R. Taylor Ripley

Mithramycin Represses Basal and Cigarette Smoke-Induced Expression of ABCG2 and Inhibits Stem Cell Signaling in Lung and Esophageal Cancer Cells

Cigarette smoking at diagnosis or during therapy correlates with poor outcome in patients with lung and esophageal cancers, yet the underlying mechanisms remain unknown. In this study, we observed that exposure of esophageal cancer cells to cigarette smoke condensate (CSC) led to upregulation of the xenobiotic pump ABCG2, which is expressed in cancer stem cells and confers treatment resistance in lung and esophageal carcinomas. Furthermore, CSC increased the side population of lung cancer cells containing cancer stem cells. Upregulation of ABCG2 coincided with increased occupancy of aryl hydrocarbon receptor, Sp1, and Nrf2 within the ABCG2 promoter, and deletion of xenobiotic response elements and/or Sp1 sites markedly attenuated ABCG2 induction. Under conditions potentially achievable in clinical settings, mithramycin diminished basal as well as CSC-mediated increases in AhR, Sp1, and Nrf2 levels within the ABCG2 promoter, markedly downregulated ABCG2, and inhibited proliferation and tumorigenicity of lung and esophageal cancer cells. Microarray analyses revealed that mithramycin targeted multiple stem cell-related pathways in vitro and in vivo. Collectively, our findings provide a potential mechanistic link between smoking status and outcome of patients with lung and esophageal cancers, and support clinical use of mithramycin for repressing ABCG2 and inhibiting stem cell signaling in thoracic malignancies.

Polycomb Repressor Complex-2 is a Novel Target for Mesothelioma Therapy

Purpose: Polycomb group (PcG) proteins are critical epigenetic mediators of stem cell pluripotency, which have been implicated in the pathogenesis of human cancers. This study was undertaken to examine the frequency and clinical relevance of PcG protein expression in malignant pleural mesotheliomas (MPM). Experimental Design: Microarray, quantitative reverse transcriptase PCR (qRT-PCR), immunoblot, and immunohistochemistry techniques were used to examine PcG protein expression in cultured MPM, mesothelioma specimens, and normal mesothelial cells. Lentiviral short hairpin RNA techniques were used to inhibit EZH2 and EED expression in MPM cells. Proliferation, migration, clonogenicity, and tumorigenicity of MPM cells either exhibiting knockdown of EZH2 or EED, or exposed to 3-deazaneplanocin A (DZNep), and respective controls were assessed by cell count, scratch and soft agar assays, and murine xenograft experiments. Microarray and qRT-PCR techniques were used to examine gene expression profiles mediated by knockdown of EZH2 or EED, or DZNep. Results: EZH2 and EED, which encode components of polycomb repressor complex-2 (PRC-2), were overexpressed in MPM lines relative to normal mesothelial cells. EZH2 was overexpressed in approximately 85% of MPMs compared with normal pleura, correlating with diminished patient survival. Overexpression of EZH2 coincided with decreased levels of miR-101 and miR-26a. Knockdown of EZH2 orEED, or DZNep treatment, decreased global H3K27Me3 levels, and significantly inhibited proliferation, migration, clonogenicity, and tumorigenicity of MPM cells. Common as well as differential gene expression profiles were observed following knockdown of PRC-2 members or DZNep treatment. Conclusions: Pharmacologic inhibition of PRC-2 expression/activity is a novel strategy for mesothelioma therapy. Clin Cancer Res; 18(1); 77–90. ©2011 AACR.

Operative management for recurrent and metastatic adrenocortical carcinoma

A review of all resections for recurrent or metastatic ACC was performed to identify patients who might benefit from a surgical approach, and to identify factors that might aid in prognosis among patients with metastatic disease.

Pulmonary Resection for Metastatic Adrenocortical Carcinoma: The National Cancer Institute Experience

BACKGROUND Adrenocortical carcinoma (ACC) is a rare neoplasm with a high propensity for locoregional recurrences and distant metastases for which there are no effective systemic therapies. This study was undertaken to determine outcomes of patients undergoing pulmonary metastasectomy for ACC. METHODS A single-institution retrospective review was performed of patients undergoing pulmonary metastasectomy for ACC from 1979 to 2010. RESULTS Twenty-six patients underwent 60 pulmonary metastasectomies. Fifteen patients (58%) underwent unilateral thoracotomy, 6 (23%) had staged thoracotomies, and 5 (19%) underwent median sternotomy as the initial thoracic procedure. Median number and size of lesions were 6 and 2 cm, respectively. Twenty-three patients (88%) were rendered free of disease in the lung, and 14 (54%) were rendered completely free of disease. Median overall and 5-year actuarial survivals from initial pulmonary metastasectomy were 40 months and 41%, respectively, with a median potential follow-up of 120 months. Median recurrence-free survival (RFS) and 5-year RFS for ipsilateral thoracic recurrences were 6 months, and 25%, respectively. The median RFS in the contralateral thorax was 5 months. Time to first recurrence after adrenalectomy and T stage of the primary tumor, but not adjuvant or neoadjuvant chemotherapy, were associated with increased overall survival after pulmonary metastasectomy. CONCLUSIONS This study represents the most comprehensive review of outcomes of patients undergoing pulmonary metastasectomy for ACC. Given the lack of effective systemic therapies, pulmonary metastasectomy may be beneficial in properly selected patients.

Pulmonary Resection for Metastatic Gastric Cancer

Introduction: Sixteen percent of patients with gastric cancer will develop pulmonary metastases. Standard of care for these patients is systemic chemotherapy with a median survival of 6 months and a 5-year survival of only 2%. Our aim was to critically evaluate the published data on pulmonary resection for metastatic gastric cancer (MGC) and to analyze the potential rationale for surgical management to determine which patients may benefit from this approach. Methods: The Pubmed and SCOPUS databases were queried for all studies reporting on pulmonary resections for MGC. All available clinicopathologic data were analyzed. Results: Twenty-one studies from 1975 to 2008 reported 48 pulmonary resections in 43 patients including five repeat resections and four extrapulmonary metastasectomies. Eighty-two percent (34/43) of patients had solitary lesions with a median size of 24 mm (4–90 mm). Median time from gastrectomy to pulmonary resection was 35 months (0–120 months). At a median follow-up of 23 months, 15 of 43 (35%) patients were alive without disease, and two patients died without disease. Median survival was 29 months (3–84 months) after pulmonary metastasectomy and 65 months (5–180 months) after gastrectomy. Fifty-six percent (24/43) of patients had another recurrence at a median of 12 months (range: 6–48 months) after resection including 30% (13/43) of patients with pulmonary recurrences. Overall 5-year survival was 33%. Conclusions: Pulmonary metastasectomy for MGC can potentially result in long-term survival in a highly selected group of patients and should be considered for those who present with small, isolated lesions after a prolonged disease-free interval.

Liver Directed Therapy for Renal Cell Carcinoma

Background: Metastatic renal cell carcinoma (RCC) to the liver portrays a poor prognosis and liver directed therapy remains controversial. We aimed to determine potential selection criteria for patients who might benefit from this strategy. Materials and Methods: We evaluated 247 consecutive patients with RCC metastatic to the liver from a prospectively maintained database. Results: Eighteen patients received liver directed therapy (18/247, 7%). Ten patients underwent liver resection (10/247, 4%) and eight patients underwent radiofrequency ablation (RFA, 8/247, 3%). All were rendered free of disease in the liver. Five had synchronous liver disease and underwent synchronous resections with their primary. Mortality was 0%. Fourteen had single (surgery 7, RFA 7) and four (surgery 3, RFA 1) had multiple liver lesions, respectively. Median size of lesions was 5cm (0.5 - 10cm) and 2.5cm (1 - 6cm) in the surgery and RFA groups, respectively. Median DFI was 10 months, and no difference was observed in those with a longer vs. shorter than median DFI (p = 0.95); liver specific progression free survival for the surgery and RFA groups were 4 and 6 months, respectively (p= 0.93). 1, 3 and 5-year actuarial survivals for the whole group were 89%, 40%, 27%. Median survival for the surgery group was 24 (3 to 254+) months, and for the RFA group 15.6 (7-56+) months (p = 0.56). Metachronous liver disease was associated with prolonged survival (p = 0.02). Conclusions: Liver directed therapy for RCC is safe. For highly selected patients with metachronous liver RCC metastases, liver directed therapy should be considered in a multidisciplinary manner.

Liver Resection for Metastatic Melanoma with Postoperative Tumor-Infiltrating Lymphocyte Therapy

BackgroundPatients with metastatic melanoma to the liver (MML) have a median survival of 4 to 6 months. This study evaluated patients who underwent liver resection with intent to receive postoperative tumor-infiltrating lymphocyte (TIL) therapy.MethodsRetrospective analysis of a prospective database identified patients with MML who underwent liver resection from 1980 to 2008.ResultsA total of 539 patients had MML, and 39% (204 of 539) had tumor collected for TIL. A total of 17% (35 of 204) underwent liver resection for TIL. The 3-year overall survival was 53%. Lack of extrahepatic disease (P = .026), negative margin (P = .056), and single hepatic metastasis (P = .04) predicted survival after univariate analysis. Only lack of extrahepatic disease remained a significant predictor of survival after multivariate analysis (P = .043). A total of 31% (11 of 35) underwent complete resection without TIL, and 69% (24 of 35) underwent resection with synchronous intrahepatic and extrahepatic disease with intent to receive TIL. For 9 of 11 patients (2 of 11 excluded for gene therapy), 3-year survival was 80%. A total of 4 (44%) of 9 experienced recurrence, with a median disease-free survival of 1.2 years. For 24 patients (69%) with residual disease, 3-year survival was 51% (2 of 24 excluded for gene therapy). A total of 63% (15 of 24) received postoperative TIL (3-year survival 65%), and 29% (7 of 24) did not. A total of 40% (6 of 15) had disease that partially responded to TIL; the disease of 67% (4 of 6) had not progressed at median follow-up of 55 months (range, 42–197+ months). The seven patients who did not receive TIL had a median survival of 4.6 months.ConclusionsResection of MML with TIL should be considered because it can result in prolonged survival in a highly selected group of patients.

Regional Chemotherapy in Locally Advanced Pancreatic Cancer: RECLAP Trial

BackgroundPancreatic cancer is the fourth leading cause of cancer death in the United States. Surgery offers the only chance for cure. However, less than twenty percent of patients are considered operative candidates at the time of diagnosis. A common reason for being classified as unresectable is advanced loco-regional disease.A review of the literature indicates that almost nine hundred patients with pancreatic cancer have received regional chemotherapy in the last 15 years. Phase I studies have shown regional administration of chemotherapy to be safe. The average reported response rate was approximately 26%. The average 1-year survival was 39%, with an average median survival of 9 months. Of the patients that experienced a radiographic response to therapy, 78 (78/277, 28%) patients underwent exploratory surgery following regional chemotherapy administration; thirty-two (41%) of those patients were amenable to pancreatectomy. None of the studies performed analyses to identify factors predicting response to regional chemotherapy.Progressive surgical techniques combined with current neoadjuvant chemoradiotherapy strategies have already yielded emerging support for a multimodality approach to treatment of advanced pancreatic cancer.Intravenous gemcitabine is the current standard treatment of pancreatic cancer. However, >90% of the drug is secreted unchanged affecting toxicity but not the cancer per se. Gemcitabine is converted inside the cell into its active drug form in a rate limiting reaction. We hypothesize that neoadjuvant regional chemotherapy with continuous infusion of gemcitabine will be well tolerated and may improve resectability rates in cases of locally advanced pancreatic cancer.DesignThis is a phase I study designed to evaluate the feasibility and toxicity of super-selective intra-arterial administration of gemcitabine in patients with locally advanced, unresectable pancreatic adenocarcinoma. Patients considered unresectable due to locally advanced pancreatic cancer will receive super-selective arterial infusion of gemcitabine over 24 hours via subcutaneous indwelling port. Three to six patients will be enrolled per dose cohort, with seven cohorts, plus an additional six patients at the maximum tolerated dose; accrual is expected to last 36 months. Secondary objectives will include the determination of progression free and overall survival, as well as the conversion rate from unresectable to potentially resectable pancreatic cancer.Trial RegistrationClinicalTrials.gov ID: NCT01294358

Expanding surgical treatment of pancreatic cancer: the role of regional chemotherapy.

Objectives Pancreatic cancer is a lethal disease that offers little chance of long-term survival for patients with unresectable tumors. Surgery remains the most effective means of attaining prolonged survival, yet its role remains limited. Regional chemotherapy has been described for patients with pancreatic cancer, including reports of objective tumor regression allowing for tumor resection in previously unresectable cases. However, comprehensive data have not been reviewed to date. Methods A review of the literature from 1995 to 2010 was performed to analyze the results of regional chemotherapy administered to patients with advanced pancreatic cancer. Reports of individual cases, postoperative regional therapy, and treatment of mixed tumor types were excluded. Results Twenty-one reports of 895 total patients with pancreatic cancer were reviewed. Greater than 95% of the patients had stage III or IV adenocarcinoma. Objective response rates ranged from nil to 58%, with associated median survivals of 4 to 22 months. Low-grade gastrointestinal and hematologic toxicities were not uncommon. Conclusions Regional chemotherapy can be administered safely to patients with pancreatic cancer but with unclear benefit. Advanced pancreatic tumors converted to resectable status by the use of regional chemotherapy may improve patient survival.

Paraneoplastic granulocytosis in metastatic melanoma

Paraneoplastic syndromes are an uncommon, yet well-described, phenomenon in cancer patients. The syndrome of granulocytosis caused by granulocyte colony-stimulating factor (G-CSF) production by tumors is rare and is difficult to diagnose in patients receiving treatment for metastatic disease. From January 2005 to May 2009, 626 patients were evaluated for treatment of metastatic melanoma. At initial evaluation or during the course of treatment, six patients had an elevated white blood cell count and no evidence of infection. All six had significantly elevated serum G-CSF. The level of serum G-CSF was directly correlated with the absolute neutrophil count. In-vitro assay of melanoma tumor from two patients showed elevated G-CSF in cell culture supernatant. The paraneoplastic syndrome of granulocytosis resulting from ectopic G-CSF production in patients with metastatic melanoma is rare. This diagnosis should be considered when common causes of granulocytosis have been ruled out.