Bruno Vincenzi

Effects of KRAS, BRAF, NRAS, and PIK3CA mutations on the efficacy of cetuximab plus chemotherapy in chemotherapy-refractory metastatic colorectal cancer: a retrospective consortium analysis

BACKGROUND Following the discovery that mutant KRAS is associated with resistance to anti-epidermal growth factor receptor (EGFR) antibodies, the tumours of patients with metastatic colorectal cancer are now profiled for seven KRAS mutations before receiving cetuximab or panitumumab. However, most patients with KRAS wild-type tumours still do not respond. We studied the effect of other downstream mutations on the efficacy of cetuximab in, to our knowledge, the largest cohort to date of patients with chemotherapy-refractory metastatic colorectal cancer treated with cetuximab plus chemotherapy in the pre-KRAS selection era. METHODS 1022 tumour DNA samples (73 from fresh-frozen and 949 from formalin-fixed, paraffin-embedded tissue) from patients treated with cetuximab between 2001 and 2008 were gathered from 11 centres in seven European countries. 773 primary tumour samples had sufficient quality DNA and were included in mutation frequency analyses; mass spectrometry genotyping of tumour samples for KRAS, BRAF, NRAS, and PIK3CA was done centrally. We analysed objective response, progression-free survival (PFS), and overall survival in molecularly defined subgroups of the 649 chemotherapy-refractory patients treated with cetuximab plus chemotherapy. FINDINGS 40.0% (299/747) of the tumours harboured a KRAS mutation, 14.5% (108/743) harboured a PIK3CA mutation (of which 68.5% [74/108] were located in exon 9 and 20.4% [22/108] in exon 20), 4.7% (36/761) harboured a BRAF mutation, and 2.6% (17/644) harboured an NRAS mutation. KRAS mutants did not derive benefit compared with wild types, with a response rate of 6.7% (17/253) versus 35.8% (126/352; odds ratio [OR] 0.13, 95% CI 0.07-0.22; p<0.0001), a median PFS of 12 weeks versus 24 weeks (hazard ratio [HR] 1.98, 1.66-2.36; p<0.0001), and a median overall survival of 32 weeks versus 50 weeks (1.75, 1.47-2.09; p<0.0001). In KRAS wild types, carriers of BRAF and NRAS mutations had a significantly lower response rate than did BRAF and NRAS wild types, with a response rate of 8.3% (2/24) in carriers of BRAF mutations versus 38.0% in BRAF wild types (124/326; OR 0.15, 95% CI 0.02-0.51; p=0.0012); and 7.7% (1/13) in carriers of NRAS mutations versus 38.1% in NRAS wild types (110/289; OR 0.14, 0.007-0.70; p=0.013). PIK3CA exon 9 mutations had no effect, whereas exon 20 mutations were associated with a worse outcome compared with wild types, with a response rate of 0.0% (0/9) versus 36.8% (121/329; OR 0.00, 0.00-0.89; p=0.029), a median PFS of 11.5 weeks versus 24 weeks (HR 2.52, 1.33-4.78; p=0.013), and a median overall survival of 34 weeks versus 51 weeks (3.29, 1.60-6.74; p=0.0057). Multivariate analysis and conditional inference trees confirmed that, if KRAS is not mutated, assessing BRAF, NRAS, and PIK3CA exon 20 mutations (in that order) gives additional information about outcome. Objective response rates in our series were 24.4% in the unselected population, 36.3% in the KRAS wild-type selected population, and 41.2% in the KRAS, BRAF, NRAS, and PIK3CA exon 20 wild-type population. INTERPRETATION While confirming the negative effect of KRAS mutations on outcome after cetuximab, we show that BRAF, NRAS, and PIK3CA exon 20 mutations are significantly associated with a low response rate. Objective response rates could be improved by additional genotyping of BRAF, NRAS, and PIK3CA exon 20 mutations in a KRAS wild-type population. FUNDING Belgian Federation against Cancer (Stichting tegen Kanker).

Epithelial-mesenchymal transition and stemness features in circulating tumor cells from breast cancer patients.

Currently used methods to detect and enumerate circulating tumor cells (CTCs) rely on the expression of the epithelial cell adhesion molecule (EpCAM) and cytokeratins. This selection may exclude cells that have undergone intrinsic modifications of their phenotype, as epithelial-mesenchymal transition (EMT). Aim of the study was to investigate the expression of EMT and stemness markers in CTCs from breast cancer patients in all stages of disease. 92 female breast cancer patients were enrolled. CTCs were isolated by CELLection™ Dynabeads® coated with the monoclonal antibody toward EpCam. Samples found positive for CTCs presence (CD45−/CK+) were evaluated for the expression of ER alpha, HER2, ALDH1, vimentin, and fibronectin. Samples negative for CTCs presence (CD45−/CK−) were also evaluated for the expression of vimentin and fibronectin, used as markers of EMT. CTCs were found in 66% of patients. The distribution of CTCs presence according to stage and grade of disease was found statistically significant. The expression of ALDH1 on CTCs was found to correlate to stage of disease and to the expression of vimentin and fibronectin. In 34% of patients, we detected cells with negative CK/CD45 expression but positive expression of vimentin and fibronectin. There is an urgent need for optimizing CTCs detection methods through the inclusion of EMT markers. The detection of cells in mesenchymal transition, retaining EMT and stemness features, may contribute to discover additional therapeutic targets useful to eradicate micrometastatic disease in breast cancer.

High concordance of KRAS status between primary colorectal tumors and related metastatic sites: implications for clinical practice.

PURPOSE Several studies have suggested that KRAS somatic mutations may predict resistance to cetuximab- and panitumumab-based treatments in metastatic colorectal cancer (CRC) patients. Nevertheless, most experiences were conducted on samples from primaries. The aim of this study was to evaluate the grade of concordance in terms of KRAS status between primaries and related metastases. PATIENTS AND METHODS We analyzed KRAS codon 12 and 13 mutations from formalin-fixed sections of 107 CRC primaries and related metastases. Eight pairs were excluded from the analysis because of the low amount of tumor tissue in the available samples. The main characteristics were: 50 men, 49 women; median age at diagnosis, 71 years (range, 41-84). The metastatic sites analyzed were the liver in 80 patients (80.8%), lung in seven patients (7.1%), and other sites in 12 patients (12.1%). RESULTS A KRAS mutation was found in 38 (38.4%) primary tumors and in 36 (36.4%) related metastases. The rate of concordance was 96.0% (95% confidence interval, 90.0%-98.9%). Discordance was observed in only four (4%) patients. CONCLUSIONS Our results indicate that the detection of KRAS mutations in either primary or metastatic tumors from patients with CRC is concordant and this assessment could be used to predict response to targeted therapies such as cetuximab and panitumumab.

Repeated intermittent low-dose therapy with zoledronic acid induces an early, sustained, and long-lasting decrease of peripheral vascular endothelial growth factor levels in cancer patients.

Purpose: On the basis of stimulating data on animals reporting that weekly regimens of zoledronic acid (ZA) were effective in reducing skeletal tumor burden, we designed a study on humans to investigate the potential antiangiogenic role of a weekly low-dose therapy with ZA in patients with malignancies. Experimental Design: Twenty-six consecutive patients with advanced solid cancer and bone metastases received 1 mg of ZA every week for four times (days 1, 7, 14, and 21) followed by 4 mg of ZA with a standard 28-day schedule repeated thrice (days 28, 56, and 84). Patients were prospectively evaluated for circulating levels of vascular endothelial growth factor (VEGF) just before the beginning of drug infusion (0) and again at 7, 14, 21, 28, 56, and 84 days after the first ZA infusion. Results: The median VEGF basal value showed an early statistically significant (P = 0.038) decrease 7 days after the first 1-mg infusion of ZA. This effect on VEGF-circulating levels persisted also after the following 1-mg infusions at 14 (P = 0.002), 21 (P = 0.001), and 28 days (P = 0.008). Interestingly, the decrease of VEGF-circulating levels persisted also at each programmed time point during the second phase of the study (ZA 4 mg every 4 weeks). No significant differences were recorded in platelet levels, WBC count, or hemoglobin concentration before and after each ZA infusion. Conclusions: In the present study, we report that a repeated low-dose therapy with ZA is able to induce an early significant and long-lasting decrease of VEGF levels in cancer patients.

Prognostic impact of VEGF, CD31, CD34, and CD105 expression and tumour vessel invasion after radical surgery for IB–IIA non-small cell lung cancer

Aims: To evaluate the prognostic impact of tumour angiogenesis assessed by vascular endothelial growth factor (VEGF), microvessel density (MVD), and tumour vessel invasion in patients who had undergone radical resection for stage IB–IIA non-small cell lung cancer (NSCLC). Methods: Fifty one patients (42 men, nine women; mean age, 62.3 years; SD, 6.9) undergoing complete surgical resection (35 lobectomy, 16 pneumonectomy) of pathological stage IB (n  =  43) and IIA (n  =  8) NSCLC were evaluated retrospectively. No patient underwent postoperative chemotherapy or neoadjuvant treatment. Tumour specimens were stained for VEGF and specific MVD markers: CD31, CD34, and CD105. Results: VEGF expression significantly correlated with high CD105 expression (p < 0.0001) and tumour vessel invasion (p  =  0.04). Univariate analysis showed that those patients with VEGF overexpression (p  =  0.0029), high MVD by CD34 (p  =  0.0081), high MVD by CD105 (p  =  0.0261), and tumour vessel invasion (p  =  0.0245) have a shorter overall survival. Furthermore, multivariate Cox regression analysis showed that MVD by CD34 (p  =  0.007), tumour vessel invasion (p  =  0.024), and VEGF expression (p  =  0.042) were significant predictive factors for overall survival. Finally, the presence of both risk factors, tumour vessel invasion and MVD by CD34, was highly predictive of poor outcome (odds ratio, 3.4; 95% confidence interval, 1.7 to 6.5; p  =  0.0002). Conclusions: High MVD by CD34 and tumour vessel invasion are more closely related to poor survival than the other neoangiogenetic factors in stage IB–IIA NSCLC. This may be because these factors are more closely related to the metastatic process.

Early Skin Toxicity as a Predictive Factor for Tumor Control in Hepatocellular Carcinoma Patients Treated with Sorafenib

INTRODUCTION Sorafenib is an oral multikinase inhibitor that targets Raf kinase and receptor tyrosine kinases and has led to a longer median overall survival (OS) time and time to progression (TTP) in patients with advanced hepatocellular carcinoma (HCC). This study was conducted to assess the link between the antitumor efficacy of sorafenib and its early cutaneous side effects in advanced HCC patients. MATERIALS AND METHODS All patients received 800 mg daily of sorafenib until progression or unacceptable toxicities. We retrospectively analyzed the incidence of rash and hand-foot skin reactions (HFSR) during the first month of treatment, comparing tumor control (partial response plus stable disease) and TTP. RESULTS Sixty-five HCC patients treated with sorafenib were included in this analysis: 47 (73.3%) received sorafenib after failure of some local treatment, whereas 18 (27.7%) received it as first-line treatment. Twenty-nine patients developed at least grade 1 skin toxicity (rash, 13; HFSR, 16). In patients who developed skin toxicity, the tumor control rate was 48.3%, versus 19.4% in patients without cutaneous side effects. The median TTP was 8.1 months in the group of patients with skin toxicity versus 4.0 months in those without skin toxicity. This difference was also statistically significant on multivariate analysis. A borderline statistically significant difference was also observed in terms of OS in patients with early skin toxicity. CONCLUSIONS Skin toxicity should be closely monitored in HCC patients treated with sorafenib in relation to its potential role as a surrogate marker of efficacy.

Receptor Activator of NF-kB (RANK) Expression in Primary Tumors Associates with Bone Metastasis Occurrence in Breast Cancer Patients

Background Receptor activator of NFkB (RANK), its ligand (RANKL) and the decoy receptor of RANKL (osteoprotegerin, OPG) play a pivotal role in bone remodeling by regulating osteoclasts formation and activity. RANKL stimulates migration of RANK-expressing tumor cells in vitro, conversely inhibited by OPG. Materials and Methods We examined mRNA expression levels of RANKL/RANK/OPG in a publicly available microarray dataset of 295 primary breast cancer patients. We next analyzed RANK expression by immunohistochemistry in an independent series of 93 primary breast cancer specimens and investigated a possible association with clinicopathological parameters, bone recurrence and survival. Results Microarray analysis showed that lower RANK and high OPG mRNA levels correlate with longer overall survival (P = 0.0078 and 0.0335, respectively) and disease-free survival (P = 0.059 and 0.0402, respectively). Immunohistochemical analysis of RANK showed a positive correlation with the development of bone metastases (P = 0.023) and a shorter skeletal disease-free survival (SDFS, P = 0.037). Specifically, univariate analysis of survival showed that “RANK-negative” and “RANK-positive” patients had a SDFS of 105.7 months (95% CI: 73.9–124.4) and 58.9 months (95% CI: 34.7–68.5), respectively. RANK protein expression was also associated with accelerated bone metastasis formation in a multivariate analysis (P = 0.029). Conclusions This is the first demonstration of the role of RANK expression in primary tumors as a predictive marker of bone metastasis occurrence and SDFS in a large population of breast cancer patients.

Fever After Zoledronic Acid Administration Is Due to Increase in TNF-α and IL-6

The most common adverse event typically associated with bisphosphonate therapy is transient fever. The aim of this study was to define the role of the main cytokines of the acute-phase reaction interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) involved in the pathogenesis of zoledronic acid-induced fever. Eighteen consecutive cancer patients with bone metastases were treated, for the first time, with a single dose of 4 mg zoledronic acid infusion. They were prospectively evaluated for circulating TNF-α, interferon-γ (IFN-γ), and IL-6 levels at different times, just before and 1, 2, 7, and 21 days after diphosphonate infusion. Clinical and standard laboratory parameters were recorded at the same time points. TNF-α circulating levels increased significantly 1 and 2 days after zoledronic acid infusion (respectively, p = 0.002 and p < 0.001) and then decreased to levels similar to the basal levels. IL-6 levels increased significantly 1 day after the infusion (p = 0.007), returning to values similar to ...

Circulating tumour cells lacking cytokeratin in breast cancer: the importance of being mesenchymal

Circulating tumour cells (CTCs) are independent predictor of prognosis in metastatic breast cancer. Nevertheless, in one third of patients, circulating tumour cells are undetected by conventional methods. Aim of the study was to assess the prognostic value of circulating tumour cells expressing mesenchymal markers in metastatic breast cancer patients. We isolated CTC from blood of 55 metastatic breast cancer patients. CTC were characterized for cytokeratins and markers of epithelial mesenchymal transition. The gain of mesenchymal markers in CTC was correlated to prognosis of patients in a follow‐up of 24 months. The presence of mesenchymal markers on CTC more accurately predicted worse prognosis than the expression of cytokeratins alone. Because of the frequent loss of epithelial antigens by CTC, assays targeting epithelial antigens may miss the most invasive cell population. Thus, there is an urgent need to improve detection methods to identify CTC which undergone epithelial mesenchymal transition program.

The biological properties of cetuximab.

Cetuximab is a recombinant chimeric human murine immunoglobulin G1 antibody that binds to the extra-cellular domain of epidermal growth factor receptor with a higher affinity than either endogenous ligand. This binding inhibits receptor phosphorylation and activation and it leads to receptor internalization and degradation. Several studies have shown that cetuximab is able to inhibit growth of epidermal growth factor receptor (EGFR)-expressing tumour cells in vitro. Moreover, treatment with cetuximab results in a marked inhibition of tumour growth in nude mice bearing xenografts of human cancer cell lines. These results are linked to cetuximab biological effects as inhibition of cell cycle, tumour progression, neo-angiogenesis, invasion and metastatization, as well as increase and activation of pro-apoptotic molecules. Additionally, cetuximab potentiates, in combination, the effects of chemotherapy and radiation therapy in eradicating well-established tumours in nude mice and it may even reverse the resistance to some cytotoxic agents in these xenografts. Moreover, numerous clinical trials demonstrated cetuximab efficacy in different tumour types. It has been approved by Food and Drugs Administration in the treatment of metastatic colorectal cancer as single agent or in combination with chemotherapy, in locally and regionally advanced head and neck squamous cell carcinoma in combination with radiation, and as monotherapy for recurrent and metastatic head and neck squamous cell carcinoma after failing platinum-based chemotherapy. This paper will overview all the experimental and pre-clinical data on the biological properties of cetuximab.