Immunocytochemical detection of tumor necrosis factor-alpha in infiltrating tumor cells in the cerebrospinal fluid from five patients with leptomeningeal carcinomatosis

Evaluation of apoptosis in cytologic specimens

A hallmark of neoplasia is dysregulated apoptosis, programmed cell death. Apoptosis is crucial for normal tissue homeostasis. Dysregulation of apoptotic pathways leads to reduced cytocidal responses to chemotherapeutic drugs or radiation and is a frequent contributor to therapeutic resistance in cancer. The literature pertaining to detection of apoptotic pathway constituents in cytologic specimens is reviewed herein. Virtually all methods for detecting apoptosis, including classic cytomorphologic evaluation, TUNEL assay, immunocytochemistry, and gene sequence analysis, may be applied to cytologic samples as well as tissue. Components of both intrinsic and extrinsic apoptotic pathways have been studied, including many reports examining p53 and bcl-2, as well as studies of caspase inhibitory proteins XIAP and survivin, death receptors and ligands such as Fas, Fas-ligand, and TRAIL. p53 undergoes oncogenic alteration more than any other protein; its immunocytochemical detection almost always connotes loss of its physiologic role as an inducer of apoptosis in response to a damaged genome. Several reports establish cytologic sampling as being as useful as tissue sampling. In one respect cytologic sampling is superior to tissue sampling in particular, by allowing clinicians to repeat sampling of the same tumor before and after administration of therapy; a number of reports use this approach to attempt to predict tumor response by assaying the effect of chemotherapy on the induction of apoptosis.

Leptomeningeal metastases from solid tumors (meningeal carcinomatosis)

Leptomeningeal metastases (LM) are increasingly recognized as a devastating complication of solid tumors. Improved treatment of primary malignancy and advances in diagnostic imaging have led to an apparent increase in the number of patients diagnosed with LM. Unfortunately, therapeutic options remain limited. Radiotherapy is used to treat bulky tumor and provide symptomatic relief. Intrathecal chemotherapy benefits a selected subset of patients. The challenge to the future is to delineate the molecular mechanisms underlying LM and to develop novel therapeutic or prophylactic modalities to combat LM.

Meningeal carcinomatosis as the initial manifestation of a gallbladder adenocarcinoma associated with a Krukenberg tumor

A case of malignant neoplasm is described in which the initial manifestations were mental dysfunction and meningeal irritation, mimicking chronic or subacute meningitis. Physical examination showed cranial nerve involvement and a pelvic tumor. There was progressive deterioration, and death occurred in 2 weeks. The autopsy revealed a gallbladder adenocarcinoma, meningeal carcinomatosis, and ovarian metastasis presenting as a Krukenberg tumor. The authors emphasize the importance of including meningeal carcinomatosis as a possibility in the differential diagnosis of non-characteristic clinical pictures, as well as the importance of the cerebrospinal fluid cytologic examination, repeated as needed, in order to confirm this diagnosis.

Leptomeningeal metastases

LM is an increasingly common neurologic complication of cancer with variable clinical manifestations. Although there are no curative treatments, currently available therapies can preserve neurologic function and potentially improve quality of life. Further research into the mechanisms of leptomeningeal metastasis will elucidate molecular and cellular pathways that may allow identification of potential targets to interrupt this process early or to prevent this complication. Animal models are needed to further define the pathophysiology of LM and to provide an experimental system to test novel treatments [242-245]. There is an urgent need to develop new drug-based or radiation-based treatments for patients with LM. Randomized clinical trials are the appropriate study design to determine the efficacy of new treatments for LM. However, surrogate markers for response must be developed to facilitate the identification of effective regimens. Survival is not the optimal end point for such studies as most patients who develop this complication already have advanced, incurable cancer. Prevention of or delay in neurologic progression is one objective that has been utilized in recent randomized trials in patients with LM, and this end point deserves further attention. Although the development of LM represents a poor prognostic marker in patients with cancer it is important for physicians to recognize the symptoms and signs of the disease and establish the diagnosis as early in the disease course as possible. This may provide an opportunity for effective intervention that can improve quality of life, prevent further neurologic deterioration and, for a subset of patients, improve survival.

Vascular cell adhesion molecule-1 is a key adhesion molecule in melanoma cell adhesion to the leptomeninges

Leptomeningeal metastases occur in up to 8% of patients with systemic malignancies and have a poor prognosis. A better understanding of the pathophysiologic processes underlying leptomeningeal metastases is needed for more effective treatment strategies. We hypothesized that tumor cells will have to adhere to the well-vascularized leptomeninges, because the cerebrospinal fluid lacks nutrients and growth factors for efficient tumor cell proliferation. Specific receptor-ligand interactions, which are unknown until now, will mediate this adhesion process. We determined the growth characteristics of B16F-10 melanoma cells in cerebrospinal fluid. The expression levels of specific adhesion molecules on both mouse leptomeningeal cells (MLMC) and murine B16F-10 melanoma cells were measured by immunofluorescence flow cytometry. We used mAbs to determine the function of these specific adhesion molecules on B16F-10 melanoma cell adhesion to a leptomeningeal cell layer under static and (cerebrospinal fluid-like) flow conditions. B16F-10 melanoma cells did not proliferate in cerebrospinal fluid because of a lack of nutrients and growth factors. MLMC expressed low levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), beta1- and beta3-integrin subunits, and CD44. VCAM-1 expression on MLMC was shown to be up-regulated by TNF-alpha. Blocking VCAM-1 on the MLMC with a mAb resulted in a 60% inhibition of melanoma cell adhesion to a leptomeningeal cell layer under flow but not under static conditions. No additive inhibitory effect on melanoma cell adhesion was found by concomitant blocking of the beta1- and beta3-integrin subunits and CD44 with mAbs. Our experiments indicate that cerebrospinal fluid does not support B16F-10 melanoma cell proliferation, suggesting the need for melanoma cell adhesion to the well-vascularized leptomeninges. VCAM-1, expressed on MLMC, is an important mediator of in vitro melanoma cell adhesion under (cerebrospinal fluid-like) flow conditions.

Carcinoma-associated collagen type III and type IV immune localization and Ito cell transformation indicate tumor-related changes in sinusoids of the human liver

The deterioration of extracellular matrix turnover is a key event in tumor progression. It has been assumed that Ito cell transformation is stimulated by tumor-derived factors. In the present study changes in the occurrence of collagen type III and IV and Ito cell transformation are described in the sinusoids of patients with malignant gastrointestinal tumors without liver metastases, and around metastatic liver tumors using routine histology, electron microscopy as well as light microscopical and ultrastructural immunohistochemistry. Dilated sinusoids filled with lymphoid cells and variable perisinusoidal fibrosis were detected light microscopically. Collagen type III and IV immune deposits were increased perisinusoidally. Ultrastructural immunohistochemistry showed increased staining in the space of Disse and around Ito and transitional cells for both types of collagen. Ito cells were transformed into transitional cells. Pit cells appeared in the inflammatory infiltrate in sinusoids. Ito cells were significantly increased in number pericentrally and periportally. It is suggested that stimuli, which can influence Ito cellular behaviour are produced by inflammatory cells in sinusoids, resident sinusoidal cells, tumor cells or by tumor stroma. It is concluded that transformed Ito cells and increased amounts of collagen type III and IV in sinusoids of patients with malignant tumors without liver metastases or around metastatic tumors may predict tumor-related alterations of liver parenchyma, which may serve as a barrier for further outgrowths of the cancer cells.