Diffuse plane xanthoma: clinicopathologic study of 8 cases

We report a 17-year-old woman who had two synchronous solid and cystic tumors of the pancreas (SCTP) detected by abdominal echography and computed tomography. There was a 6 x 5 cm mass in the pancreatic body and a 3 x 3 cm mass in the tail, with the two lesions being separate. No distal metastases were detected. The resected tumors consisted of solid and cystic components and both were well demarcated with fibrous capsules. The larger tumor was predominantly solid and the smaller one was mostly hemorrhagic. On microscopy, the tumor cells were small, eosinophilic, and arranged, in part, like pseudorosettes. The tumor cells were immunohistochemically positive for alpha-1 antitrypsin, neuron-specific enolase, and synaptophysin. The final diagnosis was SCTP arising synchronously and independently at two sites. As far as we know, only one case of multicentric SCTP has been reported previously. Local recurrence of SCTP suggests the possibility of multicentric occurrence, and we believe that reports of such cases may increase in the future with advances in echography and computed tomography.     

Sex cord-stromal and steroid cell tumors of the ovary

Gonadal cell types that derive from the coelomic epithelium (sex cords) or mesenchymal cells of the embryonic gonads include granulosa cells, theca cells, fibroblasts, Leydig cells, and Sertoli cells. Ovarian tumors of these cell types are called sex cord-stromal tumors. This group of tumors represents approximately 8% of ovarian neoplasms and affects all age groups. The more common types are granulosa cell tumors (GCTs), fibrothecomas, and Sertoli-Leydig cell tumors. Sex cord-stromal tumors are of interest partly because of their hormonal effects, which are rare for other ovarian neoplasms. These effects include estrogenic effects (pseudoprecocious puberty, endometrial bleeding, endometrial hyperplasia and carcinoma) and virilization. The variety of gross appearances of these tumors, ranging from large multicystic masses to small solid masses, would appear to preclude a specific radiologic diagnosis. However, in many patients, both clinical and radiologic clues can suggest the diagnosis, including predominantly fibrous content at ultrasound or magnetic resonance imaging (fibrothecoma), large hemorrhagic multicystic mass in a child with pseudoprecocious puberty (juvenile GCT), and associated syndromes such as Peutz-Jeghers syndrome (sex cord tumor with annular tubules) or Ollier disease and Maffucci syndrome (juvenile GCT).     

Interleukin 2 expression by tumor cells alters both the immune response and the tumor microenvironment

Microenvironmental conditions within solid tumors can have marked effects on the growth of the tumors and their response to therapies. The disorganized growth of tumors and their attendant vascular systems tends to result in areas of the tumors that are deficient in oxygen (hypoxic). Cells within these hypoxic areas are more resistant to conventional therapies such as radiation and chemotherapy. Here, we examine the hypoxic state of EMT6 mouse mammary tumors and the location of host cells within the different areas of the tumors to determine whether such microenvironmental conditions might also affect their ability to be recognized by the immune system. Hypoxia within tumors was quantified by flow cytometry and visualized by immunohistochemistry using a monoclonal antibody (ELK3-51) against cellular adducts of 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetam ide (EF5), a nitroimidazole compound that binds selectively to hypoxic cells. Thy-1+ cells, quantified using a monoclonal antibody, were found only in the well-oxygenated areas. The location of these Thy-1+ cells was also examined in EMT6 tumors that had been transfected with the gene for interleukin-2 (IL-2) because these tumors contain greatly increased numbers of host cells. Surprisingly, we found that IL-2-transfected tumors had significantly decreased hypoxia compared to parental tumors. Furthermore, using the fluorescent dye Hoechst 33342, an in vivo marker of perfused vessels, combined with immunochemical staining of PECAM-1 (CD31) as a marker of tumor vasculature, we found increased vascularization in the IL-2-transfected tumors. Thus, expression of IL-2 at the site of tumor growth may enhance tumor immunity not only by inducing the generation of tumor-reactive CTLs but also by allowing increased infiltration of activated T cells into the tumors.     

Role of androgens in testicular tumor development in inhibin-deficient mice

To understand gonadal tumor development, we have previously created a mouse model in which mice deficient in the inhibins develop gonadal sex cord-stromal tumors with essentially 100% penetrance. These tumors develop as early as 4 weeks of age and cause cancer cachexia-like symptoms and subsequent death in the inhibin-deficient mice. Gonadectomized inhibin-deficient mice eventually develop adrenal cortical tumors with nearly 100% penetrance. These studies have identified inhibin as a novel secreted tumor suppressor protein with specificity for the gonads and adrenal glands. Sex steroids have been implicated to influence gonadal tumor development in humans and mice. To determine the role of androgens in gonadal tumorigenesis in inhibin-deficient male mice, we have used a genetic intercross strategy, breeding inhibin alpha mutant mice with tfm (testicular feminization, a naturally occurring androgen receptor mutant) carrying females to eventually generate compound mutant male mice that lack inhibins and carry the tfm mutation. These compound mutant mice, like inhibin-deficient mice, continue to develop testicular tumors and the accompanying cancer cachexia-like wasting syndrome. Consistent with these findings, elevated levels of activins A and B secreted from the gonadal tumors are seen in the adult compound mutant mice as well as the secondary pathological consequences of these high activin levels in the livers and glandular stomachs. However, in contrast to male mice lacking only inhibin, in which essentially 100% of the testicular tumors are hemorrhagic, 65% of the tumors in these compound mutant male mice are less hemorrhagic, and approximately 50% of the compound mutants live longer than 17 weeks of age (95% of the male mice lacking only inhibin die by 12 weeks). These results suggest that androgens are not required for testicular tumor development in inhibin-deficient mice, but may play a regulatory role in testicular tumor progression.     

The normal and pathologic ischiorectal fossa at CT and MR imaging

A wide spectrum of disease processes involve the ischiorectal fossa, including congenital and developmental lesions; inflammatory, traumatic, and hemorrhagic conditions; primary tumors; and pathologic processes outside the ischiorectal fossa with secondary involvement. Both computed tomography (CT) and magnetic resonance (MR) imaging are useful in the definitive diagnosis of these pathologic conditions, with MR imaging being the modality of choice because of its superior contrast resolution and multiplanar capability. In Gartner duct cyst, both CT and MR imaging demonstrate a well-defined, round mass; in tailgut cyst, CT demonstrates a well-defined retrorectal mass with a solid or cystic appearance. MR imaging in particular plays a major role in the assessment of fistula in ano, infection, and hematoma. Lipoma and pelvic plexiform neurofibroma typically have low attenuation and high signal intensity at CT and MR imaging, respectively. Recurrent rectal tumor appears at both modalities as an irregular soft-tissue mass with or without central necrosis in the presacral space, perineum, or pelvic sidewall. Familiarity with the imaging features and differential diagnoses of various ischiorectal pathologic processes will facilitate prompt, accurate diagnosis and treatment.     

Schwannoma cells induce a tumor-cell-specific cytotoxic-T-cell response upon transplantation into syngeneic rats but escape elimination through the secretion of immunosuppressive factors

Tumor cells often express antigens that can be recognized by the immune system. Despite induction of an immune response, the tumor cells escape their elimination. We have studied the mechanisms and factors which mediate these events in a syngeneic tumor model. NV2Cd rat schwannoma cells were transplanted into BDIX rats. After injection of 10(7) to 2 x 10(7) cells, tumors grew very slowly for 10 to 12 days. After that time, rapid growth was observed. The tumors consisted of compact areas of spindle-shaped cells with small cysts, many blood vessels and central necrotic areas. During tumor growth, the number of spleen cells and T lymphocytes increased, and cytotoxic T cells with specificity for the NV2Cd tumor cells were detected. The strong specific cellular immune response did not prevent the increase in tumor volume. We studied the biological activity of the fluid present in the cysts of the tumor. At a concentration of 1 ng to 10 microg protein per ml, the cyst fluid inhibited the proliferation of splenic T lymphocytes and B lymphocytes and of lymphoma cells, but enhanced the proliferation of NV2Cd tumor cells. The cyst fluids contain the immunosuppressive transforming growth factors (TGF)-beta1, -beta2 and -beta3, also the vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF). Antibodies directed against TGF-beta relieved the suppression of T-cell growth by cyst fluid, but did not influence the proliferation of NV2Cd cells. The growth-modulating factors present in the tumor cyst fluid were also detected in conditioned medium from NV2Cd cells cultured in vitro. Our data suggest that tumors can escape the cellular immune response by the production of factors that inhibit lymphocytes. They also enhance their own growth environment by secreted factors.     

Evaluation of an assay for detecting telomerase activity in neoplastic tissues of dogs

OBJECTIVE: To determine feasibility of using the telomere repeat amplification protocol (TRAP) assay to detect telomerase activity in tumors of dogs. SAMPLE POPULATION: Samples of tumor or normal tissue were obtained from client-owned dogs that underwent surgical biopsy during the period of January 1996 through December 1997. PROCEDURE: The TRAP assay was used to detect telomerase activity in malignant or benign tumors of dogs. Telomerase status (positive or negative) was compared with results of histologic examination for each sample to estimate specificity and sensitivity of this assay for the diagnosis of malignancy. RESULTS: Of 26 malignant tumors, 24 were telomerase positive on TRAP assay, whereas 3 of 4 benign tumors and 3 of 3 normal tissues were telomerase negative. Analysis of these results indicated an estimated sensitivity of 92% and specificity of 86% for tumor analysis, using the TRAP assay. CONCLUSION: The TRAP assay can be used to measure telomerase activity in malignant tumors of dogs. CLINICAL RELEVANCE: Because telomerase activation may be required for indefinite longevity of cells, it may also serve as a tumor marker and therapeutic target. The TRAP assay can be used to detect telomerase in samples of fluid as well as tissues obtained from solid tumors. Therefore, it may have considerable clinical value in rapid and noninvasive diagnosis of neoplasia in dogs. Additional studies must be completed to more accurately determine sensitivity and specificity of the assay.     

Acute hemorrhagic leukoencephalitis: recovery and reversal of magnetic resonance imaging findings in a child

A case of acute hemorrhagic leukoencephalitis (AHLE) in a 6-year-old girl is reported. The presentation was typical for acute hemorrhagic leukoencephalitis, with acute onset of a rapidly progressive neurologic disorder with asymmetric involvement of brain, with polymorphonuclear predominant peripheral leukocytosis and cerebrospinal fluid pleocytosis. Cerebrospinal fluid findings not previously reported included elevation of IgG and the presence of myelin basic protein. Additional previously unreported findings were striking abnormalities on magnetic resonance imaging (MRI) of the brain, in contrast to normal findings on computed tomography (CT). The child was treated with high dose intravenous steroids and made a full recovery, with a parallel disappearance of all of her cerebrospinal fluid abnormalities and almost all of her abnormalities on MRI. Detailed examination of cerebrospinal fluid and MRI of brain should facilitate early diagnosis in other cases of suspected acute hemorrhagic leukoencephalitis and high-dose steroid therapy may lead to improved clinical outcomes.     

Targeting the tumor vasculature: inhibition of tumor growth by a vascular endothelial growth factor-toxin conjugate

Tumor-derived vascular endothelial growth factor (VEGF)/ vascular permeability factor (VPF) plays an important role in neovascularization and the development of tumor stroma. Furthermore, VEGF receptors are over-expressed in the endothelial cells of tumor vasculature and almost non-detectable in the vascular endothelium of adjoining normal tissues. The differential expression of receptor offers a selective advantage for targeting cytotoxic toxin polypeptides. We have prepared a vascular targeting reagent by chemically linking recombinant VEGF to a truncated form of diphtheria toxin. The VEGF-toxin conjugate was selectively toxic to endothelial cell lines and inhibited experimental neovascularization of the chick chorioallantoic membrane. In the present study, we examined the effects of VEGF-toxin conjugate on solid tumor growth. Athymic nude mice with established subcutaneous tumors were treated with daily intraperitoneal injections of the VEGF-toxin conjugate or free toxin. When compared with control animals treated with the toxin polypeptide alone, the conjugate-treated animals displayed a significant inhibition of tumor growth. Histological analysis of tumors from conjugate-treated animals revealed hemorrhagic necrosis consistent with a vascular-mediated injury. In contrast, highly vascularized normal tissues from conjugate-treated animals demonstrated no evidence of hemorrhage or tissue injury. The conjugate was well tolerated without apparent toxicities. Our results illustrate the anti-tumor activity of a VEGF-toxin conjugate selectively targeting the tumor neovasculature.     

Clinical positron emission tomography for brain tumors: comparison of fludeoxyglucose F 18 and L-methyl-11C-methionine

PURPOSE: To evaluate the differences between fludeoxyglucose F 18 (FDG) and L-methyl-11C-methionine (11C-methionine) as tracers for positron emission tomography (PET) in the evaluation of brain tumors. METHODS: We analyzed 10 patients with histologically verified cerebral glioma or meningioma and 1 patient with a neuroradiologic diagnosis of low-grade glioma by using FDG, 11C-methionine, and PET. We qualitatively and quantitatively evaluated the extent and degree of accumulation of FDG and 11C-methionine in the tumor tissue. RESULTS: Although PET with FDG depicted malignant tumors as a hot spot in all cases, it was not able to delineate the extent of the tumor. Conversely, PET with 11C-methionine outlined the tumors as areas of increased accumulation of 11C-methionine, regardless of the degree of malignancy. CONCLUSION: PET with FDG and with 11C-methionine can play complementary roles in the evaluation of brain tumors.     

Effect of transvascular fluid exchange on pressure-flow relationship in tumors: a proposed mechanism for tumor blood flow heterogeneity

Tumor blood flow (TBF) is characterized by spatial and temporal heterogeneities. Despite the crucial role of TBF in tumor growth, metastasis, and therapy, the mechanisms underlying these heterogeneities are not fully understood. Tumor vessels are, in general, more leaky than normal vessels and this may enhance the efficiency of fluid exchange between the vascular and the interstitial space. The coupling between transvascular fluid exchange and hemodynamics in tumors has not been explored previously. To investigate the role of transvascular fluid exchange on afferent and efferent blood flow, we modeled the tumor vasculature as an equivalent single vessel which is permeable and deformable and embedded in a fluid medium with uniform pressure. Simulations were carried out to examine the effects of vessel leakiness, vessel compliance, and interstitial fluid pressure on (a) pressure-flow relationship, (b) arterial-venous pressure relationship, and (c) pressure profile along the vessel. Experiments suggested by model simulations required an independent control of arterial and venous pressure and tumor blood flow. To this end, we perfused tissue-isolated tumors ex vivo and obtained data on perfusate flow rate vs arterial and venous pressures. The simulations predicted the following trends as a result of an enhanced fluid filtration across the vessel wall: (a) for a fixed arterial-venous pressure difference, efferent flow decreases with increasing venous pressure, (b) changes in venous pressure are not completely transmitted to the arterial side, and (c) the pressure profile along the vessel becomes less steep. The experimental results confirmed these trends and indicated that vascular and interstitial flow are coupled in isolated tumors. The implications of this coupling for the spatial and temporal heterogeneity in TBF are discussed.     

Luteotropic effect of pregnant mare serum gonadotropin in cattle

The ability to accurately assess tumor size and orientation to surrounding vital structures is an important consideration during preoperative evaluation. The authors report on nine children with solid tumors (hepatoblastoma [1], neuroblastoma [2], adrenal cortical carcinoma [2], liver adenoma [1], primitive neuroectodermal tumor [PNET] [1], and stage V Wilms' tumor [2]) for whom tumor resectability was questioned because of the tumors' close proximity to major blood vessels (noted through conventional radiographic imaging). The children had scanning with spiral volumetric acquisition computerized tomography, (CT) which obtains images during continuous rotation of the x-ray source while the patient moves at a constant velocity through the gantry. This technique is rapid (18 to 30 seconds), and is similar with respect to radiation exposure; little or no sedation is required, and the contrast dose is lower than that of conventional CT. Three-dimensional reconstruction of spiral CT imaging provided useful information that allowed successful resection in all nine cases. The authors suggest that spiral CT may become an important imaging modality in the preoperative evaluation of pediatric solid tumors and that further evaluation of this new methodology is warranted.     

Liver metastases from breast cancer 14 years after radical mastectomy; successful treatment with hepatic arterial infusion chemotherapy and systemic endocrine therapy--a case report

The patient was a 73-year-old woman who was admitted to our hospital for epigastric discomfort and body weight loss. She had undergone radical right mastectomy in March 1982. Ultrasonography and computed tomography revealed multiple tumors in the liver. Three of the tumor markers (CA-125, CA 19-9, and CA 15-3) were positive. US-guided fine needle aspiration biopsy of the liver tumor showed small atypical cells with solid cell nests. Immunohistochemical tests revealed estrogen receptor was positive. We diagnosed the patient as recurrent breast cancer metastatic to liver, 14 years postoperatively. The liver tumors were successfully controlled with the combination of intra-arterial infusion chemotherapy (5-fluorouracil, epirubicin, and mitomycin C) along with systemic endocrine therapy (medroxyprogesterone acetate and fadrozole hydrochloride hydrate).     

Differences in the recognition of tumor-specific CD8+ T cells derived from solid tumor, metastatic lymph nodes and ascites in patients with gastric cancer

We established gastric cancer-specific CD8+ T-cell (T(CD8+)) lines derived from different lymphocyte sources in the same patients by repeated stimulation with mitomycin-C-treated autologous tumor cells with low-dose interleukin-2, and we compared recognition patterns among the T(CD8+) derived from solid tumor, lymph node metastasis and ascites in the same patient (n = 3) to determine their similarities and differences for therapeutic purposes. We confirmed that gastric cancer-specific T(CD8+) lines can be isolated, in a MHC class I-restricted manner, from solid tumors, metastatic lymph nodes and malignant ascites. T(CD8+) lines derived from tumor-infiltrating lymphocytes (TIL) in solid tumor recognized autologous tumor cells derived from solid tumor, but not autologous tumor cells derived from ascites or metastatic lymph node, while T(CD8+) lines derived from tumor-associated lymphocytes (TAL) in malignant ascites recognized autologous tumor cells derived from ascites, but not tumor cells from solid tumor or metastatic lymph node. Furthermore, T(CD8+) lines derived from regional lymph node lymphocytes (RLNL) recognized autologous tumor cells derived from metastatic lymph nodes, but not tumor cells derived from ascites. No significant differences were seen in MHC class I expression among the tumors derived from solid tumor, lymph node metastasis or ascites in the same patient. This suggests that there are differences of recognition patterns among the TILs, TALs and RLNLs in the same patient and that it is important to consider the source of lymphocytes, e.g., a combination of TILs, TALs and RLNLs, for adoptive immunotherapy in gastric cancer patients.     

Observations on the etiology and pathogenesis of intraductal papillary-mucinous neoplasms of the pancreas

During the last two decades, intraductal papillary-mucinous neoplasms have been recognised as a group that should be distinguished from ductal adenocarcinomas. The literature for these tumors is confusing with the use of many different terms such as mucinous duct ectasia and, sometimes, there is a failure to distinguish them from mucinous cystic tumors. The recognition and apparently increasing incidence of these neoplasms is perhaps entirely attributable to improved diagnostic and imaging methods such as endoscopic retrograde pancreatography and computerized tomography. Experimental, molecular, and epidemiologic data suggest that the etiology of IPMN overlaps that of solid ductal adenocarcinomas.     

Ancrod: understanding the agent

Five primary ovarian carcinomas composed of a high-grade neuroendocrine tumor of non-small-cell type and a surface-epithelial-stromal tumor are reported. The five tumors presented in women aged 36 to 77 (mean, 57) years with abdominal distension or a palpable mass in three cases, right lower quadrant pain with tenderness and fever in one case, and a cervicovaginal smear showing a high estrogen effect in one postmenopausal patient. The tumors were unilateral, 9 to 30 (mean, 16) cm in greatest dimension, and had solid and cystic components. Three tumors were stage I; one, stage II; and one, stage III. Two patients who received chemotherapy died of tumor 8 and 36 months postoperatively, another who refused chemotherapy but later received radiation died of tumor after 19 months, a fourth was lost to follow-up, and a fifth was treated recently. Microscopically, the neuroendocrine components of all the tumors were composed predominantly of sheets, closely packed islands, cords, and trabeculae of epithelial cells with little intervening stroma. The tumor cells in the neuroendocrine areas were medium-sized to large compared with the cells of small cell carcinoma, and they contained scanty to moderate amounts of cytoplasm and hyperchromatic nuclei with coarse chromatin clumping in three cases and abundant cytoplasm and vesicular nuclei with single, large eosinophilic nucleoli in the other two. In all the cases, areas of necrosis and single-cell necrosis were extensive, and mitotic figures were abundant. Positive argyrophil and argentaffin reactions were observed in occasional to many cells in all cases. The glandular components of the tumors were grade 1/3 endometrioid adenocarcinoma (one case), grade 2/3 mucinous adenocarcinoma (2 cases), and mucinous borderline tumor with small foci of mucinous adenocarcinoma (two cases). Numerous enterochromaffin cells were identified in hematoxylin and eosin sections of the borderline mucinous components of two tumors; occasional nonargentaffin argyrophilic cells were present in the endometrioid and mucinous carcinoma components. Luteinized stromal cells were present focally in two cases, including the case in which there was evidence of a high estrogen level. Immunohistochemical studies in five cases showed staining of most cells in the solid components for cytokeratin and chromogranin A and some to most cells for serotonin and neuron-specific enolase. Neuropeptides that were detected in the solid component of one or more of the cases included vasoactive intestinal peptide, somatostatin, gastrin, and glucagon; negative results were obtained for pancreatic polypeptide and insulin. Flow cytometry in four tumors revealed that the neuroendocrine component was aneuploid in two, suspicious for aneuploidy in one, and diploid in one. Tumors of the type described are distinct pathologically from primary ovarian carcinoid tumors and small cell carcinoma of pulmonary type. Although experience with this type of tumor is limited, the prognosis appears to be poor.     

Exposure to high ambient temperature increases absorption and plasma concentrations of transdermal nicotine

Granulosa cell tumors with bizarre nuclei (GCT-BN) are rare lesions with a prognosis apparently similar to that of conventional granulosa cell tumors (GCT-NOS). The immunohistochemical features of GCT-BN have not been described, and the exact nature of the bizarre nuclei (BN) is unclear. Thirteen GCT-BN were studied with antibodies to cytokeratin, vimentin, epithelial membrane antigen, muscle-specific actin, alpha smooth muscle actin, desmin, and S-100 protein. Six cases were also examined by fluorescence in situ hybridization for trisomy 12, a nonrandom chromosomal aberration found in a proportion of ovarian sex-cord stromal tumors. Histologically, 12 tumors (86%) contained BN areas interspersed with large areas of GCT-NOS. The remaining tumor contained only microscopic foci of GCT-NOS. Immunohistochemically, the tumors stained for vimentin (13 tumors), S-100 protein (11 tumors), muscle-specific actin (10 tumors), cytokeratin (eight tumors), alpha smooth muscle actin (eight tumors), and desmin (one tumor), but none stained for epithelial membrane antigen. Immunostaining results for the BN and GCT-NOS areas were concordant in eight (73%) of the 11 tumors in which both areas could be independently assessed. The remaining three tumors (27%) showed discordant results for only one of the eight markers used. In five patients, trisomy 12 was detected by fluorescence in situ hybridization in areas of BN but not in areas of GCT-NOS present in the same tumor. Trisomy 12 was also present in another BN tumor in which the foci of GCT-NOS were too small to be evaluated. We conclude that within GCT-BN, areas with BN are immunohistochemically similar to areas of GCT-NOS present in the same tumor. The finding of trisomy 12 in areas with BN but not GCT-NOS in the same tumor, however, suggests that cells with BN represent a genetically distinct clone of tumor cells arising within GCT-NOS.     

Dysregulated expression of CD66a (BGP, C-CAM), an adhesion molecule of the CEA family, in endometrial cancer

CD66a (BGP, C-CAM) is an adhesion molecule of the carcinoembryonic antigen family that has been shown to be down-regulated in colorectal, prostate, and breast cancers. The purpose of the present study was to determine its expression pattern in the normal human endometrium and in endometrial neoplasia. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody on a series of 24 normal endometrial samples and 47 endometrial carcinomas. Strong CD66a expression was observed in glandular and luminal epithelial cells of the normal endometrium with a consistent localization at the apical poles of these cells throughout the cycle. In late secretory (premenstrual) phase, loss of cellular polarity resulted in a membranous expression pattern in some glandular cells. In the analyzed tumor samples increasing areas with a complete loss of expression were observed with increasing malignancy grade. The apical expression pattern of the normal epithelium was changed to a membranous all-around pattern in 55% of the tumors, mostly in solid areas. This change correlated with malignancy grade and could be observed in 3 of 15 G1 tumors, 4 of 12 G2 tumors, 11 of 12 G3 tumors, and 8 of 8 serous-papillary carcinomas. Areas with membranous expression pattern could be observed along with areas with a normal apical expression pattern in lower grade carcinomas and with areas with complete loss of expression in high grade tumors. Northern blot analysis showed a loss of mRNA expression in tumor samples and HEC-1B endometrial adenocarcinoma cells. Loss of protein expression in the tumor samples was also observed by Western blot. In conclusion, CD66a protein expression is dysregulated in endometrial carcinomas, showing reduction or loss of expression with increasing malignancy grade and a change from the apical to a membranous localization.     

Tumor antigens and tumor vaccines: peptides as immunogens

Tumor antigens recognized by human cytotoxic T lymphocytes (CTL) have been identified for multiple types of solid tumors. These include both shared and unique antigens. Unique antigens are those expressed uniquely by one patient's tumor, and shared antigens are those present on tumor cells from many different patients. Many of the shared antigens are derived from tissue-specific differentiation antigens, oncogenes, or a set of antigens expressed only in tumors or in testis. In addition to advances in understanding tumor antigens that stimulate CTL and T-helper cell responses, there have been advances in understanding immunity in general, including the characterization of cytokines, the recognition of the dendritic cell as an optimal antigen-presenting cell (APC), and the characterization of costimulatory molecules as critical components of antigen presentation. Together, these developments have breathed new life into tumor immunology, and they promise to lead to a new generation of peptide- and cell-based tumor vaccines.     

Tumor angiogenesis predicts recurrence in invasive colorectal cancer when controlled for Dukes staging

Tumor angiogenesis is associated with metastasis in several types of solid tumors, including melanoma, breast, prostate, lung, bladder, and oral-cavity tumors. The purpose of this study was to determine whether tumor angiogenesis could predict recurrence following curative surgery for colorectal cancer. Thirty-five patients were studied, including 13 patients with recurrent tumor and 22 without. Representative formalin-fixed, paraffin-embedded sections of invasive colorectal cancers from these patients were sectioned. The endothelial cells of microvessels within the tumors were highlighted by immunohistochemical staining for CD31. The most active areas were identified and the microvessels counted in a x 400 field (0.152 mm2) by two observers in a blinded fashion. Tumor microvessel count (p = 0.0062). Dukes' staging (p = 0.0004), vascular invasion (p = 0.0280), and tumor grade (p = 0.0559) were all significantly associated with tumor recurrence. Tumor microvessel counts > or = 65 per x 400 field were associated with tumor recurrence (p = 0.0035, relative risk [RR] = 11.3). Controlling for Dukes' stage, a multivariate logistic regression model revealed that a tumor microvessel count > or = 65 is an important predictor of tumor recurrence (p = 0.0783, RR = 6.0). A backwards elimination proportional hazards model revealed that a microvessel count > or = 65 shows a trend toward independent prediction of time to tumor recurrence (p = 0.1203, RR = 2.967) when controlled for Dukes' staging (p = 0.0029, RR = 9.089). Despite the small number of patients studied, these results suggest that the number of microvessels in sections of invasive colorectal adenocarcinoma immunohistochemically stained with CD31 may be an important independent predictor of tumor recurrence and time to recurrence.