Dynamic contrast-enhanced MRI versus 18F-misonidazol-PET/CT to predict pathologic response in bevacizumab-based neoadjuvant therapy in breast cancer

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Background: To investigate the role of DCE-MRI versus 18F-Misonidazole (FMISO) positron emission tomography (PET/CT) in the prediction of pathological response to bevacizumab-based neodajuvant therapy. Methods: 73 chemotherapy naïve, stage II and III breast cancer (BC) patients (pts) were enrolled in a phase II, single-arm, multicenter, open-label and prospective clinical trial. Pts received single infusion of bevacizumab (15 mg/ kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy (NAC) consisting of 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/ kg) every 21 days (C2-C5), followed by surgery. Tumor proliferation, hypoxia and perfusion were evaluated respectively using 18F-Fluorothymidine (FLT) and 18F-Misonidazole (FMISO) positron emission tomography (PET/CT) and dynamic contrast enhancement magnetic resonance (DCE-MR). Serial imaging studies were performed in parallel at several time points including baseline (BL) and 14-21 days after bevacizumab alone (C1). Results: After only one administration of bev, tumor proliferation and perfusion assessed using FLT-PET and DCE-MRI significantly decrease (-26% and -46%, p<0.001) but these changes were not found to be associated with final response. Most important, changes in tumor hypoxia induced by bevacizumab was significantly associated with pathological response (p= 0.004) and was an independent predictor of response in multivariate analysis (RR=0.95, IC 95% 0.92-0.99, p=0.02). Decrease in FMISO uptake >10% yielded a ROC curve area of 0.7 (95% CI: 0.56 - 0.85) with high specificity (94%). Conclusions: Our findings suggest a significant value of early changes in tumor hypoxia assessed by FMISO-PET as a biomarker of pathological response in bevacizumab-based neoadjuvant therapy in breast cancer.

P5-14-22: Prospective Observational Study To Describe the Clinicopathological and Biological Characteristics and the Management of Metastatic Breast Cancer Patients Who Experienced Complete or Partial Remission or Disease Stabilization during at Least 3 Years

Background

Trastuzumab has shown an improvement in survival outcomes among patients with HER2+ metastatic breast cancer (MBC). Identification of pathological, clinical factors and tumor genetic profile that may predict long-term remission has become a key-issue. We aimed to describe the clinicopathological and biological characteristics of MBC patients who experienced complete response (CR), partial response (PR), or stable disease (SD) during at least 3 years and their management in routine clinical practice.

Methods: Multicenter, observational, cross-sectional study. Data were collected from women with HER2+ MBC treated with a trastuzumab-based regimen who maintained a partial or complete remission or disease stabilization beyond 3 years. The interim results from the first 65 patients evaluated are presented.

Results: Median age: 59 (52-70) years. Metastatic disease was diagnosed after a median of 23.5 (1.6−48.8) months since primary tumor diagnosis. The predominant tumor type was ductal carcinoma (89.2%) and 47% showed histological grade III. Mean tumor size: 3.6±2.2cm (anatomical pathology), 5.1±2.8cm (imaging studies). Hormonal status: Progesterone receptor positive 46% and estrogen receptor positive 43%. Most common metastatic sites: lung (23%), liver (17%) and bone (14%). Overexpression of HER2 was assessed by IHC in 97% of patients, of whom 94% were HER2+ (3+) and 17% had FISH+ HER2 status. Tumor was positive for p53 and Ki67 in 23% and 41.5%, respectively. Surgery was performed on 83% of patients, of which 73% underwent radical mastectomy; 96% had their axillary nodes removed. Surgery of metastases was performed on 7.8%. First line chemotherapy was received by 91% with the most frequent schemes being paclitaxel (24%), vinorelbine (15%) and paclitaxel/carboplatine (14%). First line hormonal therapy and radiotherapy was used in 45% and 12%, respectively. All patients received first line trastuzumab, administered on a weekly schedule in 51%. Trastuzumab was used in combination in most of patients (89.2%) with a median number of cycles of 18 (7.0−41.5) and during a median of 53.3±25 months. 66% of patients achieved a CR, 21% PR and 13% had SD. Median time since trastuzumab was initiated to CR, PR or SD was 5 (4-7) months. Median duration of CR, PR or SD was 56 (44.5−78.0) months. Trastuzumab was maintained beyond CR, PR or SD in 99% during a median of 46.5 (35-67) months. 75% of patients continue on treatment with trastuzumab. Only 2 patients discontinued trastuzumab due to toxicity. At the time of the analysis, 19% had progressed, 57% were alive and free of disease and among patients on treatment (93%), 54% were on trastuzumab. Cardiac toxicity was the most common toxicity (36%) among those suffering at least one (22%).

Conclusions: The preliminary findings support that trastuzumab provides a substantial long-term survival benefit with a manageable safety profile in HER2+ MBC patients. This study adds to the evidence that there may be benefit in continuing trastuzumab after achieving remission or disease stabilization. Final results will be presented in the forthcoming congress.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-22.

Exemestane versus anastrozole as front-line endocrine therapy in postmenopausal patients with hormone receptor-positive, advanced breast cancer: final results from the Spanish Breast Cancer Group 2001-03 phase 2 randomized trial

BACKGROUND

Several aromatase inhibitor studies have reported variations in the inhibitory potency of these agents that could lead to differences in clinical outcomes. In the current study, the authors formally evaluated the activity of anastrozole and exemestane in postmenopausal women with hormone-responsive, advanced breast cancer.

METHODS

Postmenopausal women who had measurable disease according to Response Evaluation Criteria in Solid Tumors and had not received previous endocrine therapy for advanced breast cancer were randomized to receive either oral exemestane 25 mg daily or oral anastrozole 1 mg daily until they had disease progression. The primary endpoint was the objective response rate (ORR), and secondary endpoints included the clinical benefit rate (CBR), time to progression (TTP), overall survival, and safety. Crossover to the other aromatase inhibitor was permitted at the time of disease progression; ORR, CBR, and TTP after second-line treatment also were explored.

RESULTS

In total, 103 patients were enrolled. The median patient age was 71.6 years, 52.4% of patients had visceral disease, and 75.8% of patients had ≥ 2 disease sites. Half of the patients had received previous tamoxifen, and 60% had received previous chemotherapy. The efficacy observed in the exemestane and anastrozole groups was an ORR of 36.2% and 46%, respectively; a CBR of 59.6% and 68%, respectively, and a TTP of 6.1 months and 12.1 months, respectively. At progression, 28 patients crossed over to the other aromatase inhibitor, including 16 patients who switched to exemestane (CBR, 43.7%; TTP, 4.4 months) and 12 patients who switched to anastrozole (CBR, 8.3%; TTP, 2 months). Both drugs were generally well tolerated, and no study drug-related serious adverse events were reported.

CONCLUSIONS

In this phase 2 randomized trial, no significant differences in clinical activity were observed in favor of exemestane to justify a superiority phase 3 trial design in the first-line setting.

Effects of strontium-doped bioactive glass on the differentiation of cultured osteogenic cells

There is accumulating evidence that strontium-containing biomaterials have positive effects on bone tissue repair. We investigated the in vitro effect of a new Sr-doped bioactive glass manufactured by the sol-gel method on osteoblast viability and differentiation. Osteoblasts isolated from foetal mouse calvaria were cultured in the presence of bioactive glass particles; particles were undoped (B75) or Sr-doped with 1 wt.% (B75-Sr1) and 5 wt.% (B75-Sr5). Morphological analysis was carried out by contrast-phase microscopy and scanning electron microscopy (SEM). Cell viability was evaluated by the MTS assay at 24 h, 48 h and 72 h. At 24 h, day 6 and day 12, osteoblast differentiation was evaluated by assaying alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion and gene expression of various bone markers, using Real-Time-PCR. Alizarin Red staining and ALP histoenzymatic localisation were performed on day 12. Microscopic observations and MTS showed an absence of cytotoxicity in the three investigated bioactive glasses. B75-Sr5 particles in cell cultures, in comparison with those of B75 and B75-Sr1, resulted in a significant up-regulation of Runx2, Osterix, Dlx5, collagen I, ALP, bone sialoprotein (BSP) and OC mRNA levels on day 12, which was associated with an increase of ALP activity on day 6 and OC secretion on day 12. In conclusion, osteoblast differentiation of foetal mouse calvarial cells was enhanced in the presence of bioactive glass particles containing 5 wt.% strontium. Thus, B75-Sr5 may represent a promising bone-grafting material for bone regeneration procedures.

Imaging physicochemical reactions occurring at the pore surface in binary bioactive glass foams by micro ion beam analysis

In this work, the physicochemical reactions occurring at the surface of bioactive sol-gel derived 3D glass scaffolds via a complete PIXE characterization were studied. 3D glass foams in the SiO(2)-CaO system were prepared by sol-gel route. Samples of glass scaffolds were soaked in biological fluids for periods up to 2 days. The surface changes were characterized using particle induced X-ray emission (PIXE) associated to Rutherford backscattering spectroscopy (RBS), which are efficient methods to perform quantitative chemical maps. Elemental maps of major and trace elements at the glass/biological fluids interface were obtained at the micrometer scale for every interaction time. Results revealed interconnected macropores and physicochemical reactions occurring at the surface of pores. The micro-PIXE-RBS characterization of the pores/biological fluids interface shows the glass dissolution and the rapid formation of a Ca rich layer with the presence of phosphorus that came from biological fluids. After 2 days, a calcium phosphate-rich layer containing magnesium is formed at the surface of the glass scaffolds. We demonstrate that quantities of phosphorus provided only by the biological medium have a significant impact on the development and the formation of the phosphocalcic layer.

Phase I study of oral vinorelbine and capecitabine in patients with metastatic breast cancer

BACKGROUND

To determine the recommended doses of oral vinorelbine (VN) and capecitabine (C) in metastatic breast cancer.

PATIENTS AND METHODS

Eighteen patients with metastatic breast cancer received oral VN (on days 1 and 8) and C (on days 1 to 14) every three weeks at one of four dose levels: I) 60 mg/m(2) and 1650 mg/m(2)/day; II) 70 mg/m(2) and 1650 mg/m(2)/day; III) 70 mg/m(2) and 2000 mg/m(2)/day; IV) 80 mg/m(2) and 2000 mg/m(2)/day, respectively. The primary endpoint was to determine the recommended doses for the combination of oral VN and C in metastatic breast cancer. Secondary endpoints include evaluating response rate, safety profile and whether or not VN dosage escalation was required.

RESULTS

Severe neutropenia occurred in 28% of patients; and severe anaemia and leucopenia were observed in one patient each (6%). One patient developed febrile neutropenia. Non-hematological toxicities were rare. The response rate was 28% (95% CI: 10-54) in the intention-to-treat population.

CONCLUSION

The recommended dose is 80 mg/m(2) of oral VN on days 1 and 8, and 2000 mg/m(2)/day of C from days 1 to 14 in three weekly cycles. A phase II study with this schedule is currently under way.

Phase I/II study of a 3 weekly liposome-encapsulated doxorubicin/docetaxel/pegfligrastrim in combination with weekly trastuzumab as primary treatment in HER2 positive (HER2+) early stage breast cancer (ESBC) patients (pt). GEICAM 2003–03 study

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Background: The liposome-encapsulated form of doxorubicin (Myocet™) (M) seems to be safe in terms of cardiotoxicity in combination with standard doses of trastuzumab (H) and paclitaxel in BC. This phase I/II study of M, H, docetaxel (T) and pegfligrastrim (N) was designed to evaluate the efficacy and safety of the combination, and define the MTD, in order to examine the selected regimen in a phase II trial. Methods: Cohorts of 3 HER2+ (FISH+) ESBC pt were treated at fixed dose of N (6 mg) and H (2 mg/kg/week). M and T were administered at the following dose levels (DL) (mg/m2): DL0, 60/75; DL-1, 55/75; DL-2, 50/70; DL-3, 50/65; DL-4, 50/60. The MTD was defined as >1/6 pt in any cohort experiencing a predefined dose-limiting toxicity (DLT) in cycle (cy) 1 or 2. LVEF was assessed at baseline and every 2 cy. Results: Nineteen pt have been enrolled in phase I; all are evaluable for efficacy and toxicity. Median age was 45. Twelve pt (63%) were premenopausal. Median tumour size was 45 mm (20–80); 13 (68%) and 6 pt (32%) presented with stage II and IIIA BC respectively. Six (32%) of tumours were G3. DLT were G3 diarrhoea, febrile neutropenia, thrombocytopenia, infection, and G4 asthenia. Three additional pt were treated at DL-4 for confirmation of the recommended dose; none of them had a DLT. One pt (DL-2) experienced asymptomatic, reversible LVEF decrease to 49%. All pt have been assessed for pathological response: 6 (32%) and 5 pt (26%) achieved one pCR and one pPR in breast, defined as Miller and Payne score of 5 and 4, respectively. Conclusions: Concomitant administration of M plus THN is highly active regimen with manageable toxicity in pt with HER2+ ESBC tumours. DL-4 has been selected as the DL for the ongoing phase II study with an enrolment target of 59 pt.

No significant financial relationships to disclose.

Plasma zinc levels inversely correlate with vascular cell adhesion molecule-1 concentration in children with sickle cell disease

Zinc deficiency has been implicated in impaired cell-mediated immunity of children with sickle cell disease (SCD). However, its influence on the expression of vascular cell-adhesion molecule-1 (VCAM-1) on endothelial cells, a protein involved in vasoocclusion, has not been previously investigated. We therefore measured (soluble) sVCAM-1 and zinc in 76 SCD children and 96 non-SCD children, mean age 7.73 years and 11.24 years, respectively. Although mean zinc levels of both groups were within the normal range (approximately 14.5 micromol/l), 14.5 % of SCD and 11% of non-SCD children (without inflammation) had levels below normal (10.7 micromol/L). Mean sVCAM-1 concentrations of SCD children (837 microg/l) were significantly higher than those of controls (627 microg/l) (p < 0.001). Differences persisted after taking into account age, hemoglobin phenotype, and inflammation (alpha-l acid glycoprotein >l g/l and C-reactive protein >10 mg/I). sVCAM-1 negatively correlated with serum (r = -0.444) and red blood cells zinc (r = -0.242, p < 0.05) but not with acute-phase proteins. Mean sVCAM-1 tended to be higher in SCD children with than in those without a history of a health problem (infection, pain crisis or were transfused; not significant). Data suggest that zinc may modulate the clinical status of SCD children through VCAM-1 expression, and zinc supplementation may be beneficial in these patients.

Preoperative chemoradiotherapy with capecitabine and oxaliplatin in locally advanced rectal carcinoma: Preliminary results

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Background: Preoperative chemoradiotherapy has shown to improve local control and sphincter preservation with decreased acute toxicity compared with postoperative treatment in locally advanced rectal carcinoma. The primary endpoint of this phase II trial was pathologic tumor response. Secondary endpoints were sphincter preservation and toxicity. Methods: Inclusion criteria: rectal adenocarcinoma <12 cms from anal verge, clinical stage T3–4 and/or N+, adequate renal, hematological and liver function. Planned sample for this trial was 43 patients. Treatment scheme: pelvic radiotherapy (50.4 Gy/28 fractions) and chemotherapy: Capecitabine 825 mg/m2/12 hours on days 1–5 + Oxaliplatin 50 mg/m2 on day 1 every week (weeks 1–6). Surgery with TME was performed between 6–8 weeks after the end of the treatment. Adjuvant chemotherapy was administered after surgery according each center criteria. Results: 37 patients have been recruited between February and December 2005. 26 male/11 female. Median age 70 years (range 38–79). Clinical stage (determined by EUS+CT or RMI): cT2 1p/cT3 33p/cT4 3p/cN+ 27p. Tumor location (from anal verge): ≤ 5 cm in 15p, >5 cm in 22p. Surgery (performed in 26 patients) consisted of low anterior resection in 13p and abdominal-perineal resection in 13p. Tumor downstaging was observed in 17p (65%), 20 (77%) had negative lymph nodes, including 6p with complete pathological response (23%) and four with only microfoci of tumor remaining (15%). Main adverse effects (NCI-CTC): diarrhea G3–4 19%, sensitive peripheral neurotoxicity G1 38%, skin G2 11%, nausea/vomiting G2 11%, fatigue/malaise G3 4%, neutropenia G3 7%. Conclusions: Preliminary results show that preoperative chemoradiotherapy with capecitabine and oxaliplatin is a well tolerated regimen for locally advanced operable rectal cancer leading to a high probability of tumor downstaging.

No significant financial relationships to disclose.