Metastatic Progression In Patients Research Articles

Transformation of adenocarcinoma into small cell lung cancer as one of the mechanisms of acquired resistance to anti-EGFR tyrosine kinase inhibitors

Transformation of adenocarcinoma into small cell lung cancer (SCLC) is a rare and unique biological property of a cancer cell that is responsible for the mechanism of acquired resistance to EGFR tyrosine kinase inhibitors. There are very few clinical observations of phenotypic cellular transformation during metastatic progression of lung cancer in the literature. The aim of the work is to demonstrate clinical observation of phenotypic transformation of metastatic EGFR-mutated adenocarcinoma into small cell lung cancer with neuroendocrine differentiation during therapy with tyrosine kinase inhibitors. Case report. Due to the rarity of this biological phenomenon, we describe our own observation of the transformation of EGFR-mutated metastatic adenocarcinoma into DCLC with neuroendocrine differentiation, which occurred in a 42-year-old woman during treatment with gefitinib. Conclusions. Transformation and changes in cell phenotype during tyrosine kinase inhibitor therapy were the cause of resistance and failure of further treatment with osimertinib in the second line. It was concluded that it is necessary to consider this mechanism of resistance in clinical practice and to perform repeat biopsies during metastatic progression in patients with EGFR-mutated lung adenocarcinoma.

Abstract 2757: Investigating regulatory drivers of prostate cancer metastasis in circulating tumor cells

Abstract Prostate cancer is the most common cancer in men and the second-leading cause of death. Most prostate cancer deaths are due to metastasis, particularly to the bone. Metastasis occurs when cells from the primary tumor travel through the blood as circulating tumor cells (CTCs) and settle in metastatic sites. CTCs are difficult to collect from patients, and understanding the relationships between CTCs and the tumor phenotypes of origin could reveal mechanisms of cancer metastasis. Hence, we utilized several genetically engineered mouse models (GEMMs) of metastatic prostate cancer to evaluate tumor phenotypes and CTCs. We compared the tumor phenotypes of several GEMMs of metastatic prostate cancer and identified a level of heterogeneity among tumors, particularly focusing on a GEMM that demonstrated severe metastasis, especially to the bone. Next, we analyzed CTCs from this GEMM and focused our analysis on transcriptional states that are regulated by proteins called master regulators (MRs). MRs control the expression of groups of genes called regulons, and pharmacologically inhibiting these MRs may lead to reversal of cancer phenotypes. We hypothesized that these MRs may be mechanistic drivers of CTC cell state in prostate cancer metastasis. We investigated MRs enriched in CTCs from mice and screened and validated Lap2, the lamina-associated polypeptide 2 protein, as a regulatory driver in mice with metastatic prostate cancer. Analysis of bulk RNA-seq profiles from primary and metastatic prostate samples in The Cancer Genome Atlas and Stand Up to Cancer cohorts, respectively, revealed that the regulon-based activity of Lap2 was significantly higher in the latter group. Moreover, analysis of single-cell RNA-seq profiles of CTCs isolated from prostate cancer patients confirmed aberrant Lap2 activity. Finally, the role of Lap2 was assessed in human tissue from an engineered multi-organ-on-a-chip model of metastasis. Silencing of Lap2 production in cells dissociated from mouse CTC-derived organoids inhibited extravasation to the bone in the model, suggesting a critical role for Lap2 in metastasis. Our findings illustrate the unique transcriptional profile of prostate cancer CTCs associated with their metastatic potential. We identified Lap2 as a novel driver of CTC dissemination and metastasis in mice and validated its activity in human prostate cancer, which can aid future therapies to prevent metastatic progression in patients. Citation Format: Aunika Zheng, Aleksandar Obradovic, Kacey Ronaldson-Bouchard, Gordana Vunjak-Novakovic, Andrea Califano, Peter A. Sims, Cory Abate-Shen, Arianna Giacobbe. Investigating regulatory drivers of prostate cancer metastasis in circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2757.

Convolutional Neural Network Classification of Pretreatment Biopsies of Rectal Adenocarcinoma Predicts Complete Clinical Response to Short-Course Radiation and Consolidation Chemotherapy

<h3>Purpose/Objective(s)</h3> Nonoperative treatment of rectal cancer (RCa) with short course radiation (SCRT) (25 Gy in 5 fractions) followed by chemotherapy results in high treatment efficacy while maintaining rectal function. Identifying patients likely to experience a complete response to nonoperative management could prevent overtreatment with chemotherapy and reduce the risk of metastatic progression for incomplete responders. We constructed a convolutional neural network (CNN) classifier of pre-treatment histopathological images to identify patients who will experience a complete response to SCRT and consolidation chemotherapy. <h3>Materials/Methods</h3> Image files of hematoxylin and eosin-stained pre-treatment rectal adenocarcinoma biopsies (n=15) were acquired using the Zeiss microscopy software suite. Files were segmented using grid tools in the ZEN software package. Grid images comprised largely of whitespace were manually removed. Grid images were exported to .jpeg format, preserving micron scale pixel resolution. This analysis utilized 32 .jpeg images belonging to complete responders and 37 .jpeg images belonging to partial responders as the basis for data augmentation to generate a more robust training cohort. We employed the architecture and weights of the well-known VGG16 model with fine tuning of the later layers of the model during training. Regularization, dropout, and early stopping were implemented to prevent overfitting. <h3>Results</h3> Utilizing the VGG16 model with frozen nodal weights resulted in poor classification accuracy and failure to improve via monitoring loss function (training accuracy: 0.3152, validation accuracy: 0.33). Unfreezing, or pruning, after the 7th layer of the VGG16 model and allowing fine tuning of the transferred architecture improved this approach. Later network architectural layers are hypothesized to represent the most sophisticated image features. When nodal weights in VGG16's later layers were allowed to be updated based on training from histopathological slide images the classifiers accuracy improved (training accuracy: 0.9457, validation accuracy: 0.944). Further, loss function was reliably minimized (Epoch 10 validation set binary cross-entropy loss: 0.610, Epoch 50 validation set binary cross-entropy loss: 0.0648). <h3>Conclusion</h3> This is the first study to utilize imaging features extracted by a CNN to predict biological behavior or responsiveness to therapy in rectal cancer. We demonstrated that a transfer learning and layer pruning approach outperforms classical transfer learning utilizing previously deeply trained architectures. While future studies to refine and validate this CNN classifier are warranted, deep learning methods can play a role in preventing overtreatment vs metastatic progression in patients receiving SCRT for RCa.

A0311 - Adverse pathology and metastatic progression in patients treated by focal HIFU for unilateral localized prostate cancer: Results at mid-term follow-up in a series of 96 patients

A0311 - Adverse pathology and metastatic progression in patients treated by focal HIFU for unilateral localized prostate cancer: Results at mid-term follow-up in a series of 96 patients

Antizyme Inhibitor 1 Regulates Matrikine Expression and Enhances the Metastatic Potential of Aggressive Primary Prostate Cancer.

AZIN1 was identified as driver of metastatic progression in high-risk prostate cancer through matrikine regulation.

Abstract 1850: Role of microRNAs in circulating tumor cells glutamine metabolism pathways

Abstract Circulating tumor cells (CTCs) has an important role in the spread of cancers and metastasis. CTCs are believed to be the most promising model to understand metastatic progression in patients with cancer. Glutamine, an alternative carbon source to glucose, has recently been shown to be important for the cancer cell survival, growth and progression. The role of glutamine metabolism in CTCs is not known. MicroRNAs (miRNAs) are a group of highly conserved noncoding RNAs and approximately 22 nucleotides in length. Here, we postulate that CTCs have unique microRNAs (miRNAs) expression compared to resident tumor cells. And miRNAs control CTC glutamine metabolism for the metastasis. In this study, we used 3 primary CTC cultures to study how miRNA controlling glutamine metabolism. We identified several miRNAs have high expressions in CTCs and these miRNAs are regulating glutamine metabolism in CTCs. Our results demonstrate the metabolic miRNA targets of CTCs on cancer progression. These insights will present a unique opportunity for diagnosing and treating cancer through CTCs. Note: This abstract was not presented at the meeting. Citation Format: Ziwen Zhu, Sarah N. Owen, Abhinav Achreja, Sunitha Nagrath, Deepak Nagrath. Role of microRNAs in circulating tumor cells glutamine metabolism pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1850.

Abstract 3114: In vitro culture system for circulating tumor cell

Abstract Circulating tumor cells (CTCs) detection could be considered a real-time “liquid biopsy” approach and contains several advantages such as being minimally invasive, easy and safe to perform, multiple samples can be taken over time, better prognosis to indicate an elevated risk of metastases, improved therapy monitoring, and providing live disease status information. CTC analysis is a promising new diagnostic field for estimating the risk for metastatic relapse and metastatic progression in patients with cancer. However, the number of CTCs is very low so the establishment of cell culture from CTCs becomes the most challenging over the past year. In this study, we development a cost-effective and reproducible in vitro system for primary CTC cultures or established cell lines from CTCs. 8 CTC cell lines were generated from patients including breast cancer, small cell lung cancer, pancreatic cancer and expanded for more than one year. These cell lines exhibit the tissue-specific markers and also correlated with clinical treatment response from patients. This system provides an opportunity for broad applications of CTCs for personalized oncology and advancing precision medicine. Citation Format: Chen Yin-Ju, Long-Sheng Lu, Hsin-Lun Lee, Lai-Lei Ting, Jeng-Fong Chiou. In vitro culture system for circulating tumor cell [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3114.

LIF Drives Neural Remodeling in Pancreatic Cancer and Offers a New Candidate Biomarker.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive stroma and pathogenic modifications to the peripheral nervous system that elevate metastatic capacity. In this study, we show that the IL6-related stem cell-promoting factor LIF supports PDAC-associated neural remodeling (PANR). LIF was overexpressed in tumor tissue compared with healthy pancreas, but its receptors LIFR and gp130 were expressed only in intratumoral nerves. Cancer cells and stromal cells in PDAC tissues both expressed LIF, but only stromal cells could secrete it. Biological investigations showed that LIF promoted the differentiation of glial nerve sheath Schwann cells and induced their migration by activating JAK/STAT3/AKT signaling. LIF also induced neuronal plasticity in dorsal root ganglia neurons by increasing the number of neurites and the soma area. Notably, injection of LIF-blocking antibody into PDAC-bearing mice reduced intratumoral nerve density, supporting a critical role for LIF function in PANR. In serum from human PDAC patients and mouse models of PDAC, we found that LIF titers positively correlated with intratumoral nerve density. Taken together, our findings suggest LIF as a candidate serum biomarker and diagnostic tool and a possible therapeutic target for limiting the impact of PANR in PDAC pathophysiology and metastatic progression.Significance: This study suggests a target to limit neural remodeling in pancreatic cancer, which contributes to poorer quality of life and heightened metastatic progression in patients. Cancer Res; 78(4); 909-21. ©2017 AACR.

Coexistence of sarcoidosis and metastatic lesions: A diagnostic and therapeutic dilemma.

Sarcoidosis, a chronic, inflammatory disease that affects various different organs, is characterized by noncaseating epitheloid granulomas. This systemic inflammatory process is associated with an increased risk of cancer. Several cases of sarcoidosis that mimic metastatic tumor progression in radiological findings have been reported so far. However, there are also cases that have presented a coexistence of sarcoidosis and metastasis, which have caused a diagnostic and therapeutic dilemma. Due to inadequate current therapies, a reliable differentiation between benign and malignant lesions is crucial. This review focuses on the residual risk of the coexistence of metastases within radiological suspicious lesions in patients with a history of solid tumors and sarcoidosis, as well as immunological findings, in order to explain the potential associations. Sarcoidosis has the potential to promote metastasis as it includes tumor-promoting and immune-regulating cell subsets. Notably, myeloid derived suppressor cells may serve a pivotal role in metastatic progression in patients with sarcoidosis. In addition, the present review also evaluates the potential novel diagnostic approaches, which may be able to differentiate between metastatic lesions and sarcoidosis. The risk of coexistent metastasis in sarcoidosis lesions must be considered by clinical practitioners, and a multidisciplinary approach may be required to avoid misdiagnosis and the subsequent unnecessary surgery or insufficient treatments.

Testes-specific protease 50 promotes cell invasion and metastasis by increasing NF-kappaB-dependent matrix metalloproteinase-9 expression.

The high mortality in breast cancer is often associated with metastatic progression in patients. Previously we have demonstrated that testes-specific protease 50 (TSP50), an oncogene overexpressed in breast cancer samples, could promote cell proliferation and tumorigenesis. However, whether TSP50 also has a key role in cell invasion and cancer metastasis, and the mechanism underlying the process are still unclear. Here we found that TSP50 overexpression greatly promoted cell migration, invasion, adhesion and formation of the stellate structures in 3D culture system in vitro as well as lung metastasis in vivo. Conversely, TSP50 knockdown caused the opposite changes. Mechanistic studies revealed that NF-κB signaling pathway was required for TSP50-induced cell migration and metastasis, and further results indicated that TSP50 overexpression enhanced expression and secretion of MMP9, a target gene of NF-κB signaling. In addition, knockdown of MMP9 resulted in inhibition of cell migration and invasion in vitro and lung metastasis in vivo. Most importantly, immunohistochemical staining of human breast cancer samples strongly showed that the coexpression of TSP50 and p65 as well as TSP50 and MMP9 were correlated with increased metastasis and poor survival. Furthermore, we found that some breast cancer diagnosis-associated features such as tumor size, tumor grade, estrogen receptors (ER) and progesterone receptors (PR) levels, were correlated well with TSP50/p65 and TSP50/MMP9 expression status. Taken together, this work identified the TSP50 activation of MMP9 as a novel signaling mechanism underlying human breast cancer invasion and metastasis.

Thymoquinone restores radiation-induced TGF-β expression and abrogates EMT in chemoradiotherapy of breast cancer cells.

Radiotherapy remains a prime approach to adjuvant therapies in patients with early and advanced breast cancer. In spite of therapeutic success, metastatic progression in patients undergoing therapy, limits its application. However, effective therapeutic strategies to understand the cellular and molecular machinery in inhibiting radiation-induced metastatic progression, which is poorly understood so far, need to be strengthened. Ionizing radiation was known to prompt cancer cell's metastatic ability by eliciting Transforming Growth Factor-beta (TGF-β), a key regulator in epithelial-mesenchymal transdifferentiation and radio-resistance. In this viewpoint, we employed thymoquinone as a radiosensitizer to investigate its migration and invasion reversal abilities in irradiated breast cancer cell lines by assessing their respective attributes. The role of metastasis regulatory molecules like TGF-β, E-cadherin, and integrin αV and its downstream molecules were determined using RT-PCR, western blotting, immunofluorescence, and extracellular TGF-β levels affirmed through ELISA assays. These studies affirmed the TGF-β restoring ability of thymoquinone in radiation-driven migration and invasion. Also, results demonstrated that the epithelial markers E-cadherin and cytokeratin 19 were downregulated whereas mesenchymal markers like integrin αV, MMP9, and MMP2 were upregulated by irradiation treatment; however thymoquinone pre-sensitization has reverted the expression of these proteins back to control proteins expression. Here, paclitaxel was chosen as an apoptosis inducer in TGF-β restored cells and confirmed its cytotoxic effects in radiation alone and thymoquinone sensitized irradiated cells. We conclude that this therapeutic modality is effective in preventing radiation-induced epithelial-mesenchymal transdifferentiation and concomitant induction of apoptosis in breast cancer.

Current status of pharmacological treatment of colorectal cancer.

To review the clinical trials for the development in drugs for chemotherapeutic treatment of colorectal cancer (CRC). A systematic review identified randomized controlled trials (RCTs) assessing drugs for the treatment of CRC or adenomatous polyps from www.clinicaltrials.gov. Various online medical databases were searched for relevant publications. Combination treatment regimens of standard drugs with newer agents have been shown to improve overall survival, disease-free survival, time to progression and quality of life compared to that with standard drugs alone in patients with advanced colorectal cancer. The FOLFOXIRI regimen has been associated with a significantly higher response rate, progression-free survival and overall survival compared to the FOLFIRI regimen. Oxaliplatin plus intravenous bolus fluorouracil and leucovorin has been shown to be superior for disease-free survival when compared to intravenous bolus fluorouracil and leucovorin. In addition, oxaliplatin regimens were more likely to result in successful surgical resections. First line treatment with cetuximab plus fluorouracil, leucovorin and irinotecan has been found to reduce the risk of metastatic progression in patients with epidermal growth factor receptor-positive colorectal cancer with unresectable metastases. The addition of bevacizumab has been shown to significantly increase overall and progression-free survival when given in combination with standard therapy.

Giant-cell tumor of bone, anti-RANKL therapy

Giant-cell tumor of bone (GCTB) is a rare osteolytic tumor of the bone. Although classified as a benign tumor, GCTB is characterized by local aggressiveness and risk of local recurrence. In addition, GTCB can in some cases lead to the development of so-called 'benign' chest metastases. Surgical resection by intralesional curettage with high-speed burring and polymethylmethacrylate cement is the standard treatment for resectable tumors. In cases of metastatic or unresectable disease (when planned surgical procedure is impossible or would result in severe morbidity), medical treatments such as cytotoxic chemotherapy or interferon-α have limited efficacy. Bisphosphonates have been proposed as a therapeutic option to reduce osteoclast activity. In bone, various pathological states may result from an imbalance in the RANK (receptor activator of nuclear factor kappa-B)/RANKL (receptor activator of nuclear factor kappa-B ligand)/OPG (osteoprotegerin) pathway. Involvement of the RANKL pathway in pathogenesis of GCTB was first proposed in 2000. Denosumab is a fully human monoclonal antibody that binds and inhibits RANKL, thereby preventing the activation of the RANK pathway. As it showed the possibility to counteract osteoclast activation in GCTB and prevent the known physiopathological role of RANKL, denosumab has been under evaluation in the clinic as a treatment for GCTB since 2005. Results of a first Phase II trial demonstrate the therapeutic potential of denosumab to inhibit progressive bone destruction and metastatic progression in patients with unsalvageable giant-cell tumor (GCT), and have also provided key insights into the biology of GCT. Denosumab is currently a therapeutic option for patients with unresectable GCTB but its place in the global therapeutic strategy has not yet been defined.

Correlation of SMAD4 mutational status and local or metastatic progression in patients with pancreatic cancer.

e14730 Background: Pancreatic cancer remains resistant to many key cytotoxic chemotherapeutic agents and novel targeted therapies. The molecular heterogeneity of this cancer may account for therapy failures to date, although the growing arsenal of novel targeted agents could translate into patient survival. A better understanding of the cellular and molecular features of advanced disease will afford new opportunities for investigation, therapeutic intervention and clinical management of patients afflicted with pancreatic cancer. Methods: This study examined the expression profiles of Smad4 in 45 samples of surgically resected pancreatic cancer. Of these 45 patients, 32 underwent pancreaticoduodenectomy. The clinicopathological parameters, the histologic features were determined and correlated to the stage at initial diagnosis, patterns of failure (locally advanced v metastatic disease) and the status SMAD4 genes. Results: Among the 45 patients, 40% of patients died with metastatic disease and 15 % died with locally advanced evolution. SMAD4 genetic status was determined in 25 patients and seems to be correlated with a high grade histologic features and progression to metastasis. Complementary data about correlation between the mutational status of SMAD4 and survival will be presented during congress. Conclusions: SMAD4 gene inactivation seems to be associated with poorer prognosis and disease progression. Prospective validation of SMAD4 as a predictive biomarker may personalize treatment strategies for patients with pancreatic cancer.

Circulating Tumor Cells in Breast Cancer: Detection Systems, Molecular Characterization, and Future Challenges

Background: Circulating tumor cell (CTC) analysis is a promising new diagnostic field for estimating the risk for metastatic relapse and metastatic progression in patients with cancer. Content: Different analytical systems for CTC isolation and detection have been developed as immunocytochemical and molecular assays, most including separation steps by size or biological characteristics, such as expression of epithelial- or cancer-specific markers. Recent technical advancements in CTC detection and characterization include methods based on multiplex reverse-transcription quantitative PCR and approaches based on imaging and microfilter and microchip devices. New areas of research are directed toward developing novel assays for CTC molecular characterization. QC is an important issue for CTC analysis, and standardization of micrometastatic cell detection and characterization methodologies is important for the incorporation of CTCs into prospective clinical trials to test their clinical utility. The molecular characterization of CTCs can provide important information on the molecular and biological nature of these cells, such as the status of hormone receptors and epidermal and other growth factor receptor family members, and indications of stem-cell characteristics. This information is important for the identification of therapeutic targets and resistance mechanisms in CTCs as well as for the stratification of patients and real-time monitoring of systemic therapies. Summary: CTC analysis can be used as a liquid biopsy approach for prognostic and predictive purposes in breast and other cancers. In this review we focus on state-of-the-art technology platforms for CTC isolation, imaging, and detection; QC of CTC analysis; and ongoing challenges for the molecular characterization of CTCs.

Circulating Tumor Cells in Breast Cancer: Detection Systems, Molecular Characterization, and Future Challenges

Circulating tumor cell (CTC) analysis is a promising new diagnostic field for estimating the risk for metastatic relapse and metastatic progression in patients with cancer. Different analytical systems for CTC isolation and detection have been developed as immunocytochemical and molecular assays, most including separation steps by size or biological characteristics, such as expression of epithelial- or cancer-specific markers. Recent technical advancements in CTC detection and characterization include methods based on multiplex reverse-transcription quantitative PCR and approaches based on imaging and microfilter and microchip devices. New areas of research are directed toward developing novel assays for CTC molecular characterization. QC is an important issue for CTC analysis, and standardization of micrometastatic cell detection and characterization methodologies is important for the incorporation of CTCs into prospective clinical trials to test their clinical utility. The molecular characterization of CTCs can provide important information on the molecular and biological nature of these cells, such as the status of hormone receptors and epidermal and other growth factor receptor family members, and indications of stem-cell characteristics. This information is important for the identification of therapeutic targets and resistance mechanisms in CTCs as well as for the stratification of patients and real-time monitoring of systemic therapies. CTC analysis can be used as a liquid biopsy approach for prognostic and predictive purposes in breast and other cancers. In this review we focus on state-of-the-art technology platforms for CTC isolation, imaging, and detection; QC of CTC analysis; and ongoing challenges for the molecular characterization of CTCs.

Relationships between levels of CXCR4 and VEGF and blood-borne metastasis and survival in patients with osteosarcoma

The present study was designed to determine whether the expression of chemokine receptor CXCR4 and vascular endothelial growth factor (VEGF) is correlated with the extent of metastasis and the survival of patients with osteosarcoma. Using tissue microarrays, we analyzed the expression of CXCR4 and VEGF in tumor tissues collected from 56 patients with osteosarcoma. A two-year follow-up was performed to evaluate tumor metastatic behavior and the overall survival of the patients. There was a significant correlation between the expression of CXCR4 and the expression of VEGF in tumor tissues of these patients (P = 0.002). Univariate analysis revealed that expression of these proteins was correlated with clinical stage, but not age, gender, or serum alkaline phosphatase levels. The patients with tumors expressing CXCR4 and VEGF had worse overall survival rates compared with the patients with tumors that did not express CXCR4 (P = 0.03) or VEGF (P = 0.04). These data indicate that CXCR4 and VEGF expression is highly correlated with metastatic progression in patients with osteosarcoma and had predictive value for the metastasis and survival of osteosarcoma patients.

P90 ribosomal S6 kinase 2 promotes invasion and metastasis of human head and neck squamous cell carcinoma cells

Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of human cancer and frequently metastasizes to LNs. Identifying metastasis-promoting factors is of immense clinical interest, as the prognosis for patients with even a single unilateral LN metastasis is extremely poor. Here, we report that p90 ribosomal S6 kinase 2 (RSK2) promotes human HNSCC cell invasion and metastasis. We determined that RSK2 was overexpressed and activated in highly invasive HNSCC cell lines compared with poorly invasive cell lines. Expression of RSK2 also correlated with metastatic progression in patients with HNSCC. Ectopic expression of RSK2 substantially enhanced the invasive capacity of HNSCC cells, while inhibition of RSK2 activity led to marked attenuation of invasion in vitro. Additionally, shRNA knockdown of RSK2 substantially reduced the invasive and metastatic potential of HNSCC cells in vitro and in vivo in a xenograft mouse model, respectively. Mechanistically, we determined that cAMP-responsive element-binding protein (CREB) and Hsp27 are phosphorylated and activated by RSK2 and are important for the RSK2-mediated invasive ability of HNSCC cells. Our findings suggest that RSK2 is involved in the prometastatic programming of HNSCC cells, through phosphorylation of proteins in a putative signaling network. Moreover, targeting RSK2 markedly attenuates in vitro invasion and in vivo metastasis of HNSCC cells, suggesting that RSK2 may represent a therapeutic target in the treatment of metastatic HNSCC.

KRAS Mutation Correlates With Accelerated Metastatic Progression in Patients With Colorectal Liver Metastases

Observational studies of patients with primary colorectal cancer have identified KRAS mutation as a marker of poor prognosis. To examine more directly whether KRAS mutations are associated with accelerated metastatic progression, we evaluated KRAS mutation as well as Ki-67 expression in patients with colorectal liver metastases not treated with cetuximab. KRAS mutation status was assessed in a series of resected or sampled colorectal liver metastases. In a subset of these tumors, Ki-67 antigen expression was assessed by immunohistochemical stains. Median follow-up after liver resection or biopsy was 2.3 years. KRAS mutation in the liver metastasis was detected in 27% of the 188 patients. High Ki-67 expression in the liver metastasis was identified in 62% of 124 patients analyzed. Both markers were associated with multiple liver metastases and shorter time interval to their detection. KRAS mutation and high Ki-67 expression were independent predictors of poor survival after colon resection (hazard ratio [HR] 1.9 [95% confidence interval (95% CI), 1.1-3.4], HR 2.6 [95% CI, 1.4-4.8], respectively). Tumors with high Ki-67 expression were less likely to be selected for liver resection, and KRAS mutation was independently associated with poor survival after liver resection (HR 2.4 [95% CI, 1.4-4.0]). KRAS mutation is associated with more rapid and aggressive metastatic behavior of colorectal liver metastases. These data suggest an important role for KRAS activation in colorectal cancer progression and support continued efforts to develop KRAS pathway inhibitors for this disease.

A Preoperative Nomogram for Disease Recurrence Following Radical Prostatectomy for Prostate Cancer

Background: Few published studies have combined clinical prognostic factors into risk profiles that can be used to predict the likelihood of recurrence or metastatic progression in patients following treatment of prostate cancer. We developed a nomogram that allows prediction of disease recurrence through use of preoperative clinical factors for patients with clinically localized prostate cancer who are candidates for treatment with a radical prostatectomy. Methods: By use of Cox proportional hazards regression analysis, we modeled the clinical data and disease follow-up for 983 men with clinically localized prostate cancer whom we intended to treat with a radical prostatectomy. Clinical data included pretreatment serum prostate-specific antigen levels, biopsy Gleason scores, and clinical stage. Treatment failure was recorded when there was clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on a separate sample of 168 men, also from our institution. Results: Treatment failure (i.e., cancer recurrence) was noted in 196 of the 983 men, and the patients without failure had a median follow-up of 30 months (range, 1-146 months). The 5-year probability of freedom from failure for the cohort was 73% (95% confidence interval = 69%-76%). The predictions from the nomogram appeared accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (i.e., comparison of the predicted probability with the actual outcome) of 0.79. Conclusions: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among men with clinically localized prostate cancer treated with radical prostatectomy.