The cholesterol biosynthesis enzyme FAXDC2 couples Wnt/ß-catenin to RTK/MAPK signaling.

Wnts, cholesterol, and MAPK signaling are essential for development and adult homeostasis. Here, we report that fatty acid hydroxylase domain containing 2 (FAXDC2), a previously uncharacterized enzyme, functions as a methyl sterol oxidase catalyzing C4 demethylation in the Kandutsch-Russell branch of the cholesterol biosynthesis pathway. FAXDC2, a paralog of MSMO1, regulated the abundance of the specific C4-methyl sterols lophenol and dihydro-T-MAS. Highlighting its clinical relevance, FAXDC2 was repressed in Wnt/ß-catenin-high cancer xenografts, in a mouse genetic model of Wnt activation, and in human colorectal cancers. Moreover, in primary human colorectal cancers, the sterol lophenol, regulated by FAXDC2, accumulated in the cancerous tissues and not in adjacent normal tissues. FAXDC2 linked Wnts to RTK/MAPK signaling. Wnt inhibition drove increased recycling of RTKs and activation of the MAPK pathway, and this required FAXDC2. Blocking Wnt signaling in Wnt-high cancers caused both differentiation and senescence; and this was prevented by knockout of FAXDC2. Our data show the integration of 3 ancient pathways, Wnts, cholesterol synthesis, and RTK/MAPK signaling, in cellular proliferation and differentiation.

Current advances in targeted therapy for metastatic colorectal cancer - Clinical translation and future directions.

The last two decades have witnessed major breakthroughs in the development of targeted therapy for patients with metastatic colorectal cancer (mCRC), an achievement which stems largely from advances in translational research. Precision medicine is now widely practiced in routine oncological care, where systemic therapy is individualized based on clinical factors such as primary tumor sidedness, location and number of metastases, as well as molecular factors such as the RAS and BRAF mutation status, mismatch repair / microsatellite status and presence of other actionable genomic alterations in the tumor. The optimal selection of patients with RAS and BRAF-wild type (WT), left-sided primary tumor for treatment with epidermal growth factor receptor (EGFR) and chemotherapy (chemo) has markedly improved survival in the first-line setting. The pivotal trials of cetuximab in combination with BRAF/ MEK inhibitor for BRAF V600E mutant mCRC, and panitumumab with KRAS G12C inhibitor in KRAS(G12C)-mutant mCRC have been practice-changing. Anti-HER2 small molecular inhibitor, antibodies and antibody-drug conjugates have significantly improved the treatment outcome of patients with HER2 amplified mCRC. Anti-angiogenesis agents are now used across all lines of treatment and novel combinations with immune-checkpoint inhibitors are under active investigation in MSS mCRC. The non-invasive monitoring of molecular resistance to targeted therapies using Next Generation Sequencing analysis of circulating tumor-derived DNA (ctDNA) and captured sequencing of tumors have improved patient selection for targeted therapies. This review will focus on how latest advances, challenges and future directions in the development of targeted therapies in mCRC.

Bioengineered hydrogels enhance ex vivo preservation of patient-derived tumor explants for drug evaluation.

Ex vivo patient-derived tumor slices (PDTS) are currently limited by short-term viability in culture. Here, we show how bioengineered hydrogels enable the identification of key matrix parameters that significantly enhance PDTS viability compared to conventional culture systems. As demonstrated using single-cell RNA sequencing and high-dimensional flow cytometry, hydrogel-embedded PDTS tightly preserved cancer, cancer-associated fibroblast, and various immune cell populations and subpopulations in the corresponding original tumor. Cell-cell communication networks within the tumor microenvironment, including immune checkpoint ligand-receptor interactions, were also maintained. Remarkably, our results from a co-clinical trial suggest hydrogel-embedded PDTS may predict sensitivity to immune checkpoint inhibitors (ICIs) in head and neck cancer patients. Further, we show how these longer term-cultured tumor explants uniquely enable the sampling and detection of temporal evolution in molecular readouts when treated with ICIs. By preserving the compositional heterogeneity and complexity of patient tumors, hydrogel-embedded PDTS provide a valuable tool to facilitate experiments targeting the tumor microenvironment.

Inferring cancer disease response from radiology reports using large language models with data augmentation and prompting.

OBJECTIVE: To assess large language models on their ability to accurately infer cancer disease response from free-text radiology reports. MATERIALS AND METHODS: We assembled 10 602 computed tomography reports from cancer patients seen at a single institution. All reports were classified into: no evidence of disease, partial response, stable disease, or progressive disease. We applied transformer models, a bidirectional long short-term memory model, a convolutional neural network model, and conventional machine learning methods to this task. Data augmentation using sentence permutation with consistency loss as well as prompt-based fine-tuning were used on the best-performing models. Models were validated on a hold-out test set and an external validation set based on Response Evaluation Criteria in Solid Tumors (RECIST) classifications. RESULTS: The best-performing model was the GatorTron transformer which achieved an accuracy of 0.8916 on the test set and 0.8919 on the RECIST validation set. Data augmentation further improved the accuracy to 0.8976. Prompt-based fine-tuning did not further improve accuracy but was able to reduce the number of training reports to 500 while still achieving good performance. DISCUSSION: These models could be used by researchers to derive progression-free survival in large datasets. It may also serve as a decision support tool by providing clinicians an automated second opinion of disease response. CONCLUSIONS: Large clinical language models demonstrate potential to infer cancer disease response from radiology reports at scale. Data augmentation techniques are useful to further improve performance. Prompt-based fine-tuning can significantly reduce the size of the training dataset.

The distinct clinical trajectory, metastatic sites, and immunobiology of microsatellite-instability-high cancers.

Microsatellite-instability-high (MSI-H) cancers form a spectrum of solid organ tumors collectively known as Lynch Syndrome cancers, occurring not only in a subset of colorectal, endometrial, small bowel, gastric, pancreatic, and biliary tract cancers but also in prostate, breast, bladder, and thyroid cancers. Patients with Lynch Syndrome harbor germline mutations in mismatch repair genes, with a high degree of genomic instability, leading to somatic hypermutations and, therefore, oncogenesis and cancer progression. MSI-H cancers have unique clinicopathological characteristics compared to their microsatellite-stable (MSS) counterparts, marked by a higher neoantigen load, immune cell infiltration, and a marked clinical response to immune checkpoint blockade. Patients with known Lynch Syndrome may be detected early through surveillance, but some patients present with disseminated metastatic disease. The treatment landscape of MSI-H cancers, especially colorectal cancers, has undergone a paradigm shift and remains to be defined, with immune checkpoint blockade coming to the forefront of treatment strategies in the stage IV setting. We summarize in this review the clinical features of MSI-H cancers with a specific interest in the pattern of spread or recurrence, disease trajectory, and treatment strategies. We also summarize the tumor-immune landscape and genomic profile of MSI-H cancers and potential novel therapeutic strategies.

Recommended testing algorithms for NTRK gene fusions in pediatric and selected adult cancers: Consensus of a Singapore Task Force.

The occurrence of neurotrophic tyrosine receptor kinase (NTRK) gene fusions in a wide range of tumor types presents an attractive opportunity for using a tropomyosin receptor kinase (TRK) inhibitor as cancer therapy. Recent clinical studies have demonstrated highly efficacious outcomes associated with the use of TRK inhibitors, such as larotrectinib and entrectinib in NTRK fusion-bearing cancers, in both adult and pediatric populations. While NTRK gene fusions are commonly found in some uncommon adult and pediatric malignancies, they are also found, albeit rarely, in a wide range of more common malignancies. The potential value of testing for NTRK gene fusions in practically all advanced malignancies is underpinned by the remarkable therapeutic outcomes that TRK inhibitors offer. This requirement presents practical and financial challenges in real-world oncological practice. Furthermore, different testing platforms exist to detect NTRK gene fusions, each with its advantages and disadvantages. It is, therefore, imperative to develop strategies for NTRK gene fusion testing in an attempt to optimize the use of limited tissue specimen and financial resources, and to minimize the turnaround time. A multidisciplinary task force of Singapore medical experts in both public and private sectors was convened in late 2020 to propose testing algorithms for adult colorectal tumors, sarcomas, non-small cell lung cancer, and pediatric cancers, with particular adaptation to the Singapore oncological practice. The recommendations presented here highlight the heterogeneity of NTRK-fusion positive cancers, and emphasize the need to customize the testing methods to each tumor type to optimize the workflow.

Molecular docking-aided identification of small molecule inhibitors targeting ß-catenin-TCF4 interaction.

Here we report a molecular docking-based approach to identify small molecules that can target the ß-catenin (ß-cat)-TCF4 protein-protein interaction (PPI), a key effector complex for nuclear Wnt signaling activity. Specifically, we developed and optimized a computational model of ß-cat using publicly available ß-cat protein crystal structures, and existing ß-cat-TCF4 interaction inhibitors as the training set. Using our computational model to an in silico screen predicted 27 compounds as good binders to ß-cat, of which 3 were identified to be effective against a Wnt-responsive luciferase reporter. In vitro functional validation experiments revealed GB1874 as an inhibitor of the Wnt pathway that targets the ß-cat-TCF4 PPI. GB1874 also affected the proliferation and stemness of Wnt-addicted colorectal cancer (CRC) cells in vitro. Encouragingly, GB1874 inhibited the growth of CRC tumor xenografts in vivo, thus demonstrating its potential for further development into therapeutics against Wnt-associated cancer indications.

DUSP16 promotes cancer chemoresistance through regulation of mitochondria-mediated cell death.

Drug resistance is a major obstacle to the treatment of most human tumors. In this study, we find that dual-specificity phosphatase 16 (DUSP16) regulates resistance to chemotherapy in nasopharyngeal carcinoma, colorectal cancer, gastric and breast cancer. Cancer cells expressing higher DUSP16 are intrinsically more resistant to chemotherapy-induced cell death than cells with lower DUSP16 expression. Overexpression of DUSP16 in cancer cells leads to increased resistance to cell death upon chemotherapy treatment. In contrast, knockdown of DUSP16 in cancer cells increases their sensitivity to treatment. Mechanistically, DUSP16 inhibits JNK and p38 activation, thereby reducing BAX accumulation in mitochondria to reduce apoptosis. Analysis of patient survival in head & neck cancer and breast cancer patient cohorts supports DUSP16 as a marker for sensitivity to chemotherapy and therapeutic outcome. This study therefore identifies DUSP16 as a prognostic marker for the efficacy of chemotherapy, and as a therapeutic target for overcoming chemoresistance in cancer.

CD30+OX40+ Treg is associated with improved overall survival in colorectal cancer.

Regulatory T cells (Tregs) are often enriched in tumors, where their immunosuppressive function has a key role in tumor persistence and progression. In colorectal cancer (CRC), however, Tregs are frequently associated with an improved clinical outcome. Tumor-infiltrating Tregs have been shown to exhibit a distinct signature comprising the co-stimulatory molecules (OX40, 4-1BB), cytokine receptors (IL1R2, IL21R, CCR8, CD30), and co-inhibitory molecules (PD-L1, TIGIT). Here, we showed by flow cytometry that circulating CD45RO+ Tregs from patients with CRC (n = 25) have elevated CD30 and OX40 expression compared to healthy subjects (n = 14). We identified co-expression of CD30 and OX40 on circulating CD45RO+ Tregs using single-cell images captured by the DEPArray™ system. The frequency of CD30+OX40+CD45RO+ Tregs was significantly higher in CRC patients than in healthy subjects (P < 0.001). Importantly, receiver operating characteristic analysis confirmed that this CD30+OX40+ Treg subset could strongly discriminate between CRC patients and healthy subjects with the highest accuracy of 92.3%, an AUC of 0.92, a sensitivity of 88%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 82.35%, and a trade-off value of 3.44%, compared to other Treg subsets. Consistently, multiplex-IHC/IF of tumor-infiltrating Tregs revealed a significant association between high densities of CD30+OX40+ Tregs and improved overall survival; no such association was found for other subsets. These data suggest a potential role for CD30+OX40+ Tregs as a diagnostic or prognostic biomarker in CRC.

Lineage-dependent gene expression programs influence the immune landscape of colorectal cancer.

Immunotherapy for metastatic colorectal cancer is effective only for mismatch repair-deficient tumors with high microsatellite instability that demonstrate immune infiltration, suggesting that tumor cells can determine their immune microenvironment. To understand this cross-talk, we analyzed the transcriptome of 91,103 unsorted single cells from 23 Korean and 6 Belgian patients. Cancer cells displayed transcriptional features reminiscent of normal differentiation programs, and genetic alterations that apparently fostered immunosuppressive microenvironments directed by regulatory T cells, myofibroblasts and myeloid cells. Intercellular network reconstruction supported the association between cancer cell signatures and specific stromal or immune cell populations. Our collective view of the cellular landscape and intercellular interactions in colorectal cancer provide mechanistic information for the design of efficient immuno-oncology treatment strategies.

Recommendations to improve the clinical adoption of NGS-based cancer diagnostics in Singapore.

Next-generation sequencing (NGS)-based diagnostics have demonstrated clinical utility in predicting improved survival benefits with targeted treatment in certain cancer types, and positive cost-benefit in several healthcare systems. However, clinical adoption in Singapore remains low despite commercial availability of these diagnostics. This expert opinion review examines the key challenges to the clinical adoption of NGS-based diagnostics in Singapore, provides recommendations on impactful initiatives to improve adoption, and also offers practical guidance on specific cancer types in which NGS-based diagnostics are appropriate for use in Singapore. Limited patient affordability is one major challenge to clinical adoption of NGS-based diagnostics, which could be improved by enabling patient access to more funds for specific cancer types with clear benefits. Expert opinion based on current evidence and clinical experience supports the upfront use of hotspot panels in advanced non-small cell lung cancer (NSCLC), metastatic colorectal cancer, advanced and recurrent ovarian cancer, and acute myeloid leukemia. Comprehensive genomic profiling could be considered for upfront use in select patients with NSCLC and ovarian cancer, or in refractory patients with the four cancer types. Wider adoption of NGS-based diagnostics will improve the delivery of cancer care in Singapore and Asia-Pacific, and thus lead to better patient outcomes.

What is the value of third-line chemotherapy in advanced gastroesophageal cancer? A 5-year retrospective analysis at a single center.

AIM: The survival benefit of using a non-cross resistant second-line chemotherapy in the third-line setting in metastatic gastroesophageal cancer is unproven. We evaluated the utility of third-line chemotherapy in patients treated at a single institution. METHODS: Between 2010 and 2014, efficacy and toxicity data of patients who received three or more lines of systemic therapies for metastatic gastroesophageal adenocarcinoma at the National Cancer Centre Singapore was retrospectively analyzed. RESULTS: Thirty-two (6%) patients received three or more lines of chemotherapy. The median age and ECOG performance status were 59 years (36-82) and 1 (0-2), respectively. Majority of patients (88%) had tumor located in the stomach and 13 patients (41%) had diffuse histology or poorly cohesive or signet ring cells. Four (12%) patients had HER2-positive disease. Prior therapy was platinum (100%), fluoropyrimidine (97%), taxane (63%), irinotecan (28%), anthracycline (13%) and ramucirumab (3%). Third-line therapy consisted of 24 (75%) monotherapy, 6 (19%) doublet, 1 (3%) triplet chemotherapy and 1 (3%) clinical trial. Monotherapy irinotecan (44%) was most common, followed by docetaxel (19%) and paclitaxel (9%). Of 22 patients evaluable for response, there was 1 (5%) partial response, 9 (41%) stable disease. Median overall survival was 18.3 weeks (4.3-65.1). Of 30 patients evaluable for toxicities, 17 (57%) experienced at least one grade 3 or 4 toxicities. CONCLUSION: The benefit of using non-cross resistant second-line regimens as third-line chemotherapy was small with moderate toxicity. Newer agents such as nivolumab or TAS-102 or clinical trial may be preferred.

PRL3-zumab as an immunotherapy to inhibit tumors expressing PRL3 oncoprotein.

Tumor-specific antibody drugs can serve as cancer therapy with minimal side effects. A humanized antibody, PRL3-zumab, specifically binds to an intracellular oncogenic phosphatase PRL3, which is frequently expressed in several cancers. Here we show that PRL3-zumab specifically inhibits PRL3+ cancer cells in vivo, but not in vitro. PRL3 antigens are detected on the cell surface and outer exosomal membranes, implying an 'inside-out' externalization of PRL3. PRL3-zumab binds to surface PRL3 in a manner consistent with that in classical antibody-dependent cell-mediated cytotoxicity or antibody-dependent cellular phagocytosis tumor elimination pathways, as PRL3-zumab requires an intact Fc region and host FcγII/III receptor engagement to recruit B cells, NK cells and macrophages to PRL3+ tumor microenvironments. PRL3 is overexpressed in 80.6% of 151 fresh-frozen tumor samples across 11 common cancers examined, but not in patient-matched normal tissues, thereby implicating PRL3 as a tumor-associated antigen. Targeting externalized PRL3 antigens with PRL3-zumab may represent a feasible approach for anti-tumor immunotherapy.

Real-Time Tumor Gene Expression Profiling to Direct Gastric Cancer Chemotherapy: Proof-of-Concept "3G" Trial.

Purpose: The oxaliplatin plus S-1 and cisplatin plus S-1 regimens are interchangeably used in the management of advanced gastric cancer. The previously reported G-intestinal (G1) and G-diffuse (G2) intrinsic gene expression signatures showed promise for stratifying patients according to their tumor sensitivity to oxaliplatin or cisplatin.Experimental Design: The proof-of-concept, multicenter, open-label phase II "3G" trial was done to prospectively evaluate the feasibility and efficacy of using genomic classifiers to tailor treatment in gastric cancer. Patients' tumors were classified as "G1" or "G2" using a nearest-prediction template method, or "G3" (unclear assignment) when FDR ≥ 0.05. The first 30 patients in the "G1" cohort were assigned oxaliplatin plus S-1 (SOX) chemotherapy; thereafter, subsequently recruited "G1" patients were treated with cisplatin plus S-1 (SP) chemotherapy. "G2" patients and "G3" patients were treated with SP and SOX chemotherapy, respectively.Results: A total of 48, 21, and 12 patients, respectively, were given "G1," "G2," and "G3" genomic assignments. Median turnaround time was 7 days (IQR, 5-9). Response rates were 44.8%, 8.3%, 26.7%, and 55.6% for the "G1-SOX," "G1-SP," "G2," "G3" cohorts, respectively; and was higher in G1 patients treated with SOX compared with SP (P = 0.033). Exploratory analyses using the genomic classifier of Lei and colleagues validated the utility of the metabolic signature as a biomarker for predicting benefit from chemotherapy (log-rank P = 0.004 for PFS), whereas the Asian Cancer Research Group classifier did not demonstrate any predictive value.Conclusions: This bench-to-bedside effort establishes a reasonable turnaround time for gene expression profiling and possible utility of genomic classifiers in gastric cancer treatment stratification. Clin Cancer Res; 24(21); 5272-81. ©2018 AACR.

Germline Pathogenic Variants in Homologous Recombination and DNA Repair Genes in an Asian Cohort of Young-Onset Colorectal Cancer.

BACKGROUND: Growing evidence suggests a role for cancer susceptibility genes such as BRCA2 and PALB2 in young-onset colorectal cancers. Using a cohort of young colorectal cancer patients, we sought to identify and provide functional evidence for germline pathogenic variants of DNA repair genes not typically associated with colorectal cancer. METHODS: We recruited 88 patients with young-onset colorectal cancers seen at a general oncology center. Whole-exome sequencing was performed to identify variants in DNA repair and colorectal cancer predisposition genes. Pathogenic BRCA2 and PALB2 variants were analyzed using immunoblot and immunofluorescence on patient-derived lymphoblastoid cells. RESULTS: In general, our cohort displayed characteristic features of young-onset colorectal cancers. Most patients had left-sided tumors and were diagnosed at late stages. Four patients had familial adenomatous polyposis, as well as pathogenic APC variants. We identified 12 pathogenic variants evenly distributed between DNA repair and colorectal cancer predisposition genes. Six patients had pathogenic variants in colorectal cancer genes: APC (n = 4) and MUTYH monoallelic (n = 2). Another six had pathogenic variants in DNA repair genes: ATM (n = 1), BRCA2 (n = 1), PALB2 (n = 1), NTHL1 (n = 1), and WRN (n = 2). Pathogenic variants BRCA2 c.9154C>T and PALB2 c.1059delA showed deficient homologous recombination repair, evident from the impaired RAD51 nuclear localization and foci formation. CONCLUSION: A substantial portion of pathogenic variants in young-onset colorectal cancer was found in DNA repair genes not previously associated with colorectal cancer. This may have implications for the management of patients. Further studies are needed to ascertain the enrichment of pathogenic DNA repair gene variants in colorectal cancers.

Evaluation of Long-Term Outcomes of Microsatellite Instability Status in an Asian Cohort of Sporadic Colorectal Cancers.

PURPOSE: Microsatellite instability in colorectal cancer (CRC) and its long-term outcomes remains poorly studied in Asians. We investigate the prognostic significance of microsatellite instability in an Asian population and assess its clinical impact in patients who undergo adjuvant chemotherapy. METHODS: Six hundred fifty-four consecutive CRC patients who underwent surgical resection between January 2010 and December 2012 were recruited. Survival was estimated using the Kaplan-Meier approach. Univariate Cox proportional hazard models were used to estimate the hazard ratios for variables associated with survival. A subgroup analyses was performed for stage III patients who underwent chemotherapy to evaluate the prognostic significance of microsatellite instability in this group. RESULTS: Five hundred ninety-one (90.4%) patients were microsatellite stable (MSS) while 63 (9.6%) were microsatellite instable (MSI). Three years recurrence-free survival (RFS) and disease-specific survival (DSS) were 83.7 versus 73.7% (p = 0.295) and 87.1 versus 91.2% (p = 0.307) in MSS and MSI tumors, respectively. Among stage III patients who received adjuvant therapy, MSI status was found to be an adverse prognostic factor for RFS (HR 2.74 (95% CI 1.43-5.26), p = 0.002). This remained significant on multivariate analysis (HR 2.38 (95% CI 1.15-4.93), p = 0.018). Adjuvant chemotherapy was associated with survival benefit for patients with MSS tumors (HR 0.35, 95% CI 0.17-0.69, p = 0.002) but not MSI tumors (HR 0.67, 95% CI 0.08-8.15, p = 0.750). CONCLUSIONS: MSI status is not a prognostic indicator in the general CRC population but appears to be an adverse prognostic indicator for RFS in stage III CRC patients who received adjuvant chemotherapy.

VHL Deficiency Drives Enhancer Activation of Oncogenes in Clear Cell Renal Cell Carcinoma.

Protein-coding mutations in clear cell renal cell carcinoma (ccRCC) have been extensively characterized, frequently involving inactivation of the von Hippel-Lindau (VHL) tumor suppressor. Roles for noncoding cis-regulatory aberrations in ccRCC tumorigenesis, however, remain unclear. Analyzing 10 primary tumor/normal pairs and 9 cell lines across 79 chromatin profiles, we observed pervasive enhancer malfunction in ccRCC, with cognate enhancer-target genes associated with tissue-specific aspects of malignancy. Superenhancer profiling identified ZNF395 as a ccRCC-specific and VHL-regulated master regulator whose depletion causes near-complete tumor elimination in vitro and in vivoVHL loss predominantly drives enhancer/superenhancer deregulation more so than promoters, with acquisition of active enhancer marks (H3K27ac, H3K4me1) near ccRCC hallmark genes. Mechanistically, VHL loss stabilizes HIF2α-HIF1ß heterodimer binding at enhancers, subsequently recruiting histone acetyltransferase p300 without overtly affecting preexisting promoter-enhancer interactions. Subtype-specific driver mutations such as VHL may thus propagate unique pathogenic dependencies in ccRCC by modulating epigenomic landscapes and cancer gene expression.Significance: Comprehensive epigenomic profiling of ccRCC establishes a compendium of somatically altered cis-regulatory elements, uncovering new potential targets including ZNF395, a ccRCC master regulator. Loss of VHL, a ccRCC signature event, causes pervasive enhancer malfunction, with binding of enhancer-centric HIF2α and recruitment of histone acetyltransferase p300 at preexisting lineage-specific promoter-enhancer complexes. Cancer Discov; 7(11); 1284-305. ©2017 AACR.See related commentary by Ricketts and Linehan, p. 1221This article is highlighted in the In This Issue feature, p. 1201.

Metronomic vinorelbine (oral) in combination with sorafenib in advanced non-small cell lung cancer.

BACKGROUND: To date, biomarkers to predict benefit from anti-angiogenic therapy are still lacking. Sorafenib and metronomic oral vinorelbine combination was studied and changes in blood and DCE-MRI parameters were investigated as biomarkers for benefit. MATERIAL AND METHODS: Patients with advanced NSCLC were recruited to 3 successive cohorts. Each cohort was given a fixed metronomic (3 times a week) dose of oral vinorelbine at 60 mg/week, 90 mg/week, or 120 mg/week respectively. Within each cohort, patients received a starting dose of sorafenib at 200mg bid for 4 weeks. In the absence of dose-limiting toxicities, each patient's dose of sorafenib was escalated to 400mg bid for 4 weeks, 600 mg bid for 4 weeks and finally 800 mg bid. Biomarkers measured include DCE-MRI parameters, circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPs), and plasma thrombospondin (TSP-1). RESULTS: 48 evaluable patients were analyzed. There were 4 (8.9%) patients with partial response (PR) and 7 (15.2%) with cavitary response (CaR). Two subpopulations of CECs (CEC(hi), CEC(lo)) were identified that trended in opposite directions during treatment, with CEC(hi) demonstrating an upward trend in contrast to CEC(lo). Higher baseline CEC(hi) and lower baseline blood flow (F) and fractional intravascular blood volume (V1) predicted for response. Multivariate analysis revealed a lower baseline V1, and dynamic changes of CEC during treatment (CEC increase, sum of CEC(hi) and CEC(lo)) predicted for improved survival. CONCLUSIONS: Sorafenib and metronomic oral vinorelbine is active in advanced NSCLC. Baseline levels and changes in DCE parameters and CEC may be useful predictive biomarkers.