Brain metastases are among the most feared complications in breast cancer, as no therapy exists that prevents or eliminates breast cancer spreading to the brain. New therapeutic strategies depend on specific knowledge of tumor cell properties that allow breast cancer cell growth within the brain tissue. To provide information in this direction, we established a human breast cancer cell model for brain metastasis based on circulating tumor cells from a breast cancer patient and variants of these cells derived from bone or brain lesions in immunodeficient mice. The brain-derived cells showed an increased potential for brain metastasis in vivo and exhibited a unique protein expression profile identified by large-scale proteomic analysis. This protein profile is consistent with either a selection of predisposed cells or bioenergetic adaptation of the tumor cells to the unique energy metabolism of the brain. Increased expression of enzymes involved in glycolysis, tricarboxylic acid cycle, and oxidative phosphorylation pathways suggests that the brain metastatic cells derive energy from glucose oxidation. The cells further showed enhanced activation of the pentose phosphate pathway and the glutathione system, which can minimize production of reactive oxygen species resulting from an enhanced oxidative metabolism. These changes promoted resistance of brain metastatic cells to drugs that affect the cellular redox balance. Importantly, the metabolic alterations are associated with strongly enhanced tumor cell survival and proliferation in the brain microenvironment. Thus, our data support the hypothesis that predisposition or adaptation of the tumor cell energy metabolism is a key element in breast cancer brain metastasis, and raise the possibility of targeting the functional differentiation in breast cancer brain lesions as a novel therapeutic strategy. [Cancer Res 2007;67(4):1472-86]

PURPOSE To evaluate the efficacy of cetuximab plus taxane/carboplatin (TC) as first-line treatment of advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS This multicenter, open-label, phase III study enrolled 676 chemotherapy-naïve patients with stage IIIB (pleural effusion) or IV NSCLC, without restrictions by histology or epidermal growth factor receptor expression. Patients were randomly assigned to cetuximab/TC or TC. TC consisted of paclitaxel (225 mg/m(2)) or docetaxel (75 mg/m(2)), at the investigator's discretion, and carboplatin (area under the curve = 6) on day 1 every 3 weeks for < or = six cycles; cetuximab (400 mg/m(2) on day 1, 250 mg/m(2) weekly) was administered until progression or unacceptable toxicity. The primary end point was progression-free survival assessed by independent radiologic review committee (PFS-IRRC); overall response rate (ORR), overall survival (OS), quality of life (QoL), and safety were key secondary end points. PFS and ORR assessed by investigators were also evaluated. Results Median PFS-IRRC was 4.40 months with cetuximab/TC versus 4.24 months with TC (hazard ratio [HR] = 0.902; 95% CI, 0.761 to 1.069; P = .236). Median OS was 9.69 months with cetuximab/TC versus 8.38 months with TC (HR = 0.890; 95% CI, 0.754 to 1.051; P = .169). ORR-IRRC was 25.7% with cetuximab/TC versus 17.2% with TC (P = .007). The safety profile of this combination was manageable and consistent with its individual components. CONCLUSION The addition of cetuximab to TC did not significantly improve the primary end point, PFS-IRRC. There was significant improvement in ORR by IRRC. The difference in OS favored cetuximab but did not reach statistical significance.

PURPOSE The anti-epidermal growth factor receptor (EGFR) antibody cetuximab is efficacious in multiple tumor types. Patient selection with markers predictive of benefit may enhance its therapeutic index. This retrospective, correlative analysis of the phase III trial BMS099 of cetuximab in advanced non-small-cell lung cancer (NSCLC) was conducted to identify molecular markers for the selection of patients most likely to benefit from cetuximab. METHODS In BMS099, 676 chemotherapy-naïve patients with stage IIIB (pleural effusion) or stage IV NSCLC of any histology or EGFR expression status were randomly assigned to taxane/carboplatin (T/C) with or without cetuximab. Biomarkers analyzed included K-Ras and EGFR mutations by direct sequencing, EGFR protein expression by immunohistochemistry (IHC), and EGFR gene copy number by fluorescent in situ hybridization (FISH). Relationships between biomarker status and progression-free survival (PFS), overall survival (OS), and overall response rate (ORR) were assessed by log-rank tests per treatment arm for treatment-specific effects and across the total evaluable population. Results Tumor samples were available from 225 randomly assigned patients. K-Ras mutations were found in 17% of evaluable patients (35 of 202 patients), EGFR mutations were found in 10% (17 of 166 patients), EGFR positivity by IHC was found in 89% (131 of 148 patients), and FISH positivity was found in 52% (54 of 104 patients). No significant associations were found between biomarker status and PFS, OS, and ORR in the treatment-specific analyses. CONCLUSION In contrast with colorectal cancer, and within the limitations of the data set, efficacy parameters did not appear to correlate with K-Ras mutation status or with any of the EGFR-related biomarkers evaluated. Additional exploratory analyses are essential to identify predictive markers and to optimize patient selection for cetuximab therapy in NSCLC.

First-line treatment with cetuximab plus gemcitabine/platinum is well tolerated and can be administered safely in patients with advanced NSCLC. Differences in response rate, progression-free survival, and overall survival suggest that the addition of cetuximab to platinum/gemcitabine may improve clinical outcomes. Larger studies are in progress to address this hypothesis.

Grade 3/4 AEs occurred in 40.6% (gefitinib) and 81.6% (docetaxel) of patients. The incidence of interstitial lung disease (ILD) was 5.7% (n=14) and 2.9% (n=7) with gefitinib and docetaxel, respectively. There were four deaths due to AEs in the gefitinib arm (three possibly treatment-related due to ILD; one due to pneumonia that was not considered treatment-related), and none in the docetaxel arm. Biomarker data will also be reported. Conclusions: Non-inferiority in overall survival between gefitinib and docetaxel was not demonstrated according to predefined criteria. However, there was no statistically significant difference in survival between the two groups. Imbalances in the proportion and type of post-study treatments in both arms have complicated interpretation of survival results. The secondary endpoints are largely unaffected by subsequent therapy and provide further evidence of the clinical efficacy of gefitinib in Japanese patients. AEs were consistent with those previously observed for both treatments.

Combinatorial antibody libraries have the potential to display the entire immunological record of an individual, allowing one to detect and recover any antibody ever made, irrespective of whether it is currently being produced. We have termed this the ''fossil record'' of an individual's antibody response. To determine whether cancer patients have ever made antibodies with diseasefighting potential, we screened combinatorial antibody libraries from cancer patients for immunoglobulins that can identify metastatic tumor cells. This strategy yielded human antibodies specific for the activated conformation of the adhesion receptor integrin ␣v␤3 that is associated with a metastatic phenotype. In a remarkable example of convergent evolution, two of these antibodies were shown to contain the Arg-Gly-Asp integrin recognition motif of the natural ligand within the third complementarity-determining region of the heavy chain. These antibodies interfered with lung colonization by human breast cancer cells in a mouse model and inhibited existing metastatic disease. Our data imply that, at least at some time, these antibodies were part of a patient's surveillance system against metastatic cells, targeting the activated conformer of integrin ␣v␤3 and disrupting its functions. The ligand-mimetic nature of these antibodies, combined with specificity for a single receptor, is unique in the integrin-ligand repertoire. The convergent evolution of critical sequences in antibodies and other ligands that bind to the same target means that the immune response has sufficient power to find a best chemical solution for the optimization of binding energy, even though antibodies evolve in real time, as compared with billions of years for the natural ligand. convergent evolution ͉ human antibodies ͉ integrin ␣v␤3 C ombinatorial antibody libraries allow the cloning of the entire immunological repertoire of an individual (1, 2). One advantage of this method is that, in principle, it allows the resurrection of any antibody that an individual has ever made, irrespective of whether the antibody is currently being produced. We have referred to this feature of combinatorial antibody libraries as the ''fossil record'' of an individual's immunological history (3).In cancer, the successful establishment of a tumor in the host does not necessarily mean that there was a failure to produce antitumor antibodies. Tumor establishment also could be due to the fact that the growth rate of the malignant cells outstripped the ability of the immune response to deal with the tumor mass or that the target antigen has been modulated. Over the years, these ideas have been generally termed "immune surveillance", but there has been no simple way to test this concept. Insofar as we can now clone the fossil record, we can study whether patients with cancer have made antibodies with specificities unique to cancer cells and whether such antibodies can influence the outcome of the host-tumor encounter.To test these ideas, we took advantage of studies in our laboratory that...

Metastasis is the main cause of death in cancer patients, and understanding mechanisms that control tumor cell dissemination may lead to improved therapy. Tumor cell adhesion receptors contribute to cancer spreading. We noted earlier that tumor cells can expressing the adhesion receptor integrin αvβ3 in distinct states of activation, and found that cells which metastasize from the blood stream express it in a constitutively high affinity form. Here, we analyzed steps of the metastatic cascade in vivo and asked, when and how the affinity state of integrin αvβ3 confers a critical advantage to cancer spreading. Following tumor cells by real time PCR, non-invasive bioluminescence imaging, intravital microscopy and histology allowed us to identify tumor cell extravasation from the blood stream as a rate-limiting step supported by high affinity αvβ3. Successful transendothelial migration depended on cooperation between tumor cells and platelets involving the high affinity tumor cell integrin and release of platelet granules. Thus, this study identifies the high affinity conformer of integrin αvβ3 and its interaction with platelets as critical for early steps during hematogenous metastasis and target for prevention of metastatic disease.

A B S T R A C T PurposeTo determine the dose of cetuximab that can be safely combined with irinotecan for treatment of pediatric and adolescent patients with refractory solid tumors. Patients and MethodsThis open-label, phase I study enrolled patients ages 1 to 18 years with advanced refractory solid tumors, including tumors of the CNS. Patient cohorts by age group (children, ages 1 to 12 years; adolescents, ages 13 to 18 years) received escalating weekly doses of cetuximab (75, 150, 250 mg/m 2 ) in a 3 ϩ 3 design, plus irinotecan (16 or 20 mg/m 2 /d) for 5 days for 2 consecutive weeks every 21 days. The primary end points were establishing the maximum-tolerated dose (MTD), recommended phase II dose (RPIID), and pharmacokinetics of the combination. Preliminary safety and efficacy data were also collected. ResultsTwenty-seven children and 19 adolescents received a median of 7.1 and 6.0 weeks of cetuximab therapy, respectively. Cetuximab 250 mg/m 2 weekly plus irinotecan 16 mg/m 2 /d (pediatric) or 20 mg/m 2 /d (adolescent) have been established as the MTD/RPIID. Dose-limiting toxicities included diarrhea and neutropenia. Mild to moderate (grade 1 to 2) acneiform rash occurred in a majority of patients; no grade 3 to 4 rashes were observed. Cetuximab demonstrated dose-dependent clearance in both children and adolescents, similar to that in adults. There were two confirmed partial responses, both in patients with CNS tumors. Stable disease was achieved in 18 patients overall, including 10 patients with CNS tumors (38.5%). ConclusionThe cetuximab/irinotecan combination can be given safely to children and adolescents with cancer. Promising activity, particularly in CNS tumors, warrants phase II evaluation of this regimen.