1–3, N0–1, HER-2-positive patients were identified from a pooled database, classified by the 70-gene signature as good or poor prognosis, and correlated with long-term outcome. A total of 89 of these patients did not receive adjuvant chemotherapy.

Results:

In the group of 89 chemotherapy-naive patients, after a median follow-up of 7.4 years, 35 (39%) distant recurrences and 29 (33%) breast cancer-specific deaths occurred. The 70-gene signature classified 20 (22%) patients as good prognosis, with 10-year distant disease-free survival (DDFS) of 84%, compared with 69 (78%) poor prognosis patients with 10-year DDFS of 55%. The estimated hazard ratios (HRs) were 4.5 (95% confidence interval (CI) 1.1–18.7, P=0.04) and 3.8 (95% CI 0.9–15.8, P=0.07) for DDFS and breast cancer-specific survival (BCSS), respectively. In multivariate analysis adjusted for known prognostic factors and hormonal therapy, HRs were 5.8 (95% CI 1.3–26.7, P=0.03) and 4.7 (95% CI 1.0–21.7, P=0.05) for DDFS and BCSS, respectively.

Interpretation:

The 70-gene prognosis signature is an independent prognostic indicator that identifies a subgroup of HER-2-positive early breast cancer with a favourable long-term outcome.     

Predictors of recurrence in breast cancer patients with a pathologic complete response after neoadjuvant chemotherapy

Background:

Although a pathologic complete response (pCR) after neoadjuvant chemotherapy is associated with favourable outcomes, a small proportion of patients with pCR have recurrence. This study was designed to identify factors predictive of recurrence in patients with pCR.

Methods:

A total of 449 breast cancer patients received neoadjuvant chemotherapy, and 88 evaluable patients had a pCR, defined as no evidence of invasive carcinoma in the breast at surgery. The clinical stage was II in 61 patients (69%), III in 27 (31%). All patients received taxanes and 92% received anthracyclines. Among 43 patients with HER2-positive tumours, 27 received trastuzumab. Cox regression analyses were performed to identify predictors of recurrence.

Results:

Median follow-up was 46.0 months. There were 12 recurrences, including 8 distant metastases. The rate of locoregional recurrence was 10.4% after breast-conserving surgery, as compared with 2.5% after mastectomy. Multivariate analysis revealed that axillary metastases (hazard ratio (HR), 13.6; P<0.0001) and HER2-positive disease (HR, 5.0; P<0.019) were significant predictors of recurrence. Five of six patients with both factors had recurrence. Inclusion of trastuzumab was not an independent predictor among patients with HER2-positive breast cancer.

Conclusion:

Our study results suggest that HER2 status and axillary metastases are independent predictors of recurrence in patients with pCR.     

Assessment of residual tumour by FDG-PET: conventional imaging and clinical examination following primary chemotherapy of large and locally advanced breast cancer

Background:

The aim of this was to evaluate FDG-PET (2-(fluorine-18)-fluoro-2-deoxy-D-glucose positron emission tomography) for assessment of residual tumour after primary chemotherapy of large and locally advanced breast cancer in comparison with conventional imaging modalities.

Methods:

In a prospective multicentre trial, 99 patients underwent one or more breast imaging modalities before surgery in addition to clinical examination, namely, FDG-PET (n=89), mammography (n=47), ultrasound (n=46), and magnetic resonance imaging (MRI) (n=46). The presence of residual tumour by conventional imaging, dichotomised as positive or negative, and the level of FDG uptake (standardised uptake values, SUV) were compared with histopathology, which served as the reference standard. Patients with no residual tumour or only small microscopic foci of residual tumour were classified as having minimal residual disease and those with extensive microscopic and macroscopic residual tumour tissue were classified as having gross residual disease.

Results:

By applying a threshold SUV of 2.0, the sensitivity of FDG-PET for residual tumour was 32.9% (specificity, 87.5%) and increased to 57.5% (specificity, 62.5%) at a threshold SUV of 1.5. Conventional imaging modalities were more sensitive in identifying residual tumour, but had a low corresponding specificity; sensitivity and specificity were as follows: MRI 97.6 and 40.0%, mammography 92.5 and 57.1%, ultrasound 92.0 and 37.5%, respectively. Breast MRI provided the highest accuracy (91.3%), whereas FDG-PET had the lowest accuracy (42.7%).

Conclusions:

FDG-PET does not provide an accurate assessment of residual tumour after primary chemotherapy of breast cancer. Magnetic resonance imaging offers the highest sensitivity, but all imaging modalities have distinct limitations in the assessment of residual tumour tissue when compared with histopathology.     

Circulating tumour cells in the central and the peripheral venous compartment in patients with metastatic breast cancer

Background:

The enumeration of circulating tumour cells (CTC) has prognostic significance in patients with metastatic breast cancer (MBC) and monitoring of CTC levels over time has considerable potential to guide treatment decisions. However, little is known on CTC kinetics in the human bloodstream.

Methods:

In this study, we compared the number of CTC in both 7.5 ml central venous blood (CVB) and 7.5 ml peripheral venous blood (PVB) from 30 patients with MBC starting with a new line of chemotherapy.

Results:

The number of CTC was found to be significantly higher in CVB (median: 43.5; range: 0–4036) than in PVB (median: 33; range: 0–4013) (P=0.001). When analysing samples pairwise, CTC counts were found to be significantly higher in CVB than in PVB in 12 out of 26 patients with detectable CTC. In contrast, only 2 out of 26 patients had higher CTC counts in PVB as compared with CVB, whereas in 12 remaining patients no significant difference was seen. The pattern of CTC distribution was independent of the sites of metastatic involvement.

Conclusion:

A substantial difference in the number of CTC was observed between CVB and PVB of patients with MBC. Registration of the site of blood collection is warranted in studies evaluating the role of CTC assessment in these patients.     

High rate of extra-haematological toxicity compromises dose-dense sequential adjuvant chemotherapy for breast cancer

Background:

A dose-dense strategy has been considered to improve results of adjuvant chemotherapy for breast cancer. This randomised phase II trial investigated the feasibility of this approach with sequential anthracyclines and taxanes-based chemotherapy.

Methods:

Patients with high-risk node-positive breast cancer were treated with three cycles of fluorouracil 500 mg m⁻², epirubicin 100 mg m⁻², cyclophosphamide 500 mg m⁻² (FEC 100) followed by three cycles of docetaxel 100 mg m⁻² delivered at 2-weekly intervals supported by primary prophylaxis with filgrastim. All patients were randomised to either uninterrupted treatment (arm A) or to have a 2-week additional period of rest between the FEC and docetaxel (arm B). The primary endpoint was the rate of success of chemotherapy delivery. Using a two-stage Fleming design, 120 patients were required with one interim analysis.

Results:

In March 2005, enrolment was stopped into arm A after the observation of severe skin toxicities. Following the planned interim analysis, the study was closed because of the high rate of grade 3/4 skin toxicities in both arms (arm A: 32.4% and arm B: 18.9%).

Conclusion:

Sequential dose-dense FEC 100 followed by docetaxel 100 mg m⁻² is not feasible. Feasibility still depends largely on several factors including the choice of drugs, dosage and sequence of administration.     

Impact of tumour size on axillary involvement and distant dissemination in breast cancer

Background:

Tumour size and nodal involvement are the two main prognostic factors in breast cancer (BC). Their impact on the natural history of BC is not fully captured by analyses that ignore their quantitative nature.

Method:

Data pertaining to 18 159 patients treated with primary surgery: 3661 at the Institut Gustave-Roussy (IGR, France) between 1954 and 1983, and 14 498 in the breast cancer registry in the Stockholm–Gotland Health Care region (SG, Sweden) between 1976 and 1999, were collected. The risks of distant metastases (DMs) and of nodal involvement were analysed according to tumour size with parametric models.

Results:

Using SG 1976–1990 as the reference group, relative risks (RRs) for DM were equal to 1.42 (95% CI: 1.29–1.56; P<10⁻¹⁰) in IGR and 0.61 (95% CI: 0.55–0.67; P<10⁻¹⁰) in SG 1991–1999. Differences in tumour size explained the increased risk in IGR (RR adjusted for tumour size 1.09; 95% CI: 0.99–1.20; P=0.07), but not the decreased risk in SG 1991–1999 (adjusted RR: 0.63; 95% CI: 0.57–0.69; P<10⁻¹⁰). The relationship between tumour size and DM risk changed significantly during the 1990s.

Conclusion:

Early diagnosis is sufficient to explain differences in the prognosis before 1990. After 1990, the use of adjuvant systemic therapies is the main reason for the reduction in DM.     

Trastuzumab beyond progression in HER2-positive advanced breast cancer: the Royal Marsden experience

Background:

Recent UK clinical guidance advises against continuing trastuzumab (T) beyond disease progression (PD) in the absence of brain metastases in patients with HER-2 positive (+ve) advanced breast cancer .We have retrospectively evaluated the outcome of patients with HER-2+ve locally advanced (LA) or metastatic breast cancer (MBC) who continued T beyond PD, treated in our unit.

Methods:

All HER-2+ve patients on our prospectively maintained database with LA or MBC who received T beyond PD after adjuvant or one line of T for advanced disease were assessed for response and outcome. From the timepoint of T continuation beyond PD, we calculated the overall disease control rate, time to progression (TTP), and overall survival (OS).

Results:

One hundred and fourteen patients with HER-2+ve LA or MBC treated with T beyond PD were identified. The main site of disease was visceral_in 84 (74%) patients. Seventy-six (66%) had one line of chemotherapy before continuation of T beyond PD and 21 (19%) had two or more. Post-progression, 66 (58%) received T combined with chemotherapy. Of the 93 (82%) patients with documented clinical or radiological response evaluation, 67 (59%) were considered as having stable disease or better. The median TTP was 24 weeks (95% CI: 21–28) and the median OS was 19 months (95% CI: 12–24).

Conclusion:

Our results from an unselected group of patients provide additional evidence that continuation of T beyond PD is of clinical benefit.     

Progesterone receptor expression is an independent prognostic variable in early breast cancer: a population-based study

Background:

Progesterone receptor (PR) expression assessment in early invasive breast cancer remains controversial. This study sought to re-evaluate PR expression as a potential therapeutic guide in early breast cancer; particularly in oestrogen receptor (ER)-positive, lymph node (LN)-negative disease.

Methods:

A population cohort of 1074 patients presenting to a single Cancer Centre over 4 years (2000–2004) underwent surgery for primary invasive breast cancer with curative intent. Prospective data collection included patient demographics, pathology, ER and PR expression, HER2 status, adjuvant chemotherapy and endocrine therapy. Progesterone receptor expression was compared with (all causes) overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS).

Results:

Overall survival was 71.0% and BCSS was 83.0% at median follow-up of 8.34 years. Absent PR expression was significantly associated with poorer prognosis for OS, BCSS and DFS (P<0.0001, log-rank), even within the ER-positive, LN-negative group (hazard ratio for BCSS 3.17, 95% CI 1.43–7.01) and was not influenced by endocrine therapy. Cox''s regression analysis demonstrated that PR expression was an independent prognostic variable.

Conclusion:

Absence of PR expression is a powerful, independent prognostic variable in operable, primary breast cancer even in ER-positive, LN-negative patients receiving endocrine therapy. Absence of PR expression should be re-evaluated as a biomarker for poor prognosis in ER-positive breast cancer and such patients considered for additional systemic therapy.