Angiogenesis inhibitors in the treatment of small cell and non-small cell lung cancer

Therapies in the pipeline for small-cell lung cancer

INTRODUCTION OR BACKGROUND

Small-cell lung cancer (SCLC) represents ~15% of all cases of lung cancer and is characterized by a rapid tumour doubling time, early onset disease dissemination and high sensitivity to chemotherapy.

SOURCES OF DATA

We searched MEDLINE and OVID databases for articles in English published from January 1980 to February 2015.

AREAS OF AGREEMENT

Platinum-based chemotherapy, thoracic radiotherapy and prophylactic cranial irradiation are standard of care. Benefit from second-line chemotherapy is limited.

AREAS OF CONTROVERSY

The role of platinum/irinotecan chemotherapy in the Western population and the role of maintenance therapies remain to be established.

GROWING POINTS

Knowledge of the biology of SCLC has expanded exponentially and many potential therapeutic targets have been identified.

AREAS TIMELY FOR DEVELOPING RESEARCH

The use of circulating tumour cells can help investigating molecular alterations occurring within tumour cells, understanding drug resistance mechanisms and evaluating new treatments.

Targeted therapies in small cell lung cancer: a review

Small cell lung cancer (SCLC) is an aggressive form of lung cancer that is characterized by a rapid doubling time, early onset of dissemination and high sensitivity to chemotherapy. Despite the potential for cure in patients with limited disease with concurrent chemoradiation and an initial good response to chemotherapy in extensive disease, there is a high chance of disease relapse with an overall poor median survival for both stages. With increasing translational research and a better understanding of the molecular basis of cancer, a number of molecular targets have been identified in various preclinical studies. This review summarizes potentially viable targets and new agents that have been developed and employed in recent, ongoing and future clinical trials to attempt to improve clinical outcomes in this disease.

Antiangiogenic effect of inhibitors of cytochrome P450 on rats with glioblastoma multiforme

Cytochrome P450 epoxygenase catalyzes 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) from arachidonic acid (AA). In 1996, our group identified the expression of the cytochrome P450 2C11 epoxygenase (CYP epoxygenase) gene in astrocytes. Because of our finding an array of physiological functions have been attributed to EETs in the brain, one of the actions of EETs involves a predominant role in brain angiogenesis. Blockade of EETs formation with different epoxygenase inhibitors decreases endothelial tube formation in cocultures of astrocytes and capillary endothelial cells. The intent of this investigation was to determine if pharmacologic inhibition of formation of EETs is effective in reducing capillary formation in glioblastoma multiforme with a concomitant reduction in tumor volume and increase in animal survival time. Two mechanistically different inhibitors of CYP epoxygenase, 17-octadecynoic acid (17-ODYA) and miconazole, significantly reduced capillary formation and tumor size in glial tumors formed by injection of rat glioma 2 (RG2) cells, also resulting in an increased animal survival time. However, we observed that 17-ODYA and miconazole did not inhibit the formation of EETs in tumor tissue. This implies that 17-ODYA and miconazole appear to exert their antitumorogenic function by a different mechanism that needs to be explored.

Fast, hungry and unstable: finding the Achilles' heel of small-cell lung cancer

Over 95% of patients with small-cell lung cancer (SCLC) die within five years of diagnosis. The standard of care and the dismal prognosis for this disease have not changed significantly over the past 25 years. Some of the characteristics of SCLC that have defined it as a particularly virulent form of cancer -- rapid proliferation, excessive metabolic and angiogenic dependence, apoptotic imbalance and genetic instability -- are now being pursued as tumor-specific targets for intervention both in preclinical and early phase clinical studies. Here, we summarize areas of ongoing anti-cancer drug development, including classes of agents that target essential pathways regulating proliferation, angiogenesis, apoptotic resistance, chromosomal and protein stability, and cell-cell and cell-matrix interaction.

Multifocal lymphangioendotheliomatosis with thrombocytopenia: a rare cause of gastrointestinal bleeding in the newborn period

Severe gastrointestinal bleeding in the newborn period is a serious but uncommon phenomenon that has a broad differential diagnosis. In the following case report we describe a rare phenomenon in which a newborn presents with severe hematemesis, hematochezia, and thrombocytopenia that are resistant to repeated platelet and packed red blood cell transfusions. Previous cases have been reported, but none of the patients described presented within the first 8 days of life. The early age of presentation and refractory nature of this disease entity to multiple therapies make it a diagnostic and therapeutic dilemma for all physicians involved in the care of newborns.

Analysis of orthologous gene expression between human pulmonary adenocarcinoma and a carcinogen-induced murine model

Human adenocarcinoma (AC) is the most frequently diagnosed human lung cancer, and its absolute incidence is increasing dramatically. Compared to human lung AC, the A/J mouse-urethane model exhibits similar histological appearance and molecular changes. We examined the gene expression profiles of human and murine lung tissues (normal or AC) and compared the two species' datasets after aligning approximately 7500 orthologous genes. A list of 409 gene classifiers (P value <0.0001), common to both species (joint classifiers), showed significant, positive correlation in expression levels between the two species. A number of previously reported expression changes were recapitulated in both species, such as changes in glycolytic enzymes and cell-cycle proteins. Unexpectedly, joint classifiers in angiogenesis were uniformly down-regulated in tumor tissues. The eicosanoid pathway enzymes prostacyclin synthase (PGIS) and inducible prostaglandin E(2) synthase (PGES) were joint classifiers that showed opposite effects in lung AC (PGIS down-regulated; PGES up-regulated). Finally, tissue microarrays identified the same protein expression pattern for PGIS and PGES in 108 different non-small cell lung cancer biopsies, and the detection of PGIS had statistically significant prognostic value in patient survival. Thus, the A/J mouse-urethane model reflects significant molecular details of human lung AC, and comparison of changes in orthologous gene expression may provide novel insights into lung carcinogenesis.

Perspectives on novel therapies for bronchial carcinoma

Improvements in conventional cytotoxic treatment have probably reached a plateau for the treatment of lung cancer; therefore, new treatment strategies that are based on a better understanding of tumour biology are required. Some progress has been made for non-small cell lung cancer, in which erlotinib (Tarceva, OSI-774; Genentech), an epidermal growth factor receptor antagonist, has demonstrated a significant clinical benefit in a Phase III randomised trial, and has been licensed for second- or third-line treatment. Other therapies under investigation include angiogenesis inhibitors, COX-2 inhibitors, retinoids, farnesyl transferase inhibitors, Bcl-2 inhibitors and c-Kit antagonists. In this article the recent and ongoing Phase II and III trials of these therapies in lung cancer are summarised, and the prospects for their further clinical development are discussed.